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Sample records for residual attentional capacity

  1. Should the Functional Residual Capacity be Ignored?

    PubMed Central

    Selvi E, Chandra; K.V Rao, Kuppu; Malathi

    2013-01-01

    Aim and Objectives: The functional residual capacity was given the least importance than the other lung volume parameters. Studies have revealed the restrictive pattern of lung disease in patients with liver cirrhosis. We aimed to analyze the importance of the functional residual capacity and other lung volumes of cirrhotic patients. Subjects and Methods: Forty (40) patients with cirrhosis (Child’s-B) were enrolled in this study. The vital capacity was measured by an instrument called V02 Max 22. The other lung volumes which were measured were derived parameters. The functional residual capacity was measured by the nitrogen wash-out method. Results: The measured value of the functional residual capacity was below normal as compared to the reference value. The total lung capacity and the vital capacity were positively correlated with the functional residual capacity. The residual volume was found to be increased in twelve out of forty cirrhotic patients. Conclusion: The functional residual capacity can be determined by the compliance of the lung and the chest wall. The patients with a reduced functional residual capacity may be suffering from dyspnoea, probably due to the restrictive pattern of the lung disease. Hence, the reduced lung volumes of the subjects may be due to the abnormalities in the mechanics of ventilation. PMID:23450122

  2. Attention Capacity and Task Difficulty in Visual Search

    ERIC Educational Resources Information Center

    Huang, Liqiang; Pashler, Harold

    2005-01-01

    When a visual search task is very difficult (as when a small feature difference defines the target), even detection of a unique element may be substantially slowed by increases in display set size. This has been attributed to the influence of attentional capacity limits. We examined the influence of attentional capacity limits on three kinds of…

  3. Attentional flexibility and memory capacity in conductors and pianists.

    PubMed

    Wöllner, Clemens; Halpern, Andrea R

    2016-01-01

    Individuals with high working memory (WM) capacity also tend to have better selective and divided attention. Although both capacities are essential for skilled performance in many areas, evidence for potential training and expertise effects is scarce. We investigated the attentional flexibility of musical conductors by comparing them to equivalently trained pianists. Conductors must focus their attention both on individual instruments and on larger sections of different instruments. We studied students and professionals in both domains to assess the contributions of age and training to these skills. Participants completed WM span tests for auditory and visual (notated) pitches and timing durations, as well as long-term memory tests. In three dichotic attention tasks, they were asked to detect small pitch and timing deviations from two melodic streams presented in baseline (separate streams), selective-attention (concentrating on only one stream), and divided-attention (concentrating on targets in both streams simultaneously) conditions. Conductors were better than pianists in detecting timing deviations in divided attention, and experts detected more targets than students. We found no group differences for WM capacity or for pitch deviations in the attention tasks, even after controlling for the older age of the experts. Musicians' WM spans across multimodal conditions were positively related to selective and divided attention. High-WM participants also had shorter reaction times in selective attention. Taken together, conductors showed higher attentional flexibility in successfully switching between different foci of attention. PMID:26404532

  4. Working memory capacity, controlled attention and aiming performance under pressure.

    PubMed

    Wood, Greg; Vine, Samuel J; Wilson, Mark R

    2016-07-01

    This study explored the possibility that individual differences in working memory capacity (WMC) could predict those individuals who would experience attentional disruptions and performance decrements under pressure. Two WMC groups performed a Stroop handgun task under counterbalanced conditions of threat whilst wearing eye-tracking equipment that measured visual search activity and quiet eye (QE) aiming duration. Performance was measured in terms of shooting accuracy. Low-WMC individuals experienced impaired visual search time to locate the target and reduced QE durations when shooting at incongruent target words. Furthermore, the low-WMC group experienced significant reductions in shooting accuracy when anxious. Conversely, high-WMC individuals experienced no significant differences in attentional control or performance across congruency or threat conditions. Results support the suggestion that WMC is not only a good predictor of an individual's ability to control their attention but can also predict those likely to fail under pressure. PMID:26021749

  5. Capacity-constrained traffic assignment in networks with residual queues

    SciTech Connect

    Lam, W.H.K.; Zhang, Y.

    2000-04-01

    This paper proposes a capacity-constrained traffic assignment model for strategic transport planning in which the steady-state user equilibrium principle is extended for road networks with residual queues. Therefore, the road-exit capacity and the queuing effects can be incorporated into the strategic transport model for traffic forecasting. The proposed model is applicable to the congested network particularly when the traffic demands exceeds the capacity of the network during the peak period. An efficient solution method is proposed for solving the steady-state traffic assignment problem with residual queues. Then a simple numerical example is employed to demonstrate the application of the proposed model and solution method, while an example of a medium-sized arterial highway network in Sioux Falls, South Dakota, is used to test the applicability of the proposed solution to real problems.

  6. Channel Capacity of MC-CDMA and Impact of Residual ICI

    NASA Astrophysics Data System (ADS)

    Adachi, Koichi; Adachi, Fumiyuki; Nakagawa, Masao

    Orthogonal frequency division multiplexing (OFDM), which uses a number of narrowband orthogonal sub-carriers, is a promising transmission technique. Also multi-carrier code division multi-access (MC-CDMA), which combines OFDM and frequency-domain spreading, has been attracting much attention as a future broadband wireless access. It was shown that MC-CDMA has lower channel capacity than OFDM, due to inter-code interference (ICI) resulting from orthogonality distortion caused by frequency-selective fading. Recently, many ICI cancellers have been proposed to mitigate the effect of ICI. In this paper, we derive a channel capacity expression for MC-CDMA assuming perfect ICI cancellation taking into account both frequency diversity gain and space diversity gain and compare it to that of OFDM. Furthermore, we derive a channel capacity expression for the case of imperfect ICI cancellation to discuss the impact of the residual ICI.

  7. Attentional Capacity Limits Gap Detection during Concurrent Sound Segregation.

    PubMed

    Leung, Ada W S; Jolicoeur, Pierre; Alain, Claude

    2015-11-01

    Detecting a brief silent interval (i.e., a gap) is more difficult when listeners perceive two concurrent sounds rather than one in a sound containing a mistuned harmonic in otherwise in-tune harmonics. This impairment in gap detection may reflect the interaction of low-level encoding or the division of attention between two sound objects, both of which could interfere with signal detection. To distinguish between these two alternatives, we compared ERPs during active and passive listening with complex harmonic tones that could include a gap, a mistuned harmonic, both features, or neither. During active listening, participants indicated whether they heard a gap irrespective of mistuning. During passive listening, participants watched a subtitled muted movie of their choice while the same sounds were presented. Gap detection was impaired when the complex sounds included a mistuned harmonic that popped out as a separate object. The ERP analysis revealed an early gap-related activity that was little affected by mistuning during the active or passive listening condition. However, during active listening, there was a marked decrease in the late positive wave that was thought to index attention and response-related processes. These results suggest that the limitation in detecting the gap is related to attentional processing, possibly divided attention induced by the concurrent sound objects, rather than deficits in preattentional sensory encoding. PMID:26226073

  8. Divided Attention Capacity in Adults with Autism Spectrum Disorders and without Intellectual Disability

    ERIC Educational Resources Information Center

    Bogte, Hans; Flamma, Bert; Van Der Meere, Jaap; Van Engeland, Herman

    2009-01-01

    Earlier research showed that divided attention, an aspect of executive function, is limited in both children and adults with autism spectrum disorders (ASDs). The current study explored divided attention capacity in adults with ASD and without intellectual disability (n = 36). Divided attention was tested using a computerized variant of a…

  9. Carbon dioxide sorption capacities of coal gasification residues.

    PubMed

    Kempka, Thomas; Fernández-Steeger, Tomás; Li, Dong-Yong; Schulten, Marc; Schlüter, Ralph; Krooss, Bernhard M

    2011-02-15

    Underground coal gasification is currently being considered as an economically and environmentally sustainable option for development and utilization of coal deposits not mineable by conventional methods. This emerging technology in combination with carbon capture and sorptive CO2 storage on the residual coke as well as free-gas CO2 storage in the cavities generated in the coal seams after gasification could provide a relevant contribution to the development of Clean Coal Technologies. Three hard coals of different rank from German mining districts were gasified in a laboratory-scale reactor (200 g of coal at 800 °C subjected to 10 L/min air for 200 min). High-pressure CO2 excess sorption isotherms determined before and after gasification revealed an increase of sorption capacity by up to 42%. Thus, physical sorption represents a feasible option for CO2 storage in underground gasification cavities. PMID:21210659

  10. 20 CFR 416.946 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Responsibility for assessing your residual functional capacity. 416.946 Section 416.946 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL... Capacity § 416.946 Responsibility for assessing your residual functional capacity. (a) Responsibility...

  11. 20 CFR 416.946 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Responsibility for assessing your residual functional capacity. 416.946 Section 416.946 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL... Capacity § 416.946 Responsibility for assessing your residual functional capacity. (a) Responsibility...

  12. 20 CFR 416.946 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Responsibility for assessing your residual functional capacity. 416.946 Section 416.946 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL... Capacity § 416.946 Responsibility for assessing your residual functional capacity. (a) Responsibility...

  13. 20 CFR 416.946 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Responsibility for assessing your residual functional capacity. 416.946 Section 416.946 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL... Capacity § 416.946 Responsibility for assessing your residual functional capacity. (a) Responsibility...

  14. 20 CFR 416.946 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Responsibility for assessing your residual functional capacity. 416.946 Section 416.946 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL... Capacity § 416.946 Responsibility for assessing your residual functional capacity. (a) Responsibility...

  15. Sustained Selective Attention Skills of Preschool Children with Specific Language Impairment: Evidence for Separate Attentional Capacities

    ERIC Educational Resources Information Center

    Spaulding, Tammie J.; Plante, Elena; Vance, Rebecca

    2008-01-01

    Purpose: The present study was designed to investigate the performance of preschool children with specific language impairment (SLI) and their typically developing (TD) peers on sustained selective attention tasks. Method: This study included 23 children diagnosed with SLI and 23 TD children matched for age, gender, and maternal education level.…

  16. Does attention capacity moderate the effect of driver distraction in older drivers?

    PubMed

    Cuenen, Ariane; Jongen, Ellen M M; Brijs, Tom; Brijs, Kris; Lutin, Mark; Van Vlierden, Karin; Wets, Geert

    2015-04-01

    With age, a decline in attention capacity may occur and this may impact driving performance especially while distracted. Although the effect of distraction on driving performance of older drivers has been investigated, the moderating effect of attention capacity on driving performance during distraction has not been investigated yet. Therefore, the aim was to investigate whether attention capacity has a moderating effect on older drivers' driving performance during visual distraction (experiment 1) and cognitive distraction (experiment 2). In a fixed-based driving simulator, older drivers completed a driving task without and with visual distraction (experiment 1, N=17, mean age 78 years) or cognitive distraction (experiment 2, N=35, mean age 76 years). Several specific driving measures of varying complexity (i.e., speed, lane keeping, following distance, braking behavior, and crashes) were investigated. In addition to these objective driving measures, subjective measures of workload and driving performance were also included. In experiment 1, crash occurrence increased with visual distraction and was negatively related to attention capacity. In experiment 2, complete stops at stop signs decreased, initiation of braking at pedestrian crossings was later, and crash occurrence increased with cognitive distraction. Interestingly, for a measure of lane keeping (i.e., standard deviation of lateral lane position (SDLP)), effects of both types of distraction were moderated by attention capacity. Despite the decrease of driving performance with distraction, participants estimated their driving performance during distraction as good. These results imply that attention capacity is important for driving. Driver assessment and training programs might therefore focus on attention capacity. Nonetheless, it is crucial to eliminate driver distraction as much as possible given the deterioration of performance on several driving measures in those with low and high attention capacity

  17. Divided attention capacity in adults with autism spectrum disorders and without intellectual disability.

    PubMed

    Bogte, Hans; Flamma, Bert; Van Der Meere, Jaap; Van Engeland, Herman

    2009-05-01

    Earlier research showed that divided attention, an aspect of executive function, is limited in both children and adults with autism spectrum disorders (ASDs). The current study explored divided attention capacity in adults with ASD and without intellectual disability (n = 36). Divided attention was tested using a computerized variant of a well-known memory recognition test, with two levels of cognitive load. The effect of cognitive load on reaction time performance is considered to be inversely proportional to divided attention capacity. The study failed to provide a relationship between divided attention and ASD, contrary to earlier research. Findings indicated that only the adults with ASD who used medication had a divided attention deficit, and that this group had specific difficulty reaching a binary decision in a memory search task. An additional finding was that the participants with ASD were overall slow. Possible causes and implications of these findings are discussed. PMID:19369386

  18. Individual Differences in Working Memory Capacity and Attention, and Their Relationship with Students' Approaches to Learning

    ERIC Educational Resources Information Center

    Kyndt, Eva; Cascallar, Eduardo; Dochy, Filip

    2012-01-01

    Past research has shown that working memory capacity, attention and students' approaches to learning are all important predictors for educational achievement. In this study the interrelations between these three variables are investigated. Participants were 128 university students. Results show a negative relationship between attention and deep…

  19. The Contribution of Attentional Lapses to Individual Differences in Visual Working Memory Capacity

    PubMed Central

    Adam, Kirsten C. S.; Mance, Irida; Fukuda, Keisuke; Vogel, Edward K.

    2015-01-01

    Attentional control and working memory capacity are important cognitive abilities that substantially vary between individuals. Although much is known about how attentional control and working memory capacity relate to each other and to constructs like fluid intelligence, little is known about how trial-by-trial fluctuations in attentional engagement impact trial-by-trial working memory performance. Here, we employ a novel whole-report memory task that allowed us to distinguish between varying levels of attentional engagement in humans performing a working memory task. By characterizing low-performance trials, we can distinguish between models in which working memory performance failures are caused by either (1) complete lapses of attention or (2) variations in attentional control. We found that performance failures increase with set-size and strongly predict working memory capacity. Performance variability was best modeled by an attentional control model of attention, not a lapse model. We examined neural signatures of performance failures by measuring EEG activity while participants performed the whole-report task. The number of items correctly recalled in the memory task was predicted by frontal theta power, with decreased frontal theta power associated with poor performance on the task. In addition, we found that poor performance was not explained by failures of sensory encoding; the P1/N1 response and ocular artifact rates were equivalent for high- and low-performance trials. In all, we propose that attentional lapses alone cannot explain individual differences in working memory performance. Instead, we find that graded fluctuations in attentional control better explain the trial-by-trial differences in working memory that we observe. PMID:25811710

  20. The Influence of Attention Set, Working Memory Capacity, and Expectations on Inattentional Blindness.

    PubMed

    Kreitz, Carina; Furley, Philip; Memmert, Daniel; Simons, Daniel J

    2016-04-01

    The probability of inattentional blindness, the failure to notice an unexpected object when attention is engaged on some primary task, is influenced by contextual factors like task demands, features of the unexpected object, and the observer's attention set. However, predicting who will notice an unexpected object and who will remain inattentionally blind has proven difficult, and the evidence that individual differences in cognition affect noticing remains ambiguous. We hypothesized that greater working memory capacity might modulate the effect of attention sets on noticing because working memory is associated with the ability to focus attention selectively. People with greater working memory capacity might be better able to attend selectively to target items, thereby increasing the chances of noticing unexpected objects that were similar to the attended items while decreasing the odds of noticing unexpected objects that differed from the attended items. Our study (N = 120 participants) replicated evidence that task-induced attention sets modulate noticing but found no link between noticing and working memory capacity. Our results are largely consistent with the idea that individual differences in working memory capacity do not predict noticing of unexpected objects in an inattentional blindness task. PMID:26562879

  1. Common capacity-limited neural mechanisms of selective attention and spatial working memory encoding.

    PubMed

    Fusser, Fabian; Linden, David E J; Rahm, Benjamin; Hampel, Harald; Haenschel, Corinna; Mayer, Jutta S

    2011-09-01

    One characteristic feature of visual working memory (WM) is its limited capacity, and selective attention has been implicated as limiting factor. A possible reason why attention constrains the number of items that can be encoded into WM is that the two processes share limited neural resources. Functional magnetic resonance imaging (fMRI) studies have indeed demonstrated commonalities between the neural substrates of WM and attention. Here we investigated whether such overlapping activations reflect interacting neural mechanisms that could result in capacity limitations. To independently manipulate the demands on attention and WM encoding within one single task, we combined visual search and delayed discrimination of spatial locations. Participants were presented with a search array and performed easy or difficult visual search in order to encode one, three or five positions of target items into WM. Our fMRI data revealed colocalised activation for attention-demanding visual search and WM encoding in distributed posterior and frontal regions. However, further analysis yielded two patterns of results. Activity in prefrontal regions increased additively with increased demands on WM and attention, indicating regional overlap without functional interaction. Conversely, the WM load-dependent activation in visual, parietal and premotor regions was severely reduced during high attentional demand. We interpret this interaction as indicating the sites of shared capacity-limited neural resources. Our findings point to differential contributions of prefrontal and posterior regions to the common neural mechanisms that support spatial WM encoding and attention, providing new imaging evidence for attention-based models of WM encoding. PMID:21781193

  2. Using Hazard Functions to Assess Changes in Processing Capacity in an Attentional Cuing Paradigm

    ERIC Educational Resources Information Center

    Wenger, Michael J.; Gibson, Bradley S.

    2004-01-01

    Processing capacity-defined as the relative ability to perform mental work in a unit of time-is a critical construct in cognitive psychology and is central to theories of visual attention. The unambiguous use of the construct, experimentally and theoretically, has been hindered by both conceptual confusions and the use of measures that are at best…

  3. The Measurement of Mental Attentional Capacity: A Neo-Piagetian Developmental Study.

    ERIC Educational Resources Information Center

    Pennings, Alber H.; Hessels, Marco G. P.

    1996-01-01

    Whether mental attentional capacity increases as a linear function of age during normal childhood development, as predicted by the neo-Piagetian developmental theory of J. Pascual-Leone (1970 and later), was studied with 215 children aged 5 to 12 years. Results provide only partial support for the Pascual-Leone theory. (SLD)

  4. Handwriting Capacity in Children Newly Diagnosed with Attention Deficit Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Brossard-Racine, Marie; Majnemer, Annette; Shevell, Michael; Snider, Laurie; Belanger, Stacey Ageranioti

    2011-01-01

    Preliminary evidence suggests that children with Attention Deficit Hyperactivity Disorder (ADHD) may exhibit handwriting difficulties. However, the exact nature of these difficulties and the extent to which they may relate to motor or behavioural difficulties remains unclear. The aim of this study was to describe handwriting capacity in children…

  5. Focused attention improves working memory: implications for flexible-resource and discrete-capacity models.

    PubMed

    Souza, Alessandra S; Rerko, Laura; Lin, Hsuan-Yu; Oberauer, Klaus

    2014-10-01

    Performance in working memory (WM) tasks depends on the capacity for storing objects and on the allocation of attention to these objects. Here, we explored how capacity models need to be augmented to account for the benefit of focusing attention on the target of recall. Participants encoded six colored disks (Experiment 1) or a set of one to eight colored disks (Experiment 2) and were cued to recall the color of a target on a color wheel. In the no-delay condition, the recall-cue was presented after a 1,000-ms retention interval, and participants could report the retrieved color immediately. In the delay condition, the recall-cue was presented at the same time as in the no-delay condition, but the opportunity to report the color was delayed. During this delay, participants could focus attention exclusively on the target. Responses deviated less from the target's color in the delay than in the no-delay condition. Mixture modeling assigned this benefit to a reduction in guessing (Experiments 1 and 2) and transposition errors (Experiment 2). We tested several computational models implementing flexible or discrete capacity allocation, aiming to explain both the effect of set size, reflecting the limited capacity of WM, and the effect of delay, reflecting the role of attention to WM representations. Both models fit the data better when a spatially graded source of transposition error is added to its assumptions. The benefits of focusing attention could be explained by allocating to this object a higher proportion of the capacity to represent color. PMID:24874258

  6. 20 CFR 220.120 - The claimant's residual functional capacity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... with a low back disorder may be fully capable of the physical demands consistent with those of... functional capacity. (a) General. The claimant's impairment(s), and any related symptoms, such as pain, may... limitations that go beyond the symptoms, such as pain, that are important in the diagnosis and treatment...

  7. 20 CFR 220.120 - The claimant's residual functional capacity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... with a low back disorder may be fully capable of the physical demands consistent with those of... functional capacity. (a) General. The claimant's impairment(s), and any related symptoms, such as pain, may... limitations that go beyond the symptoms, such as pain, that are important in the diagnosis and treatment...

  8. 20 CFR 220.120 - The claimant's residual functional capacity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... with a low back disorder may be fully capable of the physical demands consistent with those of... functional capacity. (a) General. The claimant's impairment(s), and any related symptoms, such as pain, may... limitations that go beyond the symptoms, such as pain, that are important in the diagnosis and treatment...

  9. 20 CFR 220.120 - The claimant's residual functional capacity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... with a low back disorder may be fully capable of the physical demands consistent with those of... functional capacity. (a) General. The claimant's impairment(s), and any related symptoms, such as pain, may... limitations that go beyond the symptoms, such as pain, that are important in the diagnosis and treatment...

  10. 20 CFR 220.120 - The claimant's residual functional capacity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... with a low back disorder may be fully capable of the physical demands consistent with those of... functional capacity. (a) General. The claimant's impairment(s), and any related symptoms, such as pain, may... limitations that go beyond the symptoms, such as pain, that are important in the diagnosis and treatment...

  11. Impaired Contingent Attentional Capture Predicts Reduced Working Memory Capacity in Schizophrenia

    PubMed Central

    Mayer, Jutta S.; Fukuda, Keisuke; Vogel, Edward K.; Park, Sohee

    2012-01-01

    Although impairments in working memory (WM) are well documented in schizophrenia, the specific factors that cause these deficits are poorly understood. In this study, we hypothesized that a heightened susceptibility to attentional capture at an early stage of visual processing would result in working memory encoding problems. 30 patients with schizophrenia and 28 demographically matched healthy participants were presented with a search array and asked to report the orientation of the target stimulus. In some of the trials, a flanker stimulus preceded the search array that either matched the color of the target (relevant-flanker capture) or appeared in a different color (irrelevant-flanker capture). Working memory capacity was determined in each individual using the visual change detection paradigm. Patients needed considerably more time to find the target in the no-flanker condition. After adjusting the individual exposure time, both groups showed equivalent capture costs in the irrelevant-flanker condition. However, in the relevant-flanker condition, capture costs were increased in patients compared to controls when the stimulus onset asynchrony between the flanker and the search array was high. Moreover, the increase in relevant capture costs correlated negatively with working memory capacity. This study demonstrates preserved stimulus-driven attentional capture but impaired contingent attentional capture associated with low working memory capacity in schizophrenia. These findings suggest a selective impairment of top-down attentional control in schizophrenia, which may impair working memory encoding. PMID:23152783

  12. Influence of Reel Lay on Residual Stress and Ultimate Bearing Capacity of Pipe

    NASA Astrophysics Data System (ADS)

    Liao, Hongqian; Wang, Liquan

    Reel lay is a fast and cost-effective way to install subsea pipelines. During reel lay, pipe's repeated plastic bending produces residual stress, which has influence on pipe's ultimate bearing capacity. First, the deformation of pipe in reel lay is analyzed, and the cyclic bending stages are simplified for convenience of theoretical research. Based on the finite element method (FEM), the Ramberg-Osgood model is adopted to describe material's mechanical property with kinematic hardening rule, and five bending stages are simulated. Further, the influence of material parameters and geometry parameters on pipe's residual stress is studied. Finally, the effect of residual stress on pipe's external pressure bearing capacity and tensile capacity is analyzed. Some important conclusions can be drawn: (1) the influence of diameter-thick ratio on residual stress is small, and material parameters' effect on the residual stress is large; (2) the influence of residual stress on pipe's external pressure bearing capacity is small, but its influence on tensile capacity is large.

  13. Working-memory capacity, proactive interference, and divided attention: limits on long-term memory retrieval.

    PubMed

    Kane, M J; Engle, R W

    2000-03-01

    Two experiments examined how individual differences in working-memory capacity (WM) relate to proactive interference (PI) susceptibility. We tested high and low WM-span participants in a PI-buildup task under single-task or dual-task ("load") conditions. In Experiment 1, a finger-tapping task was imposed during encoding and retrieval of each list; in Experiment 2, tapping was required during encoding or retrieval. In both experiments, low spans showed greater PI than did high spans under no load, but groups showed equivalent PI under divided attention. Load increased PI only for high spans, suggesting they use attention at encoding and retrieval to combat PI. In Experiment 2, only low spans showed a dual-task cost on List 1 memory, before PI built up. Results indicate a role for attentional processing, perhaps inhibitory in nature, at encoding and retrieval, and are discussed with respect to theories of WM and prefrontal cortex function. PMID:10764100

  14. Early auditory evoked potential is modulated by selective attention and related to individual differences in visual working memory capacity.

    PubMed

    Giuliano, Ryan J; Karns, Christina M; Neville, Helen J; Hillyard, Steven A

    2014-12-01

    A growing body of research suggests that the predictive power of working memory (WM) capacity for measures of intellectual aptitude is due to the ability to control attention and select relevant information. Crucially, attentional mechanisms implicated in controlling access to WM are assumed to be domain-general, yet reports of enhanced attentional abilities in individuals with larger WM capacities are primarily within the visual domain. Here, we directly test the link between WM capacity and early attentional gating across sensory domains, hypothesizing that measures of visual WM capacity should predict an individual's capacity to allocate auditory selective attention. To address this question, auditory ERPs were recorded in a linguistic dichotic listening task, and individual differences in ERP modulations by attention were correlated with estimates of WM capacity obtained in a separate visual change detection task. Auditory selective attention enhanced ERP amplitudes at an early latency (ca. 70-90 msec), with larger P1 components elicited by linguistic probes embedded in an attended narrative. Moreover, this effect was associated with greater individual estimates of visual WM capacity. These findings support the view that domain-general attentional control mechanisms underlie the wide variation of WM capacity across individuals. PMID:25000526

  15. Working Memory Capacity and the Top-Down Control of Visual Search: Exploring the Boundaries of "Executive Attention"

    ERIC Educational Resources Information Center

    Kane, Michael J.; Poole, Bradley J.; Tuholski, Stephen W.; Engle, Randall W.

    2006-01-01

    The executive attention theory of working memory capacity (WMC) proposes that measures of WMC broadly predict higher order cognitive abilities because they tap important and general attention capabilities (R. W. Engle & M. J. Kane, 2004). Previous research demonstrated WMC-related differences in attention tasks that required restraint of habitual…

  16. Cholinergic capacity mediates prefrontal engagement during challenges to attention: Evidence from imaging genetics

    PubMed Central

    Berry, Anne S; Blakely, Randy D; Sarter, Martin; Lustig, Cindy

    2015-01-01

    In rodent studies, elevated cholinergic neurotransmission in right prefrontal cortex (PFC) is essential for maintaining attentional performance, especially in challenging conditions. Apparently paralleling the rises in acetylcholine seen in rodent studies, fMRI studies in humans reveal right PFC activation at or near Brodmann’s area 9 (BA 9) increases in response to elevated attentional demand. In the present study, we leveraged human genetic variability in the cholinergic system to test the hypothesis that the cholinergic system contributes to the BA 9 response to attentional demand. Specifically, we scanned (BOLD fMRI) participants with a polymorphism of the choline transporter gene that is thought to limit choline transport capacity (Ile89Val variant of the choline transporter gene SLC5A7, rs1013940) and matched controls while they completed a task previously used to demonstrate demand-related increases in right PFC cholinergic transmission in rats and right PFC activation in humans. As hypothesized, we found that although controls showed the typical pattern of robust BA 9 responses to increased attentional demand, Ile89Val participants did not. Further, pattern analysis of activation within this region significantly predicted participant genotype. Additional exploratory pattern classification analyses suggested that Ile89Val participants differentially recruited orbitofrontal cortex and parahippocampal gyrus to maintain attentional performance to the level of controls. These results contribute to a growing body of translational research clarifying the role of cholinergic signaling in human attention and functional neural measures, and begin to outline the risk and resiliency factors associated with potentially suboptimal cholinergic function with implications for disorders characterized by cholinergic dysregulation. PMID:25536497

  17. EFFECTS OF SUSTAINED PRONGF BLOCKADE ON ATTENTIONAL CAPACITIES IN AGED RATS WITH COMPROMISED CHOLINERGIC SYSTEM

    PubMed Central

    YEGLA, BRITTNEY; PARIKH, VINAY

    2014-01-01

    Disruption in nerve growth factor (NGF) signaling via trkA receptors compromises the integrity of the basal forebrain (BF) cholinergic system, yielding cognitive, specifically attentional, impairments in Alzheimer’s disease (AD). Although normal aging is considered a risk factor for AD, the mechanisms underlying the selective vulnerability of the aging cholinergic system to trkA disruption is not clear. The levels of proNGF, a proneurotrophin that possesses higher affinity for p75 receptors, increase in aging. The present study was designed to test the hypothesis that cholinergic and attentional dysfunction in aged rats with reduced BF trkA receptors occurs due to the overactivation of endogenous proNGF signaling. We employed a viral vector that produced trkA shRNA to suppress trkA receptors in the corticopetal cholinergic neurons of aged rats. BF trkA suppression impaired animals’ performance on signal trials in both the sustained attention task (SAT) and the cognitively-taxing distractor version of SAT (dSAT) and these deficits were normalized by chronic intracerebroventricular administration of proNGF antibody. Moreover, depolarization-evoked ACh release and the density of cortical cholinergic fibers were partially restored in these animals. However, SAT/dSAT scores reflecting overall performance did not improve following proNGF blockade in trkA knockdown rats due to impaired performance in non-signal trials. Sustained proNGF blockade alone did not alter baseline attentional performance but produced moderate impairments during challenging conditions. Collectively, our findings indicate that barring proNGF-p75 signaling may exert some beneficial effects on attentional capacities specifically when BF trkA signaling is abrogated. However, endogenous proNGF may also possess neurotrophic effects and blockade of this proneurotrophin may not completely ameliorate attentional impairments in AD and potentially hinder performance during periods of high cognitive load

  18. 20 CFR 404.1546 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Responsibility for assessing your residual functional capacity. 404.1546 Section 404.1546 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness...

  19. 20 CFR 404.1546 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Responsibility for assessing your residual functional capacity. 404.1546 Section 404.1546 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness...

  20. 20 CFR 404.1546 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Responsibility for assessing your residual functional capacity. 404.1546 Section 404.1546 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness...

  1. 20 CFR 404.1546 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Responsibility for assessing your residual functional capacity. 404.1546 Section 404.1546 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness...

  2. 20 CFR 404.1546 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Responsibility for assessing your residual functional capacity. 404.1546 Section 404.1546 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness...

  3. 20 CFR 220.126 - Relationship of ability to do work and residual functional capacity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Relationship of ability to do work and... Relationship of ability to do work and residual functional capacity. (a) If the claimant can do his or her previous work (his or her usual work or other applicable past work), the Board will determine he or she...

  4. Dopamine and cognitive control: sex-by-genotype interactions influence the capacity to switch attention.

    PubMed

    Gurvich, C; Rossell, S L

    2015-03-15

    Cognitive performance in healthy persons varies widely between individuals. Sex differences in cognition are well reported, and there is an emerging body of evidence suggesting that the relationship between dopaminergic neurotransmission, implicated in many cognitive functions, is modulated by sex. Here, we examine the influence of sex and genetic variations along the dopaminergic pathway on aspects of cognitive control. A total of 415 healthy individuals, selected from an international consortium linked to Brain Research and Integrative Neuroscience Network (BRAINnet), were genotyped for two common and functional genetic variations of dopamine regulating genes: the catechol-O-methyltransferase [COMT] gene (rs4680) and the dopamine receptor D2 [DRD2] gene (rs6277). Cognitive measures were selected to explore sustained attention (using a continuous performance task), switching of attention (using a Trails B adaptation) and working memory (a visual computerised adaptation of digit span). While there were no main effects for genotype across any tasks, analyses revealed significant sex by genotype interactions for the capacity to switch attention. In relation to COMT, superior performance was noted in females with the Val/Val genotype and for DRD2, superior performance was seen for TT females and CC males. These findings highlight the importance of considering genetic variation in baseline dopamine levels in addition to sex, when considering the impact of dopamine on cognition in healthy populations. These findings also have important implications for the many neuropsychiatric disorders that implicate dopamine, cognitive changes and sex differences. PMID:25510197

  5. Prediction of pilot reserve attention capacity during air-to-air target tracking

    NASA Technical Reports Server (NTRS)

    Onstott, E. D.; Faulkner, W. H.

    1977-01-01

    Reserve attention capacity of a pilot was calculated using a pilot model that allocates exclusive model attention according to the ranking of task urgency functions whose variables are tracking error and error rate. The modeled task consisted of tracking a maneuvering target aircraft both vertically and horizontally, and when possible, performing a diverting side task which was simulated by the precise positioning of an electrical stylus and modeled as a task of constant urgency in the attention allocation algorithm. The urgency of the single loop vertical task is simply the magnitude of the vertical tracking error, while the multiloop horizontal task requires a nonlinear urgency measure of error and error rate terms. Comparison of model results with flight simulation data verified the computed model statistics of tracking error of both axes, lateral and longitudinal stick amplitude and rate, and side task episodes. Full data for the simulation tracking statistics as well as the explicit equations and structure of the urgency function multiaxis pilot model are presented.

  6. Working Memory Capacity: Attention Control, Secondary Memory, or Both? A Direct Test of the Dual-Component Model

    ERIC Educational Resources Information Center

    Unsworth, Nash; Spillers, Gregory J.

    2010-01-01

    The current study examined the extent to which attention control abilities, secondary memory abilities, or both accounted for variation in working memory capacity (WMC) and its relation to fluid intelligence. Participants performed various attention control, secondary memory, WMC, and fluid intelligence measures. Confirmatory factor analyses…

  7. Time-of-day effects on postural control and attentional capacities in children.

    PubMed

    Baccouch, Rym; Zarrouk, Nidhal; Chtourou, Hamdi; Rebai, Haithem; Sahli, Sonia

    2015-04-01

    The present study aimed to examine the effect of time-of-day on postural control, body temperature, and attentional capacities in 5-6 year old children. Twelve male children (5-6-year-old) were asked to maintain an upright bipedal stance on a force platform with eyes open (EO) and eyes closed (EC) at 07:00, 10:00, 14:00, and 18:00 h. Postural control was evaluated by center of pressure (CoP) surface area (CoPArea), CoP mean velocity (CoPVm), length of the CoP displacement as a function of the surface (LFS) ratio and Romberg's index (RI). Oral temperature and the simple reaction time were also recorded at the beginning of each test session. The one way ANOVA (4 time-of-day) showed significant time-of-day effects on CoPArea (p<0.001), CoPVm (p<0.01), LFS ratio (p<0.001) and RI (p<0.01). Children's postural control was lower at 07:00 h and at 14:00 h in comparison with 10:00 h and 18:00 h. Likewise, the reaction time was significantly (p<0.001) better at 10:00 h and 18:00 h in comparison with 07:00 h and 14:00 h. Oral temperature was higher at 14:00 h and 18:00 h than 08:00 h and 10:00 h (p<0.001). In conclusion, the children's postural control fluctuates during the daytime (i.e., better postural control at 10:00 h and at 18:00 h) with a diurnal rhythm close to that of body temperature and attentional capacities. Therefore, the evaluation of changes in postural control of 5-6-year-old children using force plate measures is recommended in the middle morning or the late afternoon to avoid the post-awakening and the post-prandial phases. PMID:25623540

  8. Attentional gain and processing capacity limits predict the propensity to neglect unexpected visual stimuli.

    PubMed

    Papera, Massimiliano; Richards, Anne

    2016-05-01

    Exogenous allocation of attentional resources allows the visual system to encode and maintain representations of stimuli in visual working memory (VWM). However, limits in the processing capacity to allocate resources can prevent unexpected visual stimuli from gaining access to VWM and thereby to consciousness. Using a novel approach to create unbiased stimuli of increasing saliency, we investigated visual processing during a visual search task in individuals who show a high or low propensity to neglect unexpected stimuli. When propensity to inattention is high, ERP recordings show a diminished amplification concomitantly with a decrease in theta band power during the N1 latency, followed by a poor target enhancement during the N2 latency. Furthermore, a later modulation in the P3 latency was also found in individuals showing propensity to visual neglect, suggesting that more effort is required for conscious maintenance of visual information in VWM. Effects during early stages of processing (N80 and P1) were also observed suggesting that sensitivity to contrasts and medium-to-high spatial frequencies may be modulated by low-level saliency (albeit no statistical group differences were found). In accordance with the Global Workplace Model, our data indicate that a lack of resources in low-level processors and visual attention may be responsible for the failure to "ignite" a state of high-level activity spread across several brain areas that is necessary for stimuli to access awareness. These findings may aid in the development of diagnostic tests and intervention to detect/reduce inattention propensity to visual neglect of unexpected stimuli. PMID:26849023

  9. Attention and Working Memory Capacity: Insights from Blocking, Highlighting, and Knowledge Restructuring

    ERIC Educational Resources Information Center

    Sewell, David K.; Lewandowsky, Stephan

    2012-01-01

    The concept of attention is central to theorizing in learning as well as in working memory. However, research to date has yet to establish how attention as construed in one domain maps onto the other. We investigate two manifestations of attention in category- and cue-learning to examine whether they might provide common ground between learning…

  10. Steroidogenic capacity of residual ovarian tissue in 4-vinylcyclohexene diepoxide-treated mice.

    PubMed

    Rivera, Zelieann; Christian, Patricia J; Marion, Sam L; Brooks, Heddwen L; Hoyer, Patricia B

    2009-02-01

    Menopause is an important public health issue because of its association with a number of disorders. Androgens produced by residual ovarian tissue after menopause could impact the development of these disorders. It has been unclear, however, whether the postmenopausal ovary retains steroidogenic capacity. Thus, an ovary-intact mouse model for menopause that uses the occupational chemical 4-vinylcyclohexene diepoxide (VCD) was used to characterize the expression of steroidogenic genes in residual ovarian tissue of follicle-depleted mice. Female B6C3F1 mice (age, 28 days) were dosed daily for 20 days with either vehicle or VCD (160 mg kg(-1) day(-1)) to induce ovarian failure. Ovaries were collected on Day 181 and analyzed for mRNA and protein. Acyclic aged mice were used as controls for natural ovarian senescence. Relative to cycling controls, expression of mRNA encoding steroidogenic acute regulatory protein (Star); cholesterol side-chain cleavage (Cyp11a1); 3beta-hydroxysteroid dehydrogenase (Hsd3b); 17alpha-hydroxylase (Cyp17a1); scavenger receptor class B, type 1 (Scarb1); low-density lipoprotein receptor (Ldlr); and luteinizing hormone receptor (Lhcgr) was enriched in VCD-treated ovaries. In acyclic aged ovaries, mRNA expression for only Cyp17a1 and Lhcgr was greater than that in controls. Compared to cycling controls, ovaries from VCD-treated and aged mice had similar levels of HSD3B, CYP17A1, and LHCGR protein. The pattern of protein immunofluorescence staining for HSD3B in follicle-depleted (VCD-treated) ovaries was homogeneous, whereas that for CYP17A1 was only seen in residual interstitial cells. Circulating levels of FSH and LH were increased, and androstenedione levels were detectable following follicle depletion in VCD-treated mice. These findings support the idea that residual ovarian tissue in VCD-treated mice retains androgenic capacity. PMID:18829706

  11. Preparation of agricultural residue anion exchangers and its nitrate maximum adsorption capacity.

    PubMed

    Orlando, U S; Baes, A U; Nishijima, W; Okada, M

    2002-09-01

    Anion exchangers were prepared from different agricultural residues (AR) after reaction with epichlorohydrin and dimethylamine in the presence of pyridine and N,N-dimethylformamide (EDM method). Agricultural residues anion exchangers (AR-AE) produced by the EDM method were inexpensive and showed almost the same NO3- removal capacities as Amberlite IRA-900. AR-AE produced from AR with higher hemicelluloses, lignin, ash and extractive contents resulted in the lower yields. Sugarcane bagasse with the highest alpha-cellulose contents of 51.2% had the highest yield (225%) and lowest preparation cost. The highest maximum adsorption capacity (Qmax) for nitrate was obtained from rice hull (1.21 mmol g(-1)) and pine bark natural exchangers (1.06 mmol g(-1)). No correlation was found between Qmax and alpha-cellulose content in the original AR. AR-AE produced from different AR demonstrated comparable Qmax due to the removal of non-active compounds such as extractives, lignin and hemicelluloses from AR during the preparation process. Similar preparation from pure cellulose and pure alkaline lignin demonstrated that the EDM method could not produce anion exchangers from pure lignin due to its solubilization after the reaction with epichlorohydrin. PMID:12227509

  12. Visual working memory capacity increases between ages 3 and 8 years, controlling for gains in attention, perception, and executive control.

    PubMed

    Pailian, Hrag; Libertus, Melissa E; Feigenson, Lisa; Halberda, Justin

    2016-08-01

    Research in adults has aimed to characterize constraints on the capacity of Visual Working Memory (VWM), in part because of the system's broader impacts throughout cognition. However, less is known about how VWM develops in childhood. Existing work has reached conflicting conclusions as to whether VWM storage capacity increases after infancy, and if so, when and by how much. One challenge is that previous studies did not control for developmental changes in attention and executive processing, which also may undergo improvement. We investigated the development of VWM storage capacity in children from 3 to 8 years of age, and in adults, while controlling for developmental change in exogenous and endogenous attention and executive control. Our results reveal that, when controlling for improvements in these abilities, VWM storage capacity increases across development and approaches adult-like levels between ages 6 and 8 years. More generally, this work highlights the value of estimating working memory, attention, perception, and decision-making components together. PMID:27225467

  13. Why Does Working Memory Capacity Predict Variation in Reading Comprehension? On the Influence of Mind Wandering and Executive Attention

    PubMed Central

    McVay, Jennifer C.; Kane, Michael J.

    2012-01-01

    Some people are better readers than others, and this variation in comprehension ability is predicted by measures of working memory capacity (WMC). The primary goal of this study was to investigate the mediating role of mind wandering experiences in the association between WMC and normal individual differences in reading comprehension, as predicted by the executive-attention theory of WMC (e.g., Engle & Kane, 2004). We used a latent-variable, structural-equation-model approach, testing skilled adult readers on three WMC span tasks, seven varied reading comprehension tasks, and three attention-control tasks. Mind wandering was assessed using experimenter-scheduled thought probes during four different tasks (two reading, two attention-control tasks). The results support the executive-attention theory of WMC. Mind wandering across the four tasks loaded onto a single latent factor, reflecting a stable individual difference. Most importantly, mind wandering was a significant mediator in the relationship between WMC and reading comprehension, suggesting that the WMC-comprehension correlation is driven, in part, by attention control over intruding thoughts. We discuss implications for theories of WMC, attention control, and reading comprehension. PMID:21875246

  14. Individual attentional selection capacities are reflected in interhemispheric connectivity of the parietal cortex.

    PubMed

    Vossel, Simone; Weidner, Ralph; Moos, Katharina; Fink, Gereon R

    2016-04-01

    Modelling psychophysical data using the Theory of Visual Attention (TVA) allows for a quantification of attentional sub-processes, such as the resolution of competition amongst multiple stimuli by top-down control signals for target selection (TVA-parameter α). This fMRI study investigated the neural correlates of α by comparing activity differences and changes of effective connectivity between conditions where a target was accompanied by a distractor or by a second target. Twenty-five participants performed a partial report task inside the MRI scanner. The left angular gyrus (ANG), medial frontal, and posterior cingulate cortex showed higher activity when a target was accompanied by a distractor as opposed to a second target. The reverse contrast yielded activation of a bilateral fronto-parietal network, the anterior insula, anterior cingulate cortex, and left inferior occipital gyrus. A psychophysiological interaction analysis revealed that the connectivity between left ANG and the left and right supramarginal gyrus (SMG), left anterior insula, and right putamen was enhanced in the target-distractor condition in participants with worse attentional top-down control. Dynamic causal modelling suggested that the connection from left ANG to right SMG during distractor presence was modulated by α. Our data show that interindividual differences in attentional processing are reflected in changes of effective connectivity without significant differences in activation strength of network nodes. PMID:26827815

  15. Attention Control, Memory Updating, and Emotion Regulation Temporarily Reduce the Capacity for Executive Control

    ERIC Educational Resources Information Center

    Schmeichel, Brandon J.

    2007-01-01

    This research tested the hypothesis that initial efforts at executive control temporarily undermine subsequent efforts at executive control. Four experiments revealed that controlling the focus of visual attention (Experiment 1), inhibiting predominant writing tendencies (Experiment 2), taking a working memory test (Experiment 3), or exaggerating…

  16. Integration of proprioceptive signals and attentional capacity during postural control are impaired but subject to improvement in dyslexic children.

    PubMed

    Quercia, Patrick; Demougeot, Laurent; Dos Santos, Mickaël; Bonnetblanc, François

    2011-04-01

    . Altogether, these results suggest that integration of proprioceptive signals in balance control and attentional capacity are impaired in dyslexic children. However, attention capacity during the control of stance could be improved significantly. PMID:21359661

  17. The McGurk effect: An investigation of attentional capacity employing response times.

    PubMed

    Altieri, Nicholas; Lentz, Jennifer J; Townsend, James T; Wenger, Michael J

    2016-08-01

    This paper proposes a novel approach to assess audiovisual integration for both congruent and incongruent speech stimuli using reaction times (RT). The experiments are based on the McGurk effect, in which a listener is presented with incongruent audiovisual speech signals. A typical example involves the auditory consonant/b/combined with a visually articulated/g/, often yielding a perception of/d/. We quantify the amount of integration relative to the predictions of a parallel independent model as a function of attention and congruency between auditory and visual signals. We assessed RT distributions for congruent and incongruent auditory and visual signals in a within-subjects signal detection paradigm under conditions of divided versus focused attention. Results showed that listeners often received only minimal benefit from congruent auditory visual stimuli, even when such information could have improved performance. Incongruent stimuli adversely affected performance in divided and focused attention conditions. Our findings support a parallel model of auditory-visual integration with interactions between auditory and visual channels. PMID:27188651

  18. Relationship between transdiaphragmatic and mouth twitch pressures at functional residual capacity.

    PubMed

    Laghi, F; Tobin, M J

    1997-03-01

    The clinical application of transdiaphragmatic twitch pressure (Pdi,tw) response to phrenic nerve stimulation has been hindered by the requirement for placement of oesophageal and gastric balloons. Investigators have reported that mouth twitch pressure (Pmo,tw) estimates Pdi,tw accurately at lung volumes above and below functional residual capacity (FRC). However, it is not known whether Pmo,tw estimates Pdi,tw accurately when stimulation is performed at FRC during relaxed conditions. The aim of this study was to develop a simple method whereby measurements of Pmo could be used to predict oesophageal twitch pressure (Poes,tw) and possibly Pdi,tw at FRC. The study was performed in 11 healthy volunteers during phrenic nerve stimulation. At FRC, 9 of the 11 subjects showed a poor correlation between Pmo,tw and Poes,tw, and between Pmo,tw and Pdi,tw, probably due to varying degrees of glottic closure. Stimulations performed while subjects maintained an inspiratory flow of approximately 50 mL x s(-1), or at the point of reattaining FRC during an inspiration preceded by a limited exhalation, produced good correlations between Pmo,tw and Poes,tw (r=0.97 in both instances) and Pmo,tw and Pdi,tw (r=0.96 and r=0.95, respectively), with a steep slope. The respective slopes for the Pmo,tw Poes,tw relationship were 0.88 and 0.94, and for the Pmo,tw Pdi,tw relationship, 0.59 and 0.54. Unfortunately, these manoeuvres produced a significant increase in transpulmonary pressure (3.6+/-0.6 (SE) and 5.6+/-1.4 cmH2O, respectively), suggesting change in diaphragmatic length. Stimulations delivered while subjects performed an inspiratory effort or during exhalation against a high resistance preceded by a limited inhalation could not be used to predict Poes,tw and Pdi,tw from Pmo,tw. In conclusion, although transdiaphragmatic and oesophageal twitch pressure could be predicted from mouth twitch pressure during some inspiratory manoeuvres mouth twitch pressure was not reliable for the

  19. A method of estimating the functional residual capacity of infants with respiratory distress syndrome.

    PubMed

    Richardson, P; Wyman, M; Jung, A L

    1980-11-01

    This report describes and evaluates a new method of estimating the functional residual capacity (FRC) of newborn infants receiving continuous positive airway pressure (CPAP). Standard nitrogen washout methods of measuring lung volume are time consuming, frequently interfere with patient care, and may be hazardous to prematurely born infants. The authors are using a four-breath nitrogen washout technique to estimate the FRC of infants. The method was evaluated using: (1) a mechanical lung model, and (2) results from 32 newborn infants with RDS. The actual volume of the mechanical lung model was 21.6 ml and the estimated volume was 21.4 +/- 2.3 (SD) n = 13. Using different volumes in the mechanical lung model and comparing with estimated FRCs yielded a correlation coefficient of 0.96 (n = 15). Comparing the FRC of infants determined by standard nitrogen washout with the estimated FRC yielded a correlation coefficient of 0.92, n = 145. Thus, the results of the two methods are in good agreement. The new method reduces the period of breathing pure oxygen from several minutes to just a few seconds, thus, decreasing the dangers of absorption atelectasis and oxygen toxicity. The new system also lends itself well to micro-processor automation. PMID:7000439

  20. Methylphenidate enhances cognitive performance in adults with poor baseline capacities regardless of attention-deficit/hyperactivity disorder diagnosis.

    PubMed

    Agay, Nirit; Yechiam, Eldad; Carmel, Ziv; Levkovitz, Yechiel

    2014-04-01

    We compare the view that the effect of methylphenidate (MPH) is selective to individuals with attention-deficit/hyperactivity disorder (ADHD) with an alternative approach suggesting that its effect is more prominent for individuals with weak baseline capacities in relevant cognitive tasks. To evaluate theses 2 approaches, we administered sustained attention, working memory, and decision-making tasks to 20 ADHD adults and 19 control subjects, using a within-subject placebo-controlled design. The results demonstrated no main effects of MPH in the decision-making tasks. In the sustained attention and working-memory tasks, MPH enhanced performance of both ADHD and non-ADHD adults to a similar extent compared with placebo. Hence, the effect of MPH was not selective to ADHD adults. In addition, those benefitting most from MPH in all 3 task domains tended to be individuals with poor task performance. However, in most tasks, individuals whose performance was impaired by MPH were not necessarily better (or worse) performers. The findings suggest that the administration of MPH to adults with ADHD should consider not only clinical diagnosis but also their functional (performance-based) profile. PMID:24525641

  1. Monitoring cholinergic activity during attentional performance in mice heterozygous for the choline transporter: a model of cholinergic capacity limits.

    PubMed

    Paolone, Giovanna; Mallory, Caitlin S; Koshy Cherian, Ajeesh; Miller, Thomas R; Blakely, Randy D; Sarter, Martin

    2013-12-01

    Reductions in the capacity of the human choline transporter (SLC5A7, CHT) have been hypothesized to diminish cortical cholinergic neurotransmission, leading to risk for cognitive and mood disorders. To determine the acetylcholine (ACh) release capacity of cortical cholinergic projections in a mouse model of cholinergic hypofunction, the CHT+/- mouse, we assessed extracellular ACh levels while mice performed an operant sustained attention task (SAT). We found that whereas SAT-performance-associated increases in extracellular ACh levels of CHT+/- mice were significantly attenuated relative to wildtype littermates, performance on the SAT was normal. Tetrodotoxin-induced blockade of neuronal excitability reduced both dialysate ACh levels and SAT performance similarly in both genotypes. Likewise, lesions of cholinergic neurons abolished SAT performance in both genotypes. However, cholinergic activation remained more vulnerable to the reverse-dialyzed muscarinic antagonist atropine in CHT+/- mice. Additionally, CHT+/- mice displayed greater SAT-disrupting effects of reverse dialysis of the nAChR antagonist mecamylamine. Receptor binding assays revealed a higher density of α4β2* nAChRs in the cortex of CHT+/- mice compared to controls. These findings reveal compensatory mechanisms that, in the context of moderate cognitive challenges, can overcome the performance deficits expected from the significantly reduced ACh capacity of CHT+/- cholinergic terminals. Further analyses of molecular and functional compensations in the CHT+/- model may provide insights into both risk and resiliency factors involved in cognitive and mood disorders. PMID:23958450

  2. Monitoring cholinergic activity during attentional performance in mice heterozygous for the choline transporter: a model of cholinergic capacity limits

    PubMed Central

    Cherian, Ajeesh Koshy; Miller, Thomas R.; Blakely, Randy D.; Sarter, Martin

    2013-01-01

    Reductions in the capacity of the human choline transporter (SLC5A7, CHT) have been hypothesized to diminish cortical cholinergic neurotransmission, leading to risk for cognitive and mood disorders. To determine the acetylcholine (ACh) release capacity of cortical cholinergic projections in a mouse model of cholinergic hypofunction, the CHT+/− mouse, we assessed extracellular ACh levels while mice performed an operant sustained attention task (SAT). We found that whereas SAT-performance-associated increases in extracellular ACh levels of CHT+/− mice were significantly attenuated relative to wildtype littermates, performance on the SAT was normal. Tetrodotoxin-induced blockade of neuronal excitability reduced both dialysate ACh levels and SAT performance similarly in both genotypes. Likewise, lesions of cholinergic neurons abolished SAT performance in both genotypes. However, cholinergic activation remained more vulnerable to the reverse-dialyzed muscarinic antagonist atropine in CHT+/− mice. Additionally, CHT+/− mice displayed greater SAT-disrupting effects of reverse dialysis of the nAChR antagonist mecamylamine. Receptor binding assays revealed a higher density of α4β2* nAChRs in the cortex of CHT+/− mice compared to controls. These findings reveal compensatory mechanisms that, in the context of moderate cognitive challenges, can overcome the performance deficits expected from the significantly reduced ACh capacity of CHT+/− cholinergic terminals. Further analyses of molecular and functional compensations in the CHT +/− model may provide insights into both risk and resiliency factors involved in cognitive and mood disorders. PMID:23958450

  3. Functional residual capacity tool: A practical method to assess lung volume changes during pulmonary complications in mechanically ventilated patients.

    PubMed

    Veena, S; Palepu, Sudeep; Umamaheswara Rao, G S; Ramesh, V J

    2010-07-01

    In this report, we describe a patient in whom we used a functional residual capacity (FRC) tool available on a critical care ventilator to identify the loss of lung volume associated with pulmonary complications and increase in FRC with the application of a recruitment maneuver. The case report underlines the utility of the FRC tool in rapid visualization of the lung volume changes and the effects of application of corrective strategies in patients receiving mechanical ventilation. PMID:21253350

  4. INFLUENCE OF BUFFER CAPACITY, CHLORINE RESIDUAL, AND FLOW RATE ON CORROSION OF MILD STEEL AND COPPER

    EPA Science Inventory

    The corrosion rates of mild steel decreased as buffer capacity was increased with pH at constant alkalinity. The corrosion-promoting effect of ionic strength, however, appeared to predominate over the buffer action in water systems with relatively high total dissolved solids and ...

  5. The effect of body position, sedation, and thoracic bandaging on functional residual capacity in healthy deep-chested dogs

    PubMed Central

    Rozanski, Elizabeth A.; Bedenice, Daniela; Lofgren, Jennifer; Abrams, Julie; Bach, Jonathan; Hoffman, Andrew M.

    2010-01-01

    The objective of this study was to determine the effect of body position, chest wrap, and sedation on functional residual capacity (FRC) in 6 healthy dogs. Functional residual capacity was determined by helium dilution (re-breathing) whilst in different clinically relevant conditions. These conditions included the standing (sternal) and lateral positions in unsedated dogs and then again both standing and lateral following chest bandaging, and sedation with acepromazine, IV and butorphanol, IV. The mean FRC at each measurement point was determined, as was the change in FRC (delta FRC) from one measurement point to another. Analysis of variance (ANOVA) with repeated measures with Fisher’s LSD post hoc test was used to evaluate the effect of interventions. The differences in delta FRC were evaluated using a t-test or Wilcoxon rank-sum test. P < 0.05 was considered significant. The mean FRC at baseline, defined as standing, unsedated and unwrapped, was 75.3 ± 23.8 mL/kg. Body position or sedation had the most profound effect on FRC with right lateral recumbency lowering FRC by a median of 20.4 mL/kg and sedation lowering FRC by a median of 19.8 mL/kg. Common clinical procedures and positioning result in lowered FRC in healthy deep-chested dogs. In critically ill or injured dogs, the iatrogenic loss of FRC through chest bandaging, sedation, or body position may be clinically relevant. PMID:20357956

  6. Effects of a Physical Training Program on Physical Efficiency, Work Capacity and Classroom-Attention of Handicapped Children.

    ERIC Educational Resources Information Center

    Dresen, M. H. W.; Netelenbos, J. B.

    1983-01-01

    After a 10-week physical training program for 11 motorically handicapped Dutch children, aged eight to l4, the experimental group (N=6) demonstrated a significant increase in physical efficiency and classroom attention scores. Follow-up showed that both groups' physical efficiency scores deteriorated and that experimentals' attention scores…

  7. Neurophysiological Indicators of Residual Cognitive Capacity in the Minimally Conscious State

    PubMed Central

    Hauger, Solveig L.; Schnakers, Caroline; Andersson, Stein; Becker, Frank; Moberget, Torgeir; Giacino, Joseph T.; Schanke, Anne-Kristine; Løvstad, Marianne

    2015-01-01

    Background. The diagnostic usefulness of electrophysiological methods in assessing disorders of consciousness (DoC) remains to be established on an individual patient level, and there is need to determine what constitutes robust experimental paradigm to elicit electrophysiological indices of covert cognitive capacity. Objectives. Two tasks encompassing active and passive conditions were explored in an event-related potentials (ERP) study. The task robustness was studied in healthy controls, and their utility to detect covert signs of command-following on an individual patient level was investigated in patients in a minimally conscious state (MCS). Methods. Twenty healthy controls and 20 MCS patients participated. The active tasks included (1) listening for a change of pitch in the subject's own name (SON) and (2) counting SON, both contrasted to passive conditions. Midline ERPs are reported. Results. A larger P3 response was detected in the counting task compared to active listening to pitch change in the healthy controls. On an individual level, the counting task revealed a higher rate of responders among both healthy subjects and MCS patients. Conclusion. ERP paradigms involving actively counting SON represent a robust paradigm in probing for volitional cognition in minimally conscious patients and add important diagnostic information in some patients. PMID:26504351

  8. Measurements of functional residual capacity during intensive care treatment: the technical aspects and its possible clinical applications.

    PubMed

    Heinze, H; Eichler, W

    2009-10-01

    Direct measurement of lung volume, i.e. functional residual capacity (FRC) has been recommended for monitoring during mechanical ventilation. Mostly due to technical reasons, FRC measurements have not become a routine monitoring tool, but promising techniques have been presented. We performed a literature search of studies with the key words 'functional residual capacity' or 'end expiratory lung volume' and summarize the physiology and patho-physiology of FRC measurements in ventilated patients, describe the existing techniques for bedside measurement, and provide an overview of the clinical questions that can be addressed using an FRC assessment. The wash-in or wash-out of a tracer gas in a multiple breath maneuver seems to be best applicable at bedside, and promising techniques for nitrogen or oxygen wash-in/wash-out with reasonable accuracy and repeatability have been presented. Studies in ventilated patients demonstrate that FRC can easily be measured at bedside during various clinical settings, including positive end-expiratory pressure optimization, endotracheal suctioning, prone position, and the weaning from mechanical ventilation. Alveolar derecruitment can easily be monitored and improvements of FRC without changes of the ventilatory setting could indicate alveolar recruitment. FRC seems to be insensitive to over-inflation of already inflated alveoli. Growing evidence suggests that FRC measurements, in combination with other parameters such as arterial oxygenation and respiratory compliance, could provide important information on the pulmonary situation in critically ill patients. Further studies are needed to define the exact role of FRC in monitoring and perhaps guiding mechanical ventilation. PMID:19681779

  9. Polder Effects on Sediment-to-Soil Conversion: Water Table, Residual Available Water Capacity, and Salt Stress Interdependence

    PubMed Central

    Radimy, Raymond Tojo; Dudoignon, Patrick; Hillaireau, Jean Michel; Deboute, Elise

    2013-01-01

    The French Atlantic marshlands, reclaimed since the Middle Age, have been successively used for extensive grazing and more recently for cereal cultivation from 1970. The soils have acquired specific properties which have been induced by the successive reclaiming and drainage works and by the response of the clay dominant primary sediments, that is, structure, moisture, and salinity profiles. Based on the whole survey of the Marais Poitevin and Marais de Rochefort and in order to explain the mechanisms of marsh soil behavior, the work focuses on two typical spots: an undrained grassland since at least 1964 and a drained cereal cultivated field. The structure-hydromechanical profiles relationships have been established thanks to the clay matrix shrinkage curve. They are confronted to the hydraulic functioning including the fresh-to-salt water transfers and to the recording of tensiometer profiles. The CE1/5 profiles supply the water geochemical and geophysical data by their better accuracy. Associated to the available water capacity calculation they allow the representation of the parallel evolution of the residual available water capacity profiles and salinity profiles according to the plant growing and rooting from the mesophile systems of grassland to the hygrophile systems of drained fields. PMID:23990758

  10. Working memory capacity accounts for the ability to switch between object-based and location-based allocation of visual attention.

    PubMed

    Bleckley, M Kathryn; Foster, Jeffrey L; Engle, Randall W

    2015-04-01

    Bleckley, Durso, Crutchfield, Engle, and Khanna (Psychonomic Bulletin & Review, 10, 884-889, 2003) found that visual attention allocation differed between groups high or low in working memory capacity (WMC). High-span, but not low-span, subjects showed an invalid-cue cost during a letter localization task in which the letter appeared closer to fixation than the cue, but not when the letter appeared farther from fixation than the cue. This suggests that low-spans allocated attention as a spotlight, whereas high-spans allocated their attention to objects. In this study, we tested whether utilizing object-based visual attention is a resource-limited process that is difficult for low-span individuals. In the first experiment, we tested the uses of object versus location-based attention with high and low-span subjects, with half of the subjects completing a demanding secondary load task. Under load, high-spans were no longer able to use object-based visual attention. A second experiment supported the hypothesis that these differences in allocation were due to high-spans using object-based allocation, whereas low-spans used location-based allocation. PMID:25421317

  11. Why Does Working Memory Capacity Predict Variation in Reading Comprehension? On the Influence of Mind Wandering and Executive Attention

    ERIC Educational Resources Information Center

    McVay, Jennifer C.; Kane, Michael J.

    2012-01-01

    Some people are better readers than others, and this variation in comprehension ability is predicted by measures of working memory capacity (WMC). The primary goal of this study was to investigate the mediating role of mind-wandering experiences in the association between WMC and normal individual differences in reading comprehension, as predicted…

  12. Working Memory Capacity in a Go/No-Go Task: Age Differences in Interference, Processing Speed, and Attentional Control

    ERIC Educational Resources Information Center

    Rodríguez-Villagra, Odir Antonio; Göthe, Katrin; Oberauer, Klaus; Kliegl, Reinhold

    2013-01-01

    We tested the limits of working-memory capacity (WMC) of young adults, old adults, and children with a memory-updating task. The task consisted of mentally shifting spatial positions within a grid according to arrows, their color signaling either only go (control) or go/no-go conditions. The interference model (IM) of Oberauer and Kliegl (2006)…

  13. Orienting attention in visual working memory requires central capacity: Decreased retro-cue effects under dual-task conditions

    PubMed Central

    Berryhill, Marian E.

    2014-01-01

    The retro-cue effect (RCE) describes superior working memory performance for validly cued stimulus locations long after encoding has ended. Importantly, this happens with delays beyond the range of iconic memory. In general, the RCE is a stable phenomenon that emerges under varied stimulus configurations and timing parameters. We investigated its susceptibility to dual-task interference to determine the attentional requirements at the time point of cue onset and encoding. In Experiment 1, we compared single- with dual-task conditions. In Experiment 2, we borrowed from the psychological refractory period paradigm and compared conditions with high and low (dual-) task overlap. The secondary task was always binary tone discrimination requiring amanual response. Across both experiments, an RCE was found, but it was diminished in magnitude in the critical dual-task conditions. A previous study did not find evidence that sustained attention is required in the interval between cue offset and test. Our results apparently contradict these findings and point to a critical time period around cue onset and briefly thereafter during which attention is required. PMID:24452383

  14. The Prognostic Value of Residual Volume/Total Lung Capacity in Patients with Chronic Obstructive Pulmonary Disease.

    PubMed

    Shin, Tae Rim; Oh, Yeon-Mok; Park, Joo Hun; Lee, Keu Sung; Oh, Sunghee; Kang, Dae Ryoung; Sheen, Seungsoo; Seo, Joon Beom; Yoo, Kwang Ha; Lee, Ji-Hyun; Kim, Tae-Hyung; Lim, Seong Yong; Yoon, Ho Il; Rhee, Chin Kook; Choe, Kang-Hyeon; Lee, Jae Seung; Lee, Sang-Do

    2015-10-01

    The prognostic role of resting pulmonary hyperinflation as measured by residual volume (RV)/total lung capacity (TLC) in chronic obstructive pulmonary disease (COPD) remains poorly understood. Therefore, this study aimed to identify the factors related to resting pulmonary hyperinflation in COPD and to determine whether resting pulmonary hyperinflation is a prognostic factor in COPD. In total, 353 patients with COPD in the Korean Obstructive Lung Disease cohort recruited from 16 hospitals were enrolled. Resting pulmonary hyperinflation was defined as RV/TLC ≥ 40%. Multivariate logistic regression analysis demonstrated that older age (P = 0.001), lower forced expiratory volume in 1 second (FEV1) (P < 0.001), higher St. George Respiratory Questionnaire (SGRQ) score (P = 0.019), and higher emphysema index (P = 0.010) were associated independently with resting hyperinflation. Multivariate Cox regression model that included age, gender, dyspnea scale, SGRQ, RV/TLC, and 6-min walking distance revealed that an older age (HR = 1.07, P = 0.027), a higher RV/TLC (HR = 1.04, P = 0.025), and a shorter 6-min walking distance (HR = 0.99, P < 0.001) were independent predictors of all-cause mortality. Our data showed that older age, higher emphysema index, higher SGRQ score, and lower FEV1 were associated independently with resting pulmonary hyperinflation in COPD. RV/TLC is an independent risk factor for all-cause mortality in COPD. PMID:26425043

  15. A Novel Physiological Investigation of the Functional Residual Capacity by the Bias Flow Nitrogen Washout Technique in Infants

    PubMed Central

    Morris, Mohy G.

    2011-01-01

    Summary The dynamic functional residual capacity (FRCdyn), the lung volume most routinely measured in infants, is an unreliable volume landmark. In addition to the FRCdyn, we measured the (passive) static FRC (FRCst) by inducing a brief post-hyperventilation apnea (PHA) in 33 healthy infants aged 7.4–127.2 weeks. A commercial system for nitrogen (N2) washout to measure FRC, and a custom made system to monitor and record flow and airwayopening pressure signals in real-time were used in unison. Infants were manually hyperventilated to induce a PHA. After the last passive expiration, FRCst was estimated by measuring the volume of N2 expired after end-passive expiratory switching of the inspired gas from room air to 100% oxygen during the post-expiratory apneic pause. Repeatable intrasubject FRCst and FRCdyn measurements overlapped in most infants including the younger ones (P = 0.2839). Mean (95% confidence interval [CI]) FRCst was 21.1 (20.0–22.3), and error-corrected FRCdyn was 21.4 (20.4–22.4) ml/kg. Mean (washout time [t]) tFRCst was longer than tFRCdyn 60 sec (95% CI 55–65) versus 47 sec (95% CI 43–51) (P<0.0001). The FRC and washout time were dependent on body length, weight and age. We conclude that the FRCst is not different from the FRCdyn in infants. The FRCst is a reliable volume landmark because the PHA stabilizes the end-expiratory level by potentially abolishing the sedated infant’s breathing strategies. The FRCst lacks potential sources of errors and disadvantages associated with measuring the FRCdyn. The findings cast significant doubt on the traditional physiology of air trapping in healthy infants’ lungs. PMID:19499588

  16. Cognitive aging on latent constructs for visual processing capacity: a novel structural equation modeling framework with causal assumptions based on a theory of visual attention

    PubMed Central

    Nielsen, Simon; Wilms, L. Inge

    2015-01-01

    We examined the effects of normal aging on visual cognition in a sample of 112 healthy adults aged 60–75. A testbattery was designed to capture high-level measures of visual working memory and low-level measures of visuospatial attention and memory. To answer questions of how cognitive aging affects specific aspects of visual processing capacity, we used confirmatory factor analyses in Structural Equation Modeling (SEM; Model 2), informed by functional structures that were modeled with path analyses in SEM (Model 1). The results show that aging effects were selective to measures of visual processing speed compared to visual short-term memory (VSTM) capacity (Model 2). These results are consistent with some studies reporting selective aging effects on processing speed, and inconsistent with other studies reporting aging effects on both processing speed and VSTM capacity. In the discussion we argue that this discrepancy may be mediated by differences in age ranges, and variables of demography. The study demonstrates that SEM is a sensitive method to detect cognitive aging effects even within a narrow age-range, and a useful approach to structure the relationships between measured variables, and the cognitive functional foundation they supposedly represent. PMID:25642206

  17. Assessing the potential for increased capacity of combined heat and power facilities based on available corn stover and forest logging residue in Mississippi

    NASA Astrophysics Data System (ADS)

    Radhakrishnan, Selvarani

    The amount of available biomass feedstock and associated cost components were analyzed to determine the potential increase in energy capacity of two existing combined heat and power plants in Mississippi. The amount of corn stover and forest logging residue within a 10-mile radius can satisfy the existing requirements of CHP plants in Scott (1 MW) and Washington counties (5 MW). Transporting feedstock within a smaller source area had lower transportation costs, but higher total unit cost than the two other source buffer scenarios. However, capital costs associated with higher plant capacities were significantly higher and plant expansion may not be economically advantageous. Increasing the CHP capacity from 1 MW to 2 MW in Scott county and 5 MW to 10 MW in Washington county might be a sustainable approach by drawing feedstock from a smaller area and at lower utilization rates, while keeping transportation costs low.

  18. Negatively charged residues of the segment linking the enzyme and cytolysin moieties restrict the membrane-permeabilizing capacity of adenylate cyclase toxin.

    PubMed

    Masin, Jiri; Osickova, Adriana; Sukova, Anna; Fiser, Radovan; Halada, Petr; Bumba, Ladislav; Linhartova, Irena; Osicka, Radim; Sebo, Peter

    2016-01-01

    The whooping cough agent, Bordetella pertussis, secretes an adenylate cyclase toxin-hemolysin (CyaA) that plays a crucial role in host respiratory tract colonization. CyaA targets CR3-expressing cells and disrupts their bactericidal functions by delivering into their cytosol an adenylate cyclase enzyme that converts intracellular ATP to cAMP. In parallel, the hydrophobic domain of CyaA forms cation-selective pores that permeabilize cell membrane. The invasive AC and pore-forming domains of CyaA are linked by a segment that is unique in the RTX cytolysin family. We used mass spectrometry and circular dichroism to show that the linker segment forms α-helical structures that penetrate into lipid bilayer. Replacement of the positively charged arginine residues, proposed to be involved in target membrane destabilization by the linker segment, reduced the capacity of the toxin to translocate the AC domain across cell membrane. Substitutions of negatively charged residues then revealed that two clusters of negative charges within the linker segment control the size and the propensity of CyaA pore formation, thereby restricting the cell-permeabilizing capacity of CyaA. The 'AC to Hly-linking segment' thus appears to account for the smaller size and modest cell-permeabilizing capacity of CyaA pores, as compared to typical RTX hemolysins. PMID:27581058

  19. Negatively charged residues of the segment linking the enzyme and cytolysin moieties restrict the membrane-permeabilizing capacity of adenylate cyclase toxin

    PubMed Central

    Masin, Jiri; Osickova, Adriana; Sukova, Anna; Fiser, Radovan; Halada, Petr; Bumba, Ladislav; Linhartova, Irena; Osicka, Radim; Sebo, Peter

    2016-01-01

    The whooping cough agent, Bordetella pertussis, secretes an adenylate cyclase toxin-hemolysin (CyaA) that plays a crucial role in host respiratory tract colonization. CyaA targets CR3-expressing cells and disrupts their bactericidal functions by delivering into their cytosol an adenylate cyclase enzyme that converts intracellular ATP to cAMP. In parallel, the hydrophobic domain of CyaA forms cation-selective pores that permeabilize cell membrane. The invasive AC and pore-forming domains of CyaA are linked by a segment that is unique in the RTX cytolysin family. We used mass spectrometry and circular dichroism to show that the linker segment forms α-helical structures that penetrate into lipid bilayer. Replacement of the positively charged arginine residues, proposed to be involved in target membrane destabilization by the linker segment, reduced the capacity of the toxin to translocate the AC domain across cell membrane. Substitutions of negatively charged residues then revealed that two clusters of negative charges within the linker segment control the size and the propensity of CyaA pore formation, thereby restricting the cell-permeabilizing capacity of CyaA. The ‘AC to Hly-linking segment’ thus appears to account for the smaller size and modest cell-permeabilizing capacity of CyaA pores, as compared to typical RTX hemolysins. PMID:27581058

  20. Triceps Brachii in Incomplete Tetraplegia: EMG and Dynamometer Evaluation of Residual Motor Resources and Capacity for Strengthening

    PubMed Central

    2013-01-01

    Background: Candidates for activity-based therapy after spinal cord injury (SCI) are often selected on the basis of manual muscle test scores and the classification of the injury as complete or incomplete. However, these scores may not adequately predict which individuals have sufficient residual motor resources for the therapy to be beneficial. Objective: We performed a preliminary study to see whether dynamometry and quantitative electromyography (EMG) can provide a more detailed assessment of residual motor resources. Methods: We measured elbow extension strength using a hand-held dynamometer and recorded fine-wire EMG from the triceps brachii muscles of 4 individuals with C5, C6, or C7 level SCI and 2 able-bodied controls. We used EMG decomposition to measure motor unit action potential (MUAP) amplitudes and motor unit (MU) recruitment and firing-rate profiles during constant and ramp contractions. Results: All 4 subjects with cervical SCI (cSCI) had increased MUAP amplitudes indicative of denervation. Two of the subjects with cSCI had very weak elbow extension strength (<4 kg), dramatically reduced recruitment, and excessive firing rates (>40 pps), suggesting profound loss of motoneurons. The other 2 subjects with cSCI had stronger elbow extension (>6 kg), more normal recruitment, and more normal firing rates, suggesting a substantial remaining motoneuron population. Conclusions: Dynamometry and quantitative EMG may provide information about the extent of gray matter loss in cSCI to help guide rehabilitation strategies. PMID:24244095

  1. Attention competition with advertisement

    NASA Astrophysics Data System (ADS)

    Cetin, Uzay; Bingol, Haluk O.

    2014-09-01

    In the new digital age, information is available in large quantities. Since information consumes primarily the attention of its recipients, the scarcity of attention is becoming the main limiting factor. In this study, we investigate the impact of advertisement pressure on a cultural market where consumers have a limited attention capacity. A model of competition for attention is developed and investigated analytically and by simulation. Advertisement is found to be much more effective when the attention capacity of agents is extremely scarce. We have observed that the market share of the advertised item improves if dummy items are introduced to the market while the strength of the advertisement is kept constant.

  2. Attention competition with advertisement.

    PubMed

    Cetin, Uzay; Bingol, Haluk O

    2014-09-01

    In the new digital age, information is available in large quantities. Since information consumes primarily the attention of its recipients, the scarcity of attention is becoming the main limiting factor. In this study, we investigate the impact of advertisement pressure on a cultural market where consumers have a limited attention capacity. A model of competition for attention is developed and investigated analytically and by simulation. Advertisement is found to be much more effective when the attention capacity of agents is extremely scarce. We have observed that the market share of the advertised item improves if dummy items are introduced to the market while the strength of the advertisement is kept constant. PMID:25314476

  3. International Harmonization of Food Safety Assessment of Pesticide Residues.

    PubMed

    Ambrus, Árpád

    2016-01-13

    This paper summarizes the development of principles and methods applied within the program of the FAO/WHO Codex Alimentarius during the past 50 years for the safety assessment of pesticide residues in food and feed and establishing maximum residue limits (MRLs) to promote free international trade and assure the safety of consumers. The role of major international organizations in this process, the FAO capacity building activities, and some problematic areas that require special attention are briefly described. PMID:25660755

  4. The effect of low-NO{sub x} combustion on residual carbon in fly ash and its adsorption capacity for air entrainment admixtures in concrete

    SciTech Connect

    Pedersen, K.H.; Jensen, A.D.; Dam-Johansen, K.

    2010-02-15

    Fly ash from pulverized coal combustion contains residual carbon that can adsorb the air-entraining admixtures (AEAs) added to control the air entrainment in concrete. This is a problem that has increased by the implementation of low-NO{sub x} combustion technologies. In this work, pulverized fuel has been combusted in an entrained flow reactor to test the impact of changes in operating conditions and fuel type on the AEA adsorption of ash and NO{sub x} formation. Increased oxidizing conditions, obtained by improved fuel-air mixing or higher excess air, decreased the AEA requirements of the produced ash by up to a factor of 25. This was due to a lower carbon content in the ash and a lower specific AEA adsorptivity of the carbon. The latter was suggested to be caused by changes in the adsorption properties of the unburned char and a decreased formation of soot, which was found to have a large AEA adsorption capacity based on measurements on a carbon black. The NO{sub x} formation increased by up to three times with more oxidizing conditions and thus, there was a trade-off between the AEA requirements of the ash and NO{sub x} formation. The type of fuel had high impact on the AEA adsorption behavior of the ash. Ashes produced from a Columbian and a Polish coal showed similar AEA requirements, but the specific AEA adsorptivity of the carbon in the Columbian coal ash was up to six times higher. The AEA requirements of a South African coal ash was unaffected by the applied operating conditions and showed up to 12 times higher AEA adsorption compared to the two other coal ashes. This may be caused by larger particles formed by agglomeration of the primary coal particles in the feeding phase or during the combustion process, which gave rise to increased formation of soot. (author)

  5. [Schizophrenia and selective attention].

    PubMed

    Thomas, J; Laplante, L; Everett, J

    1989-01-01

    A comparative study of selective attention was made on 22 schizophrenic inpatients, 18 non schizophrenic inpatients and a control of 22 non psychiatric adults. Signs of schizophrenia were quantified through the BPRS (Brief Psychiatric Rating Scale) and selective attention was expressed as the capacity to resist a distracting stimulus dimension in the Stroop word-colour test. The results indicated higher distractibility in schizophrenic patients, and a positive, significative relation was found between this interference and the "activation" cluster. PMID:2566479

  6. Adaptation and Validation of QUick, Easy, New, CHEap, and Reproducible (QUENCHER) Antioxidant Capacity Assays in Model Products Obtained from Residual Wine Pomace.

    PubMed

    Del Pino-García, Raquel; García-Lomillo, Javier; Rivero-Pérez, María D; González-SanJosé, María L; Muñiz, Pilar

    2015-08-12

    Evaluation of the total antioxidant capacity of solid matrices without extraction steps is a very interesting alternative for food researchers and also for food industries. These methodologies have been denominated QUENCHER from QUick, Easy, New, CHEap, and Reproducible assays. To demonstrate and highlight the validity of QUENCHER (Q) methods, values of Q-method validation were showed for the first time, and they were tested with products of well-known different chemical properties. Furthermore, new QUENCHER assays to measure scavenging capacity against superoxide, hydroxyl, and lipid peroxyl radicals were developed. Calibration models showed good linearity (R(2) > 0.995), proportionality and precision (CV < 6.5%), and acceptable detection limits (<20.4 nmol Trolox equiv). The presence of ethanol in the reaction medium gave antioxidant capacity values significantly different from those obtained with water. The dilution of samples with powdered cellulose was discouraged because possible interferences with some of the matrices analyzed may take place. PMID:26186166

  7. Shifting Attention

    ERIC Educational Resources Information Center

    Ingram, Jenni

    2014-01-01

    This article examines the shifts in attention and focus as one teacher introduces and explains an image that represents the processes involved in a numeric problem that his students have been working on. This paper takes a micro-analytic approach to examine how the focus of attention shifts through what the teacher and students do and say in the…

  8. Attention's Accelerator.

    PubMed

    Reinhart, Robert M G; McClenahan, Laura J; Woodman, Geoffrey F

    2016-06-01

    How do people get attention to operate at peak efficiency in high-pressure situations? We tested the hypothesis that the general mechanism that allows this is the maintenance of multiple target representations in working and long-term memory. We recorded subjects' event-related potentials (ERPs) indexing the working memory and long-term memory representations used to control attention while performing visual search. We found that subjects used both types of memories to control attention when they performed the visual search task with a large reward at stake, or when they were cued to respond as fast as possible. However, under normal circumstances, one type of target memory was sufficient for slower task performance. The use of multiple types of memory representations appears to provide converging top-down control of attention, allowing people to step on the attentional accelerator in a variety of high-pressure situations. PMID:27056975

  9. Capturing Attention When Attention "Blinks"

    ERIC Educational Resources Information Center

    Wee, Serena; Chua, Fook K.

    2004-01-01

    Four experiments addressed the question of whether attention may be captured when the visual system is in the midst of an attentional blink (AB). Participants identified 2 target letters embedded among distractor letters in a rapid serial visual presentation sequence. In some trials, a square frame was inserted between the targets; as the only…

  10. Shared Attention.

    PubMed

    Shteynberg, Garriy

    2015-09-01

    Shared attention is extremely common. In stadiums, public squares, and private living rooms, people attend to the world with others. Humans do so across all sensory modalities-sharing the sights, sounds, tastes, smells, and textures of everyday life with one another. The potential for attending with others has grown considerably with the emergence of mass media technologies, which allow for the sharing of attention in the absence of physical co-presence. In the last several years, studies have begun to outline the conditions under which attending together is consequential for human memory, motivation, judgment, emotion, and behavior. Here, I advance a psychological theory of shared attention, defining its properties as a mental state and outlining its cognitive, affective, and behavioral consequences. I review empirical findings that are uniquely predicted by shared-attention theory and discuss the possibility of integrating shared-attention, social-facilitation, and social-loafing perspectives. Finally, I reflect on what shared-attention theory implies for living in the digital world. PMID:26385997

  11. The PIP training programme: building of ACP experts capacities in crop protection and food safety to support local companies to comply with EU regulations on pesticides residues.

    PubMed

    Schiffers, B C; Schubert, A; Schiffers, C; Fontaine, S; Gumusboga, N; Werner, B; Webb, M; Lugros, H; Stinglhamber, G

    2006-01-01

    Regulatory requirements, and in particular phytosanitary quality standards change rapidly. As ACP producers/exporters race to become more competitive, to keep their market share and to satisfay their customers' commercial demands (e.g. EUREP-GAP certification), the need for competent staff who are aware of the company's quality objectives and trained to follow instructions is crucial. Mastering sanitary quality is only possible if matched with a programme to build the skills of companies' human resources. The Pesticide Initiative Programme (PIP), mindful of the importance of making operators autonomous and of training them to monitor EU food safety regulations and technology on their own, has successfully developed a training programme while building a quality network of local/ACP service providers. By building the capacities of ACP experts and then securing their services as trainers, PIP also guarantees companies' access to expertise and the sustainability of their efforts to comply with new EU regulations. The training strategy developed by PIP rests on two pilars: instructor training and collective training. Instructor training consists in reinforcing the technical knowledge of local experts (agronomists, hygienists, etc.) by providing them with active teaching methods. Once the ACP experts have gained enough technical knowledge of the key areas of crop protection--mainly pesticides management--and food safety, and have demonstrated their capacity to train the technical staff of local companies, the PIP has carried out a collective training programme in 2004, 2005 and 2006. To date, more than 130 consultants covering about 15 ACP countries have received instructor training, and more than 700 people have participated in collective and in-company training sessions. PMID:17390771

  12. Cognition, emotion, and attention.

    PubMed

    Müller-Oehring, Eva M; Schulte, Tilman

    2014-01-01

    Deficits of attention, emotion, and cognition occur in individuals with alcohol abuse and addiction. This review elucidates the concepts of attention, emotion, and cognition and references research on the underlying neural networks and their compromise in alcohol use disorder. Neuroimaging research on adolescents with family history of alcoholism contributes to the understanding of pre-existing brain structural conditions and characterization of cognition and attention processes in high-risk individuals. Attention and cognition interact with other brain functions, including perceptual selection, salience, emotion, reward, and memory, through interconnected neural networks. Recent research reports compromised microstructural and functional network connectivity in alcoholism, which can have an effect on the dynamic tuning between brain systems, e.g., the frontally based executive control system, the limbic emotion system, and the midbrain-striatal reward system, thereby impeding cognitive flexibility and behavioral adaptation to changing environments. Finally, we introduce concepts of functional compensation, the capacity to generate attentional resources for performance enhancement, and brain structure recovery with abstinence. An understanding of the neural mechanisms of attention, emotion, and cognition will likely provide the basis for better treatment strategies for developing skills that enhance alcoholism therapy adherence and quality of life, and reduce the propensity for relapse. PMID:25307584

  13. Attention Genes

    ERIC Educational Resources Information Center

    Posner, Michael I.; Rothbart, Mary K.; Sheese, Brad E.

    2007-01-01

    A major problem for developmental science is understanding how the cognitive and emotional networks important in carrying out mental processes can be related to individual differences. The last five years have seen major advances in establishing links between alleles of specific genes and the neural networks underlying aspects of attention. These…

  14. Vegetable fiber fermentation by human fecal bacteria: cell wall polysaccharide disappearance and short-chain fatty acid production during in vitro fermentation and water-holding capacity of unfermented residues.

    PubMed

    Bourquin, L D; Titgemeyer, E C; Fahey, G C

    1993-05-01

    Dietary fiber from eight vegetables (broccoli, carrot, cauliflower, celery, cucumber, lettuce, onion and radish) was analyzed for chemical composition and potential in vitro fermentation by human fecal bacteria. Total dietary fiber concentration of substrates ranged from 34.9 (broccoli) to 5.8 (cucumber) g/kg edible matter. Substrate fiber fractions were composed primarily of pectic substances and cellulose with smaller concentrations of hemicelluloses and lignin. Total dietary fiber residues isolated from substrates were fermented in vitro for 24 h with fecal bacteria obtained from each of three human volunteers. Substrate dry matter disappearance during fermentation was highest for carrot (63.7%) and lowest for cucumber (49.4%). Averaged across all substrates, disappearances of arabinose, galactose, glucose, mannose, xylose and uronic acids during fermentation were 96, 90, 54, 68, 51 and 97%, respectively. Short-chain fatty acid (SCFA) production during substrate fermentation averaged 10.5 mmol SCFA/g dry matter fermented. Averaged across all substrates, production of the major SCFA, acetate, propionate and butyrate, occurred in the molar ratio 76:14:10. Potential water-holding capacity of substrates was not influenced by fiber source and averaged 2.04 g H2O/g original substrate dry matter. Extent of substrate fermentation, SCFA production and substrate potential water-holding capacity were significantly different among inoculum donors, indicating that considerable inter-individual variation exists in the potential in vivo fermentation of vegetable fiber. PMID:8387579

  15. Mental Attention in Gifted and Nongifted Children

    ERIC Educational Resources Information Center

    Navarro, Jose I.; Ramiro, Pedro; Lopez, Jose M.; Aguilar, Manuel; Acosta, Manuel; Montero, Juan

    2006-01-01

    The relationship between the construct of mental attention and "giftedness" is not well established. Gifted individuals could make effective use of their executive functions and this could be related to their mental attentional capacity. The dialectic constructivist model developed by Pascual-Leone introduced the concept of mental attention or…

  16. Does mindfulness meditation improve attention in attention deficit hyperactivity disorder?

    PubMed Central

    Modesto-Lowe, Vania; Farahmand, Pantea; Chaplin, Margaret; Sarro, Lauren

    2015-01-01

    Attention deficit hyperactivity disorder (ADHD) manifests by high levels of inattention, impulsiveness and hyperactivity. ADHD starts in childhood and results in impairments that continue into adulthood. While hyperactivity declines over time, inattention and executive function difficulties persist, leading to functional deficits. Adolescents and adults with ADHD have pervasive impairment in interpersonal and family relationships. They may develop addiction, delinquent behavior and comorbid psychiatric disorders. Despite advances in diagnosis and treatment, persistent residual symptoms are common, highlighting the need for novel treatment strategies. Mindfulness training, derived from Eastern meditation practices, may improve self-regulation of attention. It may also be a useful strategy to augment standard ADHD treatments and may be used as a potential tool to reduce impairments in patients with residual symptoms of ADHD. Clinically, this would manifest by an increased ability to suppress task-unrelated thoughts and distractions resulting in improved attention, completion of tasks and potential improvement in occupational and social function. PMID:26740931

  17. Does mindfulness meditation improve attention in attention deficit hyperactivity disorder?

    PubMed

    Modesto-Lowe, Vania; Farahmand, Pantea; Chaplin, Margaret; Sarro, Lauren

    2015-12-22

    Attention deficit hyperactivity disorder (ADHD) manifests by high levels of inattention, impulsiveness and hyperactivity. ADHD starts in childhood and results in impairments that continue into adulthood. While hyperactivity declines over time, inattention and executive function difficulties persist, leading to functional deficits. Adolescents and adults with ADHD have pervasive impairment in interpersonal and family relationships. They may develop addiction, delinquent behavior and comorbid psychiatric disorders. Despite advances in diagnosis and treatment, persistent residual symptoms are common, highlighting the need for novel treatment strategies. Mindfulness training, derived from Eastern meditation practices, may improve self-regulation of attention. It may also be a useful strategy to augment standard ADHD treatments and may be used as a potential tool to reduce impairments in patients with residual symptoms of ADHD. Clinically, this would manifest by an increased ability to suppress task-unrelated thoughts and distractions resulting in improved attention, completion of tasks and potential improvement in occupational and social function. PMID:26740931

  18. Clarification of rules involving residual functional capacity assessments; clarification of use of vocational experts and other sources at step 4 of the sequential evaluation process; incorporation of "special profile" into regulations. Final rules.

    PubMed

    2003-08-26

    For purposes of this document, "we," "our," and "SSA" refer to the Social Security Administration and State agencies that make disability determinations for the Social Security Administration. "You" and "your" refer to individuals who claim benefits from the Social Security Administration based on "disability." In this final rule we clarify our rules about the responsibility that you have to provide evidence and the responsibility that we have to develop evidence in connection with your claim of disability. This includes our rules about when we assess your residual functional capacity (RFC) and how we use this RFC assessment when we decide whether you can do your past relevant work or other work. These clarifications address issues of responsibility raised by some courts in recent cases; clarify that we may use vocational experts (VEs), vocational specialists (VSs), or other resources to obtain evidence we need to help us determine whether your impairment(s) prevents you from doing your past relevant work; add a special provision to our rules stating that, if you are at least 55 years old, and specific other circumstances are present, we will find that you are disabled; and make a number of minor editorial changes to clarify and update the language of our rules, and to use simpler language in keeping with our goal of using plain language in our regulations. PMID:12952011

  19. The Capacity to Build Organizational Capacity in Schools

    ERIC Educational Resources Information Center

    King, M. Bruce; Bouchard, Kate

    2011-01-01

    Purpose: Reformers, policymakers, and researchers have given considerable attention to organizational capacity in schools, especially in those schools that perpetuate or exacerbate achievement gaps among diverse student groups and reproduce social inequalities. There is an emerging consensus about key dimensions of school capacity and how they can…

  20. Visuospatial selective attention in chickens.

    PubMed

    Sridharan, Devarajan; Ramamurthy, Deepa L; Schwarz, Jason S; Knudsen, Eric I

    2014-05-13

    Voluntary control of attention promotes intelligent, adaptive behaviors by enabling the selective processing of information that is most relevant for making decisions. Despite extensive research on attention in primates, the capacity for selective attention in nonprimate species has never been quantified. Here we demonstrate selective attention in chickens by applying protocols that have been used to characterize visual spatial attention in primates. Chickens were trained to localize and report the vertical position of a target in the presence of task-relevant distracters. A spatial cue, the location of which varied across individual trials, indicated the horizontal, but not vertical, position of the upcoming target. Spatial cueing improved localization performance: accuracy (d') increased and reaction times decreased in a space-specific manner. Distracters severely impaired perceptual performance, and this impairment was greatly reduced by spatial cueing. Signal detection analysis with an "indecision" model demonstrated that spatial cueing significantly increased choice certainty in localizing targets. By contrast, error-aversion certainty (certainty of not making an error) remained essentially constant across cueing protocols, target contrasts, and individuals. The results show that chickens shift spatial attention rapidly and dynamically, following principles of stimulus selection that closely parallel those documented in primates. The findings suggest that the mechanisms that control attention have been conserved through evolution, and establish chickens--a highly visual species that is easily trained and amenable to cutting-edge experimental technologies--as an attractive model for linking behavior to neural mechanisms of selective attention. PMID:24753566

  1. Attentional spreading in object-based attention.

    PubMed

    Richard, Ashleigh M; Lee, Hyunkyu; Vecera, Shaun P

    2008-08-01

    The authors investigated 2 effects of object-based attention: the spread of attention within an attended object and the prioritization of search across possible target locations within an attended object. Participants performed a flanker task in which the location of the task-relevant target was fixed and known to participants. A spreading attention account predicts that object-based attention will arise from the spread of attention through an attended object. A prioritization account predicts that there will be a small, if any, object-based effect because the location of the target is known in advance and objects are not required to prioritize the deployment of attentional search. The results suggested that object-based attention operates via the spread of attention within an object. PMID:18665730

  2. The Attention Cascade Model and Attentional Blink

    ERIC Educational Resources Information Center

    Shih, Shui-I

    2008-01-01

    An attention cascade model is proposed to account for attentional blinks in rapid serial visual presentation (RSVP) of stimuli. Data were collected using single characters in a single RSVP stream at 10 Hz [Shih, S., & Reeves, A. (2007). "Attentional capture in rapid serial visual presentation." "Spatial Vision", 20(4), 301-315], and single words,…

  3. Attention and olfactory consciousness.

    PubMed

    Keller, Andreas

    2011-01-01

    Understanding the relation between attention and consciousness is an important part of our understanding of consciousness. Attention, unlike consciousness, can be systematically manipulated in psychophysical experiments and a law-like relation between attention and consciousness is waiting to be discovered. Most attempts to discover the nature of this relation are focused on a special type of attention: spatial visual attention. In this review I want to introduce another type of attention to the discussion: attention to the olfactory modality. I will first clarify the position of attention to smells in a general taxonomy of attention. I will then review the mechanisms and neuroanatomy of attention and consciousness in the olfactory system before using the newly introduced system to provide evidence that attention is necessary for consciousness. PMID:22203813

  4. A Boost and Bounce Theory of Temporal Attention

    ERIC Educational Resources Information Center

    Olivers, Christian N. L.; Meeter, Martijn

    2008-01-01

    What is the time course of visual attention? Attentional blink studies have found that the 2nd of 2 targets is often missed when presented within about 500 ms from the 1st target, resulting in theories about relatively long-lasting capacity limitations or bottlenecks. Earlier studies, however, reported quite the opposite finding: Attention is…

  5. Mindful movement and skilled attention.

    PubMed

    Clark, Dav; Schumann, Frank; Mostofsky, Stewart H

    2015-01-01

    Bodily movement has long been employed as a foundation for cultivating mental skills such as attention, self-control or mindfulness, with recent studies documenting the positive impacts of mindful movement training, such as yoga and tai chi. A parallel "mind-body connection" has also been observed in many developmental disorders. We elaborate a spectrum of mindfulness by considering ADHD, in which deficient motor control correlates with impaired (disinhibited) behavioral control contributing to defining features of excessive distractibility and impulsivity. These data provide evidence for an important axis of variation for wellbeing, in which skillful cognitive control covaries with a capacity for skillful movement. We review empirical and theoretical literature on attention, cognitive control, mind wandering, mindfulness and skill learning, endorsing a model of skilled attention in which motor plans, attention, and executive goals are seen as mutually co-defining aspects of skilled behavior that are linked by reciprocal inhibitory and excitatory connections. Thus, any movement training should engage "higher-order" inhibition and selection and develop a repertoire of rehearsed procedures that coordinate goals, attention and motor plans. However, we propose that mindful movement practice may improve the functional quality of rehearsed procedures, cultivating a transferrable skill of attention. We adopt Langer's spectrum of mindful learning that spans from "mindlessness" to engagement with the details of the present task and contrast this with the mental attitudes cultivated in standard mindfulness meditation. We particularly follow Feldenkrais' suggestion that mindful learning of skills for organizing the body in movement might transfer to other forms of mental activity. The results of mindful movement training should be observed in multiple complementary measures, and may have tremendous potential benefit for individuals with ADHD and other populations. PMID

  6. Mindful movement and skilled attention

    PubMed Central

    Clark, Dav; Schumann, Frank; Mostofsky, Stewart H.

    2015-01-01

    Bodily movement has long been employed as a foundation for cultivating mental skills such as attention, self-control or mindfulness, with recent studies documenting the positive impacts of mindful movement training, such as yoga and tai chi. A parallel “mind-body connection” has also been observed in many developmental disorders. We elaborate a spectrum of mindfulness by considering ADHD, in which deficient motor control correlates with impaired (disinhibited) behavioral control contributing to defining features of excessive distractibility and impulsivity. These data provide evidence for an important axis of variation for wellbeing, in which skillful cognitive control covaries with a capacity for skillful movement. We review empirical and theoretical literature on attention, cognitive control, mind wandering, mindfulness and skill learning, endorsing a model of skilled attention in which motor plans, attention, and executive goals are seen as mutually co-defining aspects of skilled behavior that are linked by reciprocal inhibitory and excitatory connections. Thus, any movement training should engage “higher-order” inhibition and selection and develop a repertoire of rehearsed procedures that coordinate goals, attention and motor plans. However, we propose that mindful movement practice may improve the functional quality of rehearsed procedures, cultivating a transferrable skill of attention. We adopt Langer’s spectrum of mindful learning that spans from “mindlessness” to engagement with the details of the present task and contrast this with the mental attitudes cultivated in standard mindfulness meditation. We particularly follow Feldenkrais’ suggestion that mindful learning of skills for organizing the body in movement might transfer to other forms of mental activity. The results of mindful movement training should be observed in multiple complementary measures, and may have tremendous potential benefit for individuals with ADHD and other

  7. On tide-induced lagrangian residual current and residual transport: 1. Lagrangian residual current

    USGS Publications Warehouse

    Feng, Shizuo; Cheng, Ralph T.; Pangen, Xi

    1986-01-01

    Residual currents in tidal estuaries and coastal embayments have been recognized as fundamental factors which affect the long-term transport processes. It has been pointed out by previous studies that it is more relevant to use a Lagrangian mean velocity than an Eulerian mean velocity to determine the movements of water masses. Under weakly nonlinear approximation, the parameter k, which is the ratio of the net displacement of a labeled water mass in one tidal cycle to the tidal excursion, is assumed to be small. Solutions for tides, tidal current, and residual current have been considered for two-dimensional, barotropic estuaries and coastal seas. Particular attention has been paid to the distinction between the Lagrangian and Eulerian residual currents. When k is small, the first-order Lagrangian residual is shown to be the sum of the Eulerian residual current and the Stokes drift. The Lagrangian residual drift velocity or the second-order Lagrangian residual current has been shown to be dependent on the phase of tidal current. The Lagrangian drift velocity is induced by nonlinear interactions between tides, tidal currents, and the first-order residual currents, and it takes the form of an ellipse on a hodograph plane. Several examples are given to further demonstrate the unique properties of the Lagrangian residual current.

  8. Understanding Attention Deficit Disorders.

    ERIC Educational Resources Information Center

    Villegas, Orlando; And Others

    This booklet provides basic information regarding attention deficit hyperactivity disorders (ADHD), in their separate modalities, with hyperactivity, impulsivity, and inattention. Explanations are offered concerning short attention span, impulsive behavior, hyperactivity, and beginning new activities before completing the previous one. Theories…

  9. Training Visual Attention

    ERIC Educational Resources Information Center

    Mulholland, Thomas B.

    1974-01-01

    The effects of brain waves and alpha rhythms on attentiveness to visual stimuli are discussed, and preliminary research findings and research needs are considered in connection with measuring and training for attention. (LH)

  10. Attention deficit hyperactivity disorder

    MedlinePlus

    Attention deficit hyperactivity disorder (ADHD) is a problem caused by the presence of 1 or more of ... of these behaviors. INATTENTIVE SYMPTOMS Doesn't pay attention to details or makes careless mistakes in schoolwork ...

  11. Crop residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop residues [e.g., corn (Zea mays) stover and small grain straw] are sometimes excluded when discussing cellulosic energy crops per se, but because of the vast area upon which they are grown and their current role in the development of cellulosic energy systems. This chapter focuses on current cor...

  12. Attention Deficit Hyperactivity Disorder

    MedlinePlus

    ... us to find out more about ADHD. Share Attention Deficit Hyperactivity Disorder (Easy-to-Read) Download PDF Download ePub Order ... attention deficit/hyperactivity disorder , or ADHD . What is attention deficit/hyperactivity disorder, or ADHD? ADHD is a common mental disorder ...

  13. Can the Focus of Attention Accommodate Multiple, Separate Items?

    ERIC Educational Resources Information Center

    Gilchrist, Amanda L.; Cowan, Nelson

    2011-01-01

    Researchers of working memory currently debate capacity limits of the focus of attention, the proposed mental faculty in which items are most easily accessed. Cowan (1999) suggested that its capacity is about 4 chunks, whereas others have suggested that its capacity is only 1 chunk. Recently, Oberauer and Bialkova (2009) found evidence that 2…

  14. Does focused endogenous attention prevent attentional capture in pop-out visual search?

    PubMed Central

    Seiss, Ellen; Kiss, Monika; Eimer, Martin

    2009-01-01

    To investigate whether salient visual singletons capture attention when they appear outside the current endogenous attentional focus, we measured the N2pc component as a marker of attentional capture in a visual search task where target or nontarget singletons were presented at locations previously cued as task-relevant, or in the uncued irrelevant hemifield. In two experiments, targets were either defined by colour, or by a combination of colour and shape. The N2pc was elicited both for attended singletons and for singletons on the uncued side, demonstrating that focused endogenous attention cannot prevent attentional capture by salient unattended visual events. However, N2pc amplitudes were larger for attended and unattended singletons that shared features with the current target, suggesting that top-down task sets modulate the capacity of visual singletons to capture attention both within and outside the current attentional focus. PMID:19473304

  15. Attention Alters Perceived Attractiveness.

    PubMed

    Störmer, Viola S; Alvarez, George A

    2016-04-01

    Can attention alter the impression of a face? Previous studies showed that attention modulates the appearance of lower-level visual features. For instance, attention can make a simple stimulus appear to have higher contrast than it actually does. We tested whether attention can also alter the perception of a higher-order property-namely, facial attractiveness. We asked participants to judge the relative attractiveness of two faces after summoning their attention to one of the faces using a briefly presented visual cue. Across trials, participants judged the attended face to be more attractive than the same face when it was unattended. This effect was not due to decision or response biases, but rather was due to changes in perceptual processing of the faces. These results show that attention alters perceived facial attractiveness, and broadly demonstrate that attention can influence higher-level perception and may affect people's initial impressions of one another. PMID:26966228

  16. Attention is necessary for subliminal instrumental conditioning.

    PubMed

    Mastropasqua, Tommaso; Turatto, Massimo

    2015-01-01

    The capacity of humans and other animals to provide appropriate responses to stimuli anticipating motivationally significant events is exemplified by instrumental conditioning. Interestingly, in humans instrumental conditioning can occur also for subliminal outcome-predicting stimuli. However, it remains unclear whether attention is necessary for subliminal instrumental conditioning to take place. In two experiments, human participants had to learn to collect rewards (monetary gains) while avoiding punishments (monetary losses), on the basis of subliminal outcome-predicting cues. We found that instrumental conditioning can proceed subconsciously only if spatial attention is aligned with the subliminal cue. Conversely, if spatial attention is briefly diverted from the subliminal cue, then instrumental conditioning is blocked. In humans, attention but not awareness is therefore mandatory for instrumental conditioning, thus revealing a dissociation between awareness and attention in the control of motivated behavior. PMID:26257144

  17. The Goldilocks effect in infant auditory attention.

    PubMed

    Kidd, Celeste; Piantadosi, Steven T; Aslin, Richard N

    2014-01-01

    Infants must learn about many cognitive domains (e.g., language, music) from auditory statistics, yet capacity limits on their cognitive resources restrict the quantity that they can encode. Previous research has established that infants can attend to only a subset of available acoustic input. Yet few previous studies have directly examined infant auditory attention, and none have directly tested theorized mechanisms of attentional selection based on stimulus complexity. This work utilizes model-based behavioral methods that were recently developed to examine visual attention in infants (e.g., Kidd, Piantadosi, & Aslin, 2012). The present results demonstrate that 7- to 8-month-old infants selectively attend to nonsocial auditory stimuli that are intermediately predictable/complex with respect to their current implicit beliefs and expectations. These findings provide evidence of a broad principle of infant attention across modalities and suggest that sound-to-sound transitional statistics heavily influence the allocation of auditory attention in human infants. PMID:24990627

  18. The division of attention and the human auditory evoked potential

    NASA Technical Reports Server (NTRS)

    Hink, R. F.; Van Voorhis, S. T.; Hillyard, S. A.; Smith, T. S.

    1977-01-01

    The sensitivity of the scalp-recorded, auditory evoked potential to selective attention was examined while subjects responded to stimuli presented to one ear (focused attention) and to both ears (divided attention). The amplitude of the N1 component was found to be largest to stimuli in the ear upon which attention was to be focused, smallest to stimuli in the ear to be ignored, and intermediate to stimuli in both ears when attention was divided. The results are interpreted as supporting a capacity model of attention.

  19. Aging, exercise, and attention.

    PubMed

    Hawkins, H L; Kramer, A F; Capaldi, D

    1992-12-01

    The authors investigated the relationship among aging, attentional processes, and exercise in 2 experiments. First they examined age differences on 2 attentional tasks, a time-sharing task and an attentional flexibility task. Young adults alternated attention between 2 sequenced tasks more rapidly and time-shared the processing of 2 tasks more efficiently than older adults. They then investigated the effects of aerobic exercise on the same 2 attentional tasks in older adults. Following the 10-week exercise program, older exercisers showed substantially more improvement in alternation speed and time-sharing efficiency than older controls. Interestingly, this exercise effect was specific to dual-task processing. Both groups of subjects showed equivalent effects on single-task performance. These results indicate that aerobic exercise can exert a beneficial influence on the efficiency of at least 2 different attentional processes in older adults. PMID:1466833

  20. Overriding auditory attentional capture.

    PubMed

    Dalton, Polly; Lavie, Nilli

    2007-02-01

    Attentional capture by color singletons during shape search can be eliminated when the target is not a feature singleton (Bacon & Egeth, 1994). This suggests that a "singleton detection" search strategy must be adopted for attentional capture to occur. Here we find similar effects on auditory attentional capture. Irrelevant high-intensity singletons interfered with an auditory search task when the target itself was also a feature singleton. However, singleton interference was eliminated when the target was not a singleton (i.e., when nontargets were made heterogeneous, or when more than one target sound was presented). These results suggest that auditory attentional capture depends on the observer's attentional set, as does visual attentional capture. The suggestion that hearing might act as an early warning system that would always be tuned to unexpected unique stimuli must therefore be modified to accommodate these strategy-dependent capture effects. PMID:17557587

  1. When Higher Working Memory Capacity Hinders Insight

    ERIC Educational Resources Information Center

    DeCaro, Marci S.; Van Stockum, Charles A., Jr.; Wieth, Mareike B.

    2016-01-01

    Higher working memory capacity (WMC) improves performance on a range of cognitive and academic tasks. However, a greater ability to control attention sometimes leads individuals with higher WMC to persist in using complex, attention-demanding approaches that are suboptimal for a given task. We examined whether higher WMC would hinder insight…

  2. Embodied Infant Attention

    ERIC Educational Resources Information Center

    Robertson, Steven S.; Johnson, Sarah L.

    2009-01-01

    Does real time coupling between mental and physical activity early in development have functional significance? To address this question, we examined the habituation of visual attention and the subsequent response to change in two groups of 3-month-olds with different patterns of movement-attention coupling. In suppressors, the typical decrease in…

  3. Urbanization decreases attentional engagement.

    PubMed

    Linnell, Karina J; Caparos, Serge; de Fockert, Jan W; Davidoff, Jules

    2013-10-01

    Exposure to the urban environment has been shown dramatically to increase the tendency to process contextual information. To further our understanding of this effect of urbanization, we compared performance on a local-selection task of a remote people, the Himba, living traditionally or relocated to town. We showed that (a) spatial attention was defocused in urbanized Himba but focused in traditional Himba (Experiment 1), despite urbanized Himba performing better on a working memory task (Experiment 3); (b) imposing a cognitive load made attention as defocused in traditional as in urbanized Himba (Experiment 2); and (c) using engaging stimuli/tasks made attention as focused in urbanized Himba, and British, as in traditional Himba (Experiments 4 and 5). We propose that urban environments prioritize exploration at the expense of attentional engagement and cognitive control of attentional selection. PMID:23339348

  4. Contingent Attentional Capture

    NASA Technical Reports Server (NTRS)

    Remington, Roger; Folk, Charles L.

    1994-01-01

    Four experiments address the degree of top-down selectivity in attention capture by feature singletons through manipulations of the spatial relationship and featural similarity of target and distractor singletons in a modified spatial cuing paradigm. Contrary to previous studies, all four experiments show that when searching for a singleton target, an irrelevant featural singleton captures attention only when defined by the same feature value as the target. Experiments 2, 3, and 4 provide a potential explanation for this empirical discrepancy by showing that irrelevant singletons can produce distraction effects that are independent of shifts of spatial attention. The results further support the notion that attentional capture is contingent on top-down attention control settings but indicates that such settings can be instantiated at the level of feature values.

  5. Residual Cap

    NASA Technical Reports Server (NTRS)

    2006-01-01

    10 May 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a summertime view of the south polar residual cap of Mars. In this image, mesas composed largely of solid carbon dioxide are separated from one another by irregularly-shaped depressions. The variation in brightness across this scene is a function of several factors including, but not limited to, varying proportions of dust and solid carbon dioxide, undulating topography, and differences in the roughness of the slopes versus the flat surfaces.

    Location near: 86.7oS, 343.3oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  6. Attention Deficit Hyperactivity Disorder

    MedlinePlus

    ... finish things? If so, your child may have attention deficit hyperactivity disorder (ADHD). Nearly everyone shows some of these behaviors at times, but ADHD lasts more than 6 months and causes problems ...

  7. Attention enhances feature integration.

    PubMed

    Paul, Liza; Schyns, Philippe G

    2003-08-01

    Perceptual processing delays between attribute dimensions (e.g. color, form and motion) [Proceedings of the Royal Society of London Series B 264 (1997) 1407] have been attributed to temporal processing asynchronies resulting from functional segregation of visual information [Science 240 (1988) 740]. In addition, several lines of evidence converge to suggest that attention plays an important role in the integration of functionally processed information. However, exactly how attention modulates the temporal integration of information remains unclear. Here, we examined how attention modulates the integration of color and form into a unitary perception. Results suggest that attending to the location of an object enhances the integration of its defining attributes by speeding up the perceptual processing of each attribute dimension. Moreover, the perceptual asynchrony between attributes remains constant across attended and unattended conditions because attention seems to offer each processing dimension an equal processing advantage. PMID:12826102

  8. Attention samples stimuli rhythmically.

    PubMed

    Landau, Ayelet Nina; Fries, Pascal

    2012-06-01

    Overt exploration or sampling behaviors, such as whisking, sniffing, and saccadic eye movements, are often characterized by a rhythm. In addition, the electrophysiologically recorded theta or alpha phase predicts global detection performance. These two observations raise the intriguing possibility that covert selective attention samples from multiple stimuli rhythmically. To investigate this possibility, we measured change detection performance on two simultaneously presented stimuli, after resetting attention to one of them. After a reset flash at one stimulus location, detection performance fluctuated rhythmically. When the flash was presented in the right visual field, a 4 Hz rhythm was directly visible in the time courses of behavioral performance at both stimulus locations, and the two rhythms were in antiphase. A left visual field flash exerted only partial reset on performance and induced rhythmic fluctuation at higher frequencies (6-10 Hz). These findings show that selective attention samples multiple stimuli rhythmically, and they position spatial attention within the family of exploration behaviors. PMID:22633805

  9. Attention Reorients Periodically.

    PubMed

    Dugué, Laura; Roberts, Mariel; Carrasco, Marisa

    2016-06-20

    Reorienting of voluntary attention enables the processing of stimuli at previously unattended locations. Although studies have identified a ventral fronto-parietal network underlying attention [1, 2], little is known about whether and how early visual areas are involved in involuntary [3, 4] and even less in voluntary [5] reorienting, and their temporal dynamics are unknown. We used transcranial magnetic stimulation (TMS) over the occipital cortex to interfere with attentional reorienting and study its role and temporal dynamics in this process. Human observers performed an orientation discrimination task, with either valid or invalid attention cueing, across a range of stimulus contrasts. Valid cueing induced a behavioral response gain increase, higher asymptotic performance for attended than unattended locations. During subsequent TMS sessions, observers performed the same task, with high stimulus contrast. Based on phosphene mapping, TMS double pulses were applied at one of various delays to a consistent brain location in retinotopic areas (V1/V2), corresponding to the evoked signal of the target or distractor, in a valid or invalid trial. Thus, the stimulation was identical for the four experimental conditions (valid/invalid cue condition × target/distractor-stimulated). TMS modulation of the target and distractor were both periodic (5 Hz, theta) and out of phase with respect to each other in invalid trials only, when attention had to be disengaged from the distractor and reoriented to the target location. Reorientation of voluntary attention periodically involves V1/V2 at the theta frequency. These results suggest that TMS probes theta phase-reset by attentional reorienting and help link periodic sampling in time and attention reorienting in space. PMID:27265395

  10. Attention allocation before antisaccades.

    PubMed

    Klapetek, Anna; Jonikaitis, Donatas; Deubel, Heiner

    2016-01-01

    In the present study, we investigated the distribution of attention before antisaccades. We used a dual task paradigm, in which participants made prosaccades or antisaccades and discriminated the orientation of a visual probe shown at the saccade goal, the visual cue location (antisaccade condition), or a neutral location. Moreover, participants indicated whether they had made a correct antisaccade or an erroneous prosaccade. We observed that, while spatial attention in the prosaccade task was allocated only to the saccade goal, attention in the antisaccade task was allocated both to the cued location and to the antisaccade goal. This suggests parallel attentional selection of the cued and antisaccade locations. We further observed that in error trials--in which participants made an incorrect prosaccade instead of an antisaccade--spatial attention was biased towards the prosaccade goal. These erroneous prosaccades were mostly unnoticed and were often followed by corrective antisaccades with very short latencies (<100 ms). Data from error trials therefore provide further evidence for the parallel programming of the reflexive prosaccade to the cue and the antisaccade to the intended location. Taken together, our results suggest that attention allocation and saccade goal selection in the antisaccade task are mediated by a common competitive process. PMID:26790843

  11. Interocular conflict attracts attention.

    PubMed

    Paffen, Chris L E; Hessels, Roy S; Van der Stigchel, Stefan

    2012-02-01

    During binocular rivalry, perception alternates.between dissimilar images presented dichoptically. Since.its discovery, researchers have debated whether the phenomenon is subject to attentional control. While it is now clear that attentional control over binocular rivalry is possible, the opposite is less evident: Is interocular conflict (i.e., the situation leading to binocular rivalry) able to attract attention?In order to answer this question, we used a change blindness paradigm in which observers looked for salient changes in two alternating frames depicting natural scenes. Each frame contained two images: one for the left and one for the right eye. Changes occurring in a single image (monocular) were detected faster than those occurring in both images (binocular). In addition,monocular change detection was also faster than detection in fused versions of the changed and unchanged regions. These results show that interocular conflict is capable of attracting attention, since it guides visual attention toward salient changes that otherwise would remain unnoticed for longer. The results of a second experiment indicated that interocular conflict attracts attention during the first phase of presentation, a phase during which the stimulus is abnormally fused [added]. PMID:22167536

  12. Hierarchical nonlinear dynamics of human attention.

    PubMed

    Rabinovich, Mikhail I; Tristan, Irma; Varona, Pablo

    2015-08-01

    Attention is the process of focusing mental resources on a specific cognitive/behavioral task. Such brain dynamics involves different partially overlapping brain functional networks whose interconnections change in time according to the performance stage, and can be stimulus-driven or induced by an intrinsically generated goal. The corresponding activity can be described by different families of spatiotemporal discrete patterns or sequential dynamic modes. Since mental resources are finite, attention modalities compete with each other at all levels of the hierarchy, from perception to decision making and behavior. Cognitive activity is a dynamical process and attention possesses some universal dynamical characteristics. Thus, it is time to apply nonlinear dynamical theory for the description and prediction of hierarchical attentional tasks. Such theory has to include the analyses of attentional control stability, the time cost of attention switching, the finite capacity of informational resources in the brain, and the normal and pathological bifurcations of attention sequential dynamics. In this paper we have integrated today's knowledge, models and results in these directions. PMID:25869439

  13. Can Rhesus Monkey Learn Executive Attention?

    PubMed

    Bramlett-Parker, Jessica; Washburn, David A

    2016-01-01

    A growing body of data indicates that, compared to humans, rhesus monkeys perform poorly on tasks that assess executive attention, or voluntary control over selection for processing, particularly under circumstances in which attention is attracted elsewhere by competing stimulus control. In the human-cognition literature, there are hotly active debates about whether various competencies such as executive attention, working memory capacity, and fluid intelligence can be improved through training. In the current study, rhesus monkeys (Macaca mulatta) completed an attention-training intervention including several inhibitory-control tasks (a Simon task, numerical Stroop task, global/local interference task, and a continuous performance task) to determine whether generalized improvements would be observed on a version of the Attention Network Test (ANT) of controlled attention, which was administered before and after the training intervention. Although the animals demonstrated inhibition of prepotent responses and improved in executive attention with practice, this improvement did not generalize to the ANT at levels consistently better than were observed for control animals. Although these findings fail to encourage the possibility that species differences in cognitive competencies can be ameliorated through training, they do advance our understanding of the competition between stimulus-control and cognitive-control in performance by nonhuman and human primates. PMID:27304969

  14. A Neural Theory of Visual Attention: Bridging Cognition and Neurophysiology

    ERIC Educational Resources Information Center

    Bundesen, Claus; Habekost, Thomas; Kyllingsbaek, Soren

    2005-01-01

    A neural theory of visual attention (NTVA) is presented. NTVA is a neural interpretation of C. Bundesen's (1990) theory of visual attention (TVA). In NTVA, visual processing capacity is distributed across stimuli by dynamic remapping of receptive fields of cortical cells such that more processing resources (cells) are devoted to behaviorally…

  15. Analysis of Attention and Analogical Reasoning in Children of Poverty

    ERIC Educational Resources Information Center

    Weatherholt, Tara N.; Harris, Ruby C.; Burns, Barbara M.; Clement, Catherine

    2006-01-01

    This study examined the relationship between specific attentional aspects of processing capacity and analogical reasoning in children from low-income families. 77 children aged 48-77 (M = 56.7) months were assessed on an analogical reasoning task (matrices subtest of the Kaufman Brief Intelligence Test) and on computerized attention tasks designed…

  16. Enclothed Cognition and Controlled Attention during Insight Problem-Solving

    ERIC Educational Resources Information Center

    Van Stockum, Charles A., Jr.; DeCaro, Marci S.

    2014-01-01

    Individual differences in working memory capacity (WMC) increase the ability and tendency to devote greater attentional control to a task--improving performance on a wide range of skills. In addition, recent research on enclothed cognition demonstrates that the situational influence of wearing a white lab coat increases controlled attention, due…

  17. Attention and reading skills.

    PubMed

    Commodari, Elena; Guarnera, Maria

    2005-04-01

    Attention plays a critical role in information processing. Its adequate functioning is required for correct development of complex cognitive abilities and regular scholastic progress. Children with attention deficits often have difficulties in reading, writing, and arithmetic. The present study investigated interactions among reading skills, overall scholastic performance as rated by teachers, and components of attention: visual reaction time, simple immediate span of attention, and selectivity. The sample was 98 students in the first and second years of public junior high school (age range 11-14 years, M = 12.6, SD = 1.2), i.e., with expected already well-established reading. Reading was evaluated using Comprehension, Accuracy, and Speed tests. Overall scholastic performance was obtained by means of teachers' ratings. Simple Reaction Time, Digit Span, and Color-Word Interference, included in a multitask computerized test, assessed attention. Analysis confirmed the hypothesis that the reading skills are strongly predictive of the Scholastic Assessment rated by the teachers. High scholastic ratings were correlated with Reading Speed and Accuracy rather than Reading Comprehension. Poor readers showed worse performances on the Digit Span test which measures simple immediate span of attention. Good and poor readers obtained a similar score on the Color-Word Interference task. This observation seems to contrast with the more common interpretation of this effect, suggesting that reading is an automatic process and, therefore, the semantic dimension overcomes the controlled perceptual one. According to other studies, an alternative explanation is suggested. In conclusion, present results confirm the hypothesis of a strong link among reading speed and accuracy, scholastic assessment as rated by teachers, simple immediate span of attention, and visual reaction time. PMID:15974348

  18. Project DyAdd: Visual Attention in Adult Dyslexia and ADHD

    ERIC Educational Resources Information Center

    Laasonen, Marja; Salomaa, Jonna; Cousineau, Denis; Leppamaki, Sami; Tani, Pekka; Hokkanen, Laura; Dye, Matthew

    2012-01-01

    In this study of the project DyAdd, three aspects of visual attention were investigated in adults (18-55 years) with dyslexia (n = 35) or attention deficit/hyperactivity disorder (ADHD, n = 22), and in healthy controls (n = 35). Temporal characteristics of visual attention were assessed with Attentional Blink (AB), capacity of visual attention…

  19. Selective Attention and Attention Switching: Towards a Unified Developmental Approach

    ERIC Educational Resources Information Center

    Hanania, Rima; Smith, Linda B.

    2010-01-01

    We review and relate two literatures on the development of attention in children: one concerning flexible attention switching and the other concerning selective attention. The first is a growing literature on preschool children's performances in an attention-switching task indicating that children become more flexible in their attentional control…

  20. The residual caries dilemma.

    PubMed

    Weerheijm, K L; Groen, H J

    1999-12-01

    Restorative dentistry is based on the assumption that bacterial infection of demineralized dentine should prompt operative intervention. One of the concepts of practical dentistry is to create a favourable environment for caries arrest with minimal operative intervention. The progress of remaining primary caries is key to any discussion of this concept. This discussion is important for the atraumatic restorative treatment (ART) approach, since the removal of all carious dentine is sometimes difficult using hand instruments only. In this paper the results of possible measures to guard against the effects of residual carious and its consequences are reviewed, in order to obtain an impression of the justification for (in)complete excavation of occlusal dentinal caries. Three types of measure are considered: isolating the caries process from the oral environment, excavating the carious dentine, and using a cariostatic filling material. Each of these measures contributes to the arrest of the caries process. However, none of these measures can arrest this process by itself. A combination of all three seems necessary. It is concluded that although residual caries does not seem to be the criterion for rerestoration, one has to strive for as complete caries removal as possible. If this cannot be fulfilled the sealing capacities of the filling material seem to be more important than its cariostatic properties. PMID:10600078

  1. Gaze Cueing of Attention

    PubMed Central

    Frischen, Alexandra; Bayliss, Andrew P.; Tipper, Steven P.

    2007-01-01

    During social interactions, people’s eyes convey a wealth of information about their direction of attention and their emotional and mental states. This review aims to provide a comprehensive overview of past and current research into the perception of gaze behavior and its effect on the observer. This encompasses the perception of gaze direction and its influence on perception of the other person, as well as gaze-following behavior such as joint attention, in infant, adult, and clinical populations. Particular focus is given to the gaze-cueing paradigm that has been used to investigate the mechanisms of joint attention. The contribution of this paradigm has been significant and will likely continue to advance knowledge across diverse fields within psychology and neuroscience. PMID:17592962

  2. SINGLE-BREATH DIFFUSING CAPACITY AND LUNG VOLUMES IN SMALL LABORATORY MAMMALS

    EPA Science Inventory

    The authors measured the single-breath diffusing capacity for carbon monoxide (DLco), total lung capacity(TLC), functional residue capacity(FRC), and residual volume(RV) in anesthetized male hamsters, rats, guinea pigs, and rabbits whose weights varied from 40 to 3,500g. TLC (def...

  3. Interactions of attention, emotion and motivation.

    PubMed

    Raymond, Jane

    2009-01-01

    Although successful visually guided action begins with sensory processes and ends with motor control, the intervening processes related to the appropriate selection of information for processing are especially critical because of the brain's limited capacity to handle information. Three important mechanisms--attention, emotion and motivation--contribute to the prioritization and selection of information. In this chapter, the interplay between these systems is discussed with emphasis placed on interactions between attention (or immediate task relevance of stimuli) and emotion (or affective evaluation of stimuli), and between attention and motivation (or the predicted value of stimuli). Although numerous studies have shown that emotional stimuli modulate mechanisms of selective attention in humans, little work has been directed at exploring whether such interactions can be reciprocal, that is, whether attention can influence emotional response. Recent work on this question (showing that distracting information is typically devalued upon later encounters) is reviewed in the first half of the chapter. In the second half, some recent experiments exploring how prior value-prediction learning (i.e., learning to associate potential outcomes, good or bad, with specific stimuli) plays a role in visual selection and conscious perception. The results indicate that some aspects of motivation act on selection independently of traditionally defined attention and other aspects interact with it. PMID:19733764

  4. Capacity Building of MAGDAS

    NASA Astrophysics Data System (ADS)

    Yumoto, K.

    2011-12-01

    Under the framework of the MAGDAS Project of SERC (at Kyushu University), this report will cover the three phases of "Capacity Building": (1) Development of instrument capacity, (2) Development of data analysis capacity, and (3) Development of science capacity. Capacity Building is one of the major goals of IHY and ISWI, as specified by the organizers of IHY and ISWI.

  5. Attention Capture by Faces

    ERIC Educational Resources Information Center

    Langton, Stephen R. H.; Law, Anna S.; Burton, A. Mike; Schweinberger, Stefan R.

    2008-01-01

    We report three experiments that investigate whether faces are capable of capturing attention when in competition with other non-face objects. In Experiment 1a participants took longer to decide that an array of objects contained a butterfly target when a face appeared as one of the distracting items than when the face did not appear in the array.…

  6. Perceptual objects capture attention.

    PubMed

    Yeshurun, Yaffa; Kimchi, Ruth; Sha'shoua, Guy; Carmel, Tomer

    2009-06-01

    A recent study has demonstrated that the mere organization of some elements in the visual field into an object attracts attention automatically [Kimchi, R., Yeshurun, Y., & Cohen-Savransky, A. (2007). Automatic, stimulus-driven attentional capture by objecthood. Psychonomic Bulletin & Review, 14(1), 166-172]. We tested whether similar results will emerge when the target is not a part of the object and with simplified task demands. A matrix of 16 black L elements in various orientations preceded the presentation of a Vernier target. The target was either added to the matrix (Experiment 1), or appeared after its offset (Experiment 2). On some trials four elements formed a square-like object, and on some of these trials the target appeared in the center of the object. No featural uniqueness or abrupt onset was associated with the object and it did not predict the target location or the direction of the target's horizontal offset. Performance was better when the target appeared in the center of the object than in a different location than the object, even when the target appeared after the matrix offset. These findings support the hypothesis that a perceptual object captures attention (Kimchi et al., 2007), and demonstrate that this automatic deployment of attention to the object is robust and involves a spatial component. PMID:18299141

  7. Visual attention and stability

    PubMed Central

    Mathôt, Sebastiaan; Theeuwes, Jan

    2011-01-01

    In the present review, we address the relationship between attention and visual stability. Even though with each eye, head and body movement the retinal image changes dramatically, we perceive the world as stable and are able to perform visually guided actions. However, visual stability is not as complete as introspection would lead us to believe. We attend to only a few items at a time and stability is maintained only for those items. There appear to be two distinct mechanisms underlying visual stability. The first is a passive mechanism: the visual system assumes the world to be stable, unless there is a clear discrepancy between the pre- and post-saccadic image of the region surrounding the saccade target. This is related to the pre-saccadic shift of attention, which allows for an accurate preview of the saccade target. The second is an active mechanism: information about attended objects is remapped within retinotopic maps to compensate for eye movements. The locus of attention itself, which is also characterized by localized retinotopic activity, is remapped as well. We conclude that visual attention is crucial in our perception of a stable world. PMID:21242140

  8. Expectancy, Attention, and Time.

    ERIC Educational Resources Information Center

    Barnes, Ralph; Jones, Mari Riess

    2000-01-01

    Examined the influence of contextual timing manipulations on prospective time judgments through 7 experiments involving a total of 199 college students. Discusses results in terms of various stimulus-based models of prospective time judgments, including those that appeal to attentional periodicities and entrainment. (SLD)

  9. MAOA Influences the Trajectory of Attentional Development.

    PubMed

    Lundwall, Rebecca A; Rasmussen, Claudia G

    2016-01-01

    Attention is vital to success in all aspects of life (Meck and Benson, 2002; Erickson et al., 2015), hence it is important to identify biomarkers of later attentional problems early enough to intervene. Our objective was to determine if any of 11 genes (APOE, BDNF, HTR4, CHRNA4, COMT, DRD4, IGF2, MAOA, SLC5A7, SLC6A3, and SNAP25) predicted the trajectory of attentional development within the same group of children between infancy and childhood. We recruited follow up participants from children who participated as infants in visual attention studies and used a similar task at both time points. Using multilevel modeling, we associated changes in the participant's position in the distribution of scores in infancy to his/her position in childhood with genetic markers on each of 11 genes. While all 11 genes predicted reaction time (RT) residual scores, only Monoamine oxidase A (MAOA) had a significant interaction including time point. We conclude that the MAOA single nucleotide polymorphism (SNP) rs1137070 is useful in predicting which girls are likely to develop slower RTs on an attention task between infancy and childhood. This early identification is likely to be helpful in early intervention. PMID:27610078

  10. MAOA Influences the Trajectory of Attentional Development

    PubMed Central

    Lundwall, Rebecca A.; Rasmussen, Claudia G.

    2016-01-01

    Attention is vital to success in all aspects of life (Meck and Benson, 2002; Erickson et al., 2015), hence it is important to identify biomarkers of later attentional problems early enough to intervene. Our objective was to determine if any of 11 genes (APOE, BDNF, HTR4, CHRNA4, COMT, DRD4, IGF2, MAOA, SLC5A7, SLC6A3, and SNAP25) predicted the trajectory of attentional development within the same group of children between infancy and childhood. We recruited follow up participants from children who participated as infants in visual attention studies and used a similar task at both time points. Using multilevel modeling, we associated changes in the participant’s position in the distribution of scores in infancy to his/her position in childhood with genetic markers on each of 11 genes. While all 11 genes predicted reaction time (RT) residual scores, only Monoamine oxidase A (MAOA) had a significant interaction including time point. We conclude that the MAOA single nucleotide polymorphism (SNP) rs1137070 is useful in predicting which girls are likely to develop slower RTs on an attention task between infancy and childhood. This early identification is likely to be helpful in early intervention. PMID:27610078

  11. Cortical State and Attention

    PubMed Central

    Harris, Kenneth D.; Thiele, Alexander

    2012-01-01

    Preface The brain continuously adapts its processing machinery to behavioural demands. To achieve this it rapidly modulates the operating mode of cortical circuits, controlling the way information is transformed and routed. This article will focus on two experimental approaches by which the control of cortical information processing has been investigated: the study of state-dependent cortical processing in rodents, and attention in the primate visual system. Both processes involve a modulation of low-frequency activity fluctuations and spiking correlation, and are mediated by common receptor systems. We suggest that selective attention involves processes similar to state change, operating at a local columnar level to enhance the representation of otherwise nonsalient features while suppressing internally generated activity patterns. PMID:21829219

  12. Attention-Seeking Displays.

    PubMed

    Számadó, Szabolcs

    2015-01-01

    Animal communication abounds with extravagant displays. These signals are usually interpreted as costly signals of quality. However, there is another important function for these signals: to call the attention of the receiver to the signaller. While there is abundant empirical evidence to show the importance of this stage, it is not yet incorporated into standard signalling theory. Here I investigate a general model of signalling - based on a basic action-response game - that incorporates this searching stage. I show that giving attention-seeking displays and searching for them can be an ESS. This is a very general result and holds regardless whether only the high quality signallers or both high and low types give them. These signals need not be costly at the equilibrium and they need not be honest signals of any quality, as their function is not to signal quality but simply to call the attention of the potential receivers. These kind of displays are probably more common than their current weight in the literature would suggest. PMID:26287489

  13. Attention-Seeking Displays

    PubMed Central

    Számadó, Szabolcs

    2015-01-01

    Animal communication abounds with extravagant displays. These signals are usually interpreted as costly signals of quality. However, there is another important function for these signals: to call the attention of the receiver to the signaller. While there is abundant empirical evidence to show the importance of this stage, it is not yet incorporated into standard signalling theory. Here I investigate a general model of signalling - based on a basic action-response game - that incorporates this searching stage. I show that giving attention-seeking displays and searching for them can be an ESS. This is a very general result and holds regardless whether only the high quality signallers or both high and low types give them. These signals need not be costly at the equilibrium and they need not be honest signals of any quality, as their function is not to signal quality but simply to call the attention of the potential receivers. These kind of displays are probably more common than their current weight in the literature would suggest. PMID:26287489

  14. From Behavior to Neural Dynamics: An Integrated Theory of Attention.

    PubMed

    Buschman, Timothy J; Kastner, Sabine

    2015-10-01

    The brain has a limited capacity and therefore needs mechanisms to selectively enhance the information most relevant to one's current behavior. We refer to these mechanisms as "attention." Attention acts by increasing the strength of selected neural representations and preferentially routing them through the brain's large-scale network. This is a critical component of cognition and therefore has been a central topic in cognitive neuroscience. Here we review a diverse literature that has studied attention at the level of behavior, networks, circuits, and neurons. We then integrate these disparate results into a unified theory of attention. PMID:26447577

  15. Identification of kinetically hot residues in proteins.

    PubMed Central

    Demirel, M. C.; Atilgan, A. R.; Jernigan, R. L.; Erman, B.; Bahar, I.

    1998-01-01

    A number of recent studies called attention to the presence of kinetically important residues underlying the formation and stabilization of folding nuclei in proteins, and to the possible existence of a correlation between conserved residues and those participating in the folding nuclei. Here, we use the Gaussian network model (GNM), which recently proved useful in describing the dynamic characteristics of proteins for identifying the kinetically hot residues in folded structures. These are the residues involved in the highest frequency fluctuations near the native state coordinates. Their high frequency is a manifestation of the steepness of the energy landscape near their native state positions. The theory is applied to a series of proteins whose kinetically important residues have been extensively explored: chymotrypsin inhibitor 2, cytochrome c, and related C2 proteins. Most of the residues previously pointed out to underlie the folding process of these proteins, and to be critically important for the stabilization of the tertiary fold, are correctly identified, indicating a correlation between the kinetic hot spots and the early forming structural elements in proteins. Additionally, a strong correlation between kinetically hot residues and loci of conserved residues is observed. Finally, residues that may be important for the stability of the tertiary structure of CheY are proposed. PMID:9865946

  16. Introduction of the Utrecht Tasks for Attention in Toddlers Using Eye Tracking (UTATE): A Pilot Study

    PubMed Central

    de Jong, Marjanneke; Verhoeven, Marjolein; Hooge, Ignace T. C.; van Baar, Anneloes L.

    2016-01-01

    Attention capacities underlie everyday functioning from an early age onwards. Little is known about attentional processes at toddler age. A feasible assessment of attention capacities at toddler age is needed to allow further study of attention development. In this study, a test battery is piloted that consists of four tasks which intend to measure the attention systems orienting, alerting, and executive attention: the Utrecht Tasks of Attention in Toddlers using Eye tracking [UTATE]. The UTATE assesses looking behavior that may reflect visual attention capacities, by using eye-tracking methods. This UTATE was studied in 16 Dutch 18-month-old toddlers. Results showed that the instrument is feasible and generates good quality data. A first indication of sufficient reliability was found for most of the variables. It is concluded that the UTATE can be used in further studies. Further evaluation of the reliability and validity of the instrument in larger samples is worthwhile. PMID:27199880

  17. 20 CFR 416.945 - Your residual functional capacity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... anatomical, physiological or psychological abnormalities considered alone; e.g., someone with a low back... impairment(s), and any related symptoms, such as pain, may cause physical and mental limitations that affect... that result from your symptoms, such as pain, provided by you, your family, neighbors, friends,...

  18. 20 CFR 416.945 - Your residual functional capacity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... low back disorder may be fully capable of the physical demands consistent with those of sustained... impairment(s), and any related symptoms, such as pain, may cause physical and mental limitations that affect... that result from your symptoms, such as pain, provided by you, your family, neighbors, friends,...

  19. 20 CFR 416.945 - Your residual functional capacity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... low back disorder may be fully capable of the physical demands consistent with those of sustained... impairment(s), and any related symptoms, such as pain, may cause physical and mental limitations that affect... that result from your symptoms, such as pain, provided by you, your family, neighbors, friends,...

  20. 20 CFR 404.1545 - Your residual functional capacity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...., someone with a low back disorder may be fully capable of the physical demands consistent with those of... impairment(s), and any related symptoms, such as pain, may cause physical and mental limitations that affect...), including limitations that result from your symptoms, such as pain, provided by you, your family,...

  1. 20 CFR 404.1545 - Your residual functional capacity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., physiological or psychological abnormalities considered alone; e.g., someone with a low back disorder may be... impairment(s), and any related symptoms, such as pain, may cause physical and mental limitations that affect...), including limitations that result from your symptoms, such as pain, provided by you, your family,...

  2. 20 CFR 416.945 - Your residual functional capacity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... low back disorder may be fully capable of the physical demands consistent with those of sustained... impairment(s), and any related symptoms, such as pain, may cause physical and mental limitations that affect... that result from your symptoms, such as pain, provided by you, your family, neighbors, friends,...

  3. 20 CFR 404.1545 - Your residual functional capacity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., physiological or psychological abnormalities considered alone; e.g., someone with a low back disorder may be... impairment(s), and any related symptoms, such as pain, may cause physical and mental limitations that affect...), including limitations that result from your symptoms, such as pain, provided by you, your family,...

  4. 20 CFR 404.1545 - Your residual functional capacity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...., someone with a low back disorder may be fully capable of the physical demands consistent with those of... impairment(s), and any related symptoms, such as pain, may cause physical and mental limitations that affect...), including limitations that result from your symptoms, such as pain, provided by you, your family,...

  5. 20 CFR 416.945 - Your residual functional capacity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... anatomical, physiological or psychological abnormalities considered alone; e.g., someone with a low back... impairment(s), and any related symptoms, such as pain, may cause physical and mental limitations that affect... that result from your symptoms, such as pain, provided by you, your family, neighbors, friends,...

  6. 20 CFR 404.1545 - Your residual functional capacity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...., someone with a low back disorder may be fully capable of the physical demands consistent with those of... impairment(s), and any related symptoms, such as pain, may cause physical and mental limitations that affect...), including limitations that result from your symptoms, such as pain, provided by you, your family,...

  7. Problems in the measurement of functional residual capacity.

    PubMed

    Broughton, Simon J; Sylvester, Karl P; Page, Chloe M; Rafferty, Gerrard F; Milner, Anthony D; Greenough, Anne

    2006-02-01

    Accurate assessment of lung volume in infancy is important to determine the impact of disease and the efficacy of therapies. A new generation of infant plethysmographs with lower apparatus deadspace has been produced, but gives lower volume results than those from older traditional plethysmographs. We hypothesized that the new plethysmographs might have greater sensitivity to the adiabatic effect and hence they, rather than the traditional plethysmographs, produced erroneous results. Our aim was to assess the influence of the adiabatic effect on the results of a contemporary plethysmograph, an older traditional plethysmograph and a helium gas dilution system using a lung model. Altering the amount of copper wool within the lung model allowed the influence of the adiabatic effect on the plethysmographic results to be assessed. The measured compared to the actual volumes were significantly lower for the contemporary plethysmograph compared to the traditional plethysmograph (p < 0.001) and to the helium gas dilution system (p < 0.001). Under optimal testing conditions the contemporary plethysmograph under-recorded by 11-13%, whereas the other two systems gave similar results to the actual volumes. As the effect of the adiabatic effect was increased, the discrepancy between the results of the contemporary and the traditional plethysmographs increased. We conclude, the contemporary plethysmograph is more sensitive to adiabatic effects and hence under-records. PMID:16400197

  8. Chemistry of combined residual chlorination

    SciTech Connect

    Leao, S.F.; Selleck, R.E.

    1982-01-01

    The decay of the combined chlorine residual was investigated in this work. Recent concerns about the formation of undesirable compounds such as chloroform with free residual chlorination have focused attention on the alternative use of combined residual chlorination. This work investigates the applicability of reactions proposed to describe the transformations and decay of the combined residual with time. Sodium hypochlorite was added to buffered solutions of ammonia with the chlorine residual being monitored over periods extending up to 10 days. The reaction was studied at four initial concentrations of hypochlorite of 100, 50, 25 and 10 mg/L as Cl/sub 2/ with molar application ratios of chlorine to ammonia, defined herein as M ratios, of 0.90, 0.50, 0.25 and 0.05 at each hypochlorite dose. Sixty-eight experiments were conducted at the pH of 6.6 and 7.2. The conclusions are: (1) in the absence of free chlorine, the concentration of NH/sub 3/ does not seem to affect the rate of disappearance of the residual other than through the formation of NHCl/sub 2/ by NH/sub 2/Cl hydrolysis; (2) the reaction between NHCl/sub 2/ and NH/sub 4//sup +/ to form NH/sub 2/Cl is either much slower than reported by Gray et. al. or the mechanism is different with a rate limiting step not involving NH/sub 3/ or NH/sub 4//sup +/; (3) a redox reaction in addition to the first-order decomposition of NHCl/sub 2/ appears necessary. Model simulation results indicated that a reaction of the type NH/sub 2/Cl + NHCl/sub 2/ ..-->.. P added to the first-order NHCl/sub 2/ decomposition can explain the results observed except at the higher chlorine doses.

  9. Attentional control in patients with temporal lobe epilepsy.

    PubMed

    Hudson, John M; Flowers, Kenneth A; Walster, Kerri L

    2014-03-01

    Across different studies, patients with temporal lobe epilepsy (TLE) demonstrate impairments on numerous measures of attentional control that are classically associated with frontal lobe functioning. One aspect of attentional control that has not been examined in TLE is the ability to execute two modality-specific tasks concurrently. We sought to examine the status of dual-task coordination in TLE. We further examined the cohorts' performance on a range of traditional measures of attentional control. Eighteen TLE patients and 22 healthy controls participated in the study. Dual-task performance involved comparing the capacity to execute a tracking and a digit recall task simultaneously with the capacity to execute the tasks separately. We also administered measures of: set shifting (odd-man-out test), sustained attention (elevator counting), selective attention (elevator counting with distraction), and divided attention (trail making test). We found that the proportional decrement in dual-task performance relative to single-task performance did not vary between the groups (TLE = 92.48%; controls = 93.70%), nor was there a significant difference in sustained attention (p > .10). Patients with TLE did demonstrate marked deficits in selective attention (p < .0001), divided attention (p < .01), and set shifting (p < .01). These findings add to the knowledge about cognitive dysfunction in TLE, indicating that impairments in attentional control in TLE tend to be selective. The greatest deficits appear to be on tasks that invoke a high level of processing resources. In contrast, sustained attention is less compromised and the capacity to allocate cognitive resources appears to be normal in patients with TLE. PMID:23323970

  10. Attentional Engagement in Infancy: The Interactive Influence of Attentional Inertia and Attentional State

    ERIC Educational Resources Information Center

    Oakes, Lisa M.; Ross-Sheehy, Shannon; Kannass, Kathleen N.

    2004-01-01

    We evaluated the interactive influences of attentional state and attentional inertia on infants' level of attentional engagement. We assessed infants' distraction latencies longitudinally at 6.5 and 9 months as they explored toys, and we coded both their attentional state (focused vs. casual) and how long they had been looking at the toy at each…

  11. Directing driver attention with augmented reality cues

    PubMed Central

    Rusch, Michelle L.; Schall, Mark C.; Gavin, Patrick; Lee, John D.; Dawson, Jeffrey D.; Vecera, Shaun; Rizzo, Matthew

    2013-01-01

    This simulator study evaluated the effects of augmented reality (AR) cues designed to direct the attention of experienced drivers to roadside hazards. Twenty-seven healthy middle-aged licensed drivers with a range of attention capacity participated in a 54 mile (1.5 hour) drive in an interactive fixed-base driving simulator. Each participant received AR cues to potential roadside hazards in six simulated straight (9 mile long) rural roadway segments. Drivers were evaluated on response time for detecting a potentially hazardous event, detection accuracy for target (hazard) and non-target objects, and headway with respect to the hazards. Results showed no negative outcomes associated with interference. AR cues did not impair perception of non-target objects, including for drivers with lower attentional capacity. Results showed near significant response time benefits for AR cued hazards. AR cueing increased response rate for detecting pedestrians and warning signs but not vehicles. AR system false alarms and misses did not impair driver responses to potential hazards. PMID:24436635

  12. Peripheral Attentional Targets under Covert Attention Lead to Paradoxically Enhanced Alpha Desynchronization in Neurofibromatosis Type 1

    PubMed Central

    Silva, Gilberto; Ribeiro, Maria J.; Costa, Gabriel N.; Violante, Inês; Ramos, Fabiana; Saraiva, Jorge; Castelo-Branco, Miguel

    2016-01-01

    The limited capacity of the human brain to process the full extent of visual information reaching the visual cortex requires the recruitment of mechanisms of information selection through attention. Neurofibromatosis type-1 (NF1) is a neurodevelopmental disease often exhibiting attentional deficits and learning disabilities, and is considered to model similar impairments common in other neurodevelopmental disorders such as autism. In a previous study, we found that patients with NF1 are more prone to miss targets under overt attention conditions. This finding was interpreted as a result of increased occipito-parietal alpha oscillations. In the present study, we used electroencephalography (EEG) to study alpha power modulations and the performance of patients with NF1 in a covert attention task. Covert attention was required in order to perceive changes (target offset) of a peripherally presented stimulus. Interestingly, alpha oscillations were found to undergo greater desynchronization under this task in the NF1 group compared with control subjects. A similar pattern of desynchronization was found for beta frequencies while no changes in gamma oscillations could be identified. These results are consistent with the notion that different attentional states and task demands generate different patterns of abnormal modulation of alpha oscillatory processes in NF1. Under covert attention conditions and while target offset was reported with relatively high accuracy (over 90% correct responses), excessive desynchronization was found. These findings suggest an abnormal modulation of oscillatory activity and attentional processes in NF1. Given the known role of alpha in modulating attention, we suggest that alpha patterns can show both abnormal increases and decreases that are task and performance dependent, in a way that enhanced alpha desynchronization may reflect a compensatory mechanism to keep performance at normal levels. These results suggest that dysregulation of

  13. Attention deficit hyperactivity disorder.

    PubMed

    Kulkarni, Madhuri

    2015-03-01

    Attention Deficit Hyperactivity Disorder (ADHD) is a common behavioral disorder in children. It is characterized by motor hyperactivity, impulsivity and inattention inappropriate for the age. Approximately 5-10 % of school age children are diagnosed to have ADHD. The affected children show significant impairment in social behavior and academic performance. The DSM-5 criteria are useful in diagnosing three subtypes of ADHD based on presence of symptoms described in 3 domains viz ., inattention, hyperactivity and impulsivity. Co-morbidities like specific learning disability, anxiety disorder, oppositional defiant disorder are commonly associated with ADHD.Education of parents and teachers, behavioral therapy and medication are main components of management. Methylphenidate and Atomoxetine are effective in controlling symptoms of ADHD in most children. Research studies estimated that 30-60 % of children continue to show symptoms of ADHD in adulthood. The general practitioner can play an important role in early diagnosis, appropriate assessment and guiding parents for management of children with ADHD. PMID:25186567

  14. Attention Deficit Hyperactivity Disorder

    PubMed Central

    Matthews, Marguerite; Nigg, Joel T.

    2014-01-01

    Over the last two decades, there have been numerous technical and methodological advances available to clinicians and researchers to better understand attention deficit hyperactivity disorder (ADHD) and its etiology. Despite the growing body of literature investigating the disorder’s pathophysiology, ADHD remains a complex psychiatric disorder to characterize. This chapter will briefly review the literature on ADHD, with a focus on its history, the current genetic insights, neurophysiologic theories, and the use of neuroimaging to further understand the etiology. We address some of the major concerns that remain unclear about ADHD, including subtype instability, heterogeneity, and the underlying neural correlates that define the disorder. We highlight that the field of ADHD is rapidly evolving; the descriptions provided here will hopefully provide a sturdy foundation for which to build and improve our understanding of the disorder. PMID:24214656

  15. Attention deficit hyperactivity disorder.

    PubMed

    Thapar, Anita; Cooper, Miriam

    2016-03-19

    Attention deficit hyperactivity disorder (ADHD) is a childhood-onset neurodevelopmental disorder with a prevalence of 1·4-3·0%. It is more common in boys than girls. Comorbidity with childhood-onset neurodevelopmental disorders and psychiatric disorders is substantial. ADHD is highly heritable and multifactorial; multiple genes and non-inherited factors contribute to the disorder. Prenatal and perinatal factors have been implicated as risks, but definite causes remain unknown. Most guidelines recommend a stepwise approach to treatment, beginning with non-drug interventions and then moving to pharmacological treatment in those most severely affected. Randomised controlled trials show short-term benefits of stimulant medication and atomoxetine. Meta-analyses of blinded trials of non-drug treatments have not yet proven the efficacy of such interventions. Longitudinal studies of ADHD show heightened risk of multiple mental health and social difficulties as well as premature mortality in adult life. PMID:26386541

  16. Attentional Control in Visual Signal Detection: Effects of Abrupt-Onset and No-Onset Stimuli

    ERIC Educational Resources Information Center

    Sewell, David K.; Smith, Philip L.

    2012-01-01

    The attention literature distinguishes two general mechanisms by which attention can benefit performance: gain (or resource) models and orienting (or switching) models. In gain models, processing efficiency is a function of a spatial distribution of capacity or resources; in orienting models, an attentional spotlight must be aligned with the…

  17. 33 CFR 158.320 - Reception facilities: Capacity, and exceptions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Reception facilities: Capacity... HOMELAND SECURITY (CONTINUED) POLLUTION RECEPTION FACILITIES FOR OIL, NOXIOUS LIQUID SUBSTANCES, AND... Residue § 158.320 Reception facilities: Capacity, and exceptions. (a) Except as allowed in paragraph...

  18. 33 CFR 158.320 - Reception facilities: Capacity, and exceptions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Reception facilities: Capacity... HOMELAND SECURITY (CONTINUED) POLLUTION RECEPTION FACILITIES FOR OIL, NOXIOUS LIQUID SUBSTANCES, AND... Residue § 158.320 Reception facilities: Capacity, and exceptions. (a) Except as allowed in paragraph...

  19. 33 CFR 158.320 - Reception facilities: Capacity, and exceptions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Reception facilities: Capacity... HOMELAND SECURITY (CONTINUED) POLLUTION RECEPTION FACILITIES FOR OIL, NOXIOUS LIQUID SUBSTANCES, AND... Residue § 158.320 Reception facilities: Capacity, and exceptions. (a) Except as allowed in paragraph...

  20. 33 CFR 158.320 - Reception facilities: Capacity, and exceptions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Reception facilities: Capacity... HOMELAND SECURITY (CONTINUED) POLLUTION RECEPTION FACILITIES FOR OIL, NOXIOUS LIQUID SUBSTANCES, AND... Residue § 158.320 Reception facilities: Capacity, and exceptions. (a) Except as allowed in paragraph...

  1. 33 CFR 158.320 - Reception facilities: Capacity, and exceptions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Reception facilities: Capacity... HOMELAND SECURITY (CONTINUED) POLLUTION RECEPTION FACILITIES FOR OIL, NOXIOUS LIQUID SUBSTANCES, AND... Residue § 158.320 Reception facilities: Capacity, and exceptions. (a) Except as allowed in paragraph...

  2. Flexible cognitive resources: competitive content maps for attention and memory.

    PubMed

    Franconeri, Steven L; Alvarez, George A; Cavanagh, Patrick

    2013-03-01

    The brain has finite processing resources so that, as tasks become harder, performance degrades. Where do the limits on these resources come from? We focus on a variety of capacity-limited buffers related to attention, recognition, and memory that we claim have a two-dimensional 'map' architecture, where individual items compete for cortical real estate. This competitive format leads to capacity limits that are flexible, set by the nature of the content and their locations within an anatomically delimited space. We contrast this format with the standard 'slot' architecture and its fixed capacity. Using visual spatial attention and visual short-term memory as case studies, we suggest that competitive maps are a concrete and plausible architecture that limits cognitive capacity across many domains. PMID:23428935

  3. Response inhibition and attentional control in anxiety.

    PubMed

    Pacheco-Unguetti, Antonia Pilar; Acosta, Alberto; Lupiáñez, Juan; Román, Naiker; Derakshan, Nazanin

    2012-01-01

    Traditionally, anxiety has been associated with a selective attentional bias for threat and a decreased capacity in attentional control. In two different experiments, we investigated whether individuals with different levels of self-reported state anxiety (Experiment 1) and induced anxiety (Experiment 2) had impaired response inhibition processes (attentional control deficit) as characterized by a different response style in the presence of negative stimuli under low and high perceptual load conditions. A go/no-go paradigm with emotional distractors (angry, happy, and neutral faces) was used to provide measures of perceptual sensitivity, inhibition, and response style. Our findings showed that perceptual sensitivity, as assessed by the d' parameter of signal detection theory, was reduced in all participants for angry faces under low perceptual load, where enough perceptual resources were available to be attracted by distractors. Importantly, despite similar perceptual sensitivity, the beta parameter indicated that high state anxiety individuals in both experiments were less flexible at adjusting to task demands in the presence of angry face distractors by adopting a stricter criterion. Implications of findings are discussed within current models of attentional control in anxiety. PMID:22332884

  4. Chewing and attention: a positive effect on sustained attention.

    PubMed

    Hirano, Yoshiyuki; Onozuka, Minoru

    2015-01-01

    Chewing is crushing food not only to aid swallowing and digestion, but also to help stress relief and regulate cognitive function, especially in attention. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving, suggesting a link between chewing and sustained attention. We hypothesized that chewing elevates attention and/or alertness, leading to improvements in cognitive performance. We carried out a systematic review of the PubMed database. We inspected the attributes of effects on attention in studies investigating the effects of chewing on attention or alertness conducted with pre-post design in healthy subjects, except elderly. We identified 151 references, 22 of which were included: 14 (64%) showed positive attributes of effects on attention, 1 (5%) showed negative attributes of effects on attention, 5 (23%) showed both positive and negative attributes of effects on attention, and 2 (9%) showed no significant attributes of effects on attention. Thus, positive attributes of effects of chewing on attention, especially on sustained attention, were shown in over half of the reports. These effects also appeared with improvement in mood and stress relief and were influenced by time-on-task effect. Further studies are needed, but chewing could be useful for modifying cognitive function. PMID:26075234

  5. Cognitive Control Network Contributions to Memory-Guided Visual Attention.

    PubMed

    Rosen, Maya L; Stern, Chantal E; Michalka, Samantha W; Devaney, Kathryn J; Somers, David C

    2016-05-01

    Visual attentional capacity is severely limited, but humans excel in familiar visual contexts, in part because long-term memories guide efficient deployment of attention. To investigate the neural substrates that support memory-guided visual attention, we performed a set of functional MRI experiments that contrast long-term, memory-guided visuospatial attention with stimulus-guided visuospatial attention in a change detection task. Whereas thedorsal attention networkwas activated for both forms of attention, thecognitive control network(CCN) was preferentially activated during memory-guided attention. Three posterior nodes in the CCN, posterior precuneus, posterior callosal sulcus/mid-cingulate, and lateral intraparietal sulcus exhibited the greatest specificity for memory-guided attention. These 3 regions exhibit functional connectivity at rest, and we propose that they form a subnetwork within the broader CCN. Based on the task activation patterns, we conclude that the nodes of this subnetwork are preferentially recruited for long-term memory guidance of visuospatial attention. PMID:25750253

  6. Attention Deficit Hyperactivity Disorder Basics

    MedlinePlus

    ... us to find out more about ADHD. Share Attention Deficit Hyperactivity Disorder Basics Download PDF Download ePub Order a free ... attention deficit/hyperactivity disorder , or ADHD . What is attention deficit/hyperactivity disorder, or ADHD? ADHD is a common mental disorder ...

  7. Getting the attention you need.

    PubMed

    Davenport, T H; Beck, J C

    2000-01-01

    Employees have an enormous amount of business information at their fingertips--more specifically, at their desktops. The floodgates are open; profitable possibilities abound. But having to handle all that information has pushed downsized staffs to the brink of an acute attention deficit disorder. To achieve corporate goals, business leaders need their employees' full attention--and that attention is in short supply. Authors Thomas Davenport and John Beck have studied how companies manage the attention of their employees and their site visitors. In this article, they analyze the components of attention management through three lenses--economic, psychobiological, and technological--and offer guidelines for keeping employees focused on crucial corporate tasks. Their lessons are drawn from the best practices employed by today's stickiest Web sites and by traditional attention industries such as advertising, film, and television. The authors say executives must manage attention knowing that it's a zero-sum game (there's only so much to go around). Managers should also consider capitalizing on the basic survival and competitive instincts we all have that help determine how much attention we pay to certain things. For instance, the threat of corporate demise--and the consequent loss of jobs and livelihoods--undoubtedly focuses workers' attention on the need to change. Likewise, internal competition among business units may give employees added incentive to pay attention to a profit or sales goal. Leaders today need to pay more attention to attention because it's widely misunderstood and widely mismanaged, the authors conclude. PMID:11143148

  8. Attention, Task Difficulty, and ADHD

    ERIC Educational Resources Information Center

    Nigg, Joel T.

    2005-01-01

    Comments on analysis of attention tasks in Attention Deficit Hyperactivity Disorder (ADHD) provided by Wilding (2005)points out that whereas many regulatory functions, including alertness or arousal, appear to be impaired in ADHD, demonstrating basic attention deficits in selection or orienting functions in the disorder has proven difficult. Yet…

  9. 33 CFR 157.17 - Oil residue (sludge) tank.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Type of machinery installed on the vessel; and (2) Maximum fuel oil capacity. (c) Each oil residue... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Oil residue (sludge) tank. 157.17...) POLLUTION RULES FOR THE PROTECTION OF THE MARINE ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN...

  10. Building Leadership Capacity

    ERIC Educational Resources Information Center

    Flanary, Dick

    2009-01-01

    The NASSP "Breaking Ranks" framework lays out multiple strategies for building capacity within a school, beginning with the leaders. To change an organization and increase its capacity to produce greater results, the people within the organization must change and increase their capacity. School change begins with changes in the principal, the…

  11. [Attention deficit hyperactivity disorder].

    PubMed

    Cunill, Ruth; Castells, Xavier

    2015-04-20

    Attention deficit hyperactivity disorder (ADHD) is one of the most common childhood psychiatric disorders and can persist into the adulthood. ADHD has important social, academic and occupational consequences. ADHD diagnosis is based on the fulfillment of several clinical criteria, which can vary depending on the diagnostic system used. The clinical presentation can show great between-patient variability and it has been related to a dysfunction in the fronto-striatal and meso-limbic circuits. Recent investigations support a model in which multiple genetic and environmental factors interact to create a neurobiological susceptibility to develop the disorder. However, no clear causal association has yet been identified. Although multimodal treatment including both pharmacological and psychosocial interventions is usually recommended, no convincing evidence exists to support this recommendation. Pharmacological treatment has fundamentally shown to improve ADHD symptoms in the short term, while efficacy data for psychosocial interventions are scarce and inconsistent. Yet, drug treatment is increasingly popular and the last 2 decades have witnessed a sharp increase in the prescription of anti-ADHD medications coinciding with the marketing of new drugs to treat ADHD. PMID:24787685

  12. A capacity assessment towards more resilient societies

    NASA Astrophysics Data System (ADS)

    Kuhlicke, C.; Steinführer, A.

    2012-04-01

    Social capacity building for natural hazards is a topic increasingly gaining relevance not only for so-called developing countries but also for European welfare states which are continuously challenged by the social, economic and ecological impacts of natural hazards. Following an outline of recent governance changes with regard to natural hazards, we develop a heuristic model of social capacity building by taking into account a wide range of existing expertise from different fields of research. Particular attention is paid to social vulnerability and its assessment, as well as to risk communication and risk education as specific strategies of social capacity building. We propose to distinguish between interventionist and participatory approaches, thus enabling for a better understanding of existing practices of social capacity building as well as their particular strengths and weaknesses. It is from this typology the presentation will develop two kinds of operational social capacity audits; one for communities and one for organisations. These assessments aim to identify appropriate measures and strategies regarding how to enhance, develop and build different kinds of capacities. By using these assessments participants will be able to identify strong capacities and can refer to the recommendations for tips on how to improve capacities identified as weak. That way deficits and outcomes are defined by those who are most likely to be affected by a future hazard event and most likely to be implementing improvements towards resilience.

  13. Assessment of Attention in Preschoolers

    PubMed Central

    Mahone, E.M.; Schneider, H.E.

    2012-01-01

    In the past two decades, there has been an increased interest in the assessment and treatment of preschool children presenting with concerns about attention problems. This article reviews the research and clinical literature involving assessment of attention and related skills in the preschool years. While inattention among preschoolers is common, symptoms alone do not necessarily indicate a disorder, and most often represent a normal variation in typical preschool child development. Thus, accurate identification of “disordered” attention in preschoolers can be challenging, and development of appropriate, norm-referenced tests of attention for preschoolers is also difficult. The current review suggests that comprehensive assessment of attention and related functions in the preschool child should include thorough review of the child’s history, planned observations, and formal psychometric testing. The three primary methods of psychometric assessment that have been used to characterize attentional functioning in preschool children include performance-based tests, structured caregiver interviews, and rating scales (parent, teacher, and clinician). Among performance-based methods for measurement of attention in the preschool years, tests have been developed to assess sustained attention, selective (focused) attention, span of attention (encoding/manipulation), and (top-down) controlled attention—including freedom from distractibility and set shifting. Many of these tests remain experimental in nature, and review of published methods yields relatively few commercially available, nationally normed tests of attention for preschoolers, and an overall dearth of reliability and validity studies on the available measures. PMID:23090646

  14. Dysfunctional attention in autistic savants.

    PubMed

    Casey, B J; Gordon, C T; Mannheim, G B; Rumsey, J M

    1993-11-01

    A dysfunctional attention hypothesis of the basis of savant skills was tested with a series of computerized tasks that assessed the ability to divide, shift, direct, and sustain attention. Ten healthy men with pervasive developmental disorders and unusual calendar-calculating skill, and 10 age- and sex-matched controls were tested. There were four general findings. First, the savants and controls did not differ on a measure of visual sustained attention. Second, the savants failed to detect rare auditory targets significantly more than did the controls. Third, the savants were unable to efficiently divide their attention when required to detect both visual and auditory targets simultaneously. Finally, deficient orienting or a deficit in shifting selective attention from one stimulus location to another was evidenced in overall slower reaction times for the savants across tasks requiring shifts and redirecting of attention. This deficit was attributed to an inability to disengage attention as a result of deficient orienting and overselectivity. PMID:8120129

  15. The Normalization Model of Attention

    PubMed Central

    Reynolds, John H.; Heeger, David J.

    2009-01-01

    Attention has been found to have a wide variety of effects on the responses of neurons in visual cortex. We describe a model of attention that exhibits each of these different forms of attentional modulation, depending on the stimulus conditions and the spread (or selectivity) of the attention field in the model. The model helps reconcile proposals that have been taken to represent alternative theories of attention. We argue that the variety and complexity of the results reported in the literature emerge from the variety of empirical protocols that were used, such that the results observed in any one experiment depended on the stimulus conditions and the subject’s attentional strategy, a notion that we define precisely in terms of the attention field in the model, but that has not typically been completely under experimental control. PMID:19186161

  16. A fundamental problem in determining functional residual capacity or residual volume. [of lungs

    NASA Technical Reports Server (NTRS)

    Boutellier, U.; Farhi, L. E.

    1986-01-01

    To measure a lung volume that is not directly accessible, one often follows dilution of a single-gas tracer, present initially only in the lung or in a rebreathing bag. The final volume available to the tracer is assumed to be the sum of the two initial components. Since O2 is taken up and CO2 is eliminated during the few breaths required for mixing, the total volume changes. The error in lung volume due to this volume change can exceed 10 pct. Theoretical and experimental data is presented to demonstrate the effect of CO2 and O2 exchange. A general equation, based on N2 and Ar, which allows one to circumvent the problems created by these fluxes is introduced. The pitfall of the back-extrapolation approach for a single tracer is shown.

  17. Fundamental problem in determining functional residual capacity or residual volume. [Of lungs

    SciTech Connect

    Boutellier, U.; Farhi, L.E.

    1986-05-01

    To measure a lung volume that is not directly accessible, one often follows dilution of a single-gas tracer, present initially only in the lung or in a rebreathing bag. The final volume available to the tracer is assumed to be the sum of the two initial components. Since O2 is taken up and CO2 is eliminated during the few breaths required for mixing, the total volume changes. The error in lung volume due to this volume change can exceed 10 pct. Theoretical and experimental data is presented to demonstrate the effect of CO2 and O2 exchange. A general equation, based on N2 and Ar, which allows one to circumvent the problems created by these fluxes is introduced. The pitfall of the back-extrapolation approach for a single tracer is shown.

  18. Approach to attention deficit disorder in adults

    PubMed Central

    Matas, Manuel

    2006-01-01

    OBJECTIVE To review the etiology, diagnosis, and management of attention deficit disorder (ADD) in adults. SOURCES OF INFORMATION PsycINFO, PubMed, and Psychiatry 24x7.com were searched. Several books on ADD in adults were reviewed. I also drew on my own clinical experience assessing and treating adults with ADD for more than 20 years. MAIN MESSAGE The classic triad of ADD symptoms are inattention, impulsiveness, and hyperactivity or restlessness. Although ADD is a well established brain disorder, the diagnosis remains controversial. Attention deficit disorder has been called a fad, not a legitimate diagnosis, but it is a well established, well documented, medical condition that can cause much suffering if left untreated. At one time we thought children would outgrow ADD at puberty, but we now know that many will continue to have residual symptoms throughout adolescence and adulthood. If left untreated, ADD can interfere with relationships, employment, and self-esteem. Treatment with stimulants and adjunctive care is often effective. CONCLUSION Attention deficit disorder in adults represents a substantial burden of illness. It can be diagnosed and treated successfully. PMID:17273498

  19. Inattention and Impulsivity: Differential Impact on School Readiness Capacities

    ERIC Educational Resources Information Center

    Sasser, Tyler; Bierman, Karen

    2011-01-01

    Despite the conceptual link between self-regulation skills and school readiness capacities, questions remain regarding how distinct but related facets of self-regulation (i.e., attention regulation, behavior regulation) differentially impact the development of school readiness capacities during early childhood. Additionally, little is known about…

  20. The Yin and Yang of Sleep and Attention.

    PubMed

    Kirszenblat, Leonie; van Swinderen, Bruno

    2015-12-01

    Sleep is not a single state, but a complex set of brain processes that supports several physiological needs. Sleep deprivation is known to affect attention in many animals, suggesting that a key function of sleep is to regulate attention. Conversely, tasks that require more attention drive sleep need and sleep intensity. Attention involves the ability to filter incoming stimuli based on their relative salience, and this is likely to require coordinated synaptic activity across the brain. This capacity may have only become possible with the evolution of related neural mechanisms that support two key sleep functions: stimulus suppression and synaptic plasticity. We argue here that sleep and attention may have coevolved as brain states that regulate each other. PMID:26602764

  1. Evidence for selective attention in the insect brain.

    PubMed

    de Bivort, Benjamin L; van Swinderen, Bruno

    2016-06-01

    The capacity for selective attention appears to be required by any animal responding to an environment containing multiple objects, although this has been difficult to study in smaller animals such as insects. Clear operational characteristics of attention however make study of this crucial brain function accessible to any animal model. Whereas earlier approaches have relied on freely behaving paradigms placed in an ecologically relevant context, recent tethered preparations have focused on brain imaging and electrophysiology in virtual reality environments. Insight into brain activity during attention-like behavior has revealed key elements of attention in the insect brain. Surprisingly, a variety of brain structures appear to be involved, suggesting that even in the smallest brains attention might involve widespread coordination of neural activity. PMID:27436727

  2. Attention-Modulating Effects of Cognitive Enhancers

    EPA Science Inventory

    Attention can be readily measured in experimental animal models. Animal models of attention have been used to better understand the neural systems involved in attention, how attention is impaired, and how therapeutic treatments can ameliorate attentional deficits. This review fo...

  3. Attentional Lapses of Adults with Attention Deficit Hyperactivity Disorder in Tasks of Sustained Attention.

    PubMed

    Gmehlin, Dennis; Fuermaier, Anselm B M; Walther, Stephan; Tucha, Lara; Koerts, Janneke; Lange, Klaus W; Tucha, Oliver; Weisbrod, Matthias; Aschenbrenner, Steffen

    2016-06-01

    Adults with attention deficit hyperactivity disorder (ADHD) show attentional dysfunction such as distractibility and mind-wandering, especially in lengthy tasks. However, fundamentals of dysfunction are ambiguous and relationships of neuropsychological test parameters with self-report measures of ADHD symptoms are marginal. We hypothesize that basic deficits in sustaining attention explain more complex attentional dysfunction in persons with ADHD and relate to ADHD symptoms. Attentional function was analyzed by computing ex-Gaussian parameters for 3 time Blocks in a 20 min test of sustained alertness. Changes in performance across these blocks were analyzed by comparing adult persons with ADHD (n = 24) with healthy matched controls (n = 24) and correlated with neuropsychological measures of selective and divided attention as well as self-report measures of ADHD symptoms. We found a significantly steeper increase in the number of slow responses (ex-Gaussian parameter τ) in persons with ADHD with time on task in basic sustained alertness. They also performed significantly worse in tasks of sustained selective and divided attention. However, after controlling for an increase in τ during the alertness task, significant differences between groups disappeared for divided and partly selective attention. Increases in τ in the sustained alertness task correlated significantly with self-report measures of ADHD symptoms. Our results provide evidence that very basic deficits in sustaining attention in adults with ADHD are related to infrequent slow responses (=attentional lapses), with changes over time being relevant for more complex attentional function and experienced ADHD symptoms in everyday life. PMID:27193369

  4. Diverting Attention Suppresses Human Amygdala Responses to Faces

    PubMed Central

    Morawetz, Carmen; Baudewig, Juergen; Treue, Stefan; Dechent, Peter

    2010-01-01

    Recent neuroimaging studies disagree as to whether the processing of emotion-laden visual stimuli is dependent upon the availability of attentional resources or entirely capacity-free. Two main factors have been proposed to be responsible for the discrepancies: the differences in the perceptual attentional demands of the tasks used to divert attentional resources from emotional stimuli and the spatial location of the affective stimuli in the visual field. To date, no neuroimaging report addressed these two issues in the same set of subjects. Therefore, the aim of the study was to investigate the effects of high and low attentional load as well as different stimulus locations on face processing in the amygdala using functional magnetic resonance imaging to provide further evidence for one of the two opposing theories. We were able for the first time to directly test the interaction of attentional load and spatial location. The results revealed a strong attenuation of amygdala activity when the attentional load was high. The eccentricity of the emotional stimuli did not affect responses in the amygdala and no interaction effect between attentional load and spatial location was found. We conclude that the processing of emotional stimuli in the amygdala is strongly dependent on the availability of attentional resources without a preferred processing of stimuli presented in the periphery and provide firm evidence for the concept of the attentional load theory of emotional processing in the amygdala. PMID:21160563

  5. Attentional Priority Determines Working Memory Precision

    PubMed Central

    Klyszejko, Zuzanna; Rahmati, Masih; Curtis, Clayton E

    2014-01-01

    Visual working memory is a system used to hold information actively in mind for a limited time. The number of items and the precision with which we can store information has limits that define its capacity. How much control do we have over the precision with which we store information when faced with these severe capacity limitations? Here, we tested the hypothesis that rank-ordered attentional priority determines the precision of multiple working memory representations. We conducted two psychophysical experiments that manipulated the priority of multiple items in a two-alternative forced choice task (2AFC) with distance discrimination. In Experiment 1, we varied the probabilities with which memorized items were likely to be tested. To generalize the effects of priority beyond simple cueing, in Experiment 2, we manipulated priority by varying monetary incentives contingent upon successful memory for items tested. Moreover, we illustrate our hypothesis using a simple model that distributed attentional resources across items with rank-ordered priorities. Indeed, we found evidence in both experiments that priority affects the precision of working memory in a monotonic fashion. Our results demonstrate that representations of priority may provide a mechanism by which resources can be allocated to increase the precision with which we encode and briefly store information. PMID:25240420

  6. Rats and Humans Paying Attention

    PubMed Central

    Demeter, Elise; Sarter, Martin; Lustig, Cindy

    2008-01-01

    Substantial gains have been made on the neurobiology of attention from systems neuroscience work in animal models and human cognitive neuroscience. However, the integration of rodent-based research on the specific neurotransmitter systems that subserve attention with the results from human behavioral and neuroimaging studies has been hampered by the lack of tasks that validly assess attention in both species. To address this issue, an operant sustained attention task that has been extensively used in research on the neurobiology of attention in rats was re-designed and validated for use in humans. Although humans showed better performance overall, the two species showed similar effects of several attention-related variables, including the introduction of distractor-related challenge. This task provides a useful tool for integrative, cross-species research, and may help to determine how specific neurotransmitter systems contribute to the hemodynamic changes observed in human functional neuroimaging experiments. PMID:18999353

  7. How Attention Affects Spatial Resolution

    PubMed Central

    Carrasco, Marisa; Barbot, Antoine

    2015-01-01

    We summarize and discuss a series of psychophysical studies on the effects of spatial covert attention on spatial resolution, our ability to discriminate fine patterns. Heightened resolution is beneficial in most, but not all, visual tasks. We show how endogenous attention (voluntary, goal driven) and exogenous attention (involuntary, stimulus driven) affect performance on a variety of tasks mediated by spatial resolution, such as visual search, crowding, acuity, and texture segmentation. Exogenous attention is an automatic mechanism that increases resolution regardless of whether it helps or hinders performance. In contrast, endogenous attention flexibly adjusts resolution to optimize performance according to task demands. We illustrate how psychophysical studies can reveal the underlying mechanisms of these effects and allow us to draw linking hypotheses with known neurophysiological effects of attention. PMID:25948640

  8. Self-Referenced Processing, Neurodevelopment and Joint Attention in Autism

    ERIC Educational Resources Information Center

    Mundy, Peter; Gwaltney, Mary; Henderson, Heather

    2010-01-01

    This article describes a parallel and distributed processing model (PDPM) of joint attention, self-referenced processing and autism. According to this model, autism involves early impairments in the capacity for rapid, integrated processing of self-referenced (proprioceptive and interoceptive) and other-referenced (exteroceptive) information.…

  9. Language Impairment in the Attention-Deficit/Hyperactivity Disorder Context

    ERIC Educational Resources Information Center

    Redmond, Sean M.

    2016-01-01

    Purpose: Attention-deficit/hyperactivity disorder (ADHD) is a ubiquitous designation that affects the identification, assessment, treatment, and study of pediatric language impairments (LIs). Method: Current literature is reviewed in 4 areas: (a) the capacity of psycholinguistic, neuropsychological, and socioemotional behavioral indices to…

  10. The Differential Effect of Attentional Condition on Subsequent Vocabulary Development

    ERIC Educational Resources Information Center

    Mohammed, Halah Abdulelah; Majid, Norazman Abdul; Abdullah, Tina

    2016-01-01

    This study addressed the potential methodological issues effect of attentional condition on subsequent vocabulary development from a different perspective, which addressed several potential methodological issues of previous research that have been based on psycholinguistic notion of second language learner as a limited capacity processor. The…

  11. Attentional Capture with Rapidly Changing Attentional Control Settings

    ERIC Educational Resources Information Center

    Lien, Mei-Ching; Ruthruff, Eric; Johnston, James C.

    2010-01-01

    The classic theory of spatial attention hypothesized 2 modes, voluntary and involuntary. Folk, Remington, and Johnston (1992) reported that even involuntary attention capture by stimuli requires a match between stimulus properties and what the observer is looking for. This surprising conclusion has been confirmed by many subsequent studies. In…

  12. Focus of Attention in Groups: A Self-Attention Perspective.

    ERIC Educational Resources Information Center

    Mullen, Brian; And Others

    1989-01-01

    Reports on three research studies that tested the hypothesis that the focus of attention of individuals in groups varies as a function of the group composition. The populations studied were members of the Nixon White House staff, high school students, and male undergraduate students. Results supported the idea of self-focused attention as a…

  13. Multicomponent attention deficits in attention deficit hyperactivity disorder.

    PubMed

    Kiliç, Birim Günay; Sener, Sahnur; Koçkar, Aylin Ilden; Karakaş, Sirel

    2007-04-01

    The aim of this study was to examine the specific aspects of attention, such as selective attention, sustained attention, and short-term memory in children with attention deficit hyperactivity disorder, combined subtype (ADHD-C). A total of 40 children with a diagnosis of ADHD from the 4th edition of the Diagnostic and Statistical Manual, aged 6-11 years old were compared with 40 controls matched for age and gender on a battery of tests. Short-term memory span and attention was measured by Visual Aural Digit Span Test-Revised. Stroop test and the Turkish version of Cancellation Test were used to assess selective and sustained attention, respectively. In order to check for factor structure in two groups on the test scores, principal component analysis was conducted for both groups separately. Relative to the comparison children, children with ADHD showed significant deficits on tests that are related to different aspects of attention. The results are consistent with the theories explaining the biological basis of ADHD by scattered attention networks in the brain, which have reciprocal dynamic interactions. Further comparative studies are needed to elucidate whether the cognitive processes that are known to be assessed by these tests are specific to ADHD. PMID:17362431

  14. Provocative Mathematics Questions: Drawing Attention to a Lack of Attention

    ERIC Educational Resources Information Center

    Klymchuk, Sergiy

    2015-01-01

    The article investigates the role of attention in the reflective thinking of school mathematics teachers. It analyses teachers' ability to pay attention to detail and "use" their mathematical knowledge. The vast majority of teachers can be expected to have an excellent knowledge of mathematical techniques. The question examined here is…

  15. Paying Attention to Attention: New Economies for Learning

    ERIC Educational Resources Information Center

    de Castell, Suzanne; Jenson, Jennifer

    2004-01-01

    Challenging formal education's traditional monopoly over the mass-scale acculturation of youth, the technological infrastructure of the new economy brings in its wake a new attentional economy in which any connected adult or child owns and controls a full economic share of her or his own attention. For youth who have never known the text-bound…

  16. Difficulty of Discrimination Modulates Attentional Capture by Regulating Attentional Focus

    ERIC Educational Resources Information Center

    Sawaki, Risa; Katayama, Jun'ichi

    2009-01-01

    Attentional capture for distractors is enhanced by increasing the difficulty of discrimination between the standard and the target in the three-stimulus oddball paradigm. In this study, we investigated the cognitive mechanism of this modulation of attentional capture. Event-related brain potentials were recorded from participants while they…

  17. On Gaussian feedback capacity

    NASA Technical Reports Server (NTRS)

    Dembo, Amir

    1989-01-01

    Pinsker and Ebert (1970) proved that in channels with additive Gaussian noise, feedback at most doubles the capacity. Cover and Pombra (1989) proved that feedback at most adds half a bit per transmission. Following their approach, the author proves that in the limit as signal power approaches either zero (very low SNR) or infinity (very high SNR), feedback does not increase the finite block-length capacity (which for nonstationary Gaussian channels replaces the standard notion of capacity that may not exist). Tighter upper bounds on the capacity are obtained in the process. Specializing these results to stationary channels, the author recovers some of the bounds recently obtained by Ozarow.

  18. Structure-based identification of catalytic residues

    PubMed Central

    Yahalom, Ran; Reshef, Dan; Wiener, Ayana; Frankel, Sagiv; Kalisman, Nir; Lerner, Boaz; Keasar, Chen

    2011-01-01

    The identification of catalytic residues is an essential step in functional characterization of enzymes. We present a purely structural approach to this problem, which is motivated by the difficulty of evolution-based methods to annotate structural genomics targets that have few or no homologs in the databases. Our approach combines a state-of-the-art support vector machine (SVM) classifier with novel structural features that augment structural clues by spatial averaging and Z-scoring. Special attention is paid to the class imbalance problem that stems from the overwhelming number of non-catalytic residues in enzymes compared to catalytic residues. This problem is tackled by: 1) optimizing the classifier to maximize a performance criterion that considers both type I and type II errors in the classification of catalytic and non-catalytic residues; 2) under-sampling non-catalytic residues before SVM training; and 3) during SVM training, penalizing errors in learning catalytic residues more than errors in learning non-catalytic residues. Tested on four enzyme datasets – one specifically designed by us to mimic the structural genomics scenario and three previously-evaluated datasets – our structure-based classifier is never inferior to similar structure-based classifiers and comparable to classifiers that use both structural and evolutionary features. In addition to evaluation of the performance of catalytic residue identification, we also present detailed case studies on three proteins. This analysis suggests that many false positive predictions may correspond to binding sites and other functional residues. A web server that implements the method, our own-designed database, and the source code of the programs are publicly available at http://www.cs.bgu.ac.il/~meshi/functionPrediction. PMID:21491495

  19. Structure-based identification of catalytic residues.

    PubMed

    Yahalom, Ran; Reshef, Dan; Wiener, Ayana; Frankel, Sagiv; Kalisman, Nir; Lerner, Boaz; Keasar, Chen

    2011-06-01

    The identification of catalytic residues is an essential step in functional characterization of enzymes. We present a purely structural approach to this problem, which is motivated by the difficulty of evolution-based methods to annotate structural genomics targets that have few or no homologs in the databases. Our approach combines a state-of-the-art support vector machine (SVM) classifier with novel structural features that augment structural clues by spatial averaging and Z scoring. Special attention is paid to the class imbalance problem that stems from the overwhelming number of non-catalytic residues in enzymes compared to catalytic residues. This problem is tackled by: (1) optimizing the classifier to maximize a performance criterion that considers both Type I and Type II errors in the classification of catalytic and non-catalytic residues; (2) under-sampling non-catalytic residues before SVM training; and (3) during SVM training, penalizing errors in learning catalytic residues more than errors in learning non-catalytic residues. Tested on four enzyme datasets, one specifically designed by us to mimic the structural genomics scenario and three previously evaluated datasets, our structure-based classifier is never inferior to similar structure-based classifiers and comparable to classifiers that use both structural and evolutionary features. In addition to the evaluation of the performance of catalytic residue identification, we also present detailed case studies on three proteins. This analysis suggests that many false positive predictions may correspond to binding sites and other functional residues. A web server that implements the method, our own-designed database, and the source code of the programs are publicly available at http://www.cs.bgu.ac.il/∼meshi/functionPrediction. PMID:21491495

  20. Components of attention modulated by temporal expectation.

    PubMed

    Sørensen, Thomas Alrik; Vangkilde, Signe; Bundesen, Claus

    2015-01-01

    By varying the probabilities that a stimulus would appear at particular times after the presentation of a cue and modeling the data by the theory of visual attention (Bundesen, 1990), Vangkilde, Coull, and Bundesen (2012) provided evidence that the speed of encoding a singly presented stimulus letter into visual short-term memory (VSTM) is modulated by the observer's temporal expectations. We extended the investigation from single-stimulus recognition to whole report (Experiment 1) and partial report (Experiment 2). Cue-stimulus foreperiods were distributed geometrically using time steps of 500 ms. In high expectancy conditions, the probability that the stimulus would appear on the next time step, given that it had not yet appeared, was high, whereas in low expectancy conditions, the probability was low. The speed of encoding the stimuli into VSTM was higher in the high expectancy conditions. In line with the Easterbrook (1959) hypothesis, under high temporal expectancy, the processing was also more focused (selective). First, the storage capacity of VSTM was lower, so that fewer stimuli were encoded into VSTM. Second, the distribution of attentional weights across stimuli was less even: The efficiency of selecting targets rather than distractors for encoding into VSTM was higher, as was the spread of the attentional weights of the target letters. PMID:25068851

  1. Understanding aging mechanisms in lithium-ion battery packs: From cell capacity loss to pack capacity evolution

    NASA Astrophysics Data System (ADS)

    Zheng, Yuejiu; Ouyang, Minggao; Lu, Languang; Li, Jianqiu

    2015-03-01

    Battery cell capacity loss is extensively studied so as to extend battery life in varied applications from portable consumer electronics to energy storage devices. Battery packs are constructed especially in energy storage devices to provide sufficient voltage and capacity. However, engineering practice indicates that battery packs always fade more critically than cells. We investigate the evolution of battery pack capacity loss by analyzing cell aging mechanisms using the "Electric quantity - Capacity Scatter Diagram (ECSD)" from a system point of view. The results show that cell capacity loss is not the sole contributor to pack capacity loss. The loss of lithium inventory variation at anodes between cells plays a significant role in pack capacity evolution. Therefore, we suggest more attention could be paid to the loss of lithium inventory at anodes in order to mitigate pack capacity degradation.

  2. Heat Capacity Analysis Report

    SciTech Connect

    A. Findikakis

    2004-11-01

    The purpose of this report is to provide heat capacity values for the host and surrounding rock layers for the waste repository at Yucca Mountain. The heat capacity representations provided by this analysis are used in unsaturated zone (UZ) flow, transport, and coupled processes numerical modeling activities, and in thermal analyses as part of the design of the repository to support the license application. Among the reports that use the heat capacity values estimated in this report are the ''Multiscale Thermohydrologic Model'' report, the ''Drift Degradation Analysis'' report, the ''Ventilation Model and Analysis Report, the Igneous Intrusion Impacts on Waste Packages and Waste Forms'' report, the ''Dike/Drift Interactions report, the Drift-Scale Coupled Processes (DST and TH Seepage) Models'' report, and the ''In-Drift Natural Convection and Condensation'' report. The specific objective of this study is to determine the rock-grain and rock-mass heat capacities for the geologic stratigraphy identified in the ''Mineralogic Model (MM3.0) Report'' (BSC 2004 [DIRS 170031], Table 1-1). This report provides estimates of the heat capacity for all stratigraphic layers except the Paleozoic, for which the mineralogic abundance data required to estimate the heat capacity are not available. The temperature range of interest in this analysis is 25 C to 325 C. This interval is broken into three separate temperature sub-intervals: 25 C to 95 C, 95 C to 114 C, and 114 C to 325 C, which correspond to the preboiling, trans-boiling, and postboiling regimes. Heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of material by one degree (Nimick and Connolly 1991 [DIRS 100690], p. 5). The rock-grain heat capacity is defined as the heat capacity of the rock solids (minerals), and does not include the effect of water that exists in the rock pores. By comparison, the rock-mass heat capacity considers the heat capacity of both solids and pore

  3. Variable capacity gasification burner

    SciTech Connect

    Saxon, D.I.

    1985-03-05

    A variable capacity burner that may be used in gasification processes, the burner being adjustable when operating in its intended operating environment to operate at two different flow capacities, with the adjustable parts being dynamically sealed within a statically sealed structural arrangement to prevent dangerous blow-outs of the reactants to the atmosphere.

  4. Liquid heat capacity lasers

    DOEpatents

    Comaskey, Brian J.; Scheibner, Karl F.; Ault, Earl R.

    2007-05-01

    The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

  5. Problems of Excess Capacity

    NASA Technical Reports Server (NTRS)

    Douglas, G.

    1972-01-01

    The problems of excess capacity in the airline industry are discussed with focus on the following topics: load factors; fair rate of return on investment; service-quality rivalry among airlines; pricing (fare) policies; aircraft production; and the impacts of excess capacity on operating costs. Also included is a discussion of the interrelationships among these topics.

  6. Caffeine Modulates Attention Network Function

    ERIC Educational Resources Information Center

    Brunye, Tad T.; Mahoney, Caroline R.; Lieberman, Harris R.; Taylor, Holly A.

    2010-01-01

    The present work investigated the effects of caffeine (0 mg, 100 mg, 200 mg, 400 mg) on a flanker task designed to test Posner's three visual attention network functions: alerting, orienting, and executive control [Posner, M. I. (2004). "Cognitive neuroscience of attention". New York, NY: Guilford Press]. In a placebo-controlled, double-blind…

  7. Brain Mechanisms of Attentional Control.

    ERIC Educational Resources Information Center

    Wilke, Thomas

    Lack of attentional control--inability to concentrate--has often made the difference between successful and unsuccessful performance on the part of athletes. Attention is controlled neurologically by a very complex interaction of a large portion of the cerebrum and is not localized to any one structure. The mechanism involves a memory retrieval…

  8. Who needs capacity?

    PubMed

    Buchanan, Alec

    2015-01-01

    The UK Law Commission's Discussion Paper, Criminal Liability: Insanity and Automatism, recommends introducing the concept of capacity to the insanity defence. The concept of capacity has an established role in those parts of the law that concern the validity of the decisions that people make, for instance in composing a will or entering into a contract. Making mental capacity a criterion for criminal responsibility in a mentally disordered defendant, however, is potentially problematic. First, the term capacity already has several different meanings in the literature on the jurisprudence of mental abnormality. Second, using the concept of capacity in the way that the Law Commission proposes poses difficulties that relate to the provision of testimony by expert witnesses. PMID:25939285

  9. Nanofluid heat capacities

    NASA Astrophysics Data System (ADS)

    Starace, Anne K.; Gomez, Judith C.; Wang, Jun; Pradhan, Sulolit; Glatzmaier, Greg C.

    2011-12-01

    Significant increases in the heat capacity of heat transfer fluids are needed not only to reduce the costs of liquid heating and cooling processes, but also to bring clean energy producing technologies like concentrating solar power (CSP) to price parity with conventional energy generation. It has been postulated that nanofluids could have higher heat capacities than conventional fluids. In this work, nano- and micron-sized particles were added to five base fluids (poly-α olefin, mineral oil, ethylene glycol, a mixture of water and ethylene glycol, and calcium nitrate tetrahydrate), and the resulting heat capacities were measured and compared with those of the neat base fluids and the weighted average of the heat capacities of the components. The particles used were inert metals and metal oxides that did not undergo any phase transitions over the temperature range studied. In the nanofluids studied here, we found no increase in heat capacity upon the addition of the particles larger than the experimental error.

  10. Social reward shapes attentional biases.

    PubMed

    Anderson, Brian A

    2016-01-01

    Paying attention to stimuli that predict a reward outcome is important for an organism to survive and thrive. When visual stimuli are associated with tangible, extrinsic rewards such as money or food, these stimuli acquire high attentional priority and come to automatically capture attention. In humans and other primates, however, many behaviors are not motivated directly by such extrinsic rewards, but rather by the social feedback that results from performing those behaviors. In the present study, I examine whether positive social feedback can similarly influence attentional bias. The results show that stimuli previously associated with a high probability of positive social feedback elicit value-driven attentional capture, much like stimuli associated with extrinsic rewards. Unlike with extrinsic rewards, however, such stimuli also influence task-specific motivation. My findings offer a potential mechanism by which social reward shapes the information that we prioritize when perceiving the world around us. PMID:25941868

  11. Exogenous Attention Enables Perceptual Learning

    PubMed Central

    Szpiro, Sarit F. A.; Carrasco, Marisa

    2015-01-01

    Practice can improve visual perception, and these improvements are considered to be a form of brain plasticity. Training-induced learning is time-consuming and requires hundreds of trials across multiple days. The process of learning acquisition is understudied. Can learning acquisition be potentiated by manipulating visual attentional cues? We developed a protocol in which we used task-irrelevant cues for between-groups manipulation of attention during training. We found that training with exogenous attention can enable the acquisition of learning. Remarkably, this learning was maintained even when observers were subsequently tested under neutral conditions, which indicates that a change in perception was involved. Our study is the first to isolate the effects of exogenous attention and to demonstrate its efficacy to enable learning. We propose that exogenous attention boosts perceptual learning by enhancing stimulus encoding. PMID:26502745

  12. Emotional distractors can enhance attention

    PubMed Central

    Sussman, Tamara J.; Heller, Wendy; Miller, Gregory A.; Mohanty, Aprajita

    2015-01-01

    The deleterious effects of emotional distractors on attention are well demonstrated. However, it is unclear if emotional distractors inevitably disrupt task-relevant attention. Using multilevel modeling (MLM), the present study examined the impact of valence and arousal dimensions of distracting emotional stimuli and individual differences in anxiety on task-relevant processing. Consistent with prior literature, high-arousal negative distractors were associated with poor task-relevant attention compared to positive and neutral distractors. However, low-arousal negative distractors were associated with better task-relevant performance than were positive and neutral distractors. Furthermore, these effects were accentuated by individual differences in worry. These findings challenge assumptions that distraction and worry must be minimized for augmented attentional performance. Overall, these results emphasize the importance of taking into account emotional dimensions of arousal and valence as well as individual differences in anxiety when examining attention in the presence of emotional distractors. PMID:24058065

  13. Combining segmentation and attention: a new foveal attention model

    PubMed Central

    Marfil, Rebeca; Palomino, Antonio J.; Bandera, Antonio

    2014-01-01

    Artificial vision systems cannot process all the information that they receive from the world in real time because it is highly expensive and inefficient in terms of computational cost. Inspired by biological perception systems, artificial attention models pursuit to select only the relevant part of the scene. On human vision, it is also well established that these units of attention are not merely spatial but closely related to perceptual objects (proto-objects). This implies a strong bidirectional relationship between segmentation and attention processes. While the segmentation process is the responsible to extract the proto-objects from the scene, attention can guide segmentation, arising the concept of foveal attention. When the focus of attention is deployed from one visual unit to another, the rest of the scene is perceived but at a lower resolution that the focused object. The result is a multi-resolution visual perception in which the fovea, a dimple on the central retina, provides the highest resolution vision. In this paper, a bottom-up foveal attention model is presented. In this model the input image is a foveal image represented using a Cartesian Foveal Geometry (CFG), which encodes the field of view of the sensor as a fovea (placed in the focus of attention) surrounded by a set of concentric rings with decreasing resolution. Then multi-resolution perceptual segmentation is performed by building a foveal polygon using the Bounded Irregular Pyramid (BIP). Bottom-up attention is enclosed in the same structure, allowing to set the fovea over the most salient image proto-object. Saliency is computed as a linear combination of multiple low level features such as color and intensity contrast, symmetry, orientation and roundness. Obtained results from natural images show that the performance of the combination of hierarchical foveal segmentation and saliency estimation is good in terms of accuracy and speed. PMID:25177289

  14. Field of Attention for Instantaneous Object Recognition

    PubMed Central

    Yao, Jian-Gao; Gao, Xin; Yan, Hong-Mei; Li, Chao-Yi

    2011-01-01

    Background Instantaneous object discrimination and categorization are fundamental cognitive capacities performed with the guidance of visual attention. Visual attention enables selection of a salient object within a limited area of the visual field; we referred to as “field of attention” (FA). Though there is some evidence concerning the spatial extent of object recognition, the following questions still remain unknown: (a) how large is the FA for rapid object categorization, (b) how accuracy of attention is distributed over the FA, and (c) how fast complex objects can be categorized when presented against backgrounds formed by natural scenes. Methodology/Principal Findings To answer these questions, we used a visual perceptual task in which subjects were asked to focus their attention on a point while being required to categorize briefly flashed (20 ms) photographs of natural scenes by indicating whether or not these contained an animal. By measuring the accuracy of categorization at different eccentricities from the fixation point, we were able to determine the spatial extent and the distribution of accuracy over the FA, as well as the speed of categorizing objects using stimulus onset asynchrony (SOA). Our results revealed that subjects are able to rapidly categorize complex natural images within about 0.1 s without eye movement, and showed that the FA for instantaneous image categorization covers a visual field extending 20°×24°, and accuracy was highest (>90%) at the center of FA and declined with increasing eccentricity. Conclusions/Significance In conclusion, human beings are able to categorize complex natural images at a glance over a large extent of the visual field without eye movement. PMID:21283690

  15. Residual ozone determination by flow injection analysis

    SciTech Connect

    Straka, M.R.; Pacey, G.E.; Gordon, G.

    1984-09-01

    It has been proposed that ozone be used to replace free chlorine for the disinfection of drinking water and waste water. For the use of ozone in this capacity, it would be necessary to have a fast accurate and precise method to analyze for the presence of residuals. An automated method for ozone determination based on the indigo reagent method is presented. This method is based on the advantages of flow injection analysis (FIA) techniques. 19 references, 3 tables, 2 figures.

  16. Motivated attention: Incentive effects on attentional modification of prepulse inhibition

    PubMed Central

    Ashare, Rebecca L.; Hawk, Larry W.; Mazzullo, Rebecca J.

    2008-01-01

    Prepulse inhibition (PPI) of startle is greater for attended compared to ignored prestimuli, and, consistent with theories of motivated attention, initial evidence suggests that this effect is greater among participants given performance-based incentives. The present study examined a within-subjects incentive manipulation. Participants (n = 41) completed two blocks of a tone discrimination task. During the incentive block, participants received trialwise feedback with small monetary incentives for task performance. Startle eyeblink EMG responses to auditory probes were assessed at 60-, 120-, and 180-ms tone-probe stimulus onset asynchronies (SOAs). As predicted, PPI was enhanced during attended compared to ignored prestimuli only at the 120-ms SOA in the incentive condition. There was no evidence of attentional modification in the no-incentive condition. These data suggest that attentional modification of PPI is sensitive to within-subjects manipulations of incentive, providing a useful tool for testing models of motivated attention in psychopathology and psychopharmacology. PMID:17640265

  17. How can attending physicians be more attentive? On being attentive versus producing attentiveness.

    PubMed

    Klaver, Klaartje; Baart, Andries

    2016-09-01

    This article is about caregivers being attentive to patients in healthcare. From earlier work on the understanding of the other, we know that it is impossible to completely understand the experiences of others. By the sharing of subjectivity-intersubjectivity-we may try to 'grasp' the other's point of view. However, we can never assume that the same experience produces the same experience. Now, if it is principally impossible to understand the experience of one another, and if paying attention always implies an understanding of what to pay attention to, then how is it possible to be attentive to the experiences of those who are entirely at the mercy of our care? How can caregivers perceive the impossibility of understanding the experiences of patients as an appeal to be attentive to their experiences? This is discussed in this article. It departs from the authors being confronted with inexplicabilities in the empirical study of attentiveness in healthcare. It presents two examples and discusses the meaning of these emergent properties. This leads to a discussion of the existent literature on the indefiniteness and openness of attentiveness. It becomes clear why, although we can understand and predict much of it, attentiveness will always be characterized by a certain uncontrollability as well. PMID:26951520

  18. Brain Connectivity and Visual Attention

    PubMed Central

    Parks, Emily L.

    2013-01-01

    Abstract Emerging hypotheses suggest that efficient cognitive functioning requires the integration of separate, but interconnected cortical networks in the brain. Although task-related measures of brain activity suggest that a frontoparietal network is associated with the control of attention, little is known regarding how components within this distributed network act together or with other networks to achieve various attentional functions. This review considers both functional and structural studies of brain connectivity, as complemented by behavioral and task-related neuroimaging data. These studies show converging results: The frontal and parietal cortical regions are active together, over time, and identifiable frontoparietal networks are active in relation to specific task demands. However, the spontaneous, low-frequency fluctuations of brain activity that occur in the resting state, without specific task demands, also exhibit patterns of connectivity that closely resemble the task-related, frontoparietal attention networks. Both task-related and resting-state networks exhibit consistent relations to behavioral measures of attention. Further, anatomical structure, particularly white matter pathways as defined by diffusion tensor imaging, places constraints on intrinsic functional connectivity. Lastly, connectivity analyses applied to investigate cognitive differences across individuals in both healthy and diseased states suggest that disconnection of attentional networks is linked to deficits in cognitive functioning, and in extreme cases, to disorders of attention. Thus, comprehensive theories of visual attention and their clinical translation depend on the continued integration of behavioral, task-related neuroimaging, and brain connectivity measures. PMID:23597177

  19. Extended attention span training system

    NASA Technical Reports Server (NTRS)

    Pope, Alan T.; Bogart, Edward H.

    1991-01-01

    Attention Deficit Disorder (ADD) is a behavioral disorder characterized by the inability to sustain attention long enough to perform activities such as schoolwork or organized play. Treatments for this disorder include medication and brainwave biofeedback training. Brainwave biofeedback training systems feed back information to the trainee showing him how well he is producing the brainwave pattern that indicates attention. The Extended Attention Span Training (EAST) system takes the concept a step further by making a video game more difficult as the player's brainwaves indicate that attention is waning. The trainee can succeed at the game only by maintaining an adequate level of attention. The EAST system is a modification of a biocybernetic system that is currently being used to assess the extent to which automated flight management systems maintain pilot engagement. This biocybernetic system is a product of a program aimed at developing methods to evaluate automated flight deck designs for compatibility with human capabilities. The EAST technology can make a contribution in the fields of medical neuropsychology and neurology, where the emphasis is on cautious, conservative treatment of youngsters with attention disorders.

  20. The Neurocognitive Performance of Visuospatial Attention in Children with Obesity

    PubMed Central

    Tsai, Chia-Liang; Chen, Fu-Chen; Pan, Chien-Yu; Tseng, Yu-Ting

    2016-01-01

    The present study investigates the behavioral performance and event-related potentials (ERPs) in children with obesity and healthy weight children when performing a visuospatial attention task. Twenty-six children with obesity (obese group) and 26 healthy weight children (control group) were recruited. Their behavioral performance during a variant of the Posner paradigm was measured, and brain ERPs were recorded concurrently. The behavioral data revealed that the obese group responded more slowly, especially in the invalid condition, and exhibited a deficit in attentional inhibition capacity as compared to the control group. In terms of cognitive electrophysiological performance, although the obese group did not show significant differences on P3 latency elicited by the target stimuli when compared to the control group, they exhibited smaller P3 amplitudes when performing the visuospatial attention task. These results broaden previous findings, and indicate that childhood obesity is associated with a reduced ability to modulate the executive function network which supports visuospatial attention. PMID:27458421

  1. Selective attention and perceptual load in autism spectrum disorder.

    PubMed

    Remington, Anna; Swettenham, John; Campbell, Ruth; Coleman, Mike

    2009-11-01

    It has been suggested that the locus of selective attention (early vs. late in processing) is dependent on the perceptual load of the task. When perceptual load is low, irrelevant distractors are processed (late selection), whereas when perceptual load is high, distractor interference disappears (early selection). Attentional abnormalities have long been reported within autism spectrum disorder (ASD), and this study is the first to examine the effect of perceptual load on selective attention in this population. Fourteen adults with ASD and 23 adults without ASD performed a selective attention task with varying perceptual loads. Compared with the non-ASD group, the ASD group required higher levels of perceptual load to successfully ignore irrelevant distractors; moreover, the ASD group did not show any general reduction in performance speed or accuracy. These results suggest enhanced perceptual capacity in the ASD group and are consistent with previous observations regarding superior visual search abilities among individuals with ASD. PMID:19843262

  2. Contingent attentional capture or delayed allocation of attention?

    NASA Technical Reports Server (NTRS)

    Remington, R. W.; Folk, C. L.; McLean, J. P.

    2001-01-01

    Under certain circumstances, external stimuli will elicit an involuntary shift of spatial attention, referred to as attentional capture. According to the contingent involuntary orienting account (Folk, Remington, & Johnston, 1992), capture is conditioned by top-down factors that set attention to respond involuntarily to stimulus properties relevant to one's behavioral goals. Evidence for this comes from spatial cuing studies showing that a spatial cuing effect is observed only when cues have goal-relevant properties. Here, we examine alternative, decision-level explanations of the spatial cuing effect that attribute evidence of capture to postpresentation delays in the voluntary allocation of attention, rather than to on-line involuntary shifts in direct response to the cue. In three spatial cuing experiments, delayed-allocation accounts were tested by examining whether items at the cued location were preferentially processed. The experiments provide evidence that costs and benefits in spatial cuing experiments do reflect the on-line capture of attention. The implications of these results for models of attentional control are discussed.

  3. Refinery Capacity Report

    EIA Publications

    2016-01-01

    Data series include fuel, electricity, and steam purchased for consumption at the refinery; refinery receipts of crude oil by method of transportation; and current and projected atmospheric crude oil distillation, downstream charge, and production capacities. Respondents are operators of all operating and idle petroleum refineries (including new refineries under construction) and refineries shut down during the previous year, located in the 50 states, the District of Columbia, Puerto Rico, the Virgin Islands, Guam, and other U.S. possessions. The Refinery Capacity Report does not contain working and shell storage capacity data. This data is now being collected twice a year as of March 31 and September 30 on the Form EIA-810, "Monthly Refinery Report", and is now released as a separate report Working and Net Available Shell Storage Capacity.

  4. Knudsen heat capacity

    SciTech Connect

    Babac, Gulru; Reese, Jason M.

    2014-05-15

    We present a “Knudsen heat capacity” as a more appropriate and useful fluid property in micro/nanoscale gas systems than the constant pressure heat capacity. At these scales, different fluid processes come to the fore that are not normally observed at the macroscale. For thermodynamic analyses that include these Knudsen processes, using the Knudsen heat capacity can be more effective and physical. We calculate this heat capacity theoretically for non-ideal monatomic and diatomic gases, in particular, helium, nitrogen, and hydrogen. The quantum modification for para and ortho hydrogen is also considered. We numerically model the Knudsen heat capacity using molecular dynamics simulations for the considered gases, and compare these results with the theoretical ones.

  5. Refinery Capacity Report

    EIA Publications

    2015-01-01

    Data series include fuel, electricity, and steam purchased for consumption at the refinery; refinery receipts of crude oil by method of transportation; and current and projected atmospheric crude oil distillation, downstream charge, and production capacities. Respondents are operators of all operating and idle petroleum refineries (including new refineries under construction) and refineries shut down during the previous year, located in the 50 states, the District of Columbia, Puerto Rico, the Virgin Islands, Guam, and other U.S. possessions. The Refinery Capacity Report does not contain working and shell storage capacity data. This data is now being collected twice a year as of March 31 and September 30 on the Form EIA-810, "Monthly Refinery Report", and is now released as a separate report Working and Net Available Shell Storage Capacity.

  6. Attention-Deficit Hyperactivity Disorder.

    ERIC Educational Resources Information Center

    Barkley, Russell A.

    1998-01-01

    Attention deficit hyperactivity disorder (ADHD) may arise when key brain circuits do not develop properly, perhaps due to an altered gene or genes. Describes ADHD in detail and introduces a psychological model of ADHD. (ASK)

  7. Measuring the amplification of attention.

    PubMed

    Blaser, E; Sperling, G; Lu, Z L

    1999-09-28

    An ambiguous motion paradigm, in which the direction of apparent motion is determined by salience (i.e., the extent to which an area is perceived as figure versus ground), is used to assay the amplification of color by attention to color. In the red-green colored gratings used in these experiments, without attention instructions, salience depends on the chromaticity difference between colored stripes embedded in the motion sequence and the yellow background. Selective attention to red (or to green) alters the perceived direction of motion and is found to be equivalent to increasing the physical redness (or greenness) by 25-117%, depending on the observer and color. Whereas attention to a color drastically alters the salience of that color, it leaves color appearance unchanged. A computational model, which embodies separate, parallel pathways for object perception and for salience, accounts for 99% of the variance of the experimental data. PMID:10500237

  8. Forward capacity market CONEfusion

    SciTech Connect

    Wilson, James F.

    2010-11-15

    In ISO New England and PJM it was assumed that sponsors of new capacity projects would offer them into the newly established forward centralized capacity markets at prices based on their levelized net cost of new entry, or ''Net CONE.'' But the FCCMs have not operated in the way their proponents had expected. To clear up the CONEfusion, FCCM designs should be reconsidered to adapt them to the changing circumstances and to be grounded in realistic expectations of market conduct. (author)

  9. Panama Canal capacity analysis

    SciTech Connect

    Bronzini, M.S.

    1995-04-27

    Predicting the transit capacities of the various Panama Canal alternatives required analyzing data on present Canal operations, adapting and extending an existing computer simulation model, performing simulation runs for each of the alternatives, and using the simulation model outputs to develop capacity estimates. These activities are summarized in this paper. A more complete account may be found in the project final report (TAMS 1993). Some of the material in this paper also appeared in a previously published paper (Rosselli, Bronzini, and Weekly 1994).

  10. Topographic maps of multisensory attention.

    PubMed

    Anderson, Jeffrey S; Ferguson, Michael A; Lopez-Larson, Melissa; Yurgelun-Todd, Deborah

    2010-11-16

    The intraparietal sulcus (IPS) region is uniquely situated at the intersection of visual, somatosensory, and auditory association cortices, ideally located for processing of multisensory attention. We examined the internal architecture of the IPS region and its connectivity to other regions in the dorsal attention and cinguloinsular networks using maximal connectivity clustering. We show with resting state fMRI data from 58 healthy adolescent and young adult volunteers that points of maximal connectivity between the IPS and other regions in the dorsal attention and cinguloinsular networks are topographically organized, with at least seven maps of the IPS region in each hemisphere. Distinct clusters of the IPS exhibited differential connectivity to auditory, visual, somatosensory, and default mode networks, suggesting local specialization within the IPS region for different sensory modalities. In an independent task activation paradigm with 16 subjects, attention to different sensory modalities showed similar functional specialization within the left intraparietal sulcus region. The default mode network, in contrast, did not show a topographical relationship between regions in the network, but rather maximal connectivity in each region to a single central cluster of the other regions. The topographical architecture of multisensory attention may represent a mechanism for specificity in top-down control of attention from dorsolateral prefrontal and lateral orbitofrontal cortex and may represent an organizational unit for multisensory representations in the brain. PMID:21041658

  11. Determinants of attentive blank stares. An EFRP study.

    PubMed

    Fudali-Czyż, Agnieszka; Francuz, Piotr; Augustynowicz, Paweł

    2014-10-01

    Attentive blank stares mean a failure to notice changes in a visual scene, despite looking at the area of change (Caplovitz, Fendrich, & Hughes, 2008). In this research project we have shown that people differ in terms of attentive blank stare incidences. Novices tend to fail to notice changes in the target area more often than experts. This effect is greater in persons with low visual working memory capacity (VWMC) than with high VWMC. In addition, in a group of novices with low VWMC, attentive blank stares are more frequent compared to a group with high VWMC. Attentive blank stares did not disappear even after the high VWMC group were given expertise training. With the method of eye-fixation-related potentials (EFRP) we analyzed the amplitude of lambda response, which may reflect the state of the attentional system, during encoding information about a change, prior to a decision whether a change has occurred or not. We demonstrate that the cases of attentive blank stares are accompanied by significantly lower amplitude of the lambda response compared with cases involving change detection. In addition, we discovered greater lambda responses in a group with expertise who noticed the change than in novices. The EFRP record coming from occipital electrodes in the 80-180ms window function was marked by left-sided asymmetry in the cases of change detection and by right-sided asymmetry in the cases of attentive blank stares. PMID:25087155

  12. Effect of attention control on sustained attention during induced anxiety.

    PubMed

    Grillon, Christian; Robinson, Oliver J; Mathur, Ambika; Ernst, Monique

    2016-06-01

    Anxiety has wide-reaching and complex effects on cognitive performance. Although it can intrude on cognition and interfere with performance, it can also facilitate information processing and behavioural responses. In a previous study, we showed that anxiety induced by threat of shock facilitates performance on the Sustained Attention to Response Task, a vigilance test, which probes response inhibition to infrequent nogo stimuli. The present study sought to identify factors that may have contributed to such improved performance, including on- and off-task thinking (assessed with thought probes) and individual differences in attention control, as measured with the Attention Control Scale. Replicating our prior finding, we showed that shock threat significantly reduced errors of commission on the nogo trials. However, we extended this finding in demonstrating that this effect was driven by subjects with low attention control. We therefore confirm that anxiety increases inhibitory control of prepotent responses-a mechanism which is adaptive under threat-and show that this effect is greater in those who rely more upon such prepotent responding, i.e., those with low attentional control. PMID:25899613

  13. Pre-attentive and attentive processing of French vowels.

    PubMed

    Deguchi, Chizuru; Chobert, Julie; Brunellière, Angèle; Nguyen, Noël; Colombo, Lucia; Besson, Mireille

    2010-12-17

    This study aimed at investigating the effects of acoustic distance and of speaker variability on the pre-attentive and attentive perception of French vowels by French adult speakers. The electroencephalogram (EEG) was recorded while participants watched a silent movie (Passive condition) and discriminated deviant vowels (Active condition). The auditory sequence included 4 French vowels, /u/ (standard) and /o/, /y/ and /ø/ as deviants, produced by 3 different speakers. As the vowel /o/ is closer to /u/ than the other deviants in acoustic distance, we predicted smaller mismatch negativity (MMN) and smaller N1 component, as well as higher error rate and longer reaction times. Results were in line with these predictions. Moreover, the MMN was elicited by all deviant vowels independently of speaker variability. By contrast, the Vowel by Speaker interaction was significant in the Active listening condition thereby showing that subtle within-category differences are processed at the attentive level. These results suggest that while vowels are categorized pre-attentively according to phonemic representations and independently of speaker variability, participants are sensitive to between-speaker differences when they focus attention on vowel processing. PMID:20920484

  14. Blinded by fear? Prior exposure to fearful faces enhances attentional processing of task-irrelevant stimuli.

    PubMed

    Berggren, Nick; Derakshan, Nazanin

    2013-01-01

    Threatening information has been shown to both capture attention and enhance sensory processing. Recent evidence has also suggested that exposure to fearful stimuli may enhance perceptual processing of subsequently presented information, as well as increase attentional capacity. However, these results are inconsistent with other findings that fearful stimuli reduce task-irrelevant distraction and improve selective attention. Here, we investigated the effect of prior exposure to fearful faces on performance in the Eriksen flanker task. Across experiments, fearful cues led to increased task-irrelevant distraction for items positioned across visual space, in contrast to other emotional expressions and inverted face items, and under conditions of attentional load. Findings support the view that fearful images enhance attentional capacity, allowing one to attend to as much visual information as possible when danger is implied. Conflicting findings on the effect of fear and selective attention are discussed. PMID:23510073

  15. Attentive multidirectional associative memory with application to pattern association

    NASA Astrophysics Data System (ADS)

    Tai, Heng-Ming

    1992-07-01

    An attentive multidirectional hetero-associative memory network (AMAM) is proposed. The convergence and encoding strategies of AMAM are described. This network enables multiple associations, but with certain associations embedding more attention. This model is inspired by speculation about how associative learning and storage might occur in the nervous system. AMAM has much better error correcting capability and memory capacity than the multidirectional associative memory. Examples are illustrated to show the advantages of this model. In addition, we demonstrate and compare its recall ability for pattern recognition.

  16. Attentional rhythm: a temporal analogue of object-based attention.

    PubMed

    De Freitas, Julian; Liverence, Brandon M; Scholl, Brian J

    2014-02-01

    The underlying units of attention are often discrete visual objects. Perhaps the clearest form of evidence for this is the same-object advantage: Following a spatial cue, responses are faster to probes occurring on the same object than they are to probes occurring on other objects, while equating brute distance. Is this a fundamentally spatial effect, or can same-object advantages also occur in time? We explored this question using independently normed rhythmic temporal sequences, structured into phrases and presented either visually or auditorily. Detection was speeded when cues and probes both lay within the same rhythmic phrase, compared to when they spanned a phrase boundary, while equating brute duration. This same-phrase advantage suggests that object-based attention is a more general phenomenon than has been previously suspected: Perceptual structure constrains attention, in both space and time, and in both vision and audition. PMID:23586668

  17. Different Attentional Blink Tasks Reflect Distinct Information Processing Limitations: An Individual Differences Approach

    ERIC Educational Resources Information Center

    Kelly, Ashleigh J.; Dux, Paul E.

    2011-01-01

    To study the temporal dynamics and capacity-limits of attentional selection and encoding, researchers often employ the attentional blink (AB) phenomenon: subjects' impaired ability to report the second of two targets in a rapid serial visual presentation (RSVP) stream that appear within 200-500 ms of one another. The AB has now been the subject of…

  18. Impact of Auditory Selective Attention on Verbal Short-Term Memory and Vocabulary Development

    ERIC Educational Resources Information Center

    Majerus, Steve; Heiligenstein, Lucie; Gautherot, Nathalie; Poncelet, Martine; Van der Linden, Martial

    2009-01-01

    This study investigated the role of auditory selective attention capacities as a possible mediator of the well-established association between verbal short-term memory (STM) and vocabulary development. A total of 47 6- and 7-year-olds were administered verbal immediate serial recall and auditory attention tasks. Both task types probed processing…

  19. Longitudinal Attentional Engagement Rescues Mice from Age-Related Cognitive Declines and Cognitive Inflexibility

    ERIC Educational Resources Information Center

    Matzel, Louis D.; Light, Kenneth R.; Wass, Christopher; Colas-Zelin, Danielle; Denman-Brice, Alexander; Waddel, Adam C.; Kolata, Stefan

    2011-01-01

    Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm…

  20. Attention trees and semantic paths

    NASA Astrophysics Data System (ADS)

    Giusti, Christian; Pieroni, Goffredo G.; Pieroni, Laura

    2007-02-01

    In the last few decades several techniques for image content extraction, often based on segmentation, have been proposed. It has been suggested that under the assumption of very general image content, segmentation becomes unstable and classification becomes unreliable. According to recent psychological theories, certain image regions attract the attention of human observers more than others and, generally, the image main meaning appears concentrated in those regions. Initially, regions attracting our attention are perceived as a whole and hypotheses on their content are formulated; successively the components of those regions are carefully analyzed and a more precise interpretation is reached. It is interesting to observe that an image decomposition process performed according to these psychological visual attention theories might present advantages with respect to a traditional segmentation approach. In this paper we propose an automatic procedure generating image decomposition based on the detection of visual attention regions. A new clustering algorithm taking advantage of the Delaunay- Voronoi diagrams for achieving the decomposition target is proposed. By applying that algorithm recursively, starting from the whole image, a transformation of the image into a tree of related meaningful regions is obtained (Attention Tree). Successively, a semantic interpretation of the leaf nodes is carried out by using a structure of Neural Networks (Neural Tree) assisted by a knowledge base (Ontology Net). Starting from leaf nodes, paths toward the root node across the Attention Tree are attempted. The task of the path consists in relating the semantics of each child-parent node pair and, consequently, in merging the corresponding image regions. The relationship detected in this way between two tree nodes generates, as a result, the extension of the interpreted image area through each step of the path. The construction of several Attention Trees has been performed and partial

  1. Interfacial residual thermal strain

    NASA Astrophysics Data System (ADS)

    Kasen, M.; Santoyo, R.

    A method has been developed for assessing the influence of polymer chemical composition and of processing parameters on the magnitude of residual stress developed in glass-fibre-reinforced composites subjected to various cure cycles and subsequently cooled to cryogenic temperatures. The test method was applied to nine resin types, including epoxy, vinyl ester, polyester, cyanate ester and phenolic formulations. Results suggest that polyester resin develops substantially less overall residual strain than do the other resin systems.

  2. Uncertainty in adaptive capacity

    NASA Astrophysics Data System (ADS)

    Adger, W. Neil; Vincent, Katharine

    2005-03-01

    The capacity to adapt is a critical element of the process of adaptation: it is the vector of resources that represent the asset base from which adaptation actions can be made. Adaptive capacity can in theory be identified and measured at various scales, from the individual to the nation. The assessment of uncertainty within such measures comes from the contested knowledge domain and theories surrounding the nature of the determinants of adaptive capacity and the human action of adaptation. While generic adaptive capacity at the national level, for example, is often postulated as being dependent on health, governance and political rights, and literacy, and economic well-being, the determinants of these variables at national levels are not widely understood. We outline the nature of this uncertainty for the major elements of adaptive capacity and illustrate these issues with the example of a social vulnerability index for countries in Africa. To cite this article: W.N. Adger, K. Vincent, C. R. Geoscience 337 (2005).

  3. Visual attention on the sphere.

    PubMed

    Bogdanova, Iva; Bur, Alexandre; Hugli, Heinz

    2008-11-01

    Human visual system makes an extensive use of visual attention in order to select the most relevant information and speed-up the vision process. Inspired by visual attention, several computer models have been developed and many computer vision applications rely today on such models. However, the actual algorithms are not suitable to omnidirectional images, which contain a significant amount of geometrical distortion. In this paper, we present a novel computational approach that performs in spherical geometry and thus is suitable for omnidirectional images. Following one of the actual models of visual attention, the spherical saliency map is obtained by fusing together intensity, chromatic, and orientation spherical cue conspicuity maps that are themselves obtained through multiscale analysis on the sphere. Finally, the consecutive maxima in the spherical saliency map represent the spots of attention on the sphere. In the experimental part, the proposed method is then compared to the standard one using a synthetic image. Also, we provide examples of spots detection in real omnidirectional scenes which show its advantages. Finally, an experiment illustrates the homogeneity of the detected visual attention in omnidirectional images. PMID:18854253

  4. Attention, psychomotor functions and age.

    PubMed

    Kallus, Konrad Wolfgang; Schmitt, Jeroen A J; Benton, David

    2005-12-01

    Nutrition might play an important role to ameliorate or to buffer age-related declines in attention and psychomotor functions. The assessment of nutritional effects in aged subjects has to take into account that attention and psychomotor functions can be subdivided in different functions that are differentially affected by age. This paper gives an overview of changes in different facets of attention and psychomotor functions beyond fifty as well as assessment methods for attention and psychomotor performance. It also provides a review of models to explain the pattern of changes with increasing age, and discusses the problems of high performance variance and of age related confounding variables like health status. Two different approaches are discussed that analyse a performance profile and an experimentally oriented functional microanalysis of changes in performance with respect to the effects of nutrition on attention and psychomotor functions. Addressed are examples of missing age-related deficits or even age-related superiority. Caffeine and Ginseng are considered as examples to enhance performance in older persons. Results are in accordance with data on the positive role of physical fitness for mental performance in older persons. Performance of older persons can well be enhanced by functional food components or nutritional supplementation. The effects are comparable to the effects obtained in younger groups, while there is only weak evidence for specific compensatory effects in aged persons. Finally the role of nutrition for the processes of healthy aging is discussed. PMID:16331357

  5. Capacity Maximizing Constellations

    NASA Technical Reports Server (NTRS)

    Barsoum, Maged; Jones, Christopher

    2010-01-01

    Some non-traditional signal constellations have been proposed for transmission of data over the Additive White Gaussian Noise (AWGN) channel using such channel-capacity-approaching codes as low-density parity-check (LDPC) or turbo codes. Computational simulations have shown performance gains of more than 1 dB over traditional constellations. These gains could be translated to bandwidth- efficient communications, variously, over longer distances, using less power, or using smaller antennas. The proposed constellations have been used in a bit-interleaved coded modulation system employing state-ofthe-art LDPC codes. In computational simulations, these constellations were shown to afford performance gains over traditional constellations as predicted by the gap between the parallel decoding capacity of the constellations and the Gaussian capacity

  6. Geothermal Plant Capacity Factors

    SciTech Connect

    Greg Mines; Jay Nathwani; Christopher Richard; Hillary Hanson; Rachel Wood

    2015-01-01

    The capacity factors recently provided by the Energy Information Administration (EIA) indicated this plant performance metric had declined for geothermal power plants since 2008. Though capacity factor is a term commonly used by geothermal stakeholders to express the ability of a plant to produce power, it is a term frequently misunderstood and in some instances incorrectly used. In this paper we discuss how this capacity factor is defined and utilized by the EIA, including discussion on the information that the EIA requests from operations in their 923 and 860 forms that are submitted both monthly and annually by geothermal operators. A discussion is also provided regarding the entities utilizing the information in the EIA reports, and how those entities can misinterpret the data being supplied by the operators. The intent of the paper is to inform the facility operators as the importance of the accuracy of the data that they provide, and the implications of not providing the correct information.

  7. Dual capacity reciprocating compressor

    DOEpatents

    Wolfe, R.W.

    1984-10-30

    A multi-cylinder compressor particularly useful in connection with northern climate heat pumps and in which different capacities are available in accordance with reversing motor rotation is provided with an eccentric cam on a crank pin under a fraction of the connecting rods, and arranged for rotation upon the crank pin between opposite positions 180[degree] apart so that with cam rotation on the crank pin such that the crank throw is at its normal maximum value all pistons pump at full capacity, and with rotation of the crank shaft in the opposite direction the cam moves to a circumferential position on the crank pin such that the overall crank throw is zero. Pistons whose connecting rods ride on a crank pin without a cam pump their normal rate with either crank rotational direction. Thus a small clearance volume is provided for any piston that moves when in either capacity mode of operation. 6 figs.

  8. Dual capacity reciprocating compressor

    DOEpatents

    Wolfe, Robert W.

    1984-01-01

    A multi-cylinder compressor 10 particularly useful in connection with northern climate heat pumps and in which different capacities are available in accordance with reversing motor 16 rotation is provided with an eccentric cam 38 on a crank pin 34 under a fraction of the connecting rods, and arranged for rotation upon the crank pin between opposite positions 180.degree. apart so that with cam rotation on the crank pin such that the crank throw is at its normal maximum value all pistons pump at full capacity, and with rotation of the crank shaft in the opposite direction the cam moves to a circumferential position on the crank pin such that the overall crank throw is zero. Pistons 24 whose connecting rods 30 ride on a crank pin 36 without a cam pump their normal rate with either crank rotational direction. Thus a small clearance volume is provided for any piston that moves when in either capacity mode of operation.

  9. Attention-Deficit/Hyperactivity Disorder and Attention Networks

    PubMed Central

    Bush, George

    2010-01-01

    Research attempting to elucidate the neuropathophysiology of attention-deficit/hyperactivity disorder (ADHD) has not only shed light on the disorder itself, it has simultaneously provided new insights into the mechanisms of normal cognition and attention. This review will highlight and integrate this bidirectional flow of information. Following a brief overview of ADHD clinical phenomenology, ADHD studies will be placed into a wider historical perspective by providing illustrative examples of how major models of attention have influenced the development of neurocircuitry models of ADHD. The review will then identify major components of neural systems potentially relevant to ADHD, including attention networks, reward/feedback-based processing systems, as well as a ‘default mode' resting state network. Further, it will suggest ways in which these systems may interact and be influenced by neuromodulatory factors. Recent ADHD imaging data will be selectively provided to both illustrate the field's current level of knowledge and to show how such data can inform our understanding of normal brain functions. The review will conclude by suggesting possible avenues for future research. PMID:19759528

  10. Attention Deficits, Attention-Deficit Hyperactivity Disorder, and Intellectual Disabilities

    ERIC Educational Resources Information Center

    Deutsch, Curtis K.; Dube, William V.; McIlvane, William J.

    2008-01-01

    Attention-Deficit Hyperactivity Disorder (ADHD) and its earlier nosologic classifications have been extensively investigated since the 1960s, with PubMed listings alone exceeding 13,000 entries. Strides have been made in the diagnosis and treatment of ADHD in individuals with intellectual function in the normal range, as described in companion…

  11. Now, Pay Attention! The Effects of Instruction on Children's Attention

    ERIC Educational Resources Information Center

    Kannass, Kathleen N.; Colombo, John; Wyss, Nancy

    2010-01-01

    We investigated the effects of instructions to "stay on task" on preschoolers' attention and cognitive performance in the face of either incomprehensible or comprehensible distraction. Three- and 4-year-olds completed problem-solving tasks while a distracting event played continuously in the background under conditions of (a) no instruction, (b)…

  12. Supramodal executive control of attention.

    PubMed

    Spagna, Alfredo; Mackie, Melissa-Ann; Fan, Jin

    2015-01-01

    The human attentional system can be subdivided into three functional networks of alerting, orienting, and executive control. Although these networks have been extensively studied in the visuospatial modality, whether the same mechanisms are deployed across different sensory modalities remains unclear. In this study we used the attention network test for the visuospatial modality, in addition to two auditory variants with spatial and frequency manipulations to examine cross-modal correlations between network functions. Results showed that among the visual and auditory tasks, the effects of executive control, but not effects of alerting and orienting, were significantly correlated. These findings suggest that while alerting and orienting functions rely more upon modality-specific processes, the executive control of attention coordinates complex behavior via supramodal mechanisms. PMID:25759674

  13. Advances in understanding tissue regenerative capacity and mechanisms in animals

    PubMed Central

    Poss, Kenneth D.

    2011-01-01

    Questions about how and why tissue regeneration occurs capture the attention of countless biologists, biomedical engineers, and clinicians. Regenerative capacity differs greatly across organs and organisms, and a spectrum of model systems with different technical advantages and regenerative strategies are studied. Several key issues common to natural regenerative events are receiving new attention from improving models and approaches, including: the determination of regenerative capacity; the importance of stem cells, dedifferentation and transdifferentiation; how regenerative signals are initiated and targeted; and the mechanisms that control regenerative proliferation and patterning. PMID:20838411

  14. Task attention facilitates learning of task-irrelevant stimuli.

    PubMed

    Huang, Tsung-Ren; Watanabe, Takeo

    2012-01-01

    Attention plays a fundamental role in visual learning and memory. One highly established principle of visual attention is that the harder a central task is, the more attentional resources are used to perform the task and the smaller amount of attention is allocated to peripheral processing because of limited attention capacity. Here we show that this principle holds true in a dual-task setting but not in a paradigm of task-irrelevant perceptual learning. In Experiment 1, eight participants were asked to identify either bright or dim number targets at the screen center and to remember concurrently presented scene backgrounds. Their recognition performances for scenes paired with dim/hard targets were worse than those for scenes paired with bright/easy targets. In Experiment 2, eight participants were asked to identify either bright or dim letter targets at the screen center while a task-irrelevant coherent motion was concurrently presented in the background. After five days of training on letter identification, participants improved their motion sensitivity to the direction paired with hard/dim targets improved but not to the direction paired with easy/bright targets. Taken together, these results suggest that task-irrelevant stimuli are not subject to the attentional control mechanisms that task-relevant stimuli abide. PMID:22563424

  15. Visual short-term memory load strengthens selective attention.

    PubMed

    Roper, Zachary J J; Vecera, Shaun P

    2014-04-01

    Perceptual load theory accounts for many attentional phenomena; however, its mechanism remains elusive because it invokes underspecified attentional resources. Recent dual-task evidence has revealed that a concurrent visual short-term memory (VSTM) load slows visual search and reduces contrast sensitivity, but it is unknown whether a VSTM load also constricts attention in a canonical perceptual load task. If attentional selection draws upon VSTM resources, then distraction effects-which measure attentional "spill-over"-will be reduced as competition for resources increases. Observers performed a low perceptual load flanker task during the delay period of a VSTM change detection task. We observed a reduction of the flanker effect in the perceptual load task as a function of increasing concurrent VSTM load. These findings were not due to perceptual-level interactions between the physical displays of the two tasks. Our findings suggest that perceptual representations of distractor stimuli compete with the maintenance of visual representations held in memory. We conclude that access to VSTM determines the degree of attentional selectivity; when VSTM is not completely taxed, it is more likely for task-irrelevant items to be consolidated and, consequently, affect responses. The "resources" hypothesized by load theory are at least partly mnemonic in nature, due to the strong correspondence they share with VSTM capacity. PMID:24002967

  16. Attentional control of the processing of neural and emotional stimuli.

    PubMed

    Pessoa, Luiz; Kastner, Sabine; Ungerleider, Leslie G

    2002-12-01

    A typical scene contains many different objects that compete for neural representation due to the limited processing capacity of the visual system. At the neural level, competition among multiple stimuli is evidenced by the mutual suppression of their visually evoked responses and occurs most strongly at the level of the receptive field. The competition among multiple objects can be biased by both bottom-up sensory-driven mechanisms and top-down influences, such as selective attention. Functional brain imaging studies reveal that biasing signals due to selective attention can modulate neural activity in visual cortex not only in the presence but also in the absence of visual stimulation. Although the competition among stimuli for representation is ultimately resolved within visual cortex, the source of top-down biasing signals likely derives from a distributed network of areas in frontal and parietal cortex. Competition suggests that once attentional resources are depleted, no further processing is possible. Yet, existing data suggest that emotional stimuli activate brain regions "automatically," largely immune from attentional control. We tested the alternative possibility, namely, that the neural processing of stimuli with emotional content is not automatic and instead requires some degree of attention. Our results revealed that, contrary to the prevailing view, all brain regions responding differentially to emotional faces, including the amygdala, did so only when sufficient attentional resources were available to process the faces. Thus, similar to the processing of other stimulus categories, the processing of facial expression is under top-down control. PMID:12433381

  17. Acoustic detail guides attention allocation in a selective listening task.

    PubMed

    Wöstmann, Malte; Schröger, Erich; Obleser, Jonas

    2015-05-01

    The flexible allocation of attention enables us to perceive and behave successfully despite irrelevant distractors. How do acoustic challenges influence this allocation of attention, and to what extent is this ability preserved in normally aging listeners? Younger and healthy older participants performed a masked auditory number comparison while EEG was recorded. To vary selective attention demands, we manipulated perceptual separability of spoken digits from a masking talker by varying acoustic detail (temporal fine structure). Listening conditions were adjusted individually to equalize stimulus audibility as well as the overall level of performance across participants. Accuracy increased, and response times decreased with more acoustic detail. The decrease in response times with more acoustic detail was stronger in the group of older participants. The onset of the distracting speech masker triggered a prominent contingent negative variation (CNV) in the EEG. Notably, CNV magnitude decreased parametrically with increasing acoustic detail in both age groups. Within identical levels of acoustic detail, larger CNV magnitude was associated with improved accuracy. Across age groups, neuropsychological markers further linked early CNV magnitude directly to individual attentional capacity. Results demonstrate for the first time that, in a demanding listening task, instantaneous acoustic conditions guide the allocation of attention. Second, such basic neural mechanisms of preparatory attention allocation seem preserved in healthy aging, despite impending sensory decline. PMID:25390200

  18. Attention and blood lactate levels in equestrians performing show jumping.

    PubMed

    Perciavalle, Valentina; Di Corrado, Donatella; Scuto, Claudia; Perciavalle, Vincenzo; Coco, Marinella

    2014-06-01

    In equestrian show jumping, attention is particularly important to ensure maximum accuracy. Due to the anaerobic nature of the jumping and its requirement for precision coordination between human and horse, there may be a relation between the onset of lactic threshold and decrease in attention. In 12 healthy and injury-free equestrians (6 men, 6 women), the effects (blood lactate and glucose) of a show jumping course (250 m long with eight vertical obstacles with a height of 1.15 m height) on capacity and selectivity of attention was assessed. A typical reaction time paradigm and test of divided attention were administered. At the end of the course a significant increase of blood lactate was observed, whereas blood glucose did not significantly change. A deterioration of attention (intensity and selectivity) and a worsening of performance with increasing of blood lactate were observed. The present results led to the conclusion that the increase in blood lactate that occurs in riders executing a show jumping course is associated with worsening of both attentive capabilities and performance. PMID:25068743

  19. Task Attention Facilitates Learning of Task-Irrelevant Stimuli

    PubMed Central

    Huang, Tsung-Ren; Watanabe, Takeo

    2012-01-01

    Attention plays a fundamental role in visual learning and memory. One highly established principle of visual attention is that the harder a central task is, the more attentional resources are used to perform the task and the smaller amount of attention is allocated to peripheral processing because of limited attention capacity. Here we show that this principle holds true in a dual-task setting but not in a paradigm of task-irrelevant perceptual learning. In Experiment 1, eight participants were asked to identify either bright or dim number targets at the screen center and to remember concurrently presented scene backgrounds. Their recognition performances for scenes paired with dim/hard targets were worse than those for scenes paired with bright/easy targets. In Experiment 2, eight participants were asked to identify either bright or dim letter targets at the screen center while a task-irrelevant coherent motion was concurrently presented in the background. After five days of training on letter identification, participants improved their motion sensitivity to the direction paired with hard/dim targets improved but not to the direction paired with easy/bright targets. Taken together, these results suggest that task-irrelevant stimuli are not subject to the attentional control mechanisms that task-relevant stimuli abide. PMID:22563424

  20. Flood Bypass Capacity Optimization

    NASA Astrophysics Data System (ADS)

    Siclari, A.; Hui, R.; Lund, J. R.

    2015-12-01

    Large river flows can damage adjacent flood-prone areas, by exceeding river channel and levee capacities. Particularly large floods are difficult to contain in leveed river banks alone. Flood bypasses often can efficiently reduce flood risks, where excess river flow is diverted over a weir to bypasses, that incur much less damage and cost. Additional benefits of bypasses include ecosystem protection, agriculture, groundwater recharge and recreation. Constructing or expanding an existing bypass costs in land purchase easements, and levee setbacks. Accounting for such benefits and costs, this study develops a simple mathematical model for optimizing flood bypass capacity using benefit-cost and risk analysis. Application to the Yolo Bypass, an existing bypass along the Sacramento River in California, estimates optimal capacity that economically reduces flood damage and increases various benefits, especially for agriculture. Land availability is likely to limit bypass expansion. Compensation for landowners could relax such limitations. Other economic values could affect the optimal results, which are shown by sensitivity analysis on major parameters. By including land geography into the model, location of promising capacity expansions can be identified.

  1. The Moral Capacity Profile

    ERIC Educational Resources Information Center

    Wilks, Duffy; Ratheal, Juli D'Ann

    2011-01-01

    Effective counseling practice continues to be inevitably linked to underlying theories of behavioral causality. In this article, the authors present the Moral Capacity Profile of an individual from the perspective of the Amoral, Moral, Quasi-Moral/Quasi-Immoral, and Immoral Model of Behavior, a model that uniquely expands counseling's theoretical…

  2. Influence of methylphenidate on spatial attention asymmetry in adolescents with attention deficit hyperactivity disorder (ADHD): preliminary findings.

    PubMed

    Silk, Timothy J; Newman, Daniel P; Eramudugolla, Ranmalee; Vance, Alasdair; Bellgrove, Mark A

    2014-04-01

    Atypical asymmetries of spatial attention have been reported in children with attention deficit hyperactivity disorder (ADHD) and may be exacerbated by non-spatial factors such as attentional capacity. Although preliminary evidence suggests that asymmetries of attention in ADHD may be modifiable by the psychostimulant, methylphenidate, further placebo-controlled studies are required. This study first aimed to confirm recent evidence that increasing non-spatial processing load at fixation can unmask a spatial gradient of target detection in children with ADHD but not Controls. Second, we used placebo-controlled randomised trial methodology to ask whether 20mg of methylphenidate (MPH) could remediate any load-dependent asymmetry of spatial attention in adolescents with ADHD. Twelve male adolescents with ADHD were assessed twice in a double-blind, randomized design, under either placebo or an acute dose of methylphenidate. Thirteen typically developing adolescent Controls completed a single session under placebo. Participants completed a computer-based task in which they monitored a centrally presented rapid serial visual presentation stream for a probe stimulus, while also responding to brief peripheral events. The attentional load of the central task was manipulated by varying the target instructions but not the physical stimuli or the frequency of targets. Between-group analyses under placebo conditions indicated that increased attentional load induced a spatial gradient for target detection in the ADHD but not Controls, such that load slowed response times for left, but not, right hemi-field targets. This load-dependent spatial asymmetry in the adolescents with ADHD was abolished by administration of methylphenidate. Methylphenidate may "normalise" target detection between the hemi-fields in ADHD via enhancement of the right-lateralised ventral attention networks that support non-spatial attention. PMID:24486422

  3. Attentional modulation of perceptual stabilization.

    PubMed

    Kanai, Ryota; Verstraten, Frans A J

    2006-05-22

    Perceptual priming is generally regarded as a passive and automatic process, as it is obtained even without awareness of the prime. Recent studies have introduced a more active form of perceptual priming in which priming for a subsequent ambiguous stimulus is triggered by the subjective percept, that is, interpretation of a previous ambiguous stimulus. This phenomenon known as stabilization does not require a conscious effort to actively maintain one perceptual interpretation. In this study, we show that distraction of attention, during and even after the prime presentation, interferes with the build-up of perceptual memory for stabilization. This implies that despite the apparent automaticity, stabilization involves an active attentional process for encoding and retention. The disruption during the encoding can be attributed to the reduction in sensory signals for the prime. However, the disruption during the retention suggests that the implicit memory trace of the prime necessitates the attentional resource to fully develop. The active nature of the build-up of perceptual memory for stabilization is consistent with the idea that perceptual memory increases its strength gradually over a few seconds. These findings suggest that seemingly automatic and effortless cognitive processes can compete with online perceptual processing for common attentional resources. PMID:16720394

  4. Attention and the Testing Effect

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Picklesimer, Milton

    2016-01-01

    Memory retrieval often enhances still later memory as evidenced by the testing effect. Divided attention (DA) is known to produce different effects on encoding and retrieval, substantially disrupting the former and often producing little effect on the latter. The present experiments examine whether the mnemonic consequences of retrieval are…

  5. Perception and Attention for Visualization

    ERIC Educational Resources Information Center

    Haroz, Steve

    2013-01-01

    This work examines how a better understanding of visual perception and attention can impact visualization design. In a collection of studies, I explore how different levels of the visual system can measurably affect a variety of visualization metrics. The results show that expert preference, user performance, and even computational performance are…

  6. Attention maps in the brain

    PubMed Central

    Somers, David C.; Sheremata, Summer L.

    2014-01-01

    Over 20 distinct cerebral cortical areas contain spatial map representations of the visual field. These retinotopic, or visuotopic, cortical areas occur not only in the occipital lobe but also in the parietal, temporal, and frontal lobes. The cognitive influences of visuospatial attention operate via these cortical maps and can support selection of multiple objects at the same time. In early visual cortical areas, spatial attention enhances responses of selected items and diminishes the responses to distracting items. In higher order cortex, the maps support a spatial indexing role, keeping track of the items to be attended. These maps also support visual short-term memory (VSTM) representations. In each hemisphere, all the known maps respond selectively to stimuli presented within the contralateral visual field. However, a hemispheric asymmetry emerges when the attentional or VSTM demands of a task become significant. In the parietal lobe, the right hemisphere visuotopic maps switch from coding only contralateral visual targets to coding memory and attention targets across the entire visual field. This emergent asymmetry has important implications for understanding hemispatial neglect syndrome, and supports a dynamic network form of the representational model of neglect. PMID:25089167

  7. Deployment of Attention on Handshakes.

    PubMed

    Shen, Mowei; Yin, Jun; Ding, Xiaowei; Shui, Rende; Zhou, Jifan

    2016-01-01

    Understanding the social structures between objects, organizing, and selecting them accordingly, is fundamental to social cognition. We report an example that demonstrates the object association learned from social interactions could impact visual attention. Particularly, when two hands approach each other to perform a handshake, they tend to be attended to as a unit because of the cooperative relationship exhibited in the action: even a cue presented on a non-target hand may facilitate a response to the targets that appear on the non-cued hand (Experiment 1), indicating that attentional shift between two hands was facilitated; furthermore, the response to a target on one hand is significantly impaired by a distractor on the other hand (Experiment 2), implying that it is difficult to selectively confine attention to a single hand. These effects were dependent on the existence of the hands when cue and target appeared (Experiment 3); neither perceptual familiarity, or physical fit can explain all the attention effects (Experiment 4). These results have bearings on the perceptual root of social cognition. PMID:27242595

  8. Attentional bias in math anxiety.

    PubMed

    Rubinsten, Orly; Eidlin, Hili; Wohl, Hadas; Akibli, Orly

    2015-01-01

    Cognitive theory from the field of general anxiety suggests that the tendency to display attentional bias toward negative information results in anxiety. Accordingly, the current study aims to investigate whether attentional bias is involved in math anxiety (MA) as well (i.e., a persistent negative reaction to math). Twenty seven participants (14 with high levels of MA and 13 with low levels of MA) were presented with a novel computerized numerical version of the well established dot probe task. One of six types of prime stimuli, either math related or typically neutral, was presented on one side of a computer screen. The prime was preceded by a probe (either one or two asterisks) that appeared in either the prime or the opposite location. Participants had to discriminate probe identity (one or two asterisks). Math anxious individuals reacted faster when the probe was at the location of the numerical related stimuli. This suggests the existence of attentional bias in MA. That is, for math anxious individuals, the cognitive system selectively favored the processing of emotionally negative information (i.e., math related words). These findings suggest that attentional bias is linked to unduly intense MA symptoms. PMID:26528208

  9. Toddlers' Spontaneous Attention to Number

    ERIC Educational Resources Information Center

    Baroody, Arthur J.; Li, Xia; Lai, Meng-lung

    2008-01-01

    Hannula and Lehtinen (2001, 2005) defined spontaneous focusing on numerosity (SFON) as the tendency to notice the relatively abstract attribute of number despite the presence of other attributes. According to nativists, an innate concept of one to three directs young children's attention to these "intuitive numbers" in everyday situations--even…

  10. Attentional bias in math anxiety

    PubMed Central

    Rubinsten, Orly; Eidlin, Hili; Wohl, Hadas; Akibli, Orly

    2015-01-01

    Cognitive theory from the field of general anxiety suggests that the tendency to display attentional bias toward negative information results in anxiety. Accordingly, the current study aims to investigate whether attentional bias is involved in math anxiety (MA) as well (i.e., a persistent negative reaction to math). Twenty seven participants (14 with high levels of MA and 13 with low levels of MA) were presented with a novel computerized numerical version of the well established dot probe task. One of six types of prime stimuli, either math related or typically neutral, was presented on one side of a computer screen. The prime was preceded by a probe (either one or two asterisks) that appeared in either the prime or the opposite location. Participants had to discriminate probe identity (one or two asterisks). Math anxious individuals reacted faster when the probe was at the location of the numerical related stimuli. This suggests the existence of attentional bias in MA. That is, for math anxious individuals, the cognitive system selectively favored the processing of emotionally negative information (i.e., math related words). These findings suggest that attentional bias is linked to unduly intense MA symptoms. PMID:26528208

  11. Management of attention deficit disorder.

    PubMed

    Delcau, C M

    1984-10-01

    Attention deficit disorder occurs in 5% to 10% of school-aged children. Retrospective studies have shown an increased incidence of academic and social failure in untreated children. This paper reviews the natural course of the disorder and describes some therapeutic interventions. PMID:6484648

  12. Thinking of God Moves Attention

    ERIC Educational Resources Information Center

    Chasteen, Alison L.; Burdzy, Donna C.; Pratt, Jay

    2010-01-01

    The concepts of God and Devil are well known across many cultures and religions, and often involve spatial metaphors, but it is not well known if our mental representations of these concepts affect visual cognition. To examine if exposure to divine concepts produces shifts of attention, participants completed a target detection task in which they…

  13. Deployment of Attention on Handshakes

    PubMed Central

    Shen, Mowei; Yin, Jun; Ding, Xiaowei; Shui, Rende; Zhou, Jifan

    2016-01-01

    Understanding the social structures between objects, organizing, and selecting them accordingly, is fundamental to social cognition. We report an example that demonstrates the object association learned from social interactions could impact visual attention. Particularly, when two hands approach each other to perform a handshake, they tend to be attended to as a unit because of the cooperative relationship exhibited in the action: even a cue presented on a non-target hand may facilitate a response to the targets that appear on the non-cued hand (Experiment 1), indicating that attentional shift between two hands was facilitated; furthermore, the response to a target on one hand is significantly impaired by a distractor on the other hand (Experiment 2), implying that it is difficult to selectively confine attention to a single hand. These effects were dependent on the existence of the hands when cue and target appeared (Experiment 3); neither perceptual familiarity, or physical fit can explain all the attention effects (Experiment 4). These results have bearings on the perceptual root of social cognition. PMID:27242595

  14. Attentional Episodes in Visual Perception

    ERIC Educational Resources Information Center

    Wyble, Brad; Potter, Mary C.; Bowman, Howard; Nieuwenstein, Mark

    2011-01-01

    Is one's temporal perception of the world truly as seamless as it appears? This article presents a computationally motivated theory suggesting that visual attention samples information from temporal episodes (episodic simultaneous type/serial token model; Wyble, Bowman, & Nieuwenstein, 2009). Breaks between these episodes are punctuated by periods…

  15. Modeling selective attention using a neuromorphic analog VLSI device.

    PubMed

    Indiveri, G

    2000-12-01

    Attentional mechanisms are required to overcome the problem of flooding a limited processing capacity system with information. They are present in biological sensory systems and can be a useful engineering tool for artificial visual systems. In this article we present a hardware model of a selective attention mechanism implemented on a very large-scale integration (VLSI) chip, using analog neuromorphic circuits. The chip exploits a spike-based representation to receive, process, and transmit signals. It can be used as a transceiver module for building multichip neuromorphic vision systems. We describe the circuits that carry out the main processing stages of the selective attention mechanism and provide experimental data for each circuit. We demonstrate the expected behavior of the model at the system level by stimulating the chip with both artificially generated control signals and signals obtained from a saliency map, computed from an image containing several salient features. PMID:11112258

  16. Aging of aluminum/iron-based drinking water treatment residuals in lake water and their association with phosphorus immobilization capability.

    PubMed

    Wang, Changhui; Yuan, Nannan; Pei, Yuansheng; Jiang, He-Long

    2015-08-15

    Aluminum and Fe-based drinking water treatment residuals (DWTRs) have shown a high potential for use by geoengineers in internal P loading control in lakes. In this study, aging of Al/Fe-based DWTRs in lake water under different pH and redox conditions associated with their P immobilization capability was investigated based on a 180-day incubation test. The results showed that the DWTRs before and after incubation under different conditions have similar structures, but their specific surface area and pore volume, especially mesopores with radius at 2.1-5.0 nm drastically decreased. The oxalate extractable Al contents changed little although a small amount of Al transformed from oxidizable to residual forms. The oxalate extractable Fe contents also decreased by a small amount, but the transformation from oxidizable to residual forms were remarkable, approximately by 14.6%. However, the DWTRs before and after incubation had similar P immobilization capabilities in solutions and lake sediments. Even the maximum P adsorption capacity estimated by the Langmuir model increased after incubation. Therefore, it was not necessary to give special attention to the impact of Al and Fe aging on the effectiveness of DWTRs for geoengineering in lakes. PMID:26071931

  17. Faststats: Attention Deficit Hyperactivity Disorder (ADHD)

    MedlinePlus

    ... this? Submit What's this? Submit Button NCHS Home Attention Deficit Hyperactivity Disorder (ADHD)* Recommend on Facebook Tweet Share Compartir Data ... attention deficit disorder (ADD)" is used rather than "attention deficit hyperactivity disorder (ADHD)" in some data sources. More data Association ...

  18. Unexpected stimulation of soil methane uptake as emergent property of agricultural soils following bio-based residue application.

    PubMed

    Ho, Adrian; Reim, Andreas; Kim, Sang Yoon; Meima-Franke, Marion; Termorshuizen, Aad; de Boer, Wietse; van der Putten, Wim H; Bodelier, Paul L E

    2015-10-01

    Intensification of agriculture to meet the global food, feed, and bioenergy demand entail increasing re-investment of carbon compounds (residues) into agro-systems to prevent decline of soil quality and fertility. However, agricultural intensification decreases soil methane uptake, reducing, and even causing the loss of the methane sink function. In contrast to wetland agricultural soils (rice paddies), the methanotrophic potential in well-aerated agricultural soils have received little attention, presumably due to the anticipated low or negligible methane uptake capacity in these soils. Consequently, a detailed study verifying or refuting this assumption is still lacking. Exemplifying a typical agricultural practice, we determined the impact of bio-based residue application on soil methane flux, and determined the methanotrophic potential, including a qualitative (diagnostic microarray) and quantitative (group-specific qPCR assays) analysis of the methanotrophic community after residue amendments over 2 months. Unexpectedly, after amendments with specific residues, we detected a significant transient stimulation of methane uptake confirmed by both the methane flux measurements and methane oxidation assay. This stimulation was apparently a result of induced cell-specific activity, rather than growth of the methanotroph population. Although transient, the heightened methane uptake offsets up to 16% of total gaseous CO2 emitted during the incubation. The methanotrophic community, predominantly comprised of Methylosinus may facilitate methane oxidation in the agricultural soils. While agricultural soils are generally regarded as a net methane source or a relatively weak methane sink, our results show that methane oxidation rate can be stimulated, leading to higher soil methane uptake. Hence, even if agriculture exerts an adverse impact on soil methane uptake, implementing carefully designed management strategies (e.g. repeated application of specific residues) may

  19. Unintentionality of affective attention across visual processing stages

    PubMed Central

    Uusberg, Andero; Uibo, Helen; Kreegipuu, Kairi; Tamm, Maria; Raidvee, Aire; Allik, Jüri

    2013-01-01

    Affective attention involves bottom-up perceptual selection that prioritizes motivationally significant stimuli. To clarify the extent to which this process is automatic, we investigated the dependence of affective attention on the intention to process emotional meaning. Affective attention was manipulated by presenting affective images with variable arousal and intentionality by requiring participants to make affective and non-affective evaluations. Polytomous rather than binary decisions were required from the participants in order to elicit relatively deep emotional processing. The temporal dynamics of prioritized processing were assessed using early posterior negativity (EPN, 175–300 ms) as well as P3-like (P3, 300–500 ms) and slow wave (SW, 500–1500 ms) portions of the late positive potential. All analyzed components were differentially sensitive to stimulus categories suggesting that they indeed reflect distinct stages of motivational significance encoding. The intention to perceive emotional meaning had no effect on EPN, an additive effect on P3, and an interactive effect on SW. We concluded that affective attention went from completely unintentional during the EPN to partially unintentional during P3 and SW where top-down signals, respectively, complemented and modulated bottom-up differences in stimulus prioritization. The findings were interpreted in light of two-stage models of visual perception by associating the EPN with large-capacity initial relevance detection and the P3 as well as SW with capacity-limited consolidation and elaboration of affective stimuli. PMID:24421772

  20. Close proximity gunshot residues.

    PubMed

    Thornton, J I

    1986-04-01

    Intuitively, a hand held in close proximity to a firearm at the instant of discharge will intercept a significant amount of gunshot residue, even though the hand did not actually come into contact with the weapon. There is, however, little information specifically described in the forensic science literature concerning the residue levels which might be encountered in such an instance. The present work confirms that antimony levels consistent with an individual having fired or handled a firearm may be intercepted by a hand held in close proximity. PMID:3711843

  1. Transform coding of stereo image residuals.

    PubMed

    Moellenhoff, M S; Maier, M W

    1998-01-01

    Stereo image compression is of growing interest because of new display technologies and the needs of telepresence systems. Compared to monoscopic image compression, stereo image compression has received much less attention. A variety of algorithms have appeared in the literature that make use of the cross-view redundancy in the stereo pair. Many of these use the framework of disparity-compensated residual coding, but concentrate on the disparity compensation process rather than the post compensation coding process. This paper studies specialized coding methods for the residual image produced by disparity compensation. The algorithms make use of theoretically expected and experimentally observed characteristics of the disparity-compensated stereo residual to select transforms and quantization methods. Performance is evaluated on mean squared error (MSE) and a stereo-unique metric based on image registration. Exploiting the directional characteristics in a discrete cosine transform (DCT) framework provides its best performance below 0.75 b/pixel for 8-b gray-scale imagery and below 2 b/pixel for 24-b color imagery, In the wavelet algorithm, roughly a 50% reduction in bit rate is possible by encoding only the vertical channel, where much of the stereo information is contained. The proposed algorithms do not incur substantial computational burden beyond that needed for any disparity-compensated residual algorithm. PMID:18276294

  2. Sugarcane rice residue biochars and their applications

    NASA Astrophysics Data System (ADS)

    Wang, J. J.

    2014-12-01

    Sugarcane production in U.S. involves either pre-harvest burning or after-harvest burning of the residue. Approximately 70-90% of the dry matter of harvested sugarcane trash is lost through open field burning. This practice has caused considerable concerns over air quality and soil sustainability. We propose an alternative conservation approach to convert the sugarcane residue to biochar and used as soil amendment to conserve carbon and potentially improve soil fertility. In this study, fundamental properties of biochars made from sugarcane residue along with rice residues were tested for agronomic and environmental benefits. Sugarcane and rice harvest residues and milling processing byproducts bagasse and rice husk were converted to biochars at different pyrolysis temperatures and characterized. In general, sugarcane leave biochar contained more P, K, Ca and Mg than sugarcane bagasse biochar. Rice straw biochar had more S, K Ca but less P than rice husk biochar. Both biochars had higher available fraction of total P than that of total K. Sugarcane leave biochar converted at 450oC was dominated with various lignin derived phenols as well as non-specific aromatic compounds whereas bagasse biochar was with both lignin derived phenol and poly aromatic hydrocarbon (PAH). Rice straw char was dominated with non-specific aromatic compounds. At 750oC, charred material was dominated with aromatic ethers while losing the aromatic C=C structures. These molecular and surface property differences likely contributed to the difference in water holding capacities observed with these biochars. On the other hand, rice straw biochars produced at different pyrolysis temperatures had no significant effect on rice germination. Soils treated with sugarcane leave/trash biochar significantly enhanced sugarcane growth especially the root length. Treating soil with either sugarcane leave or bagasse char also enhanced soil adsorption capacity of atrazine; a common herbicide used in sugarcane

  3. The Structure of the Relationship between Attention and Intelligence

    ERIC Educational Resources Information Center

    Schweizer, Karl; Moosbrugger, Helfried; Goldhammer, Frank

    2005-01-01

    The relationship between attention and general intelligence was investigated considering the different types of attention: alertness, sustained attention, focused attention, attentional switching, divided attention, attention according to the supervisory attentional system, attention as inhibition, spatial attention, attention as planning,…

  4. Attentional control mediates the relationship between social anhedonia and social impairment

    PubMed Central

    Tully, Laura M.; Lincoln, Sarah Hope; Hooker, Christine I.

    2014-01-01

    Social anhedonia (SA), a trait-like disinterest in social contact and diminished capacity to experience pleasure from social interactions, is consistently associated with social impairments in both healthy and clinical populations. However, the mechanisms underlying the relationship between SA and social impairment are poorly understood. Attentional control, selecting and focusing on relevant information and inhibiting irrelevant, may be one such mechanism. We examined individual differences in SA, attentional control, and social impairment in 108 healthy adults. High SA related to low attentional control and high social impairment. Moreover, attentional control mediated the relationship between SA and social impairment, establishing attentional control as one mechanism underlying aberrations in the fundamental human need for social contact. Although both attentional deficits and social impairment have been separately noted in SA, the relationship between SA, attentional control and social impairment in this non-clinical sample reflects a novel contribution. PMID:25538647

  5. Paying attention to saccadic intrusions.

    PubMed

    Gowen, E; Abadi, R V; Poliakoff, E

    2005-12-01

    Fixation to a target in primary gaze is invariably interrupted by physiological conjugate saccadic intrusions (SI). These small idiosyncratic eye movements (usually <1 degrees in amplitude) take the form of an initial horizontal fast eye movement away from the desired eye position, followed after a variable duration by a return saccade or drift. As the aetiology of SI is still unclear, it was the aim of this study to investigate whether SI are related to exogenous or endogenous attentional processes. This was achieved by varying (a) the "bottom-up" target viewing conditions (target presence, servo control of the target, target background, target size) and (b) the 'top-down' attentional state (instruction change--'look' or 'hold eyes steady' and passive fixation versus active--'respond to change' fixation) in 13 subjects (the number of participants in each task varied between 7 and 11). We also manipulated the orientation of pure exogenous attention through a cue-target task, during which subjects were required to respond to a target, preceded by a non-informative cue by either pressing a button or making a saccade towards the target. SI amplitude, duration, frequency and direction were measured. SI amplitude was found to be significantly higher when the target was absent and SI frequency significantly lower during open loop conditions. Target size and background influenced SI behaviour in an idiosyncratic manner, although there was a trend for subjects to exhibit lower SI frequencies and amplitudes when a patterned background was present and larger SI amplitudes with larger target sizes. SI frequency decreased during the "hold eyes steady" passive command as well as during active fixation but SI direction was not influenced by the exogenous cue-target task. These results suggest that SI are related to endogenous rather than exogenous attention mechanisms. Our experiments lead us to propose that SI represent shifts in endogenous attention that reflect a baseline

  6. When Instant Gratification Isn't Soon Enough: Getting Attention in a Short-Attention-Span World

    NASA Astrophysics Data System (ADS)

    Beitler, J.

    2005-12-01

    People are bombarded with messages - so many messages from so many sources clamoring for attention, that it exceeds the capacity of any human to pay attention to all of them. Technology and media have proliferated, creating more channels and more ways to reach people--and at the same time, audiences who are more skilled at tuning out. How can you reach people without reducing your message to the dreaded sound byte? How can you make sure that your message has complexity and staying power. How can you get people to pay attention at all? The answers may be simpler than you think. The author will present case studies of effective communication approaches and information about applying them to your own situation.

  7. Seismic capacity of switchgear

    SciTech Connect

    Bandyopadhyay, K.; Hofmayer, C.; Kassir, M.; Pepper, S.

    1989-01-01

    As part of a component fragility program sponsored by the USNRC, BNL has collected existing information on the seismic capacity of switchgear assemblies from major manufacturers. Existing seismic test data for both low and medium voltage switchgear assemblies have been evaluated and the generic results are presented in this paper. The failure modes are identified and the corresponding generic lower bound capacity levels are established. The test response spectra have been used as a measure of the test vibration input. The results indicate that relays chatter at a very low input level at the base of the switchgear cabinet. This change of state of devices including relays have been observed. Breaker tripping occurs at a higher vibration level. Although the structural failure of internal elements have been noticed, the overall switchgear cabinet structure withstands a high vibration level. 5 refs., 2 figs., 2 tabs.

  8. Enhancing capacity management.

    PubMed

    Rees, Susan; Houlahan, Beth; Lavrenz, Dennise

    2014-03-01

    It is essential for organizations to be able to accept patients requiring care. Capacity planning and management are necessary to ensure an organization has an accepting physician/service, an available bed, and staff to care for the patient and family. This organization implemented strategies including communication plans, staffing guidelines, morning rounds, proactive planning, and an escalation process to reverse the trend of not being able to accept all patients. PMID:24531280

  9. Heat Capacity Mapping Mission

    NASA Technical Reports Server (NTRS)

    Nilsson, C. S.; Andrews, J. C.; Scully-Power, P.; Ball, S.; Speechley, G.; Latham, A. R. (Principal Investigator)

    1980-01-01

    The Tasman Front was delineated by airborne expendable bathythermograph survey; and an Heat Capacity Mapping Mission (HCMM) IR image on the same day shows the same principal features as determined from ground-truth. It is clear that digital enhancement of HCMM images is necessary to map ocean surface temperatures and when done, the Tasman Front and other oceanographic features can be mapped by this method, even through considerable scattered cloud cover.

  10. CROP-RESIDUE MANAGEMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our agricultural production system is under increasing pressure to provide low cost, high quality food, fiber and biofuels while maintaining and preserving the environment. Increased interest in crop residues for production system sustainability is related to the recognition that the soil, water and...

  11. CSTI High Capacity Power

    NASA Technical Reports Server (NTRS)

    Winter, Jerry M.

    1989-01-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY-86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase 1 of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY-88, the Advanced Technology Program was incorporated into NASA's new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed.

  12. CSTI high capacity power

    SciTech Connect

    Winter, J.M.

    1994-09-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase I of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY88, the Advanced Technology Program was incorporated into NASA`s new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed.

  13. Attention modulates emotional expression processing.

    PubMed

    Wronka, Eligiusz; Walentowska, Wioleta

    2011-08-01

    To investigate the time course of emotional expression processing, we recorded ERPs to facial stimuli. The first task was to discriminate emotional expressions. Enhanced negativity of the face-specific N170 was elicited by emotional as opposed to neutral faces, followed by the occipital negativity (240-340 ms poststimulus). The second task was to classify face gender. Here, N170 was unaffected by the emotional expression. However, emotional expression effect was expressed in the anterior positivity (160-250 ms poststimulus) and subsequent occipital negativity (240-340 ms poststimulus). Results support the thesis that structural encoding relevant to gender recognition and simultaneous expression analysis are independent processes. Attention modulates facial emotion processing 140-185 ms poststimulus. Involuntary differentiation of facial expression was observed later (160-340 ms poststimulus), suggesting unintentional attention capture. PMID:21332489

  14. Visual attention: The past 25 years

    PubMed Central

    Carrasco, Marisa

    2012-01-01

    This review focuses on covert attention and how it alters early vision. I explain why attention is considered a selective process, the constructs of covert attention, spatial endogenous and exogenous attention, and feature-based attention. I explain how in the last 25 years research on attention has characterized the effects of covert attention on spatial filters and how attention influences the selection of stimuli of interest. This review includes the effects of spatial attention on discriminability and appearance in tasks mediated by contrast sensitivity and spatial resolution; the effects of feature-based attention on basic visual processes, and a comparison of the effects of spatial and feature-based attention. The emphasis of this review is on psychophysical studies, but relevant electrophysiological and neuroimaging studies and models regarding how and where neuronal responses are modulated are also discussed. PMID:21549742

  15. More attention to attention? An eye-tracking investigation of selection of perceptual attributes during a task switch.

    PubMed

    Longman, Cai S; Lavric, Aureliu; Monsell, Stephen

    2013-07-01

    Switching tasks prolongs response times, an effect reduced but not eliminated by active preparation. To explore the role of attentional selection of the relevant stimulus attribute in these task-switch costs, we measured eye fixations in participants cued to identify either a face or a letter displayed on its forehead. With only 200 ms between cue and stimulus onsets, the eyes fixated the currently relevant region of the stimulus less and the irrelevant region more on switch than on repeat trials, at stimulus onset and for 500 ms thereafter, in a pattern suggestive of delayed orientation of attention to the relevant region on switch trials. With 800 ms to prepare, both switch costs and inappropriate fixations were reduced, but on switch trials participants still tended (relative to repeat trials) to fixate the now-irrelevant region more at stimulus onset and to maintain fixation on, or refixate, the irrelevant region more during the next 500 ms. The size of this attentional persistence was associated with differences in performance costs between and within participants. We suggest that reorientation of attention is an important, albeit somewhat neglected and controversial, component of advance task-set reconfiguration and that the task-set inertia (or reactivation) to which many attribute the residual task-switch cost seen after preparation includes inertia in (or reactivation of) attentional parameters. PMID:23088543

  16. A Real Attention-Getter

    NASA Technical Reports Server (NTRS)

    2003-01-01

    While most parents would agree that playing videos games is the antithesis of time well spent for their children, recent advances involving NASA biofeedback technology are proving otherwise. The same techniques used to measure brain activity in NASA pilots during flight simulation exercises are now a part of a revolutionary video game system that is helping to improve overall mental awareness for Americans of all ages, including those who suffer from Attention Deficit Hyperactivity Disorder (ADHD).

  17. Structural Variability within Frontoparietal Networks and Individual Differences in Attentional Functions: An Approach Using the Theory of Visual Attention

    PubMed Central

    Gillebert, Celine R.; Vangkilde, Signe A.; Petersen, Anders; Humphreys, Glyn W.

    2015-01-01

    Visuospatial attention allows us to select and act upon a subset of behaviorally relevant visual stimuli while ignoring distraction. Bundesen's theory of visual attention (TVA) (Bundesen, 1990) offers a quantitative analysis of the different facets of attention within a unitary model and provides a powerful analytic framework for understanding individual differences in attentional functions. Visuospatial attention is contingent upon large networks, distributed across both hemispheres, consisting of several cortical areas interconnected by long-association frontoparietal pathways, including three branches of the superior longitudinal fasciculus (SLF I-III) and the inferior fronto-occipital fasciculus (IFOF). Here we examine whether structural variability within human frontoparietal networks mediates differences in attention abilities as assessed by the TVA. Structural measures were based on spherical deconvolution and tractography-derived indices of tract volume and hindrance-modulated orientational anisotropy (HMOA). Individual differences in visual short-term memory (VSTM) were linked to variability in the microstructure (HMOA) of SLF II, SLF III, and IFOF within the right hemisphere. Moreover, VSTM and speed of information processing were linked to hemispheric lateralization within the IFOF. Differences in spatial bias were mediated by both variability in microstructure and volume of the right SLF II. Our data indicate that the microstructural and macrostrucutral organization of white matter pathways differentially contributes to both the anatomical lateralization of frontoparietal attentional networks and to individual differences in attentional functions. We conclude that individual differences in VSTM capacity, processing speed, and spatial bias, as assessed by TVA, link to variability in structural organization within frontoparietal pathways. PMID:26224851

  18. Structural Variability within Frontoparietal Networks and Individual Differences in Attentional Functions: An Approach Using the Theory of Visual Attention.

    PubMed

    Chechlacz, Magdalena; Gillebert, Celine R; Vangkilde, Signe A; Petersen, Anders; Humphreys, Glyn W

    2015-07-29

    Visuospatial attention allows us to select and act upon a subset of behaviorally relevant visual stimuli while ignoring distraction. Bundesen's theory of visual attention (TVA) (Bundesen, 1990) offers a quantitative analysis of the different facets of attention within a unitary model and provides a powerful analytic framework for understanding individual differences in attentional functions. Visuospatial attention is contingent upon large networks, distributed across both hemispheres, consisting of several cortical areas interconnected by long-association frontoparietal pathways, including three branches of the superior longitudinal fasciculus (SLF I-III) and the inferior fronto-occipital fasciculus (IFOF). Here we examine whether structural variability within human frontoparietal networks mediates differences in attention abilities as assessed by the TVA. Structural measures were based on spherical deconvolution and tractography-derived indices of tract volume and hindrance-modulated orientational anisotropy (HMOA). Individual differences in visual short-term memory (VSTM) were linked to variability in the microstructure (HMOA) of SLF II, SLF III, and IFOF within the right hemisphere. Moreover, VSTM and speed of information processing were linked to hemispheric lateralization within the IFOF. Differences in spatial bias were mediated by both variability in microstructure and volume of the right SLF II. Our data indicate that the microstructural and macrostrucutral organization of white matter pathways differentially contributes to both the anatomical lateralization of frontoparietal attentional networks and to individual differences in attentional functions. We conclude that individual differences in VSTM capacity, processing speed, and spatial bias, as assessed by TVA, link to variability in structural organization within frontoparietal pathways. PMID:26224851

  19. Attentive Tracking of Sound Sources.

    PubMed

    Woods, Kevin J P; McDermott, Josh H

    2015-08-31

    Auditory scenes often contain concurrent sound sources, but listeners are typically interested in just one of these and must somehow select it for further processing. One challenge is that real-world sounds such as speech vary over time and as a consequence often cannot be separated or selected based on particular values of their features (e.g., high pitch). Here we show that human listeners can circumvent this challenge by tracking sounds with a movable focus of attention. We synthesized pairs of voices that changed in pitch and timbre over random, intertwined trajectories, lacking distinguishing features or linguistic information. Listeners were cued beforehand to attend to one of the voices. We measured their ability to extract this cued voice from the mixture by subsequently presenting the ending portion of one voice and asking whether it came from the cued voice. We found that listeners could perform this task but that performance was mediated by attention-listeners who performed best were also more sensitive to perturbations in the cued voice than in the uncued voice. Moreover, the task was impossible if the source trajectories did not maintain sufficient separation in feature space. The results suggest a locus of attention that can follow a sound's trajectory through a feature space, likely aiding selection and segregation amid similar distractors. PMID:26279234

  20. The scaling of attention networks

    NASA Astrophysics Data System (ADS)

    Wang, Cheng-Jun; Wu, Lingfei

    2016-04-01

    We use clicks as a proxy of collective attention and construct networks to study the temporal dynamics of attention. In particular we collect the browsing records of millions of users on 1000 Web forums in two months. In the constructed networks, nodes are threads and edges represent the switch of users between threads in an hour. The investigated network properties include the number of threads N, the number of users UV, and the number of clicks, PV. We find scaling functions PV ∼ UV θ1, PV ∼N θ3, and UV ∼N θ2, in which the scaling exponents are always greater than 1. This means that (1) the studied networks maintain a self-similar flow structure in time, i.e., large networks are simply the scale-up versions of small networks; and (2) large networks are more "productive", in the sense that an average user would generate more clicks in the larger systems. We propose a revised version of Zipf's law to quantify the time-invariant flow structure of attention networks and relate it to the observed scaling properties. We also demonstrate the applied consequences of our research: forum-classification based on scaling properties.

  1. Which environmental problems get policy attention? Examining energy and agricultural sector policies in Sweden

    SciTech Connect

    Engstroem, Rebecka Nilsson, Mans Finnveden, Goeran

    2008-05-15

    Not all environmental problems get the same level of policy attention. An interesting question is thus why certain aspects receive attention and others do not. This paper studies the level of policy attention given to different environmental aspects in agriculture and energy policy in Sweden and explores empirically some factors that can explain the level of attention. The first step was to explore the link between environmental issue characteristics and the level of policy attention. The level of policy attention was measured through a content analysis of Swedish government bills. The results from the content analysis are clear and stable over the studied time period. In the agriculture sector biodiversity and toxicity are in focus whereas in the energy sector climate change and resources are given the attention. Besides these aspects, the attention is limited. These results were compared with the results from sector-wide environmental assessments of the same sectors. These assessments were based on hybrid input-output analysis and life cycle assessment methodologies. A main finding from the study is that issue importance is a necessary but not a sufficient condition for policy attention. Other explanations are needed to understand which environmental issues get attention in sectoral policy. Our assessment showed that while the level of knowledge does not provide an explanation, the presence of strong and well-organised stakeholders within the sector, with an interest in having a certain issue on the agenda, might be decisive for issue attention. Path dependency and limited attention capacity are other important factors.

  2. "Islands of Decency": Building Capacity in a Sea of Despair

    ERIC Educational Resources Information Center

    Abu El-Haj, Thea Renda

    2013-01-01

    This response focuses attention on three key issues raised by Brayboy's talk: training our analyses on the impact of neoliberal policies reshaping schools and societies, developing an engaged anthropology of education to build local capacity, and remembering the centrality of our relationships in the midst of this work. (Contains 3 notes.)

  3. Individual Differences in the Fan Effect and Working Memory Capacity

    ERIC Educational Resources Information Center

    Bunting, M.F.; Conway, A.R.A.; Heitz, R.P.

    2004-01-01

    In opposition to conceptualizing working memory (WM) in terms of a general capacity, we present four experiments that favor the view that individual differences in WM depend on attentional control. High- and low-WM participants, as assessed by the operation span task, learned unrelated sentences for which the subject and predicate of the sentences…

  4. Dissociations between developmental dyslexias and attention deficits

    PubMed Central

    Lukov, Limor; Friedmann, Naama; Shalev, Lilach; Khentov-Kraus, Lilach; Shalev, Nir; Lorber, Rakefet; Guggenheim, Revital

    2014-01-01

    We examine whether attention deficits underlie developmental dyslexia, or certain types of dyslexia, by presenting double dissociations between the two. We took into account the existence of distinct types of dyslexia and of attention deficits, and focused on dyslexias that may be thought to have an attentional basis: letter position dyslexia (LPD), in which letters migrate within words, attentional dyslexia (AD), in which letters migrate between words, neglect dyslexia, in which letters on one side of the word are omitted or substituted, and surface dyslexia, in which words are read via the sublexical route. We tested 110 children and adults with developmental dyslexia and/or attention deficits, using extensive batteries of reading and attention. For each participant, the existence of dyslexia and the dyslexia type were tested using reading tests that included stimuli sensitive to the various dyslexia types. Attention deficit and its type was established through attention tasks assessing sustained, selective, orienting, and executive attention functioning. Using this procedure, we identified 55 participants who showed a double dissociation between reading and attention: 28 had dyslexia with normal attention and 27 had attention deficits with normal reading. Importantly, each dyslexia with suspected attentional basis dissociated from attention: we found 21 individuals with LPD, 13 AD, 2 neglect dyslexia, and 12 surface dyslexia without attention deficits. Other dyslexia types (vowel dyslexia, phonological dyslexia, visual dyslexia) also dissociated from attention deficits. Examination of 55 additional individuals with both a specific dyslexia and a certain attention deficit found no attention function that was consistently linked with any dyslexia type. Specifically, LPD and AD dissociated from selective attention, neglect dyslexia dissociated from orienting, and surface dyslexia dissociated from sustained and executive attention. These results indicate that

  5. Attentional Disengagement in Adults with Williams Syndrome

    ERIC Educational Resources Information Center

    Lense, Miriam D.; Key, Alexandra P.; Dykens, Elisabeth M.

    2011-01-01

    Williams syndrome (WS) is a neurodevelopmental disorder characterized by a distinctive behavioral and cognitive profile, including widespread problems with attention. However, the specific nature of their attentional difficulties, such as inappropriate attentional allocation and/or poor attentional disengagement abilities, has yet to be…

  6. Auditory Attention Switching: A Developmental Study.

    ERIC Educational Resources Information Center

    Pearson, Deborah A.; Lane, David M.

    1991-01-01

    Studied the ability of 8- and 11-year olds, and college-age subjects, to allocate attention rapidly. Older subjects were better able to reallocate attention. The developmental change in the reallocation of attention appears to be continuous and quantitative. Improvement is linked to the ability to use active attentional strategies. (Author/GH)

  7. Properties of Attention during Reading Lessons.

    ERIC Educational Resources Information Center

    Imai, Mutsumi; And Others

    1992-01-01

    Attention during reading lessons was explored for 116 second and third graders (60 males and 56 females). Some of the concurrent and antecedent factors that influence attention were investigated. Oral reading errors undermine attention. Nominal reading group membership is more strongly related to attention than individual fluency and comprehension…

  8. 29 CFR 785.43 - Medical attention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Medical attention. 785.43 Section 785.43 Labor Regulations..., Medical Attention, Civic and Charitable Work, and Suggestion Systems § 785.43 Medical attention. Time spent by an employee in waiting for and receiving medical attention on the premises or at the...

  9. 29 CFR 785.43 - Medical attention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Medical attention. 785.43 Section 785.43 Labor Regulations..., Medical Attention, Civic and Charitable Work, and Suggestion Systems § 785.43 Medical attention. Time spent by an employee in waiting for and receiving medical attention on the premises or at the...

  10. 29 CFR 785.43 - Medical attention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Medical attention. 785.43 Section 785.43 Labor Regulations..., Medical Attention, Civic and Charitable Work, and Suggestion Systems § 785.43 Medical attention. Time spent by an employee in waiting for and receiving medical attention on the premises or at the...

  11. 29 CFR 785.43 - Medical attention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Medical attention. 785.43 Section 785.43 Labor Regulations..., Medical Attention, Civic and Charitable Work, and Suggestion Systems § 785.43 Medical attention. Time spent by an employee in waiting for and receiving medical attention on the premises or at the...

  12. 29 CFR 785.43 - Medical attention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Medical attention. 785.43 Section 785.43 Labor Regulations..., Medical Attention, Civic and Charitable Work, and Suggestion Systems § 785.43 Medical attention. Time spent by an employee in waiting for and receiving medical attention on the premises or at the...

  13. Audiovisual integration of speech falters under high attention demands.

    PubMed

    Alsius, Agnès; Navarra, Jordi; Campbell, Ruth; Soto-Faraco, Salvador

    2005-05-10

    One of the most commonly cited examples of human multisensory integration occurs during exposure to natural speech, when the vocal and the visual aspects of the signal are integrated in a unitary percept. Audiovisual association of facial gestures and vocal sounds has been demonstrated in nonhuman primates and in prelinguistic children, arguing for a general basis for this capacity. One critical question, however, concerns the role of attention in such multisensory integration. Although both behavioral and neurophysiological studies have converged on a preattentive conceptualization of audiovisual speech integration, this mechanism has rarely been measured under conditions of high attentional load, when the observers' attention resources are depleted. We tested the extent to which audiovisual integration was modulated by the amount of available attentional resources by measuring the observers' susceptibility to the classic McGurk illusion in a dual-task paradigm. The proportion of visually influenced responses was severely, and selectively, reduced if participants were concurrently performing an unrelated visual or auditory task. In contrast with the assumption that crossmodal speech integration is automatic, our results suggest that these multisensory binding processes are subject to attentional demands. PMID:15886102

  14. Raising attention to attention deficit hyperactivity disorder in schizophrenia

    PubMed Central

    Pallanti, Stefano; Salerno, Luana

    2015-01-01

    Schizophrenia and attention deficit hyperactivity disorder (ADHD) are two psychiatric disorders with a negative impact on quality of life of individuals affected. Although they are classified into distinct disorders categories, attentional dysfunction is considered as a core feature in both conditions, either at the clinical then pathophysiological level. Beyond the obvious clinical overlap between these disorders, the Research Domain Criteria approach might offer an interesting perspective for disentangling common circuits underpinning both disorders. Hence, we review evidences regarding the overlap between schizophrenia and ADHD, at the clinical level, and at the level of underlying brain mechanisms. The evidence regarding the influence of environmental risk factors in the emergence of both disorders, and their developmental trajectories is also reviewed. Among these, we will try to elucidate the complex relationship between stimulants use and psychotic symptoms, discussing the potential role of ADHD medication in inducing psychosis or in exacerbating it. We aim that, taken together, these findings may promote further investigation with important implications both for clinicians and research. In fact, considering the amounting evidence on the overlap between schizophrenia and ADHD, the delineation of their boundaries might help in the decision for diagnosis and treatment. Moreover, it may help to promote interventions focused on the prevention of both schizophrenia and ADHD, by the reduction of recognized environmental risk factors. PMID:25815254

  15. Raising attention to attention deficit hyperactivity disorder in schizophrenia.

    PubMed

    Pallanti, Stefano; Salerno, Luana

    2015-03-22

    Schizophrenia and attention deficit hyperactivity disorder (ADHD) are two psychiatric disorders with a negative impact on quality of life of individuals affected. Although they are classified into distinct disorders categories, attentional dysfunction is considered as a core feature in both conditions, either at the clinical then pathophysiological level. Beyond the obvious clinical overlap between these disorders, the Research Domain Criteria approach might offer an interesting perspective for disentangling common circuits underpinning both disorders. Hence, we review evidences regarding the overlap between schizophrenia and ADHD, at the clinical level, and at the level of underlying brain mechanisms. The evidence regarding the influence of environmental risk factors in the emergence of both disorders, and their developmental trajectories is also reviewed. Among these, we will try to elucidate the complex relationship between stimulants use and psychotic symptoms, discussing the potential role of ADHD medication in inducing psychosis or in exacerbating it. We aim that, taken together, these findings may promote further investigation with important implications both for clinicians and research. In fact, considering the amounting evidence on the overlap between schizophrenia and ADHD, the delineation of their boundaries might help in the decision for diagnosis and treatment. Moreover, it may help to promote interventions focused on the prevention of both schizophrenia and ADHD, by the reduction of recognized environmental risk factors. PMID:25815254

  16. Surface retention capacity calculation

    NASA Astrophysics Data System (ADS)

    David, Vaclav; Dostal, Tomas

    2010-05-01

    Flood wave transformation in the floodplain is the phenomenon which is researched within interdisciplinary project NIVA - Water Retention in Floodplains and Possibilities of Retention Capacity Increase. The project focuses on broad range of floodplain ecosystem services and mitigation of flooding is one of them. Despite main influence on flood wave transformation is due to flow retardation, retention in surface depressions within floodplain has been analyzed to get better overview of whole transformation process. Detail digital relief model (DRM) has been used for given purposes to be able to analyze terrain depressions volumes. The model was developed with use of stereophotogrammetric evaluation of airborne images with high resolution of 10 cm. It was essential for purposes of presented analysis not to apply pit removal routines which are often used for generation of DRM for hydrological modelling purposes. First, the methodology of analysis was prepared and tested on artificial surface. This surface was created using random raster generation, filtration and resampling with final resolution of 1000 x 1000 units and height of maximum 10 units above datum. The methodology itself is based on analysis of areas inundated by water at different elevation levels. Volume is than calculated for each depression using extraction of terrain elevations under corresponding water level. The method was then applied on the area of Lužnice River floodplain section to assess retention capacity of real floodplain. The floodplain had to be cut into sections perpendicular to main river orientation for analyses as the method was tested for square shaped area without any significant inclination. Results obtained by mentioned analysis are presented in this paper. Acknowledgement Presented research was accomplished within national project NIVA - Water Retention in Floodplains and Possibilities of Retention Capacity Increase, nr. QH82078. The project is funded by Ministry of Agriculture of

  17. Residual stresses in material processing

    SciTech Connect

    Kozaczek, K.J.; Watkins, T.R.; Hubbard, C.R.; Wang, Xun-Li; Spooner, S.

    1994-09-01

    Material manufacturing processes often introduce residual stresses into the product. The residual stresses affect the properties of the material and often are detrimental. Therefore, the distribution and magnitude of residual stresses in the final product are usually an important factor in manufacturing process optimization or component life prediction. The present paper briefly discusses the causes of residual stresses. It then adresses the direct, nondestructive methods of residual stress measurement by X-ray and neutron diffraction. Examples are presented to demonstrate the importance of residual stress measurement in machining and joining operations.

  18. How do subvocal rehearsal and general attentional resources contribute to verbal short-term memory span?

    PubMed Central

    Morra, Sergio

    2015-01-01

    Whether rehearsal has a causal role in verbal STM has been controversial in the literature. Recent theories of working memory emphasize a role of attentional resources, but leave unclear how they contribute to verbal STM. Two experiments (with 49 and 102 adult participants, respectively) followed up previous studies with children, aiming to clarify the contributions of attentional capacity and rehearsal to verbal STM. Word length and presentation modality were manipulated. Experiment 1 focused on order errors, Experiment 2 on predicting individual differences in span from attentional capacity and articulation rate. Structural equation modeling showed clearly a major role of attentional capacity as a predictor of verbal STM span; but was inconclusive on whether rehearsal efficiency is an additional cause or a consequence of verbal STM. The effects of word length and modality on STM were replicated; a significant interaction was also found, showing a larger modality effect for long than short words, which replicates a previous finding on children. Item errors occurred more often with long words and correlated negatively with articulation rate. This set of findings seems to point to a role of rehearsal in maintaining item information. The probability of order errors per position increased linearly with list length. A revised version of a neo-Piagetian model was fit to the data of Experiment 2. That model was based on two parameters: attentional capacity (independently measured) and a free parameter representing loss of partly-activated information. The model could partly account for the results, but underestimated STM performance of the participants with smaller attentional capacity. It is concluded that modeling of verbal STM should consider individual and developmental differences in attentional capacity, rehearsal rate, and (perhaps) order representation. PMID:25798114

  19. Simultaneous extraction and biotransformation process to obtain high bioactivity phenolic compounds from Brazilian citrus residues.

    PubMed

    Madeira, Jose Valdo; Macedo, Gabriela Alves

    2015-01-01

    Recent studies have pointed to a reduction in the incidence of some cancers, diabetes, and neuro-degenerative diseases as a result of human health benefits from flavanones. Currently, flavanones are obtained by chemical synthesis or extraction from plants, and these processes are only produced in the glycosylated form. An interesting environmentally friendly alternative that deserves attention regarding phenolic compound production is the simultaneous extraction and biotransformation of these molecules. Orange juice consumption has become a worldwide dietary habit and Brazil is the largest producer of orange juice in the world. Approximately half of the citrus fruit is discarded after the juice is processed, thus generating large amounts of residues (peel and pectinolytic material). Hence, finding an environmentally clean technique to extract natural products and bioactive compounds from different plant materials has presented a challenging task over the last decades. The aim of this study was to obtain phenolics from Brazilian citrus residues with high bioactivity, using simultaneous extraction (cellulase and pectinase) and biotransformation (tannase) by enzymatic process. The highest hesperetin, naringenin and ellagic acid production in the experiment were 120, 80, and 11,250 µg g(-1), respectively, at 5.0 U mL(-1) of cellulase and 7.0 U mL(-1) of tannase at 40°C and 200 rpm. Also, the development of this process generated an increase of 77% in the total antioxidant capacity. These results suggest that the bioprocess obtained innovative results where the simultaneous enzymatic and biotransformatic extracted flavanones from agro-industrial residues was achieved without the use of organic solvents. The methodology can therefore be considered a green technology. PMID:26081498

  20. SRC Residual fuel oils

    DOEpatents

    Tewari, Krishna C.; Foster, Edward P.

    1985-01-01

    Coal solids (SRC) and distillate oils are combined to afford single-phase blends of residual oils which have utility as fuel oils substitutes. The components are combined on the basis of their respective polarities, that is, on the basis of their heteroatom content, to assure complete solubilization of SRC. The resulting composition is a fuel oil blend which retains its stability and homogeneity over the long term.

  1. Residual Neuromuscular Blockade.

    PubMed

    Plummer-Roberts, Anna L; Trost, Christina; Collins, Shawn; Hewer, Ian

    2016-02-01

    This article provides an update on residual neuromuscular blockade for nurse anesthetists. The neuromuscular junction, pharmacology for producing and reversing neuromuscular blockade, monitoring sites and methods, and patient implications relating to incomplete reversal of neuromuscular blockade are reviewed. Overall recommendations include using multiple settings when employing a peripheral nerve stimulator for monitoring return of neuromuscular function and administering pharmacologic reversal when the train-of-four ratio is below 0.9. PMID:26939390

  2. Energy from rice residues

    SciTech Connect

    Mahin, D.B.

    1990-03-01

    Developing countries produce millions of tons of rice husks and straw as a byproduct of harvesting rice. Although some of these rice residues are used for fuel or other purposes, most are burned for disposal or just dumped. However, since the mid- 1980's, industrial plants for rice residue utilization have been installed in several countries and are planned in a number of others. The report provides information on systems to produce energy from rice residues that are commercially available in the United States, Europe, and various developing countries, with an emphasis on those currently used or sold on an international level. Specifically reviewed are the use of rice husks to produce: (1) industrial process heat either directly from furnaces or by generating low pressure steam in boilers; (2) mechanical and electrical power for rice milling via steam engine systems, steam turbine/generator systems, and gasifier/engine systems; and (3) electric power for the grid. The outlook for producing energy from rice straw is also assessed. In addition, the prospects for the use of energy from husks or straw in the processing of rice bran are reviewed.

  3. Attention-deficit/hyperactivity disorder.

    PubMed

    Shaywitz, B A; Fletcher, J M; Shaywitz, S E

    1997-01-01

    In this chapter we have reviewed the diagnosis and management of attention deficit disorder, focusing particularly on the role of stimulant therapy in ADHD. Hisorical review suggests that ADHD has roots that extend back almost a century. The definition of ADHD is based on inclusion and exclusion criteria that are established by history and reflect behavioral concerns. Attention-deficit/hyperactivity disorder is a chronic disorder affecting the child's home, school, and community life. The primary symptoms of the disorder manifest a developmental pattern: activity diminishes while attentional deficits persist. Major sources of concern are the secondary and often more resistant problems of learning difficulties, behavioral problems, lack of peer acceptance, and low self-esteem. An often frustrating and perplexing characteristic of the disorder is its marked variability-over time, across situations, and within the same child and similar situations. Educational management represents an important priority and often forms the cornerstone of all other therapies, nonpharmacologic or pharmacologic. Cognitive-behavioral therapies represent the most widely used alternative to pharmacotherapy. Although the effects of CBT alone are disappointing, recent studies suggest that such therapies may provide a useful adjunct to pharmacotherapy and may be helpful when children are tapered off medication. Psychotherapy, or a combination of psychotherapy and medication (termed multimodality therapy), may also be useful. Pharmacotherapy for ADHD originated almost 60 years ago, and at this time the ameliorative effects of medications in ADHD are well established. The general skepticism of experienced clinicians, coupled with a climate where parents are reluctant to medicare children, serves to limit their use except where indicated. Although the effects of stimulants on attention and activity seem well established, effects on cognition, conduct, and social behavior are more controversial

  4. Visual Attention to Radar Displays

    NASA Technical Reports Server (NTRS)

    Moray, N.; Richards, M.; Brophy, C.

    1984-01-01

    A model is described which predicts the allocation of attention to the features of a radar display. It uses the growth of uncertainty and the probability of near collision to call the eye to a feature of the display. The main source of uncertainty is forgetting following a fixation, which is modelled as a two dimensional diffusion process. The model was used to predict information overload in intercept controllers, and preliminary validation obtained by recording eye movements of intercept controllers in simulated and live (practice) interception.

  5. Attention-deficit hyperactivity disorder.

    PubMed

    Wolraich, Mark L

    2006-12-01

    Attention-deficit hyperactivity disorder (ADHD) is a challenging condition to diagnose and treat. For diagnosis, the clinician needs to establish the presence of ADHD on Diagnostic and Statistical Manual of Mental Disorders criteria requiring information from parents and teachers and considering both alternative diagnoses and co-occurring conditions. In the treatment of ADHD as a chronic illness, the clinician needs to educate the family about the condition and partner with them about treatment decisions. The 2 treatments with demonstrated efficacy for ADHD are medications (stimulant medications and a selective norepinephrine reuptake inhibiter) and behavior-modification programs. PMID:17178358

  6. Early hominin auditory capacities.

    PubMed

    Quam, Rolf; Martínez, Ignacio; Rosa, Manuel; Bonmatí, Alejandro; Lorenzo, Carlos; de Ruiter, Darryl J; Moggi-Cecchi, Jacopo; Conde Valverde, Mercedes; Jarabo, Pilar; Menter, Colin G; Thackeray, J Francis; Arsuaga, Juan Luis

    2015-09-01

    Studies of sensory capacities in past life forms have offered new insights into their adaptations and lifeways. Audition is particularly amenable to study in fossils because it is strongly related to physical properties that can be approached through their skeletal structures. We have studied the anatomy of the outer and middle ear in the early hominin taxa Australopithecus africanus and Paranthropus robustus and estimated their auditory capacities. Compared with chimpanzees, the early hominin taxa are derived toward modern humans in their slightly shorter and wider external auditory canal, smaller tympanic membrane, and lower malleus/incus lever ratio, but they remain primitive in the small size of their stapes footplate. Compared with chimpanzees, both early hominin taxa show a heightened sensitivity to frequencies between 1.5 and 3.5 kHz and an occupied band of maximum sensitivity that is shifted toward slightly higher frequencies. The results have implications for sensory ecology and communication, and suggest that the early hominin auditory pattern may have facilitated an increased emphasis on short-range vocal communication in open habitats. PMID:26601261

  7. Albermarle boosts MASC capacity

    SciTech Connect

    D`Amico, E.

    1996-07-17

    Albemarle plans to triple capacity for methylaluminum sesquichloride (MASC) at its Houston complex. The move is in response to growing demand for aluminum alkyl catalyst systems, says Greg Lambeth, product manager/organometallics North America. MASC is the key raw material for trimethylaluminum (TMA), a Ziegler-Natta cocatalyst, and for methylaluminoxane (MAO), a cocatalyst for metallocene polyolefin catalysts. {open_quotes}This is a very competitive area because of the growing importance of metallocenes in polyolefin production,{close_quotes} Lambeth says. Several companies-including Exxon Chemical, Dow Chemical, and Hoechst - have invested in metallocene catalysts this year. Others have announced plans either to convert technology from conventional Ziegler-Natta catalyst systems or to build new facilities for metallocene catalyst production. Albemarle, the largest producer of TMA and other aluminum alkyls, completed a debottlenecking project in Houston earlier this year that increased its capacity 50%. The company also expects to complete a TMA expansion project at its Orangeburg, SC facility soon.

  8. Early hominin auditory capacities

    PubMed Central

    Quam, Rolf; Martínez, Ignacio; Rosa, Manuel; Bonmatí, Alejandro; Lorenzo, Carlos; de Ruiter, Darryl J.; Moggi-Cecchi, Jacopo; Conde Valverde, Mercedes; Jarabo, Pilar; Menter, Colin G.; Thackeray, J. Francis; Arsuaga, Juan Luis

    2015-01-01

    Studies of sensory capacities in past life forms have offered new insights into their adaptations and lifeways. Audition is particularly amenable to study in fossils because it is strongly related to physical properties that can be approached through their skeletal structures. We have studied the anatomy of the outer and middle ear in the early hominin taxa Australopithecus africanus and Paranthropus robustus and estimated their auditory capacities. Compared with chimpanzees, the early hominin taxa are derived toward modern humans in their slightly shorter and wider external auditory canal, smaller tympanic membrane, and lower malleus/incus lever ratio, but they remain primitive in the small size of their stapes footplate. Compared with chimpanzees, both early hominin taxa show a heightened sensitivity to frequencies between 1.5 and 3.5 kHz and an occupied band of maximum sensitivity that is shifted toward slightly higher frequencies. The results have implications for sensory ecology and communication, and suggest that the early hominin auditory pattern may have facilitated an increased emphasis on short-range vocal communication in open habitats. PMID:26601261

  9. Video game experience and its influence on visual attention parameters: an investigation using the framework of the Theory of Visual Attention (TVA).

    PubMed

    Schubert, Torsten; Finke, Kathrin; Redel, Petra; Kluckow, Steffen; Müller, Hermann; Strobach, Tilo

    2015-05-01

    Experts with video game experience, in contrast to non-experienced persons, are superior in multiple domains of visual attention. However, it is an open question which basic aspects of attention underlie this superiority. We approached this question using the framework of Theory of Visual Attention (TVA) with tools that allowed us to assess various parameters that are related to different visual attention aspects (e.g., perception threshold, processing speed, visual short-term memory storage capacity, top-down control, spatial distribution of attention) and that are measurable on the same experimental basis. In Experiment 1, we found advantages of video game experts in perception threshold and visual processing speed; the latter being restricted to the lower positions of the used computer display. The observed advantages were not significantly moderated by general person-related characteristics such as personality traits, sensation seeking, intelligence, social anxiety, or health status. Experiment 2 tested a potential causal link between the expert advantages and video game practice with an intervention protocol. It found no effects of action video gaming on perception threshold, visual short-term memory storage capacity, iconic memory storage, top-down control, and spatial distribution of attention after 15 days of training. However, observations of a selected improvement of processing speed at the lower positions of the computer screen after video game training and of retest effects are suggestive for limited possibilities to improve basic aspects of visual attention (TVA) with practice. PMID:25834984

  10. The role of depth of encoding in attentional capture.

    PubMed

    Sasin, Edyta; Nieuwenstein, Mark; Johnson, Addie

    2015-10-01

    The aim of the current study was to examine whether depth of encoding influences attentional capture by recently attended objects. In Experiment 1, participants first had to judge whether a word referred to a living or a nonliving thing (deep encoding condition) or whether the word was written in lower- or uppercase (shallow encoding condition), and they then had to identify a digit displayed midway in a rapid serial visual presentation (RSVP) stream of 8 pictures. A picture corresponding to the previously processed word was presented either before or after the target digit. The results showed that this picture captured attention, thus resulting in an attentional blink for identification of a target digit, in the deep encoding condition but not in the shallow encoding condition. In Experiment 2, this capture effect was found to be abolished when an additional working-memory (WM) task was performed directly after the word-judgment task, suggesting that the capture effect stemmed from residual WM activation that could be erased by means of a secondary WM task. Taken together, these results suggest that deep and shallow encoding result in different degrees of WM activation, which in turn influences the likelihood of memory-driven attentional capture. PMID:25690580

  11. Altered social attention in anorexia nervosa during real social interaction

    PubMed Central

    Dalmaso, Mario; Castelli, Luigi; Scatturin, Pietro; Carli, Lorenza; Todisco, Patrizia; Palomba, Daniela; Galfano, Giovanni

    2016-01-01

    The capacity to devote attentional resources in response to body-related signals provided by others is still largely unexplored in individuals with Anorexia Nervosa (AN). Here, we tested this capacity through a novel paradigm that mimics a social interaction with a real partner. Healthy individuals (Experiment 1) and individuals with AN (Experiment 2) completed a task with another person which consisted in performing, alternatively, rapid aiming movements to lateralised targets. Generally, this task leads to a form of Inhibition of Return (IOR), which consists of longer reaction times when an individual has to respond to a location previously searched by either himself (individual IOR) or by the partner (social IOR) as compared to previously unexplored locations. IOR is considered as an important attentional mechanism that promotes an effective exploration of the environment during social interaction. Here, healthy individuals displayed both individual and social IOR that were both reliable and of the same magnitude. Individuals with AN displayed a non-significant individual IOR but a reliable social IOR that was also significantly stronger than individual IOR. These results suggest the presence of a reduced sensitivity in processing body-related stimuli conveyed by oneself in individuals with AN which is reflected in action-based attentional processes. PMID:26984784

  12. Lead sorption-desorption from organic residues.

    PubMed

    Duarte Zaragoza, Victor M; Carrillo, Rogelio; Gutierrez Castorena, Carmen M

    2011-01-01

    Sorption and desorption are mechanisms involved in the reduction of metal mobility and bioavailability in organic materials. Metal release from substrates is controlled by desorption. The capacity of coffee husk and pulp residues, vermicompost and cow manure to adsorb Pb2+ was evaluated. The mechanisms involved in the sorption process were also studied. Organic materials retained high concentrations of lead (up to 36,000 mg L(-1)); however, the mechanisms of sorption varied according to the characteristics of each material: degree of decomposition, pH, cation exchange capacity and percentage of organic matter. Vermicompost and manure removed 98% of the Pb from solution. Lead precipitated in manure and vermicompost, forming lead oxide (PbO) and lead ferrite (PbFe4O7). Adsorption isotherms did not fit to the typical Freundlich and Langmuir equations. Not only specific and non-specific adsorption was observed, but also precipitation and coprecipitation. Lead desorption from vermicompost and cow manure was less than 2%. For remediation of Pb-polluted sites, the application of vermicompost and manure is recommended in places with alkaline soils because Pb precipitation can be induced, whereas coffee pulp residue is recommended for acidic soils where Pb is adsorbed. PMID:21780703

  13. When higher working memory capacity hinders insight.

    PubMed

    DeCaro, Marci S; Van Stockum, Charles A; Wieth, Mareike B

    2016-01-01

    Higher working memory capacity (WMC) improves performance on a range of cognitive and academic tasks. However, a greater ability to control attention sometimes leads individuals with higher WMC to persist in using complex, attention-demanding approaches that are suboptimal for a given task. We examined whether higher WMC would hinder insight problem solving, which is thought to rely on associative processes that operate largely outside of close attentional control. In addition, we examined whether characteristics of the insight problems influence whether this negative relationship will be revealed. In Experiment 1, participants completed matchstick arithmetic problems, which require a similar initial problem representation for all problems. Higher WMC was associated with less accurate insight problem solving. In Experiment 2, participants completed insight word problems, which require substantially different representations for each problem. Higher WMC was again negatively associated with insight, but only after statistically controlling for shared variance between insight and incremental problem-solving accuracy. These findings suggest that WMC may benefit performance on fundamental processes common to both incremental and insight problem solving (e.g., initial problem representation), but hinder performance on the processes that are unique to insight (e.g., solution and restructuring). By considering the WMC of the individual, and the nature of the insight task, we may better understand the process of insight and how to best support it. (PsycINFO Database Record PMID:26120772

  14. The Speed of Feature-Based Attention: Attentional Advantage Is Slow, but Selection Is Fast

    ERIC Educational Resources Information Center

    Huang, Liqiang

    2010-01-01

    When paying attention to a feature (e.g., red), no attentional advantage is gained in perceiving items with this feature in very brief displays. Therefore, feature-based attention seems to be slow. In previous feature-based attention studies, attention has often been measured as the difference in performance in a secondary task. In our recent work…

  15. On the Capacity of Attention: Its Estimation and Its Role in Working Memory and Cognitive Aptitudes

    ERIC Educational Resources Information Center

    Cowan, N.; Elliott, E.M.; Scott Saults, J.; Morey, C.C.; Mattox, S.; Hismjatullina, A.; Conway, A.R.A.

    2005-01-01

    Working memory (WM) is the set of mental processes holding limited information in a temporarily accessible state in service of cognition. We provide a theoretical framework to understand the relation between WM and aptitude measures. The WM measures that have yielded high correlations with aptitudes include separate storage-and-processing task…

  16. Attention theory and training research

    NASA Technical Reports Server (NTRS)

    Connelly, James G., Jr.; Wickens, Christopher D.; Lintern, Gavan; Harwood, Kelly

    1987-01-01

    This study used elements of attention theory as a methodological basis to decompose a complex training task in order to improve training efficiency. The complex task was a microcomputer flight simulation where subjects were required to control the stability of their own helicopter while acquiring and engaging enemy helicopers in a threat enviroment. Subjects were divided into whole-task, part-task, and part/open loop adaptive task groups in a transfer of training paradigm. The effect of reducing mental workload at the early stages of learning was examined with respect to the degree that subordinate elements of the complex task could be automated through practice of consistent, learnable stimulus-response relationships. Results revealed trends suggesting the benefit of isolating consistently mapped sub-tasks for part-task training and the presence of a time-sharing skill over and above the skill required for the separate subtasks.

  17. Attention-Deficit/Hyperactivity Disorder.

    PubMed

    Bokor, Gyula; Anderson, Peter D

    2014-08-01

    Attention-deficit/hyperactivity disorder (ADHD) is a neurobiological condition of childhood onset with the hallmarks of inattention, impulsivity, and hyperactivity. Inattention includes excessive daydreaming, disorganization, and being easily distracted. Impulsivity manifests as taking an action before fully thinking of the consequences. Hyperactivity includes an excessive rate of speech and motor activity. Complications of ADHD include academic failure, low self-esteem, poor work performance, substance abuse, criminal justice issues, and social problems. ADHD is predominately due to decreased activity in the frontal lobe. Dopamine and norepinephrine are the main neurotransmitters involved in the pathophysiology of ADHD. Pharmacological treatment of ADHD includes psychostimulants, norepinephrine reuptake inhibitors, α2 agonists, bupropion, and monoamine oxidase inhibitors. The most effective medications are the psychostimulants. Nonpharmacological treatment of ADHD includes coaching, providing structure, academic accommodations, and work accommodations. PMID:25092688

  18. Attention and the testing effect.

    PubMed

    Mulligan, Neil W; Picklesimer, Milton

    2016-06-01

    Memory retrieval often enhances still later memory as evidenced by the testing effect. Divided attention (DA) is known to produce different effects on encoding and retrieval, substantially disrupting the former and often producing little effect on the latter. The present experiments examine whether the mnemonic consequences of retrieval are similarly resilient in the face of distraction or if they have a similar sensitivity to DA as study-based encoding. In 2 experiments, participants initially studied a set of word pairs (Phase 1) then engaged in restudy of some pairs and retrieval practice of others (Phase 2), followed by either an immediate or (24-hr) delayed final cued-recall test (Phase 3). Phase 2 restudy and retrieval practice occurred under full attention (FA) or DA. Phase 2 performance replicated earlier research in finding little effect of DA on retrieval success, and greater disruption to the secondary task in the retrieval than restudy condition. More importantly, the testing effect on the final test (the difference between the retrieval and restudy conditions) was greater in the DA than FA condition. Final recall was substantially reduced by DA in the restudy condition but not in the retrieval condition. This pattern was found for related and unrelated word pairs, with feedback during retrieval practice and without, for immediate as well as delayed final tests, and for high as well as low performance on the secondary task. The encoding effects of retrieval appear to be more resilient in the face of distraction than the encoding effects of restudy. (PsycINFO Database Record PMID:26618913

  19. North American fertilizer capacity data

    SciTech Connect

    Not Available

    1991-01-01

    This listing of producers and their fertilizer production capacities was compiled in January 1991 with the cooperation of the US and Canadian fertilizer industry. Capacity is only an indicator of supply. Nameplate capacity differs from planned production levels or actual production because plants often operate above or below design capacity. Unless reported otherwise, plant capacities are based on 340 days per year of operation. No adjustment is made for partial year operation. Numerical data for the production of ammonia, ammonium nitrate, nitrogen solutions, urea, phosphate rock, phosphoric acid and ammonium phosphates is included.

  20. Deficient Attention Is Hard to Find: Applying the Perceptual Load Model of Selective Attention to Attention Deficit Hyperactivity Disorder Subtypes

    ERIC Educational Resources Information Center

    Huang-Pollock, Cynthia L.; Nigg, Joel T.; Carr, Thomas H.

    2005-01-01

    Background: Whether selective attention is a primary deficit in childhood Attention Deficit Hyperactivity Disorder (ADHD) remains in active debate. Methods: We used the "perceptual load" paradigm to examine both early and late selective attention in children with the Primarily Inattentive (ADHD-I) and Combined subtypes (ADHD-C) of ADHD. Results:…

  1. Psychiatric Issues in Palliative Care: Assessing Mental Capacity

    PubMed Central

    Udo, Itoro; Mohammed, Zeid; Gash, Amanda

    2013-01-01

    Issues surrounding capacity to consent to or refuse treatment are increasingly receiving clinical and legal attention. Through the use of 3 case vignettes that involve different aspects of mental health care in palliative care settings, mental capacity issues are discussed. The vignettes tackle capacity in a patient with newly developed mental illness consequent to physical illness, capacity in a patient with mental illness but without delirium and capacity in a patient with known impairment of the mind. These discussions give credence to best practice position where physicians act in the best interests of their patients at all times. It is important to emphasize that capacity decisions have to be made on a case by case basis, within the remit of legal protection. This is a fundamental requirement of the Mental Capacity Act 2005, England & Wales (MCA). The later is used as the legal basis for these discussions. The psychiatric liaison service is a useful resource to provide consultation, advice and or joint assessment to clinicians encountering complex dilemmas involving decision-making capacity. PMID:25278761

  2. Working memory and control of attention in persons with Alzheimer's disease and mild cognitive impairment.

    PubMed

    Belleville, Sylvie; Chertkow, Howard; Gauthier, Serge

    2007-07-01

    The goal of the present study was to assess 3 attentional control processes--divided attention, manipulation capacities, and inhibition--in persons with mild cognitive impairment (MCI) and with mild Alzheimer's disease (AD). Manipulation capacities were tested by comparing immediate serial recall with alphabetical-order recall of words. Divided attention was tested with the Brown-Peterson procedure, in which participants divide their attention between simple addition tasks and consonant trigrams over delays. Inhibition was tested with the Hayling procedure, in which participants complete sentences with words irrelevant to their context. Persons with AD showed severe impairment on the 3 attentional control components. Persons with MCI exhibited impaired performance on the Brown-Peterson procedure but normal performance on the other 2 tasks. With AD and MCI participants, there was a negative correlation between general cognitive deficits and impairment on attentional control tasks, indicating that attentional control deficits increase in the MCI/AD continuum. When separating MCI with and without significant subsequent decline, those with subsequent decline showed impaired performance on both the Brown-Peterson procedure and manipulation task. These data suggest that control of attention tasks can track AD at a preclinical stage and that impairment increases gradually during the preclinical phase of AD. PMID:17605579

  3. Rumen and cecum methane emissions between steers that are either negative or positive for residual gain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cattle produce CH4 in the rumen and the cecum, and it represents a loss of feed energy. A possible cause of variation in feed efficiency may be differences in capacity to produce CH4. We hypothesized that cattle with a higher residual gain (RG) would have a decreased capacity to produce CH4. Individ...

  4. Visual Attention to Movement and Color in Children with Cortical Visual Impairment

    ERIC Educational Resources Information Center

    Cohen-Maitre, Stacey Ann; Haerich, Paul

    2005-01-01

    This study investigated the ability of color and motion to elicit and maintain visual attention in a sample of children with cortical visual impairment (CVI). It found that colorful and moving objects may be used to engage children with CVI, increase their motivation to use their residual vision, and promote visual learning.

  5. Infant Visual Attention and Object Recognition

    PubMed Central

    Reynolds, Greg D.

    2015-01-01

    This paper explores the role visual attention plays in the recognition of objects in infancy. Research and theory on the development of infant attention and recognition memory are reviewed in three major sections. The first section reviews some of the major findings and theory emerging from a rich tradition of behavioral research utilizing preferential looking tasks to examine visual attention and recognition memory in infancy. The second section examines research utilizing neural measures of attention and object recognition in infancy as well as research on brain-behavior relations in the early development of attention and recognition memory. The third section addresses potential areas of the brain involved in infant object recognition and visual attention. An integrated synthesis of some of the existing models of the development of visual attention is presented which may account for the observed changes in behavioral and neural measures of visual attention and object recognition that occur across infancy. PMID:25596333

  6. Effects of Psychological Attention on Pronoun Comprehension

    PubMed Central

    Arnold, Jennifer E.; Lao, Shin-Yi C.

    2015-01-01

    Pronoun comprehension is facilitated for referents that are focused in the discourse context. Discourse focus has been described as a function of attention, especially shared attention, but few studies have explicitly tested this idea. Two experiments used an exogenous capture cue paradigm to demonstrate that listeners’ visual attention at the onset of a story influences their preferences during pronoun resolution later in the story. In both experiments trial-initial attention modulated listeners’ transitory biases while considering referents for the pronoun, whether it was in response to the capture cue or not. These biases even had a small influence on listeners’ final interpretation of the pronoun. These results provide independently-motivated evidence that the listener’s attention influences the on-line processes of pronoun comprehension. Trial-initial attentional shifts were made on the basis of non-shared, private information, demonstrating that attentional effects on pronoun comprehension are not restricted to shared attention among interlocutors. PMID:26191533

  7. Joint Attention, Social-Cognition, and Recognition Memory in Adults

    PubMed Central

    Kim, Kwanguk; Mundy, Peter

    2012-01-01

    The early emerging capacity for Joint Attention (JA), or socially coordinated visual attention, is thought to be integral to the development of social-cognition in childhood. Recent studies have also begun to suggest that JA affects adult cognition as well, but methodological limitations hamper research on this topic. To address this issue we developed a novel virtual reality paradigm that integrates eye-tracking and virtual avatar technology to measure two types of JA in adults, Initiating Joint Attention (IJA) and Responding to Joint Attention (RJA). Distinguishing these types of JA in research is important because they are thought to reflect unique, as well as common constellations of processes involved in human social-cognition and social learning. We tested the validity of the differentiation of IJA and RJA in our paradigm in two studies of picture recognition memory in undergraduate students. Study 1 indicated that young adults correctly identified more pictures they had previously viewed in an IJA condition (67%) than in a RJA (58%) condition, η2 = 0.57. Study 2 controlled for IJA and RJA stimulus viewing time differences, and replicated the findings of Study 1. The implications of these results for the validity of the paradigm and research on the affects of JA on adult social-cognition are discussed. PMID:22712011

  8. Selective attention in the honeybee optic lobes precedes behavioral choices

    PubMed Central

    Paulk, Angelique C.; Stacey, Jacqueline A.; Pearson, Thomas W. J.; Taylor, Gavin J.; Moore, Richard J. D.; Srinivasan, Mandyam V.; van Swinderen, Bruno

    2014-01-01

    Attention allows animals to respond selectively to competing stimuli, enabling some stimuli to evoke a behavioral response while others are ignored. How the brain does this remains mysterious, although it is increasingly evident that even animals with the smallest brains display this capacity. For example, insects respond selectively to salient visual stimuli, but it is unknown where such selectivity occurs in the insect brain, or whether neural correlates of attention might predict the visual choices made by an insect. Here, we investigate neural correlates of visual attention in behaving honeybees (Apis mellifera). Using a closed-loop paradigm that allows tethered, walking bees to actively control visual objects in a virtual reality arena, we show that behavioral fixation increases neuronal responses to flickering, frequency-tagged stimuli. Attention-like effects were reduced in the optic lobes during replay of the same visual sequences, when bees were not able to control the visual displays. When bees were presented with competing frequency-tagged visual stimuli, selectivity in the medulla (an optic ganglion) preceded behavioral selection of a stimulus, suggesting that modulation of early visual processing centers precedes eventual behavioral choices made by these insects. PMID:24639490

  9. Symbiosis of executive and selective attention in working memory

    PubMed Central

    Vandierendonck, André

    2014-01-01

    The notion of working memory (WM) was introduced to account for the usage of short-term memory resources by other cognitive tasks such as reasoning, mental arithmetic, language comprehension, and many others. This collaboration between memory and other cognitive tasks can only be achieved by a dedicated WM system that controls task coordination. To that end, WM models include executive control. Nevertheless, other attention control systems may be involved in coordination of memory and cognitive tasks calling on memory resources. The present paper briefly reviews the evidence concerning the role of selective attention in WM activities. A model is proposed in which selective attention control is directly linked to the executive control part of the WM system. The model assumes that apart from storage of declarative information, the system also includes an executive WM module that represents the current task set. Control processes are automatically triggered when particular conditions in these modules are met. As each task set represents the parameter settings and the actions needed to achieve the task goal, it will depend on the specific settings and actions whether selective attention control will have to be shared among the active tasks. Only when such sharing is required, task performance will be affected by the capacity limits of the control system involved. PMID:25152723

  10. The Capacity of Visual Short-Term Memory within and between Hemifields

    ERIC Educational Resources Information Center

    Delvenne, J.F.

    2005-01-01

    Visual short-term memory (VSTM) and attention are both thought to have a capacity limit of four items [e.g. Luck, S. J., & Vogel, E. K. (1997). The capacity of visual working memory for features and conjunctions. Nature, 309, 279-281; Pylyshyn, Z. W., & Storm, R. W. (1988). Tracking multiple independent targets: evidence for a parallel tracking…

  11. The Theory Question in Research Capacity Building in Education: Towards an Agenda for Research and Practice

    ERIC Educational Resources Information Center

    Biesta, Gert; Allan, Julie; Edwards, Richard

    2011-01-01

    The question of capacity building in education has predominantly been approached with regard to the methods and methodologies of educational research. Far less attention has been given to capacity building in relation to theory. In many ways the latter is as pressing an issue as the former, given that good research depends on a combination of high…

  12. The Contribution of Working Memory to Fluid Reasoning: Capacity, Control, or Both?

    ERIC Educational Resources Information Center

    Chuderski, Adam; Necka, Edward

    2012-01-01

    Fluid reasoning shares a large part of its variance with working memory capacity (WMC). The literature on working memory (WM) suggests that the capacity of the focus of attention responsible for simultaneous maintenance and integration of information within WM, as well as the effectiveness of executive control exerted over WM, determines…

  13. Modality-specificity of Selective Attention Networks

    PubMed Central

    Stewart, Hannah J.; Amitay, Sygal

    2015-01-01

    Objective: To establish the modality specificity and generality of selective attention networks. Method: Forty-eight young adults completed a battery of four auditory and visual selective attention tests based upon the Attention Network framework: the visual and auditory Attention Network Tests (vANT, aANT), the Test of Everyday Attention (TEA), and the Test of Attention in Listening (TAiL). These provided independent measures for auditory and visual alerting, orienting, and conflict resolution networks. The measures were subjected to an exploratory factor analysis to assess underlying attention constructs. Results: The analysis yielded a four-component solution. The first component comprised of a range of measures from the TEA and was labeled “general attention.” The third component was labeled “auditory attention,” as it only contained measures from the TAiL using pitch as the attended stimulus feature. The second and fourth components were labeled as “spatial orienting” and “spatial conflict,” respectively—they were comprised of orienting and conflict resolution measures from the vANT, aANT, and TAiL attend-location task—all tasks based upon spatial judgments (e.g., the direction of a target arrow or sound location). Conclusions: These results do not support our a-priori hypothesis that attention networks are either modality specific or supramodal. Auditory attention separated into selectively attending to spatial and non-spatial features, with the auditory spatial attention loading onto the same factor as visual spatial attention, suggesting spatial attention is supramodal. However, since our study did not include a non-spatial measure of visual attention, further research will be required to ascertain whether non-spatial attention is modality-specific. PMID:26635709

  14. The Focus of Spatial Attention Determines the Number and Precision of Face Representations in Working Memory.

    PubMed

    Towler, John; Kelly, Maria; Eimer, Martin

    2016-06-01

    The capacity of visual working memory for faces is extremely limited, but the reasons for these limitations remain unknown. We employed event-related brain potential measures to demonstrate that individual faces have to be focally attended in order to be maintained in working memory, and that attention is allocated to only a single face at a time. When 2 faces have to be memorized simultaneously in a face identity-matching task, the focus of spatial attention during encoding predicts which of these faces can be successfully maintained in working memory and matched to a subsequent test face. We also show that memory representations of attended faces are maintained in a position-dependent fashion. These findings demonstrate that the limited capacity of face memory is directly linked to capacity limits of spatial attention during the encoding and maintenance of individual face representations. We suggest that the capacity and distribution of selective spatial attention is a dynamic resource that constrains the capacity and fidelity of working memory for faces. PMID:25903465

  15. On Taylor-Series Approximations of Residual Stress

    NASA Technical Reports Server (NTRS)

    Pruett, C. David

    1999-01-01

    Although subgrid-scale models of similarity type are insufficiently dissipative for practical applications to large-eddy simulation, in recently published a priori analyses, they perform remarkably well in the sense of correlating highly against exact residual stresses. Here, Taylor-series expansions of residual stress are exploited to explain the observed behavior and "success" of similarity models. Until very recently, little attention has been given to issues related to the convergence of such expansions. Here, we re-express the convergence criterion of Vasilyev [J. Comput. Phys., 146 (1998)] in terms of the transfer function and the wavenumber cutoff of the grid filter.

  16. Aerobic capacity is correlated with the ranking of boxers.

    PubMed

    Bruzas, Vidas; Stasiulis, Arvydas; Cepulenas, Algirdas; Mockus, Pranas; Statkeviciene, Birute; Subacius, Vitalijus

    2014-08-01

    The goal was to assess the aerobic capacity of boxers and its relation with sport mastery. Participants were 12 boxers from the Lithuanian national team (VO₂max - 58.03 ± 3.00 ml/kg/min) of different weight classes. Their sport mastery ranking was established according to their achieved results during the last years of participation in amateur boxing contests. In a graduated treadmill running test, the boxers' aerobic capacity indices were established. Running speed at first and second ventilatory thresholds, VO₂max, and maximal oxygen pulse had moderate to strong correlations with the boxers' sport mastery ranking. Aerobic capacity is an important fitness component of boxers in all weight categories. Special attention should be paid to development of cardiac capacity in the boxers' training processes, as with aerobic power and anaerobic threshold training. PMID:25153738

  17. High capacity oil burner

    SciTech Connect

    Pedrosa, O.A. Jr.; Couto, N.C.; Fanqueiro, R.C.C.

    1983-11-01

    The present invention relates to a high capacity oil burner comprising a cylindrical atomizer completely surrounded by a protective cylindrical housing having a diameter from 2 to 3 times greater than the diameter of said atomizer; liquid fuels being injected under pressure into said atomizer and accumulating within said atomizer in a chamber for the accumulation of liquid fuels, and compressed air being injected into a chamber for the accumulation of air; cylindrical holes communicating said chamber for the accumulation of liquid fuels with the outside and cylindrical holes communicating said chamber for the accumulation of air with said cylindrical holes communicating the chamber for the accumulation of liquids with the outside so that the injection of compressed air into said liquid fuel discharge holes atomizes said fuel which is expelled to the outside through the end portions of said discharge holes which are circumferentially positioned to be burnt by a pilot flame; said protecting cylindrical housing having at its ends perforated circular rings into which water is injected under pressure to form a protecting fan-like water curtain at the rear end of the housing and a fan-like water curtain at the flame to reduce the formation of soot; the burning efficiency of said burner being superior to 30 barrels of liquid fuel per day/kg of the apparatus.

  18. First mideast capacity planned

    SciTech Connect

    Fattah, H.

    1996-11-06

    Kuwait catalyst Co.`s (KCC) plans to build a hydrodesulfurization (HDS) catalysts plant in Kuwait will mark the startup of the first refining catalysts production in the Persian Gulf region. KCC, owned by a conglomerate of Kuwait companies and governmental agencies, has licensed catalyst manufacturing technology from Japan Energy in a deal estimated at more than 7 billion ($62 million). Plant design will be based on technology from Orient Catalyst, Japan Energy`s catalysts division. Construction is expected to begin in January 1997 for production startup by January 1998. A source close to the deal says the new plant will eventually reach a capacity of 5,000 m.t./year of HDS catalysts to supply most of Kuwait`s estimated 3,500-m.t./year demand, driven primarily by Kuwait National Petroleum refineries. KCC also expects to supply demand from other catalyst consumers in the region. Alumina supply will be acquired on the open market. KCC will take all production from the plant and will be responsible for marketing.

  19. Advanced work capacity testing.

    PubMed

    Bretz, Károly J; Dános, László; Smudla, Szilvia; Pálosi, Adrienn

    2015-01-01

    The aim of this study is to describe an accurate work capacity testing which can be used in the industry, as well as in rehabilitation process. The first part of this paper is dealing with the NIOSH lifting equation, which is a tool used by occupational health and safety professionals. The second part of this paper summarizes the features and applications of the "ErgoScope" work simulator. Static and dynamic strength of upper and lower limbs, as well as whole body efforts can be measured. The equipment makes it possible to evaluate pushing, pulling, lifting and carrying activities comprising reaching, bending and stooping movements. In the third part of this paper we demonstrate handgrip force data recorded using the "ErgoScope" work simulator comparing with handgrip force data published in the literature. "ErgoScope" work simulator is capable to measure handgrip and pinch forces, suitable to evaluate fine motor skills, hand and finger dexterity, as well as reaction times. PMID:26294589

  20. Context-Dependent Control over Attentional Capture

    ERIC Educational Resources Information Center

    Cosman, Joshua D.; Vecera, Shaun P.

    2013-01-01

    A number of studies have demonstrated that the likelihood of a salient item capturing attention is dependent on the "attentional set" an individual employs in a given situation. The instantiation of an attentional set is often viewed as a strategic, voluntary process, relying on working memory systems that represent immediate task priorities.…

  1. 34 CFR 303.706 - Public attention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 2 2014-07-01 2013-07-01 true Public attention. 303.706 Section 303.706 Education... Funds Federal and State Monitoring and Enforcement § 303.706 Public attention. Whenever a State receives... attention of the public within the State, including by posting the notice on the Web site of the lead...

  2. 34 CFR 303.706 - Public attention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Public attention. 303.706 Section 303.706 Education... Funds Federal and State Monitoring and Enforcement § 303.706 Public attention. Whenever a State receives... attention of the public within the State, including by posting the notice on the Web site of the lead...

  3. Attention to Faces in Williams Syndrome

    ERIC Educational Resources Information Center

    Riby, Deborah M.; Jones, Nicola; Brown, Philippa H.; Robinson, Lucy J.; Langton, Stephen R. H.; Bruce, Vicki; Riby, Leigh M.

    2011-01-01

    Williams syndrome (WS) is associated with distinct social behaviours. One component of the WS social phenotype is atypically prolonged face fixation. This behaviour co-exists with attention difficulties. Attention is multi-faceted and may impact on gaze behaviour in several ways. Four experiments assessed (i) attention capture by faces, (ii)…

  4. Behold: Silence and Attention in Education

    ERIC Educational Resources Information Center

    Lewin, David

    2014-01-01

    Educators continually ask about the best means to engage students and how best to capture attention. These concerns often make the problematic assumption that students can directly govern their own attention. In order to address the role and limits of attention in education, some theorists have sought to recover the significance of silence or…

  5. Properties of Attention during Reading Lessons.

    ERIC Educational Resources Information Center

    Imai, Mutsumi; And Others

    A study investigated the attention of 116 children in 6 second- and third-grade classrooms while they participated in 4 lessons involving progressively more difficult stories. Analysis of videotapes of the lessons revealed that the likelihood of a lapse of attention was highest during the first 15 seconds of attention episodes. Lapses in attention…

  6. Attention Dysfunction Subtypes of Developmental Dyslexia

    PubMed Central

    Lewandowska, Monika; Milner, Rafał; Ganc, Małgorzata; Włodarczyk, Elżbieta; Skarżyński, Henryk

    2014-01-01

    Background Previous studies indicate that many different aspects of attention are impaired in children diagnosed with developmental dyslexia (DD). The objective of the present study was to identify cognitive profiles of DD on the basis of attentional test performance. Material/Methods 78 children with DD (30 girls, 48 boys, mean age of 12 years ±8 months) and 32 age- and sex-matched non-dyslexic children (14 girls, 18 boys) were examined using a battery of standardized tests of reading, phonological and attentional processes (alertness, covert shift of attention, divided attention, inhibition, flexibility, vigilance, and visual search). Cluster analysis was used to identify subtypes of DD. Results Dyslexic children showed deficits in alertness, covert shift of attention, divided attention, flexibility, and visual search. Three different subtypes of DD were identified, each characterized by poorer performance on the reading, phonological awareness, and visual search tasks. Additionally, children in cluster no. 1 displayed deficits in flexibility and divided attention. In contrast to non-dyslexic children, cluster no. 2 performed poorer in tasks involving alertness, covert shift of attention, divided attention, and vigilance. Cluster no. 3 showed impaired covert shift of attention. Conclusions These results indicate different patterns of attentional impairments in dyslexic children. Remediation programs should address the individual child’s deficit profile. PMID:25387479

  7. Search Asymmetry, Sustained Attention, and Response Inhibition

    ERIC Educational Resources Information Center

    Stevenson, Hugh; Russell, Paul N.; Helton, William S.

    2011-01-01

    In the present experiment, we used search asymmetry to test whether the sustained attention to response task is a better measure of response inhibition or sustained attention. Participants performed feature present and feature absent target detection tasks using either a sustained attention to response task (SART; high Go low No-Go) or a…

  8. Attentional Bias for Exercise-Related Images

    ERIC Educational Resources Information Center

    Berry, Tanya R.; Spence, John C.; Stolp, Sean M.

    2011-01-01

    This research examined attentional bias toward exercise-related images using a visual probe task. It was hypothesized that more-active participants would display attentional bias toward the exercise-related images. The results showed that men displayed attentional bias for the exercise images. There was a significant interaction of activity level…

  9. Everyday Attention Failures: An Individual Differences Investigation

    ERIC Educational Resources Information Center

    Unsworth, Nash; McMillan, Brittany D.; Brewer, Gene A.; Spillers, Gregory J.

    2012-01-01

    The present study examined individual differences in everyday attention failures. Undergraduate students completed various cognitive ability measures in the laboratory and recorded everyday attention failures in a diary over the course of a week. The majority of attention failures were failures of distraction or mind wandering in educational…

  10. Persistence of Value-Driven Attentional Capture

    ERIC Educational Resources Information Center

    Anderson, Brian A.; Yantis, Steven

    2013-01-01

    Stimuli that have previously been associated with the delivery of reward involuntarily capture attention when presented as unrewarded and task-irrelevant distractors in a subsequent visual search task. It is unknown how long such effects of reward learning on attention persist. One possibility is that value-driven attentional biases are plastic…

  11. Perceptual Load Influences Selective Attention across Development

    ERIC Educational Resources Information Center

    Couperus, Jane W.

    2011-01-01

    Research suggests that visual selective attention develops across childhood. However, there is relatively little understanding of the neurological changes that accompany this development, particularly in the context of adult theories of selective attention, such as N. Lavie's (1995) perceptual load theory of attention. This study examined visual…

  12. Target Predictability, Sustained Attention, and Response Inhibition

    ERIC Educational Resources Information Center

    Carter, Leonie; Russell, Paul N.; Helton, William S.

    2013-01-01

    We examined whether the sustained attention to response task is a better measure of response inhibition or sustained attention. Participants performed a number detection task for 37.3 min using either a Sustained Attention to Response Task (SART; high Go low No-Go) or a more traditionally formatted vigilance task (TFT; high No-Go low Go) response…

  13. Attention to Affect in Language Learning

    ERIC Educational Resources Information Center

    Arnold, Jane

    2011-01-01

    As language teachers, we have to pay attention to many things in our work so why add "attention to affect"? Perhaps the simplest, most direct answer is that whatever we focus most on in our particular context, be it general English, morphosyntax, phonetics, literature, English for academic writing or any other special area, attention to affect…

  14. Bilingualism and Enhanced Attention in Early Adulthood

    ERIC Educational Resources Information Center

    Stafford, Catherine A.

    2011-01-01

    This exploratory study investigated executive attention during nonverbal and verbal processing among adults with a range of bilingual experience. Previous research has found that bilingual children control their attention better than their monolingual peers and that superior attentional control in some processing contexts persists into adulthood…

  15. Attentional Factors in Learning. Final Report.

    ERIC Educational Resources Information Center

    Johnson, Daniel F.

    Research was conducted on two selective attention systems in learning situations. The theoretical and experimental approaches are presented in a set of six papers. One paper considered directions in attention theory and five papers report experiments with pigeon and children subjects. The two attention systems are (1) coding response, which…

  16. Separable Attentional Predictors of Language Outcome

    ERIC Educational Resources Information Center

    Salley, Brenda; Panneton, Robin K.; Colombo, John

    2013-01-01

    The aim of this study was to examine the combined influences of infants' attention and use of social cues in the prediction of their language outcomes. This longitudinal study measured infants' visual attention on a distractibility task (11 months), joint attention (14 months), and language outcomes (word-object association, 14 months;…

  17. THE ELECTRICAL CAPACITY OF VALONIA : DIRECT CURRENT MEASUREMENTS.

    PubMed

    Blinks, L R; Skow, R K

    1940-11-20

    Impaled cells of Valonia were balanced in a Wheatstone bridge against a simple series-parallel circuit of two resistances and a capacity, the transient charge and discharge curves at make and break of direct current being recorded with a string galvanometer. With the resistances properly balanced, a series of characteristic deflections resulted when the balancing capacity was varied. With many cells, no complete capacity balance was ever attained over the entire transient time course; but instead either a monophasic or diphasic residual deflection always remained. This behavior is comparable to that of a polarizing electrode in D.C., although not so clearly marked; and it is concluded that Valonia usually has an appreciable polarization component, probably in parallel with a static capacity. However, some cells can be balanced almost completely against a mica condenser of proper value, which indicates that they display a nearly pure static capacity under some conditions. This static state could be produced experimentally by exposure to weak acids (acetic, carbonic, etc.) and by metabolic agents probably inducing internal acidity (low oxygen tension, long exposure to cold, narcotics, etc.). Conversely, penetrating weak bases, such as ammonia, abolished the static capacity, or even any regular polarization. Light acts something like ammonia, after an initial "acid gush" anomaly. Most of these agents likewise affect the P.D. and its response to external ionic alterations, and it seems likely that the change in capacity type reflects altered ionic permeabilities and relative mobilities. PMID:19873211

  18. Capacity Utilization Study for Aviation Security Cargo Inspection Queuing System

    SciTech Connect

    Allgood, Glenn O; Olama, Mohammed M; Lake, Joe E; Brumback, Daryl L

    2010-01-01

    In this paper, we conduct performance evaluation study for an aviation security cargo inspection queuing system for material flow and accountability. The queuing model employed in our study is based on discrete-event simulation and processes various types of cargo simultaneously. Onsite measurements are collected in an airport facility to validate the queuing model. The overall performance of the aviation security cargo inspection system is computed, analyzed, and optimized for the different system dynamics. Various performance measures are considered such as system capacity, residual capacity, throughput, capacity utilization, subscribed capacity utilization, resources capacity utilization, subscribed resources capacity utilization, and number of cargo pieces (or pallets) in the different queues. These metrics are performance indicators of the system s ability to service current needs and response capacity to additional requests. We studied and analyzed different scenarios by changing various model parameters such as number of pieces per pallet, number of TSA inspectors and ATS personnel, number of forklifts, number of explosives trace detection (ETD) and explosives detection system (EDS) inspection machines, inspection modality distribution, alarm rate, and cargo closeout time. The increased physical understanding resulting from execution of the queuing model utilizing these vetted performance measures should reduce the overall cost and shipping delays associated with new inspection requirements.

  19. Capacity utilization study for aviation security cargo inspection queuing system

    NASA Astrophysics Data System (ADS)

    Allgood, Glenn O.; Olama, Mohammed M.; Lake, Joe E.; Brumback, Daryl

    2010-04-01

    In this paper, we conduct performance evaluation study for an aviation security cargo inspection queuing system for material flow and accountability. The queuing model employed in our study is based on discrete-event simulation and processes various types of cargo simultaneously. Onsite measurements are collected in an airport facility to validate the queuing model. The overall performance of the aviation security cargo inspection system is computed, analyzed, and optimized for the different system dynamics. Various performance measures are considered such as system capacity, residual capacity, throughput, capacity utilization, subscribed capacity utilization, resources capacity utilization, subscribed resources capacity utilization, and number of cargo pieces (or pallets) in the different queues. These metrics are performance indicators of the system's ability to service current needs and response capacity to additional requests. We studied and analyzed different scenarios by changing various model parameters such as number of pieces per pallet, number of TSA inspectors and ATS personnel, number of forklifts, number of explosives trace detection (ETD) and explosives detection system (EDS) inspection machines, inspection modality distribution, alarm rate, and cargo closeout time. The increased physical understanding resulting from execution of the queuing model utilizing these vetted performance measures should reduce the overall cost and shipping delays associated with new inspection requirements.

  20. Residual strength of thin panels with cracks

    NASA Technical Reports Server (NTRS)

    Madenci, Erdogan

    1994-01-01

    The previous design philosophies involving safe life, fail-safe and damage tolerance concepts become inadequate for assuring the safety of aging aircraft structures. For example, the failure mechanism for the Aloha Airline accident involved the coalescence of undetected small cracks at the rivet holes causing a section of the fuselage to peel open during flight. Therefore, the fuselage structure should be designed to have sufficient residual strength under worst case crack configurations and in-flight load conditions. Residual strength is interpreted as the maximum load carrying capacity prior to unstable crack growth. Internal pressure and bending moment constitute the two major components of the external loads on the fuselage section during flight. Although the stiffeners in the form of stringers, frames and tear straps sustain part of the external loads, the significant portion of the load is taken up by the skin. In the presence of a large crack in the skin, the crack lips bulge out with considerable yielding; thus, the geometric and material nonlinearities must be included in the analysis for predicting residual strength. Also, these nonlinearities do not permit the decoupling of in-plane and out-of-plane bending deformations. The failure criterion combining the concepts of absorbed specific energy and strain energy density addresses the aforementioned concerns. The critical absorbed specific energy (local toughness) for the material is determined from the global specimen response and deformation geometry based on the uniaxial tensile test data and detailed finite element modeling of the specimen response. The use of the local toughness and stress-strain response at the continuum level eliminates the size effect. With this critical parameter and stress-strain response, the finite element analysis of the component by using STAGS along with the application of this failure criterion provides the stable crack growth calculations for residual strength predictions.

  1. Early vision and focal attention

    NASA Astrophysics Data System (ADS)

    Julesz, Bela

    1991-07-01

    At the thirty-year anniversary of the introduction of the technique of computer-generated random-dot stereograms and random-dot cinematograms into psychology, the impact of the technique on brain research and on the study of artificial intelligence is reviewed. The main finding-that stereoscopic depth perception (stereopsis), motion perception, and preattentive texture discrimination are basically bottom-up processes, which occur without the help of the top-down processes of cognition and semantic memory-greatly simplifies the study of these processes of early vision and permits the linking of human perception with monkey neurophysiology. Particularly interesting are the unexpected findings that stereopsis (assumed to be local) is a global process, while texture discrimination (assumed to be a global process, governed by statistics) is local, based on some conspicuous local features (textons). It is shown that the top-down process of "shape (depth) from shading" does not affect stereopsis, and some of the models of machine vision are evaluated. The asymmetry effect of human texture discrimination is discussed, together with recent nonlinear spatial filter models and a novel extension of the texton theory that can cope with the asymmetry problem. This didactic review attempts to introduce the physicist to the field of psychobiology and its problems-including metascientific problems of brain research, problems of scientific creativity, the state of artificial intelligence research (including connectionist neural networks) aimed at modeling brain activity, and the fundamental role of focal attention in mental events.

  2. Residual gas analyzer calibration

    NASA Technical Reports Server (NTRS)

    Lilienkamp, R. H.

    1972-01-01

    A technique which employs known gas mixtures to calibrate the residual gas analyzer (RGA) is described. The mass spectra from the RGA are recorded for each gas mixture. This mass spectra data and the mixture composition data each form a matrix. From the two matrices the calibration matrix may be computed. The matrix mathematics requires the number of calibration gas mixtures be equal to or greater than the number of gases included in the calibration. This technique was evaluated using a mathematical model of an RGA to generate the mass spectra. This model included shot noise errors in the mass spectra. Errors in the gas concentrations were also included in the valuation. The effects of these errors was studied by varying their magnitudes and comparing the resulting calibrations. Several methods of evaluating an actual calibration are presented. The effects of the number of gases in then, the composition of the calibration mixture, and the number of mixtures used are discussed.

  3. Focused and divided attention in Alzheimer's disease.

    PubMed

    Nebes, R D; Brady, C B

    1989-06-01

    Visual search tasks were used to examine two aspects of selective attention (focused and divided attention) in normal young and older persons and in Alzheimer patients. Normal and demented subjects were equally efficient in using a color cue to selectively search only the relevant items in an array. Thus, focused attention abilities appear to be relatively unimpaired by Alzheimer's disease. By contrast, in comparison to normals, the search time of demented patients rose disproportionately as the number of items over which they had to distribute their attention was increased. This suggests that Alzheimer patients are less efficient than normals in dividing their attention. PMID:2758855

  4. Parameter-based assessment of disturbed and intact components of visual attention in children with developmental dyslexia.

    PubMed

    Bogon, Johanna; Finke, Kathrin; Schulte-Körne, Gerd; Müller, Hermann J; Schneider, Werner X; Stenneken, Prisca

    2014-09-01

    People with developmental dyslexia (DD) have been shown to be impaired in tasks that require the processing of multiple visual elements in parallel. It has been suggested that this deficit originates from disturbed visual attentional functions. The parameter-based assessment of visual attention based on Bundesen's () theory of visual attention allows one to identify and quantify the underlying deficits. The present study provides the first groupwise comparison between children with DD (n = 12; mean age 9.84 years) and typically developing children (n = 12; mean age 9.87 years) with regard to intact and disturbed components of visual attention. From the performance on whole- and partial-report tasks, we derived individual parameter estimates of four different parameters: visual processing speed, storage capacity of visual short-term memory (VSTM), laterality of attentional weighting and efficiency of top-down control. Groupwise comparisons revealed that general attentional resources, processing speed and VSTM storage capacity, are impaired in children with DD compared to typically developing children. In contrast, selectivity parameters, laterality of attentional selection and attentional top-down control did not differ between these groups. Relating the current findings to previous results, obtained in highly comparable methodological settings, from single cases of children with DD, and from a group of adults with DD, we conclude that slowed perceptual processing speed is a primary visual attentional deficit in DD. Furthermore, reduced VSTM storage capacity seems to modulate the difficulties in written language processing imposed by the disorder. PMID:24576161

  5. Bioethics for clinicians: 3. Capacity.

    PubMed Central

    Etchells, E; Sharpe, G; Elliott, C; Singer, P A

    1996-01-01

    In the context of patient consent, "capacity" refers to the patient's ability to understand information relevant to a treatment decision and to appreciate the reasonably foreseeable consequences of a decision or lack of decision. A person may be "capable" with respect to one decision but not with respect to another. Clinicians can usually identify patients who are clearly capable or incapable, but in some cases a clinical capacity assessment is required. Such assessment may consist of cognitive status testing, general impressions of capacity or specific capacity assessment. Specific capacity assessment, in which the clinician evaluates the patient's ability to understand pertinent information and appreciate its implications, is probably the optimal method. When conducting a specific capacity assessment, the clinician must ensure that the disclosure of information is effective and must evaluate the patient's reason for his or her decision. If the assessment suggests that the patient is incapable, further assessment is generally recommended. PMID:8823211

  6. Consciousness and Attention: On Sufficiency and Necessity

    PubMed Central

    van Boxtel, Jeroen J. A.; Tsuchiya, Naotsugu; Koch, Christof

    2010-01-01

    Recent research has slowly corroded a belief that selective attention and consciousness are so tightly entangled that they cannot be individually examined. In this review, we summarize psychophysical and neurophysiological evidence for a dissociation between top-down attention and consciousness. The evidence includes recent findings that show subjects can attend to perceptually invisible objects. More contentious is the finding that subjects can become conscious of an isolated object, or the gist of the scene in the near absence of top-down attention; we critically re-examine the possibility of “complete” absence of top-down attention. We also cover the recent flurry of studies that utilized independent manipulation of attention and consciousness. These studies have shown paradoxical effects of attention, including examples where top-down attention and consciousness have opposing effects, leading us to strengthen and revise our previous views. Neuroimaging studies with EEG, MEG, and fMRI are uncovering the distinct neuronal correlates of selective attention and consciousness in dissociative paradigms. These findings point to a functional dissociation: attention as analyzer and consciousness as synthesizer. Separating the effects of selective visual attention from those of visual consciousness is of paramount importance to untangle the neural substrates of consciousness from those for attention. PMID:21833272

  7. Prefrontal control of attention to threat.

    PubMed

    Peers, Polly V; Simons, Jon S; Lawrence, Andrew D

    2013-01-01

    Attentional control refers to the regulatory processes that ensure that our actions are in accordance with our goals. Dual-system accounts view temperament as consisting of both individual variation in emotionality (e.g., trait anxiety) and variation in regulatory attentional mechanisms that act to modulate emotionality. Increasing evidence links trait variation in attentional control to clinical mood and anxiety disorder symptoms, independent of trait emotionality. Attentional biases to threat have been robustly linked to mood and anxiety disorders. However, the role of variation in attentional control in influencing such biases, and the neural underpinnings of trait variation in attentional control, are unknown. Here, we show that individual differences in trait attentional control, even when accounting for trait and state anxiety, are related to the magnitude of an attentional blink (AB) following threat-related targets. Moreover, we demonstrate that activity in dorso-lateral prefrontal cortex (DLPFC), is observed specifically in relation to control of attention over threatening stimuli, in line with neural theories of attentional control, such as guided activation theory. These results have key implications for neurocognitive theories of attentional bias and emotional resilience. PMID:23386824

  8. Introduction of germline residues improves the stability of anti-HIV mAb 2G12-IgM

    PubMed Central

    Chromikova, Veronika; Mader, Alexander; Hofbauer, Stefan; Göbl, Christoph; Madl, Tobias; Gach, Johannes S.; Bauernfried, Stefan; Furtmüller, Paul G.; Forthal, Donald N.; Mach, Lukas; Obinger, Christian; Kunert, Renate

    2015-01-01

    Immunoglobulins M (IgMs) are gaining increasing attention as biopharmaceuticals since their multivalent mode of binding can give rise to high avidity. Furthermore, IgMs are potent activators of the complement system. However, they are frequently difficult to express recombinantly and can suffer from low conformational stability. Here, the broadly neutralizing anti-HIV-1 antibody 2G12 was class-switched to IgM and then further engineered by introduction of 17 germline residues. The impact of these changes on the structure and conformational stability of the antibody was then assessed using a range of biophysical techniques. We also investigated the effects of the class switch and germline substitutions on the ligand-binding properties of 2G12 and its capacity for HIV-1 neutralization. Our results demonstrate that the introduced germline residues improve the conformational and thermal stability of 2G12-IgM without altering its overall shape and ligand-binding properties. Interestingly, the engineered protein was found to exhibit much lower neutralization potency than its wild-type counterpart, indicating that potent antigen recognition is not solely responsible for IgM-mediated HIV-1 inactivation. PMID:25748881

  9. Introduction of germline residues improves the stability of anti-HIV mAb 2G12-IgM.

    PubMed

    Chromikova, Veronika; Mader, Alexander; Hofbauer, Stefan; Göbl, Christoph; Madl, Tobias; Gach, Johannes S; Bauernfried, Stefan; Furtmüller, Paul G; Forthal, Donald N; Mach, Lukas; Obinger, Christian; Kunert, Renate

    2015-10-01

    Immunoglobulins M (IgMs) are gaining increasing attention as biopharmaceuticals since their multivalent mode of binding can give rise to high avidity. Furthermore, IgMs are potent activators of the complement system. However, they are frequently difficult to express recombinantly and can suffer from low conformational stability. Here, the broadly neutralizing anti-HIV-1 antibody 2G12 was class-switched to IgM and then further engineered by introduction of 17 germline residues. The impact of these changes on the structure and conformational stability of the antibody was then assessed using a range of biophysical techniques. We also investigated the effects of the class switch and germline substitutions on the ligand-binding properties of 2G12 and its capacity for HIV-1 neutralization. Our results demonstrate that the introduced germline residues improve the conformational and thermal stability of 2G12-IgM without altering its overall shape and ligand-binding properties. Interestingly, the engineered protein was found to exhibit much lower neutralization potency than its wild-type counterpart, indicating that potent antigen recognition is not solely responsible for IgM-mediated HIV-1 inactivation. PMID:25748881

  10. CHP Installed Capacity Optimizer Software

    Energy Science and Technology Software Center (ESTSC)

    2004-11-30

    The CHP Installed Capacity Optimizer is a Microsoft Excel spreadsheet application that determines the most economic amount of capacity of distributed generation and thermal utilization equipment (e.g., absorption chillers) to install for any user-defined set of load and cost data. Installing the optimum amount of capacity is critical to the life-cycle economic viability of a distributed generation/cooling heat and power (CHP) application. Using advanced optimization algorithms, the software accesses the loads, utility tariffs, equipment costs,more » etc., and provides to the user the most economic amount of system capacity to install.« less

  11. CHP Installed Capacity Optimizer Software

    SciTech Connect

    2004-11-30

    The CHP Installed Capacity Optimizer is a Microsoft Excel spreadsheet application that determines the most economic amount of capacity of distributed generation and thermal utilization equipment (e.g., absorption chillers) to install for any user-defined set of load and cost data. Installing the optimum amount of capacity is critical to the life-cycle economic viability of a distributed generation/cooling heat and power (CHP) application. Using advanced optimization algorithms, the software accesses the loads, utility tariffs, equipment costs, etc., and provides to the user the most economic amount of system capacity to install.

  12. Adaptive capacity and its assessment

    SciTech Connect

    Engle, Nathan L.

    2011-04-20

    This paper reviews the concept of adaptive capacity and various approaches to assessing it, particularly with respect to climate variability and change. I find that adaptive capacity is a relatively under-researched topic within the sustainability science and global change communities, particularly since it is uniquely positioned to improve linkages between vulnerability and resilience research. I identify opportunities for advancing the measurement and characterization of adaptive capacity by combining insights from both vulnerability and resilience frameworks, and I suggest several assessment approaches for possible future development that draw from both frameworks and focus on analyzing the governance, institutions, and management that have helped foster adaptive capacity in light of recent climatic events.

  13. Materials recovery from shredder residues

    SciTech Connect

    Daniels, E. J.; Jody, B. J.; Pomykala, J., Jr.

    2000-07-24

    Each year, about five (5) million ton of shredder residues are landfilled in the US. Similar quantities are landfilled in Europe and the Pacific Rim. Landfilling of these residues results in a cost to the existing recycling industry and also represents a loss of material resources that are otherwise recyclable. In this paper, the authors outline the resources recoverable from typical shredder residues and describe technology that they have developed to recover these resources.

  14. 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. PMID:26754810

  15. Attention deficit disorder: current perspectives.

    PubMed

    Shaywitz, S E; Shaywitz, B A

    1987-01-01

    This review focuses on selected issues in the rapidly proliferating scientific literature on attention deficit disorder (ADD). It encompasses a brief overview of ADD, including a review of the historical trends, causation, and a description of the clinical characteristics. Critical issues fundamental to understanding of ADD are addressed next. Evidence is presented to suggest that there are several groups of children with ADD who are currently under-identified and therefore, underserved (girls with ADD; ADD without hyperactivity). The concept is introduced of uncomplicated ADD and ADD-Plus (ADD-P), a term used to designate ADD associated with other complicating features such as conduct disorder. Specific methodologic issues and their relationship to the under-identification of these groups of children follows. This discussion encompasses the reasons for diagnostic imprecision and inconsistency, emphasizing the problem of selective referral patterns and how it results in an inaccurate portrait of ADD. We then present new approaches to the definition and diagnosis of ADD based on empiric studies designed to circumvent some of these problems. We conclude with a summary of the implications of these findings, and recommendations for public policy in ADD, particularly the need to recognize that ADD may occur even in the most intellectually gifted individuals and even in students in select colleges. Often these children with the highest potential are penalized most, not because of conceptual limitations or because they do not understand, but because educators often fail to recognize the symptom complex. Many of these children are succeeding through intelligence and great effort, but many more could succeed with proper identification. PMID:3334012

  16. Microwave emission and crop residues

    NASA Technical Reports Server (NTRS)

    Jackson, Thomas J.; O'Neill, Peggy E.

    1991-01-01

    A series of controlled experiments were conducted to determine the significance of crop residues or stubble in estimating the emission of the underlying soil. Observations using truck-mounted L and C band passive microwave radiometers showed that for dry wheat and soybeans the dry residue caused negligible attenuation of the background emission. Green residues, with water contents typical of standing crops, did have a significant effect on the background emission. Results for these green residues also indicated that extremes in plant structure, as created using parallel and perpendicular stalk orientations, can cause very large differences in the degree of attenuation.

  17. Separable Attentional Predictors of Language Outcome

    PubMed Central

    Salley, Brenda; Panneton, Robin K.; Colombo, John

    2014-01-01

    The aim of this study was to examine the combined influences of infants attention and use of social cues in the prediction of their language outcomes. This longitudinal study measured infants' visual attention on a distractibility task (11 months), joint attention (14 months), and language outcomes (word –object association, 14 months; MBCDI vocabulary size and multi-word productions at 18 months of age). Path analyses were conducted for two different language outcomes. The analysis for vocabulary revealed unique direct prediction from infants' visual attention on a distractibility task (i.e., maintaining attention to a target event in the presence of competing events) and joint attention (i.e., more frequent response to tester's bids for attention) for larger vocabulary size at outcome; this model accounted for 48% of variance in vocabulary, after controlling for baseline communication status (assessed at 11 months). The analysis for multi-word productions yielded direct effects for infants' distractibility, but not joint attention; this model accounted for 45% of variance in multi-word productions, again after controlling for baseline communication status. Indirect effects were not significant in either model. Results are discussed in light of the unique predictive role of attentional factors and social/attention cues for emerging language. PMID:25342932

  18. Encoding attentional states during visuomotor adaptation.

    PubMed

    Im, Hee Yeon; Bédard, Patrick; Song, Joo-Hyun

    2015-01-01

    We recently showed that visuomotor adaptation acquired under attentional distraction is better recalled under a similar level of distraction compared to no distraction. This paradoxical effect suggests that attentional state (e.g., divided or undivided) is encoded as an internal context during visuomotor learning and should be reinstated for successful recall (Song & Bédard, 2015). To investigate if there is a critical temporal window for encoding attentional state in visuomotor memory, we manipulated whether participants performed the secondary attention-demanding task concurrently in the early or late phase of visuomotor learning. Recall performance was enhanced when the attentional states between recall and the early phase of visuomotor learning were consistent. However, it reverted to untrained levels when tested under the attentional state of the late-phase learning. This suggests that attentional state is primarily encoded during the early phase of learning before motor errors decrease and reach an asymptote. Furthermore, we demonstrate that when divided and undivided attentional states were mixed during visuomotor adaptation, only divided attention was encoded as an internal cue for memory retrieval. Therefore, a single attentional state appears to be primarily integrated with visuomotor memory while motor error reduction is in progress during learning. PMID:26114683

  19. How do infants recognize joint attention?

    PubMed

    Gustafsson, Erik; Brisson, Julie; Beaulieu, Christelle; Mainville, Marc; Mailloux, Dominique; Sirois, Sylvain

    2015-08-01

    The emergence of joint attention is still a matter of vigorous debate. It involves diverse hypotheses ranging from innate modules dedicated to intention reading to more neuro-constructivist approaches. The aim of this study was to assess whether 12-month-old infants are able to recognize a "joint attention" situation when observing such a social interaction. Using a violation-of-expectation paradigm, we habituated infants to a "joint attention" video and then compared their looking time durations between "divergent attention" videos and "joint attention" ones using a 2 (familiar or novel perceptual component)×2 (familiar or novel conceptual component) factorial design. These results were enriched with measures of pupil dilation, which are considered to be reliable measures of cognitive load. Infants looked longer at test events that involved novel speaker and divergent attention but no changes in infants' pupil dilation were observed in any conditions. Although looking time data suggest that infants may appreciate discrepancies from expectations related to joint attention behavior, in the absence of clear evidence from pupillometry, the results show no demonstration of understanding of joint attention, even at a tacit level. Our results suggest that infants may be sensitive to relevant perceptual variables in joint attention situations, which would help scaffold social cognitive development. This study supports a gradual, learning interpretation of how infants come to recognize, understand, and participate in joint attention. PMID:26036712

  20. Are attentional control resources reduced by worry in generalized anxiety disorder?

    PubMed

    Stefanopoulou, Evgenia; Hirsch, Colette R; Hayes, Sarra; Adlam, Anna; Coker, Sian

    2014-05-01

    This is the first study to examine attentional control capacities in generalized anxiety disorder (GAD). GAD is characterized by uncontrollable worry. Individuals diagnosed with GAD and healthy participants (HPs) performed a random key-pressing task while thinking about a worrisome or a positive future event, to assess the extent to which attentional control resources are used by worry. Attentional control was also assessed when participants were not instructed to think about a specific topic using the N-back task, which varies in task difficulty, and therefore is sensitive to subtle differences in ability to handle increasing demands on attentional control within the same paradigm. GAD participants (but not HPs) were less random while worrying than thinking about a positive event during the key-pressing task, suggesting that worry consumed more attentional control resources in this population. During the N-Back task, GAD participants performed worse than HPs during the high load conditions only, indicating greater difficulty in sustaining focus on conditions requiring a higher degree of attentional control, even without concurrent task activity. Poor attentional control might underpin the difficulty of GAD individuals to stop worrying and switch to thinking more benign information. Further research could investigate whether worry consumes attentional control resources in other psychological disorders with high rates of worry (e.g., panic disorder, psychosis), as well as the extent to which attentional control is used by other forms of repetitive thinking, such as depressive rumination. PMID:24886007

  1. Are Attentional Control Resources Reduced by Worry in Generalized Anxiety Disorder?

    PubMed Central

    2014-01-01

    This is the first study to examine attentional control capacities in generalized anxiety disorder (GAD). GAD is characterized by uncontrollable worry. Individuals diagnosed with GAD and healthy participants (HPs) performed a random key-pressing task while thinking about a worrisome or a positive future event, to assess the extent to which attentional control resources are used by worry. Attentional control was also assessed when participants were not instructed to think about a specific topic using the N-back task, which varies in task difficulty, and therefore is sensitive to subtle differences in ability to handle increasing demands on attentional control within the same paradigm. GAD participants (but not HPs) were less random while worrying than thinking about a positive event during the key-pressing task, suggesting that worry consumed more attentional control resources in this population. During the N-Back task, GAD participants performed worse than HPs during the high load conditions only, indicating greater difficulty in sustaining focus on conditions requiring a higher degree of attentional control, even without concurrent task activity. Poor attentional control might underpin the difficulty of GAD individuals to stop worrying and switch to thinking more benign information. Further research could investigate whether worry consumes attentional control resources in other psychological disorders with high rates of worry (e.g., panic disorder, psychosis), as well as the extent to which attentional control is used by other forms of repetitive thinking, such as depressive rumination. PMID:24886007

  2. Force control tasks with pure haptic feedback promote short-term focused attention.

    PubMed

    Wang, Dangxiao; Zhang, Yuru; Yang, Xiaoxiao; Yang, Gaofeng; Yang, Yi

    2014-01-01

    Focused attention has great impact on our quality of life. Our learning, social skills and even happiness are closely intertwined with our capacity for focused attention. Attention promotion is replete with examples of training-induced increases in attention capability, most of which rely on visual and auditory stimulation. Pure haptic stimulation to increase attention capability is rarely found. We show that accurate force control tasks with pure haptic feedback enhance short-term focused attention. Participants were trained by a force control task in which information from visual and auditory channels was blocked, and only haptic feedback was provided. The trainees were asked to exert a target force within a pre-defined force tolerance for a specific duration. The tolerance was adaptively modified to different levels of difficulty to elicit full participant engagement. Three attention tests showed significant changes in different aspects of focused attention in participants who had been trained as compared with those who had not, thereby illustrating the role of haptic-based sensory-motor tasks in the promotion of short-term focused attention. The findings highlight the potential value of haptic stimuli in brain plasticity and serve as a new tool to extend existing computer games for cognitive enhancement. PMID:25296407

  3. Attention and curiosity in museums

    NASA Astrophysics Data System (ADS)

    Koran, John J., Jr.; Morrison, Laura; Lehman, Jeffrey R.; Koran, Mary Lou; Gandara, Luisa

    Two hundred and thirty-four museum visitors of all ages were observed as they entered the Object Gallery area of the Florida State Museum. Visitors were observed under conditions where objects were available for close inspection but could not be manipulated (baseline data) and later when the same objects were placed on tables and were available for visitors to touch, move, and use a variety of senses to inspect them (intervention data). Data were recorded on the sex, age, and number of subjects in these areas under each of the above conditions. The results obtained show a significant increase in the number of visitors entering this section of the museum when manipulatable objects were available. Baseline data showed that 58.5% of the people who entered the Object Gallery went into the drawer section. However, when manipulatable objects were made available this increased to 82.3%. Chi-square analysis was used to determine whether the presence of manipulatable objects in the area increased the number of people who entered the area. It did (p < 0.05). Chi-square analysis was also used to determine whether entering the drawer section depended on age or sex. It was found that more children entered the drawer section than adults (p < 0.05) and significantly more female children and female adults entered as a result of intervention (p < 0.05). At the same time, more male children than adults entered after intervention (p < 0.05) than before. These data are supported by considerable curiosity research indicating that both children and adults are attracted to novel as well as complex stimuli which can be manipulated in both formal and free-choice environments. The data also support the growing movement to hands-on exhibits in natural history museums and science centers around the country, as well as hands-on classroom activities from the perspective of their attention attracting and holding power and their curiosity evoking characteristics. Whether these positive factors

  4. Microbially-driven strategies for bioremediation of bauxite residue.

    PubMed

    Santini, Talitha C; Kerr, Janice L; Warren, Lesley A

    2015-08-15

    Globally, 3 Gt of bauxite residue is currently in storage, with an additional 120 Mt generated every year. Bauxite residue is an alkaline, saline, sodic, massive, and fine grained material with little organic carbon or plant nutrients. To date, remediation of bauxite residue has focused on the use of chemical and physical amendments to address high pH, high salinity, and poor drainage and aeration. No studies to date have evaluated the potential for microbial communities to contribute to remediation as part of a combined approach integrating chemical, physical, and biological amendments. This review considers natural alkaline, saline environments that present similar challenges for microbial survival and evaluates candidate microorganisms that are both adapted for survival in these environments and have the capacity to carry out beneficial metabolisms in bauxite residue. Fermentation, sulfur oxidation, and extracellular polymeric substance production emerge as promising pathways for bioremediation whether employed individually or in combination. A combination of bioaugmentation (addition of inocula from other alkaline, saline environments) and biostimulation (addition of nutrients to promote microbial growth and activity) of the native community in bauxite residue is recommended as the approach most likely to be successful in promoting bioremediation of bauxite residue. PMID:25867516

  5. Building Organizational Capacity through Trust

    ERIC Educational Resources Information Center

    Cosner, Shelby

    2009-01-01

    This article explores the cultivation of collegial trust as a central feature of the capacity-building work of 11 high school principals, nominated for their expertise with capacity building. This qualitative study examined interview data and school documents collected over 18 months. Principals regarded trust as critical and were motivated to…

  6. Measuring Capacities for Community Resilience

    ERIC Educational Resources Information Center

    Sherrieb, Kathleen; Norris, Fran H.; Galea, Sandro

    2010-01-01

    The purpose of this study was to measure the sets of adaptive capacities for Economic Development and Social Capital in the Norris et al. (2008) community resilience model with publicly accessible population indicators. Our approach involved five steps. First, we conducted a literature review on measurements of the capacities. Second, we created…

  7. Enrollment Capacity and Technology Study

    ERIC Educational Resources Information Center

    Washington Higher Education Coordinating Board, 2008

    2008-01-01

    The 2007-09 Appropriations Act provided funding to the Higher Education Coordinating Board (HECB) to study the state's capital facility and technology capacity. Specifically, "...state appropriation is provided solely to implement a capital facility and technology capacity study which will compare the 10-year enrollment projections with the…

  8. Further Investigation into Constraints and Economics of Residue Collection.

    SciTech Connect

    Brown, Lawrence F.

    1982-08-01

    This report is comprised of a series of separate studies. Each study can be read separately, but each contributes to the others and to the central theme of logging residue recovery. Section 1 presents information on how timber is sold by northwest public agencies with particular attention to procedures affecting residue materials. Section 5 describes taxes on hauling logs and chips in the four northwestern states. The purpose of Sections 2, 3, 4, and 6 is to further examine the considerable information collected during the Green Mountain timber sale. These analyses are the first steps in the further study of second-entry yarding for the recovery of logging residue. 48 refs., 7 figs., 22 tabs.

  9. Heat capacity, configurational heat capacity and fragility of hydrous magmas

    NASA Astrophysics Data System (ADS)

    Di Genova, D.; Romano, C.; Giordano, D.; Alletti, M.

    2014-10-01

    The glassy and liquid heat capacities of four series of dry and hydrous natural glasses and magma as a function of temperature and water content (up to 19.9 mol%) were investigated using differential scanning calorimetry (DSC). The analyzed compositions are basalt, latite, trachyte and pantellerite. The results of this study indicate that the measured heat capacity of glasses (Cpg) is a linear function of composition and is well reproduced by the empirical model of Richet (1987). For the investigated glasses, the partial molar heat capacity of water can be considered as independent of composition, in agreement with Bouhifd et al. (2006). For hydrous liquids, the heat capacity (Cpliq) decreases nonlinearly with increasing water content. Previously published models, combined with the partial molar heat capacity of water from the literature, are not able to reproduce our experimental data in a satisfactory way. We estimated the partial molar heat capacity of water (CpH2O) in hydrous magma over a broad compositional range. The proposed value is 41 ± 3 J mol-1 K-1. Water strongly affects the configurational heat capacity at the glass transition temperature [Cpconf (Tg)]. An increases of Cpconf (Tg) with water content was measured for the polymerized liquids (trachyte and pantellerite), while the opposite behavior was observed for the most depolymerized liquids (basalt and latite). Structural and rheological implications of this behavior are discussed in light of the presented results.

  10. CO2CRC's Otway Residual Saturation and Dissolution Test: Using Reactive Ester Tracers to Determine Residual CO2 Saturation

    NASA Astrophysics Data System (ADS)

    Myers, M.; Stalker, L.; LaForce, T.; Pejcic, B.; Dyt, C.; Ho, K.; Ennis-King, J.

    2013-12-01

    Residual trapping, that is CO2 held in the rock pore space due to capillarity, is an important storage mechanism in geo-sequestration of over the short to medium term (up to 1000 years). As such residual CO2 saturation is a critical reservoir parameter for assessing the storage capacity and security of carbon capture and storage (CCS). As a component of the CO2CRC's Residual Gas Saturation and Dissolution Test at the CO2CRC Otway Project site in Victoria (Australia), we have recently tested a suite of reactive esters (triacetin, tripropionin and propylene glycol diacetate) in a single well chemical tracer test to determine residual CO2 saturation. The goal of this project was to assess and validate a suite of possible tests that could be implemented to determine residual CO2 saturation. For this test, the chemical tracers were injected with a saturated CO2/water mixture into the formation (that is already at residual CO2 saturation) where they were allowed to 'soak' for approximately 10 days allowing for the partial hydrolysis of the esters to their corresponding carboxylic acids and alcohols. Water containing the tracers was then produced from the well resulting in over 600 tracer samples over a period of 12 hours. A selection of these samples were analysed for tracer content and to establish tracer breakthrough curves. To understand the behaviour of these chemical tracers in the downhole environment containing residually trapped supercritical CO2 and formation water, it is necessary to determine the supercritical CO2/water partition coefficients. We have previously determined these in the laboratory (Myers et al., 2012) and they are used here to model the tracer behaviour and provide an estimate of the residual CO2 saturation. Two different computational simulators were used to analyse the tracer breakthrough profiles. The first is based on simple chromatographic retardation and has been used extensively in single well chemical tracer tests to determine residual

  11. North American fertilizer capacity data

    SciTech Connect

    Not Available

    1993-02-01

    This listing of fertilizer producers and their production capacities was compiled in February 1993 with the cooperation of the US and Canadian fertilizer industry. TVA does not guarantee the completeness or accuracy of the information. Capacity is only an indicator of supply. Nameplate capacity differs from planned production levels or actual production because plants often operate above or below design capacity. Unless reported otherwise, plant capacities are based on 340 days per year of operation. No adjustment is made for partial year operation. Information is given on the following types of fertilizers: ammonia, ammonium nitrate, nitrogen solutions, urea, ammonium sulfate, phosphate rock, wet-process phosphoric acid, ammonium phosphates, concentrated superphosphates, potash, nitric acid, superphosphoric acid, upgraded phosphoric acids, normal superphosphate, elemental phosphorus, potassium sulfate, and sulfate of potash/magnesia.

  12. Heat capacity of molten halides.

    PubMed

    Redkin, Alexander A; Zaikov, Yurii P; Korzun, Iraida V; Reznitskikh, Olga G; Yaroslavtseva, Tatiana V; Kumkov, Sergey I

    2015-01-15

    The heat capacities of molten salts are very important for their practical use. Experimental investigation of this property is challenging because of the high temperatures involved and the corrosive nature of these materials. It is preferable to combine experimental investigations with empirical relationships, which allows for the evaluation of the heat capacity of molten salt mixtures. The isobaric molar heat capacities of all molten alkali and alkaline-earth halides were found to be constant for each group of salts. The value depends on the number of atoms in the salt, and the molar heat capacity per atom is constant for all molten halide salts with the exception of the lithium halides. The molar heat capacities of molten halides do not change when the anions are changed. PMID:25530462

  13. The role of attention in visual processing.

    PubMed Central

    Maunsell, John H R; Cook, Erik P

    2002-01-01

    Attention to a visual stimulus typically increases the responses of cortical neurons to that stimulus. Because many studies have shown a close relationship between the performance of individual neurons and behavioural performance of animal subjects, it is important to consider how attention affects this relationship. Measurements of behavioural and neuronal performance taken from rhesus monkeys while they performed a motion detection task with two attentional states show that attention alters the relationship between behaviour and neuronal response. Notably, attention affects the relationship differently in different cortical visual areas. This indicates that a close relationship between neuronal and behavioural performance on a given task persists over changes in attentional state only within limited regions of visual cortex. PMID:12217174

  14. Multisensory attention training for treatment of tinnitus

    PubMed Central

    D. P., Spiegel; T., Linford; B., Thompson; M. A., Petoe; K., Kobayashi; C. M., Stinear; G. D., Searchfield

    2015-01-01

    Tinnitus is the conscious perception of sound with no physical sound source. Some models of tinnitus pathophysiology suggest that networks associated with attention, memory, distress and multisensory experience are involved in tinnitus perception. The aim of this study was to evaluate whether a multisensory attention training paradigm which used audio, visual, and somatosensory stimulation would reduce tinnitus. Eighteen participants with predominantly unilateral chronic tinnitus were randomized between two groups receiving 20 daily sessions of either integration (attempting to reduce salience to tinnitus by binding with multisensory stimuli) or attention diversion (multisensory stimuli opposite side to tinnitus) training. The training resulted in small but statistically significant reductions in Tinnitus Functional Index and Tinnitus Severity Numeric Scale scores and improved attentional abilities. No statistically significant improvements in tinnitus were found between the training groups. This study demonstrated that a short period of multisensory attention training reduced unilateral tinnitus, but directing attention toward or away from the tinnitus side did not differentiate this effect. PMID:26020589

  15. Paying attention to MMN in schizophrenia.

    PubMed

    Damaso, Karlye A M; Michie, Patricia T; Todd, Juanita

    2015-11-11

    The aim of this review is to explore the phenomenon of reduced mismatch negativity (MMN) in persons with schizophrenia and the possible relationship it has with attention impairments. In doing so we discuss (i) the prediction error account of MMN, (ii) reduced MMN as a faulty predictive processing system in persons with schizophrenia, (iii) the role of these systems in relevance filtering and attentional resource protection, (iv) attentional impairments in persons with schizophrenia, and (v) research that has explored MMN and attention in schizophrenia groups. Our review of the literature suggests that no study has appropriately examined the functional impact of smaller MMN in schizophrenia on the performance of a concurrent attention task. We conclude that future research should explore this notion further in the hope that it might embed MMN findings within outcomes of functional significance to individuals with the illness and those providing treatment. This article is part of a Special Issue entitled SI: Prediction and Attention. PMID:26163366

  16. Handwriting Performance and Underlying Factors in Children with Attention Deficit Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Shen, I-Hsuan; Lee, Tsai-Yun; Chen, Chia-Ling

    2012-01-01

    Preliminary evidence suggests that handwriting difficulties are common to children with Attention Deficit Hyperactivity Disorder (ADHD). However, the nature of the task-specific impairments is needed to be clarified. The aim of this study was to describe handwriting capacity in ADHD children without DCD and identify underlying factors of…

  17. Demands on Attention and the Role of Response Priming in Visual Discrimination of Feature Conjunctions

    ERIC Educational Resources Information Center

    Fournier, Lisa R.; Herbert, Rhonda J.; Farris, Carrie

    2004-01-01

    This study examined how response mapping of features within single- and multiple-feature targets affects decision-based processing and attentional capacity demands. Observers judged the presence or absence of 1 or 2 target features within an object either presented alone or with distractors. Judging the presence of 2 features relative to the less…

  18. Temporal Context in Speech Processing and Attentional Stream Selection: A Behavioral and Neural Perspective

    ERIC Educational Resources Information Center

    Golumbic, Elana M. Zion; Poeppel, David; Schroeder, Charles E.

    2012-01-01

    The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the "Cocktail Party" effect. Yet, the neural mechanisms underlying on-line…

  19. Double Take: Parallel Processing by the Cerebral Hemispheres Reduces Attentional Blink

    ERIC Educational Resources Information Center

    Scalf, Paige E.; Banich, Marie T.; Kramer, Arthur F.; Narechania, Kunjan; Simon, Clarissa D.

    2007-01-01

    Recent data have shown that parallel processing by the cerebral hemispheres can expand the capacity of visual working memory for spatial locations (J. F. Delvenne, 2005) and attentional tracking (G. A. Alvarez & P. Cavanagh, 2005). Evidence that parallel processing by the cerebral hemispheres can improve item identification has remained elusive.…

  20. The Coherence Formation Model of Illustrated Text Comprehension: A Path Model of Attention to Multimedia Text

    ERIC Educational Resources Information Center

    Fitzhugh, Shannon Leigh

    2012-01-01

    The study reported here tests a model that includes several factors thought to contribute to the comprehension of static multimedia learning materials (i.e. background knowledge, working memory, attention to components as measured with eye movement measures). The model examines the effects of working memory capacity, domain specific (biology) and…

  1. Attention as foraging for information and value

    PubMed Central

    Manohar, Sanjay G.; Husain, Masud

    2013-01-01

    What is the purpose of attention? One avenue of research has led to the proposal that attention might be crucial for gathering information about the environment, while other lines of study have demonstrated how attention may play a role in guiding behavior to rewarded options. Many experiments that study attention require participants to make a decision based on information acquired discretely at one point in time. In real-world situations, however, we are usually not presented with information about which option to select in such a manner. Rather we must initially search for information, weighing up reward values of options before we commit to a decision. Here, we propose that attention plays a role in both foraging for information and foraging for value. When foraging for information, attention is guided toward the unknown. When foraging for reward, attention is guided toward high reward values, allowing decision-making to proceed by accept-or-reject decisions on the currently attended option. According to this account, attention can be regarded as a low-cost alternative to moving around and physically interacting with the environment—“teleforaging”—before a decision is made to interact physically with the world. To track the timecourse of attention, we asked participants to seek out and acquire information about two gambles by directing their gaze, before choosing one of them. Participants often made multiple refixations on items before making a decision. Their eye movements revealed that early in the trial, attention was guided toward information, i.e., toward locations that reduced uncertainty about value. In contrast, late in the trial, attention was guided by expected value of the options. At the end of the decision period, participants were generally attending to the item they eventually chose. We suggest that attentional foraging shifts from an uncertainty-driven to a reward-driven mode during the evolution of a decision, permitting decisions to be

  2. Can Attention be Divided Between Perceptual Groups?

    NASA Technical Reports Server (NTRS)

    McCann, Robert S.; Foyle, David C.; Johnston, James C.; Hart, Sandra G. (Technical Monitor)

    1994-01-01

    Previous work using Head-Up Displays (HUDs) suggests that the visual system parses the HUD and the outside world into distinct perceptual groups, with attention deployed sequentially to first one group and then the other. New experiments show that both groups can be processed in parallel in a divided attention search task, even though subjects have just processed a stimulus in one perceptual group or the other. Implications for models of visual attention will be discussed.

  3. Enhancing and Promoting Recovery In Attentionally Impaired People Diagnosed With Schizophrenia: Results From A Randomized Controlled Trial Of Attention Shaping In A Partial Hospital Program

    PubMed Central

    Silverstein, Steven M.; Roché, Matthew W.; Khan, Zaynab; Carson, Sarah J.; Malinovsky, Igor; Newbill, William A.; Menditto, Anthony A.; Wilkniss, Sandra M.

    2014-01-01

    The attentional impairments associated with schizophrenia are well-documented and profound. Psychopharmacological and most psychosocial interventions have been shown to have limited effect in improving attentional capacity. That said, one form of psychosocial treatment, attention shaping procedures (ASP), has been repeatedly demonstrated to produce significant and meaningful change in various aspects of participant attentiveness behaviors. To date, studies of ASP have been limited in that they have been conducted primarily with inpatients, have not assessed the generalizability of ASP's effects, and have not explored whether reinforcement is required to be contingent on performance of attentive behaviors. To address these limitations we conducted the first randomized clinical trial of ASP with people diagnosed with schizophrenia who are being treated in a partial hospital program. Our results indicate that ASP is effective in improving attention in people with schizophrenia in these types of programs, the effects of ASP generalize outside of the immediate treatment context to both other treatment groups and real world functioning, and contingent reinforcement is a critical ingredient of ASP. This project provides further evidence for the benefits of use of ASP in the recovery-oriented treatment of people diagnosed with schizophrenia who have significant attentional impairments. PMID:25264432

  4. Rhythm and Attention: Does the Beat Position of a Visual or Auditory Regular Pulse Modulate T2 Detection in the Attentional Blink?

    PubMed Central

    Bermeitinger, Christina; Frings, Christian

    2015-01-01

    The attentional blink (AB) is one impressive demonstration of limited attentional capacities in time: a second target (T2) is often missed when it should be detected within 200–600 ms after a first target. According to the dynamic attending theory, attention cycles oscillatory. Regular rhythms (i.e., pulses) should evoke expectations regarding the point of the next occurrence of a tone/element in the rhythm. At this point, more attentional resources should be provided. Thus, if rhythmic information can be used to optimize attentional release, we assume a modulation of the AB when an additional rhythm is given. We tested this idea in two experiments with a visual (Experiment 1) or an auditory (Experiment 2) rhythm. We found large AB effects. However, the rhythm did not modulate the AB. If the rhythm had an influence at all, then Experiment 2 showed that an auditory rhythm (or stimulus) falling on T2 might generally boost visual processing, irrespective of attentional resources as indexed by the AB paradigm. Our experiments suggest that oscillatory cycling attention does not affect temporal selection as tapped in the AB paradigm. PMID:26648899

  5. Ambiguity produces attention shifts in category learning.

    PubMed

    Vadillo, Miguel A; Orgaz, Cristina; Luque, David; Nelson, James Byron

    2016-04-01

    It has been suggested that people and nonhuman animals protect their knowledge from interference by shifting attention toward the context when presented with information that contradicts their previous beliefs. Despite that suggestion, no studies have directly measured changes in attention while participants are exposed to an interference treatment. In the present experiments, we adapted a dot-probe task to track participants' attention to cues and contexts while they were completing a simple category learning task. The results support the hypothesis that interference produces a change in the allocation of attention to cues and contexts. PMID:26980780

  6. Attention Stabilizes Representations in the Human Hippocampus.

    PubMed

    Aly, Mariam; Turk-Browne, Nicholas B

    2016-02-01

    Attention and memory are intricately linked, but how attention modulates brain areas that subserve memory, such as the hippocampus, is unknown. We hypothesized that attention may stabilize patterns of activity in human hippocampus, resulting in distinct but reliable activity patterns for different attentional states. To test this prediction, we utilized high-resolution functional magnetic resonance imaging and a novel "art gallery" task. On each trial, participants viewed a room containing a painting, and searched a stream of rooms for a painting from the same artist (art state) or a room with the same layout (room state). Bottom-up stimulation was the same in both tasks, enabling the isolation of neural effects related to top-down attention. Multivariate analyses revealed greater pattern similarity in all hippocampal subfields for trials from the same, compared with different, attentional state. This stability was greater for the room than art state, was unrelated to univariate activity, and, in CA2/CA3/DG, was correlated with behavior. Attention therefore induces representational stability in the human hippocampus, resulting in distinct activity patterns for different attentional states. Modulation of hippocampal representational stability highlights the far-reaching influence of attention outside of sensory systems. PMID:25766839

  7. Sequestration of CO2 in Mixtures of Bauxite Residue and Saline Wastewater

    SciTech Connect

    Dilmore, R.M.; Lu, Peng; Allen, D.E.; Soong, Yee; Hedges, S.W.; Fu, J.K.; Dobbs, C.L.; DeGalbo, A.D.; Zhu, Chen

    2008-01-01

    Experiments were conducted to explore the concept of beneficially utilizing mixtures of caustic bauxite residue slurry (pH 13) and produced oil-field brine to sequester carbon dioxide from flue gas generated from industrial point sources. Data presented herein provide a preliminary assessment of the overall feasibility of this treatment concept. The Carbonation capacity of bauxite residue/brine mixtures was considered over the full range of reactant mixture combinations in 10% increments by volume. A bauxite residue/brine mixture of 90/10 by volume exhibited a CO2 sequestration capacity of greater than 9.5 g/L when exposed to pure CO2 at 20 °C and 0.689 MPa (100 psig). Dawsonite and calcite formation were predicted to be the dominant products of bauxite/brine mixture carbonation. It is demonstrated that CO2 sequestration is augmented by adding bauxite residue as a caustic agent to acidic brine solutions and that trapping is accomplished through both mineralization and solubilization. The product mixture solution was, in nearly all mixtures, neutralized following carbonation. However, in samples (bauxite residue/brine mixture of 90/10 by volume) containing bauxite residue solids, the pH was observed to gradually increase to as high as 9.7 after aging for 33 days, suggesting that the CO2 sequestration capacity of the samples increases with aging. Our geochemical models generally predicted the experimental results of carbon sequestration capacities and solution pH.

  8. Individual differences in the executive control of attention, memory, and thought, and their associations with schizotypy.

    PubMed

    Kane, Michael J; Meier, Matt E; Smeekens, Bridget A; Gross, Georgina M; Chun, Charlotte A; Silvia, Paul J; Kwapil, Thomas R

    2016-08-01

    A large correlational study took a latent-variable approach to the generality of executive control by testing the individual-differences structure of executive-attention capabilities and assessing their prediction of schizotypy, a multidimensional construct (with negative, positive, disorganized, and paranoid factors) conveying risk for schizophrenia. Although schizophrenia is convincingly linked to executive deficits, the schizotypy literature is equivocal. Subjects completed tasks of working memory capacity (WMC), attention restraint (inhibiting prepotent responses), and attention constraint (focusing visual attention amid distractors), the latter 2 in an effort to fractionate the "inhibition" construct. We also assessed mind-wandering propensity (via in-task thought probes) and coefficient of variation in response times (RT CoV) from several tasks as more novel indices of executive attention. WMC, attention restraint, attention constraint, mind wandering, and RT CoV were correlated but separable constructs, indicating some distinctions among "attention control" abilities; WMC correlated more strongly with attentional restraint than constraint, and mind wandering correlated more strongly with attentional restraint, attentional constraint, and RT CoV than with WMC. Across structural models, no executive construct predicted negative schizotypy and only mind wandering and RT CoV consistently (but modestly) predicted positive, disorganized, and paranoid schizotypy; stalwart executive constructs in the schizophrenia literature-WMC and attention restraint-showed little to no predictive power, beyond restraint's prediction of paranoia. Either executive deficits are consequences rather than risk factors for schizophrenia, or executive failures barely precede or precipitate diagnosable schizophrenia symptoms. (PsycINFO Database Record PMID:27454042

  9. A Novel Evaluation algorithm of Urban Comprehensive Carrying Capacity Index System in Northwest China:Lanzhou city as a example

    NASA Astrophysics Data System (ADS)

    Li, Jing; Lei, Song; Ling, Ma

    2016-06-01

    With the rapid growth of the urban population and quick expansion of urban dimensions, the affecting urban development constraints of urban carrying capacity has increasingly been attracting people's attention. However, the effective synthesization of urban resources carrying capacity, urban environmental carrying capacity, economic carrying capacity, society carrying capacity and traffic carrying capacity hardly acted as an urban comprehensive carrying capacity evaluation system. In this paper, the novel comprehensive index system of urban resources carrying capacity, urban environmental carrying capacity, economic carrying capacity, society carrying capacity and traffic carrying capacity was used for analyzing and evaluating urban comprehensive carrying capacity. Firstly, the standardization of evaluation index was constructed in the urban comprehensive carrying capacity index system. In addition, the past decade data from 2002 to 2011 was analyzed and evaluated in the weighted index system. Finally, the influence mechanism of various carrying capacity factors on urban comprehensive carrying capacity was investigated in Lanzhou. Experimental results can be summarized that the variation tendency of urban comprehensive carrying capacity was the annual increase of levels and the promotion countermeasure was put forward with congenital restricting factors and acquired restricting factors.

  10. Policy Capacity for Health Reform: Necessary but Insufficient: Comment on "Health Reform Requires Policy Capacity".

    PubMed

    Adams, Owen

    2016-01-01

    Forest and colleagues have persuasively made the case that policy capacity is a fundamental prerequisite to health reform. They offer a comprehensive life-cycle definition of policy capacity and stress that it involves much more than problem identification and option development. I would like to offer a Canadian perspective. If we define health reform as re-orienting the health system from acute care to prevention and chronic disease management the consensus is that Canada has been unsuccessful in achieving a major transformation of our 14 health systems (one for each province and territory plus the federal government). I argue that 3 additional things are essential to build health policy capacity in a healthcare federation such as Canada: (a) A means of "policy governance" that would promote an approach to cooperative federalism in the health arena; (b) The ability to overcome the "policy inertia" resulting from how Canadian Medicare was implemented and subsequently interpreted; and (c) The ability to entertain a long-range thinking and planning horizon. My assessment indicates that Canada falls short on each of these items, and the prospects for achieving them are not bright. However, hope springs eternal and it will be interesting to see if the July, 2015 report of the Advisory Panel on Healthcare Innovation manages to galvanize national attention and stimulate concerted action. PMID:26673650

  11. Universality in Protein Residue Networks

    PubMed Central

    Estrada, Ernesto

    2010-01-01

    Abstract Residue networks representing 595 nonhomologous proteins are studied. These networks exhibit universal topological characteristics as they belong to the topological class of modular networks formed by several highly interconnected clusters separated by topological cavities. There are some networks that tend to deviate from this universality. These networks represent small-size proteins having <200 residues. This article explains such differences in terms of the domain structure of these proteins. On the other hand, the topological cavities characterizing proteins residue networks match very well with protein binding sites. This study investigates the effect of the cutoff value used in building the residue network. For small cutoff values, <5 Å, the cavities found are very large corresponding almost to the whole protein surface. On the contrary, for large cutoff value, >10.0 Å, only very large cavities are detected and the networks look very homogeneous. These findings are useful for practical purposes as well as for identifying protein-like complex networks. Finally, this article shows that the main topological class of residue networks is not reproduced by random networks growing according to Erdös-Rényi model or the preferential attachment method of Barabási-Albert. However, the Watts-Strogatz model reproduces very well the topological class as well as other topological properties of residue network. A more biologically appealing modification of the Watts-Strogatz model to describe residue networks is proposed. PMID:20197043

  12. 34 CFR 300.606 - Public attention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 2 2014-07-01 2013-07-01 true Public attention. 300.606 Section 300.606 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND..., and Enforcement § 300.606 Public attention. Whenever a State receives notice that the Secretary...

  13. 34 CFR 300.606 - Public attention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Public attention. 300.606 Section 300.606 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND..., and Enforcement § 300.606 Public attention. Whenever a State receives notice that the Secretary...

  14. Attentional Engagement Deficits in Dyslexic Children

    ERIC Educational Resources Information Center

    Ruffino, Milena; Trussardi, Anna Noemi; Gori, Simone; Finzi, Alessandra; Giovagnoli, Sara; Menghini, Deny; Benassi, Mariagrazia; Molteni, Massimo; Bolzani, Roberto; Vicari, Stefano; Facoetti, Andrea

    2010-01-01

    Reading acquisition requires, in addition to appropriate phonological abilities, accurate and rapid selection of sublexical orthographic units by attentional letter string parsing. Spatio-temporal distribution of attentional engagement onto 3-pseudoletter strings was studied in 28 dyslexic and 55 normally reading children by measuring attentional…

  15. Temporal Processing, Attention, and Learning Disorders

    ERIC Educational Resources Information Center

    Landerl, Karin; Willburger, Edith

    2010-01-01

    In a large sample (N = 439) of literacy impaired and unimpaired elementary school children the predictions of the temporal processing theory of dyslexia were tested while controlling for (sub)clininal attentional deficits. Visual and Auditory Temporal Order Judgement were administered as well as three subtests of a standardized attention test. The…

  16. Exogenous spatial attention decreases audiovisual integration.

    PubMed

    Van der Stoep, N; Van der Stigchel, S; Nijboer, T C W

    2015-02-01

    Multisensory integration (MSI) and spatial attention are both mechanisms through which the processing of sensory information can be facilitated. Studies on the interaction between spatial attention and MSI have mainly focused on the interaction between endogenous spatial attention and MSI. Most of these studies have shown that endogenously attending a multisensory target enhances MSI. It is currently unclear, however, whether and how exogenous spatial attention and MSI interact. In the current study, we investigated the interaction between these two important bottom-up processes in two experiments. In Experiment 1 the target location was task-relevant, and in Experiment 2 the target location was task-irrelevant. Valid or invalid exogenous auditory cues were presented before the onset of unimodal auditory, unimodal visual, and audiovisual targets. We observed reliable cueing effects and multisensory response enhancement in both experiments. To examine whether audiovisual integration was influenced by exogenous spatial attention, the amount of race model violation was compared between exogenously attended and unattended targets. In both Experiment 1 and Experiment 2, a decrease in MSI was observed when audiovisual targets were exogenously attended, compared to when they were not. The interaction between exogenous attention and MSI was less pronounced in Experiment 2. Therefore, our results indicate that exogenous attention diminishes MSI when spatial orienting is relevant. The results are discussed in terms of models of multisensory integration and attention. PMID:25341648

  17. Object-Based Attention and Cognitive Tunneling

    ERIC Educational Resources Information Center

    Jarmasz, Jerzy; Herdman, Chris M.; Johannsdottir, Kamilla Run

    2005-01-01

    Simulator-based research has shown that pilots cognitively tunnel their attention on head-up displays (HUDs). Cognitive tunneling has been linked to object-based visual attention on the assumption that HUD symbology is perceptually grouped into an object that is perceived and attended separately from the external scene. The present research…

  18. There's Little Return for Attentional Momentum

    ERIC Educational Resources Information Center

    Snyder, Janice J.; Schmidt, William C.; Kingstone, Alan

    2009-01-01

    Inhibition of return (IOR) refers to a delay in response time (RT) to targets appearing at a previously cued location. The prevailing view is that IOR reflects visual-motor inhibition. The "attentional momentum" account rejects this idea, and instead proposes that IOR reflects an automatic shift of attention away from the cued location resulting…

  19. Infant Attention and Early Childhood Executive Function

    ERIC Educational Resources Information Center

    Cuevas, Kimberly; Bell, Martha Ann

    2014-01-01

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

  20. Spatial attention systems in spatial neglect.

    PubMed

    Karnath, Hans-Otto

    2015-08-01

    It has been established that processes relating to 'spatial attention' are implemented at cortical level by goal-directed (top-down) and stimulus-driven (bottom-up) networks. Spatial neglect in brain-damaged individuals has been interpreted as a distinguished exemplar for a disturbance of these processes. The present paper elaborates this assumption. Functioning of the two attentional networks seem to dissociate in spatial neglect; behavioral studies of patients' orienting and exploration behavior point to a disturbed stimulus-driven but preserved goal-directed attention system. When a target suddenly appears somewhere in space, neglect patients demonstrate disturbed detection and orienting if it is located in contralesional direction. In contrast, if neglect patients explore a scene with voluntarily, top-down controlled shifts of spatial attention, they perform movements that are oriented into all spatial directions without any direction-specific disturbances. The paper thus argues that not the top-down control of spatial attention itself, rather a body-related matrix on top of which this process is executed, seems affected. In that sense, the traditional role of spatial neglect as a stroke model for 'spatial attention' requires adjustment. Beyond its insights into the human stimulus-driven attentional system, the disorder most notably provides vistas in how our brain encodes topographical information and organizes spatially oriented action - including the top-down control of spatial attention - in relation to body position. PMID:26004064

  1. Attention flexibly alters tuning for object categories

    PubMed Central

    Kim, Jiye G.; Kastner, Sabine

    2016-01-01

    Using functional MRI (fMRI) and a sophisticated forward encoding and decoding approach across the cortical surface, a new study examines how attention alternates tuning functions across a large set of semantic categories. The results suggest a dynamic attention mechanism that allocates greater resources to the attended and related semantic categories at the expense of unattended ones. PMID:23756038

  2. Accuracy of Information Processing under Focused Attention.

    ERIC Educational Resources Information Center

    Bastick, Tony

    This paper reports the results of an experiment on the accuracy of information processing during attention focused arousal under two conditions: single estimation and double estimation. The attention of 187 college students was focused by a task requiring high level competition for a monetary prize ($10) under severely limited time conditions. The…

  3. Spatial Reference Frame of Incidentally Learned Attention

    ERIC Educational Resources Information Center

    Jiang, Yuhong V.; Swallow, Khena M.

    2013-01-01

    Visual attention prioritizes information presented at particular spatial locations. These locations can be defined in reference frames centered on the environment or on the viewer. This study investigates whether incidentally learned attention uses a viewer-centered or environment-centered reference frame. Participants conducted visual search on a…

  4. Taking Control of Reflexive Social Attention

    ERIC Educational Resources Information Center

    Ristic, Jelena; Kingstone, Alan

    2005-01-01

    Attention is shifted reflexively to where other people are looking. It has been argued by a number of investigators that this social attention effect reflects the obligatory bottom-up activation of domain-specific modules within the inferior temporal (IT) cortex that are specialized for processing face and gaze information. However, it is also the…

  5. Do social utility judgments influence attentional processing?

    PubMed

    Shore, Danielle M; Heerey, Erin A

    2013-10-01

    Research shows that social judgments influence decision-making in social environments. For example, judgments about an interaction partners' trustworthiness affect a variety of social behaviors and decisions. One mechanism by which social judgments may influence social decisions is by biasing the automatic allocation of attention toward certain social partners, thereby shaping the information people acquire. Using an attentional blink paradigm, we investigate how trustworthiness judgments alter the allocation of attention to social stimuli in a set of two experiments. The first experiment investigates trustworthiness judgments based solely on a social partner's facial appearance. The second experiment examines the effect of trustworthiness judgments based on experienced behavior. In the first, strong appearance-based judgments (positive and negative) enhanced stimulus recognizability but did not alter the size of the attentional blink, suggesting that appearance-based social judgments enhance face memory but do not affect pre-attentive processing. However, in the second experiment, in which judgments were based on behavioral experience rather than appearance, positive judgments enhanced pre-attentive processing of trustworthy faces. This suggests that a stimulus's potential benefits, rather than its disadvantages, shape the automatic distribution of attentional resources. These results have implications for understanding how appearance- and behavior-based social cues shape attention distribution in social environments. PMID:23887150

  6. 34 CFR 300.606 - Public attention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Public attention. 300.606 Section 300.606 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND..., and Enforcement § 300.606 Public attention. Whenever a State receives notice that the Secretary...

  7. Ambiguity Produces Attention Shifts in Category Learning

    ERIC Educational Resources Information Center

    Vadillo, Miguel A.; Orgaz, Cristina; Luque, David; Nelson, James Byron

    2016-01-01

    It has been suggested that people and nonhuman animals protect their knowledge from interference by shifting attention toward the context when presented with information that contradicts their previous beliefs. Despite that suggestion, no studies have directly measured changes in attention while participants are exposed to an interference…

  8. Multielement Visual Tracking: Attention and Perceptual Organization.

    ERIC Educational Resources Information Center

    Yantis, Steven

    1992-01-01

    Presents 7 experiments with 118 undergraduates tracking multiple randomly moving visual elements under various conditions. Observers spontaneously grouped the target elements and directed attention toward this coherent nonrigid virtual object. Results support object-based theories of attention and show that perceptual grouping, a purely…

  9. 28 CFR 301.104 - Medical attention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Medical attention. 301.104 Section 301.104 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE INMATE ACCIDENT COMPENSATION General § 301.104 Medical attention. Whenever an inmate worker is injured while in the performance of assigned duty, regardless of...

  10. Attention and Communication in Rett Syndrome

    ERIC Educational Resources Information Center

    Fabio, Rosa Angela; Antonietti, Alessandro; Castelli, Ilaria; Marchetti, Antonella

    2009-01-01

    The study of selective attention and its influence on communication in patients with Rett Syndrome (RS), in which communication abilities are impaired is particularly relevant. The aim of this study was to analyse attention and communication abilities in RS. A sample of 20 children (10 girls with RS and 10 control girls, matched on mental age)…

  11. Prefrontal Parvalbumin Neurons in Control of Attention

    PubMed Central

    Kim, Hoseok; Ährlund-Richter, Sofie; Wang, Xinming; Deisseroth, Karl; Carlén, Marie

    2016-01-01

    Summary While signatures of attention have been extensively studied in sensory systems, the neural sources and computations responsible for top-down control of attention are largely unknown. Using chronic recordings in mice, we found that fast-spiking parvalbumin (FS-PV) interneurons in medial prefrontal cortex (mPFC) uniformly show increased and sustained firing during goal-driven attentional processing, correlating to the level of attention. Elevated activity of FS-PV neurons on the timescale of seconds predicted successful execution of behavior. Successful allocation of attention was characterized by strong synchronization of FS-PV neurons, increased gamma oscillations, and phase locking of pyramidal firing. Phase-locked pyramidal neurons showed gamma-phase-dependent rate modulation during successful attentional processing. Optogenetic silencing of FS-PV neurons deteriorated attentional processing, while optogenetic synchronization of FS-PV neurons at gamma frequencies had pro-cognitive effects and improved goal-directed behavior. FS-PV neurons thus act as a functional unit coordinating the activity in the local mPFC circuit during goal-driven attentional processing. PMID:26771492

  12. Contingent Attentional Capture by Conceptually Relevant Images

    ERIC Educational Resources Information Center

    Wyble, Brad; Folk, Charles; Potter, Mary C.

    2013-01-01

    Attentional capture is an unintentional shift of visuospatial attention to the location of a distractor that is either highly salient, or relevant to the current task set. The latter situation is referred to as contingent capture, in that the effect is contingent on a match between characteristics of the stimuli and the task-defined…

  13. Promises and Self-Focused Attention.

    ERIC Educational Resources Information Center

    Callahan, Sidney

    Making a promise involves a self-conscious, self-commitment to undertake an obligation in the future and involves a personal sense of control. To study promises and self-focused attention, 72 women completed measures of self-focused attention and locus of control, a questionnaire, and were asked to promise to return postcards. As predicted,…

  14. 34 CFR 303.706 - Public attention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false Public attention. 303.706 Section 303.706 Education... Funds Federal and State Monitoring and Enforcement § 303.706 Public attention. Whenever a State receives..., the State must, by means of a public notice, take such measures as may be necessary to bring...

  15. 34 CFR 300.606 - Public attention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false Public attention. 300.606 Section 300.606 Education..., and Enforcement § 300.606 Public attention. Whenever a State receives notice that the Secretary is... public notice, take such actions as may be necessary to notify the public within the State of...

  16. The Attentional Boost Effect and Context Memory

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Smith, S. Adam; Spataro, Pietro

    2016-01-01

    Stimuli co-occurring with targets in a detection task are better remembered than stimuli co-occurring with distractors--the attentional boost effect (ABE). The ABE is of interest because it is an exception to the usual finding that divided attention during encoding impairs memory. The effect has been demonstrated in tests of item memory but it is…

  17. The lasting memory enhancements of retrospective attention.

    PubMed

    Reaves, Sarah; Strunk, Jonathan; Phillips, Shekinah; Verhaeghen, Paul; Duarte, Audrey

    2016-07-01

    Behavioral research has shown that spatial cues that orient attention toward task relevant items being maintained in visual short-term memory (VSTM) enhance item memory accuracy. However, it is unknown if these retrospective attentional cues ("retro-cues") enhance memory beyond typical short-term memory delays. It is also unknown whether retro-cues affect the spatial information associated with VSTM representations. Emerging evidence suggests that processes that affect short-term memory maintenance may also affect long-term memory (LTM) but little work has investigated the role of attention in LTM. In the current event-related potential (ERP) study, we investigated the duration of retrospective attention effects and the impact of retrospective attention manipulations on VSTM representations. Results revealed that retro-cueing improved both VSTM and LTM memory accuracy and that posterior maximal ERPs observed during VSTM maintenance predicted subsequent LTM performance. N2pc ERPs associated with attentional selection were attenuated by retro-cueing suggesting that retrospective attention may disrupt maintenance of spatial configural information in VSTM. Collectively, these findings suggest that retrospective attention can alter the structure of memory representations, which impacts memory performance beyond short-term memory delays. PMID:27038756

  18. The Attentional Cost of Inattentional Blindness

    ERIC Educational Resources Information Center

    Bressan, Paola; Pizzighello, Silvia

    2008-01-01

    When our attention is engaged in a visual task, we can be blind to events which would otherwise not be missed. In three experiments, 97 out of the 165 observers performing a visual attention task failed to notice an unexpected, irrelevant object moving across the display. Surprisingly, this object significantly lowered accuracy in the primary task…

  19. Asymmetric Development of Dorsal and Ventral Attention Networks in the Human Brain

    PubMed Central

    Farrant, Kristafor; Uddin, Lucina Q.

    2015-01-01

    Two neural systems for goal-directed and stimulus-driven attention have been described in the adult human brain; the dorsal attention network (DAN) centered in the frontal eye fields (FEF) and intraparietal sulcus (IPS), and the ventral attention network (VAN) anchored in the temporoparietal junction (TPJ) and ventral frontal cortex (VFC). Little is known regarding the processes governing typical development of these attention networks in the brain. Here we use resting state functional MRI data collected from thirty 7–12 year-old children and thirty 18–31 year-old adults to examine two key regions of interest from the dorsal and ventral attention networks. We found that for the DAN nodes (IPS and FEF), children showed greater functional connectivity with regions within the network compared with adults, whereas adults showed greater functional connectivity between the FEF and extra-network regions including the posterior cingulate cortex. For the VAN nodes (TPJ and VFC), adults showed greater functional connectivity with regions within the network compared with children. Children showed greater functional connectivity between VFC and nodes of the salience network. This asymmetric pattern of development of attention networks may be a neural signature of the shift from over-representation of bottom-up attention mechanisms to greater top-down attentional capacities with development. PMID:25797238

  20. Separable Sustained and Selective Attention Factors Are Apparent in 5-Year-Old Children

    PubMed Central

    Underbjerg, Mette; George, Melanie S.; Thorsen, Poul; Kesmodel, Ulrik S.; Mortensen, Erik L.; Manly, Tom

    2013-01-01

    In adults and older children, evidence consistent with relative separation between selective and sustained attention, superimposed upon generally positive inter-test correlations, has been reported. Here we examine whether this pattern is detectable in 5-year-old children from the healthy population. A new test battery (TEA-ChJ) was adapted from measures previously used with adults and older children and administered to 172 5-year-olds. Test-retest reliability was assessed in 60 children. Ninety-eight percent of the children managed to complete all measures. Discrimination of visual and auditory stimuli were good. In a factor analysis, the two TEA-ChJ selective attention tasks (one visual, one auditory) loaded onto a common factor and diverged from the two sustained attention tasks (one auditory, one motor), which shared a common loading on the second factor. This pattern, which suggests that the tests are indeed sensitive to underlying attentional capacities, was supported by the relationships between the TEA-ChJ factors and Test of Everyday Attention for Children subtests in the older children in the sample. It is possible to gain convincing performance-based estimates of attention at the age of 5 with the results reflecting a similar factor structure to that obtained in older children and adults. The results are discussed in light of contemporary models of attention function. Given the potential advantages of early intervention for attention difficulties, the findings are of clinical as well as theoretical interest. PMID:24376591

  1. Visual storytelling in 2D and stereoscopic 3D video: effect of blur on visual attention

    NASA Astrophysics Data System (ADS)

    Huynh-Thu, Quan; Vienne, Cyril; Blondé, Laurent

    2013-03-01

    Visual attention is an inherent mechanism that plays an important role in the human visual perception. As our visual system has limited capacity and cannot efficiently process the information from the entire visual field, we focus our attention on specific areas of interest in the image for detailed analysis of these areas. In the context of media entertainment, the viewers' visual attention deployment is also influenced by the art of visual storytelling. To this date, visual editing and composition of scenes in stereoscopic 3D content creation still mostly follows those used in 2D. In particular, out-of-focus blur is often used in 2D motion pictures and photography to drive the viewer's attention towards a sharp area of the image. In this paper, we study specifically the impact of defocused foreground objects on visual attention deployment in stereoscopic 3D content. For that purpose, we conducted a subjective experiment using an eyetracker. Our results bring more insights on the deployment of visual attention in stereoscopic 3D content viewing, and provide further understanding on visual attention behavior differences between 2D and 3D. Our results show that a traditional 2D scene compositing approach such as the use of foreground blur does not necessarily produce the same effect on visual attention deployment in 2D and 3D. Implications for stereoscopic content creation and visual fatigue are discussed.

  2. To build capacity, build confidence

    NASA Astrophysics Data System (ADS)

    Hewitson, Bruce

    2015-07-01

    The history of attempts to spread scientific know-how beyond western centres of excellence is littered with failures. Capacity building needs long-term commitment, a critical mass of trainees, and a supportive home environment.

  3. Neuropsychological assessment of mental capacity.

    PubMed

    Sullivan, Karen

    2004-09-01

    The assessment of mental capacity to assist legal determinations of competency is potentially a growth area for neuropsychology, although to date neuropsychologists have published relatively little in this area. In this paper a systematic review of methods used to assess capacity is presented, including coverage of specialized tests and interviews used for this purpose. A neuropsychological model for conducting capacity assessments is proposed. This model involves comprehensive assessment of a wide range of cognitive abilities as well as assessment of specific skills and knowledge related to the type of capacity being assessed. The purpose of proposing this model is to stimulate further discussion and debate about the contribution neuropsychologists might make in this area. PMID:15673234

  4. Assessing plant residue decomposition in soil using DRIFT spectroscopy

    NASA Astrophysics Data System (ADS)

    Ouellette, Lance; Van Eerd, Laura; Voroney, Paul

    2016-04-01

    Assessment of the decomposition of plant residues typically involves the use of tracer techniques combined with measurements of soil respiration. This laboratory study evaluated use of Diffuse Reflectance Fourier Transform (DRIFT) spectroscopy for its potential to assess plant residue decomposition in soil. A sandy loam soil (Orthic Humic Gleysol) obtained from a field research plot was passed through a 4.75 mm sieve moist (~70% of field capacity) to remove larger crop residues. The experimental design consisted of a randomized complete block with four replicates of ten above-ground cover crop residue-corn stover combinations, where sampling time was blocked. Two incubations were set up for 1) Drift analysis: field moist soil (250 g ODW) was placed in 500 mL glass jars, and 2) CO2 evolution: 100 g (ODW) was placed in 2 L jars. Soils were amended with the plant residues (oven-dried at 60°C and ground to <2 mm) at rates equivalent to field mean above-ground biomass yields, then moistened to 60% water holding capacity and incubated in the dark at 22±3°C. Measurements for DRIFT and CO2-C evolved were taken after 0.5, 2, 4, 7, 10, 15, 22, 29, 36, 43, 50 64 and 72 d. DRIFT spectral data (100co-added scans per sample) were recorded with a Varian Cary 660 FT-IR Spectrometer equipped with an EasiDiff Diffuse Reflectance accessory operated at a resolution of 4 cm-1 over the mid-infrared spectrum from 4000 to 400 cm-1. DRIFT spectra of amended soils indicated peak areas of aliphatics at 2930 cm‑1, of aromatics at 1620, and 1530 cm‑1 and of polysaccharides at 1106 and 1036 cm-1. Evolved CO2 was measured by the alkali trap method (1 M NaOH); the amount of plant residue-C remaining in soil was calculated from the difference in the quantity of plant residue C added and the additional CO2-C evolved from the amended soil. First-order model parameters of the change in polysaccharide peak area over the incubation were related to those generated from the plant residue C decay

  5. Race Guides Attention in Visual Search.

    PubMed

    Otten, Marte

    2016-01-01

    It is known that faces are rapidly and even unconsciously categorized into social groups (black vs. white, male vs. female). Here, I test whether preferences for specific social groups guide attention, using a visual search paradigm. In Experiment 1 participants searched displays of neutral faces for an angry or frightened target face. Black target faces were detected more efficiently than white targets, indicating that black faces attracted more attention. Experiment 2 showed that attention differences between black and white faces were correlated with individual differences in automatic race preference. In Experiment 3, using happy target faces, the attentional preference for black over white faces was eliminated. Taken together, these results suggest that automatic preferences for social groups guide attention to individuals from negatively valenced groups, when people are searching for a negative emotion such as anger or fear. PMID:26900957

  6. Race Guides Attention in Visual Search

    PubMed Central

    Otten, Marte

    2016-01-01

    It is known that faces are rapidly and even unconsciously categorized into social groups (black vs. white, male vs. female). Here, I test whether preferences for specific social groups guide attention, using a visual search paradigm. In Experiment 1 participants searched displays of neutral faces for an angry or frightened target face. Black target faces were detected more efficiently than white targets, indicating that black faces attracted more attention. Experiment 2 showed that attention differences between black and white faces were correlated with individual differences in automatic race preference. In Experiment 3, using happy target faces, the attentional preference for black over white faces was eliminated. Taken together, these results suggest that automatic preferences for social groups guide attention to individuals from negatively valenced groups, when people are searching for a negative emotion such as anger or fear. PMID:26900957

  7. Attention in dichoptic and binocular vision

    NASA Technical Reports Server (NTRS)

    Kimchi, Ruth; Rubin, Yifat; Gopher, Daniel; Raij, David

    1989-01-01

    The ability of human subjected to mobilize attention and cope with task requirements under dichoptic and binocular viewing was investigated in an experiment employing a target search task. Subjects were required to search for a target at either the global level, the local level, or at both levels of a compound stimulus. The tasks were performed in a focused attention condition in which subjects had to attend to the stimulus presented to one eye/field (under dichoptic and binocular viewings, respectively) and to ignore the stimulus presented to the irrelevant eye/field, and in a divided attention condition in which subjects had to attend to the stimuli presented to both eyes/fields. Subjects' performance was affected mainly by attention conditions which interacted with task requirements, rather than by viewing situation. An interesting effect of viewing was found for the local-directed search task in which the cost of dividing attention was higher under binocular than under dichoptic viewing.

  8. Adolescence, Attention Allocation, and Driving Safety

    PubMed Central

    Romer, Daniel; Lee, Yi-Ching; McDonald, Catherine C.; Winston, Flaura K.

    2014-01-01

    Motor vehicle crashes are the leading source of morbidity and mortality in adolescents in the United States and the developed world. Inadequate allocation of attention to the driving task and to driving hazards are important sources of adolescent crashes. We review major explanations for these attention failures with particular focus on the roles that brain immaturity and lack of driving experience play in causing attention problems. The review suggests that the potential for overcoming inexperience and immaturity with training to improve attention to both the driving task and hazards is substantial. Nevertheless, there are large individual differences in both attentional abilities and risky driving tendencies that pose challenges to novice driver policies. Research that can provide evidence-based direction for such policies is urgently needed. PMID:24759442

  9. Visual Attention and Applications in Multimedia Technologies

    PubMed Central

    Le Callet, Patrick; Niebur, Ernst

    2013-01-01

    Making technological advances in the field of human-machine interactions requires that the capabilities and limitations of the human perceptual system are taken into account. The focus of this report is an important mechanism of perception, visual selective attention, which is becoming more and more important for multimedia applications. We introduce the concept of visual attention and describe its underlying mechanisms. In particular, we introduce the concepts of overt and covert visual attention, and of bottom-up and top-down processing. Challenges related to modeling visual attention and their validation using ad hoc ground truth are also discussed. Examples of the usage of visual attention models in image and video processing are presented. We emphasize multimedia delivery, retargeting and quality assessment of image and video, medical imaging, and the field of stereoscopic 3D images applications. PMID:24489403

  10. Holistic Processing from Learned Attention to Parts

    PubMed Central

    Chua, Kao-Wei; Richler, Jennifer J.; Gauthier, Isabel

    2016-01-01

    Attention helps us focus on what is most relevant to our goals, and prior work shows that aspects of attention can be learned. Learned inattention to parts can abolish holistic processing of faces, but it is unknown whether learned attention to parts is sufficient to cause a change from part-based to holistic processing with objects. Here, we trained subjects to individuate non-face objects (Greebles) from two categories, Ploks and Glips. Diagnostic information was in complementary halves for the two categories. Holistic processing was then tested with Plok-Glip composites that combined the kind of part that was diagnostic or non-diagnostic during training. Exposure to Greeble parts resulted in general failures of selective attention for non-diagnostic composites, but face-like holistic processing was only observed for diagnostic composites. These results demonstrate a novel link between learned attentional control and the acquisition of holistic processing. PMID:25775049

  11. Hold it! Memory affects attentional dwell time.

    PubMed

    Parks, Emily L; Hopfinger, Joseph B

    2008-12-01

    The allocation of attention, including the initial orienting and the subsequent dwell time, is affected by several bottom-up and top-down factors. How item memory affects these processes, however, remains unclear. Here, we investigated whether item memory affects attentional dwell time by using a modified version of the attentional blink (AB) paradigm. Across four experiments, our results revealed that the AB was significantly affected by memory status (novel vs. old), but critically, this effect depended on the ongoing memory context. Specifically, items that were unique in terms of memory status demanded more resources, as measured by a protracted AB. The present findings suggest that a more comprehensive understanding of memory's effects on attention can be obtained by accounting for an item's memorial context, as well as its individual item memory strength. Our results provide new evidence that item memory and memory context play a significant role in the temporal allocation of attention. PMID:19001579

  12. Safety assessment of drug residues

    SciTech Connect

    Jackson, B.A.

    1980-05-15

    The safety assessment of drug residues is part of the process for defining the conditions for the safe use of drugs in food-producing animals. The information needed to assess the safety of drug residues is provided by chemical and toxicity tests. Toxicity tests are conducted to identify the type of effect produced and to determine the exposure concentrations that would be expected not to produce the effect. These tests include acute, subacute, and chronic toxicity tests, as well as reproduction studies and other special tests. The results are used to find an acceptable daily intake for drug residues that can be used to set a tolerance.

  13. Marginally subcritical dynamics explain enhanced stimulus discriminability under attention

    PubMed Central

    Tomen, Nergis; Rotermund, David; Ernst, Udo

    2014-01-01

    Recent experimental and theoretical work has established the hypothesis that cortical neurons operate close to a critical state which describes a phase transition from chaotic to ordered dynamics. Critical dynamics are suggested to optimize several aspects of neuronal information processing. However, although critical dynamics have been demonstrated in recordings of spontaneously active cortical neurons, little is known about how these dynamics are affected by task-dependent changes in neuronal activity when the cortex is engaged in stimulus processing. Here we explore this question in the context of cortical information processing modulated by selective visual attention. In particular, we focus on recent findings that local field potentials (LFPs) in macaque area V4 demonstrate an increase in γ-band synchrony and a simultaneous enhancement of object representation with attention. We reproduce these results using a model of integrate-and-fire neurons where attention increases synchrony by enhancing the efficacy of recurrent interactions. In the phase space spanned by excitatory and inhibitory coupling strengths, we identify critical points and regions of enhanced discriminability. Furthermore, we quantify encoding capacity using information entropy. We find a rapid enhancement of stimulus discriminability with the emergence of synchrony in the network. Strikingly, only a narrow region in the phase space, at the transition from subcritical to supercritical dynamics, supports the experimentally observed discriminability increase. At the supercritical border of this transition region, information entropy decreases drastically as synchrony sets in. At the subcritical border, entropy is maximized under the assumption of a coarse observation scale. Our results suggest that cortical networks operate at such near-critical states, allowing minimal attentional modulations of network excitability to substantially augment stimulus representation in the LFPs. PMID:25202240

  14. Capacity Markets and Market Stability

    SciTech Connect

    Stauffer, Hoff

    2006-04-15

    The good news is that market stability can be achieved through a combination of longer-term contracts, auctions for far enough in the future to permit new entry, a capacity management system, and a demand curve. The bad news is that if and when stable capacity markets are designed, the markets may seem to be relatively close to where we started - with integrated resource planning. Market ideologues will find this anathema. (author)

  15. Maximizing the optical network capacity

    PubMed Central

    Bayvel, Polina; Maher, Robert; Liga, Gabriele; Shevchenko, Nikita A.; Lavery, Domaniç; Killey, Robert I.

    2016-01-01

    Most of the digital data transmitted are carried by optical fibres, forming the great part of the national and international communication infrastructure. The information-carrying capacity of these networks has increased vastly over the past decades through the introduction of wavelength division multiplexing, advanced modulation formats, digital signal processing and improved optical fibre and amplifier technology. These developments sparked the communication revolution and the growth of the Internet, and have created an illusion of infinite capacity being available. But as the volume of data continues to increase, is there a limit to the capacity of an optical fibre communication channel? The optical fibre channel is nonlinear, and the intensity-dependent Kerr nonlinearity limit has been suggested as a fundamental limit to optical fibre capacity. Current research is focused on whether this is the case, and on linear and nonlinear techniques, both optical and electronic, to understand, unlock and maximize the capacity of optical communications in the nonlinear regime. This paper describes some of them and discusses future prospects for success in the quest for capacity. PMID:26809572

  16. Maximizing the optical network capacity.

    PubMed

    Bayvel, Polina; Maher, Robert; Xu, Tianhua; Liga, Gabriele; Shevchenko, Nikita A; Lavery, Domaniç; Alvarado, Alex; Killey, Robert I

    2016-03-01

    Most of the digital data transmitted are carried by optical fibres, forming the great part of the national and international communication infrastructure. The information-carrying capacity of these networks has increased vastly over the past decades through the introduction of wavelength division multiplexing, advanced modulation formats, digital signal processing and improved optical fibre and amplifier technology. These developments sparked the communication revolution and the growth of the Internet, and have created an illusion of infinite capacity being available. But as the volume of data continues to increase, is there a limit to the capacity of an optical fibre communication channel? The optical fibre channel is nonlinear, and the intensity-dependent Kerr nonlinearity limit has been suggested as a fundamental limit to optical fibre capacity. Current research is focused on whether this is the case, and on linear and nonlinear techniques, both optical and electronic, to understand, unlock and maximize the capacity of optical communications in the nonlinear regime. This paper describes some of them and discusses future prospects for success in the quest for capacity. PMID:26809572

  17. Measuring depth profiles of residual stress with Raman spectroscopy

    SciTech Connect

    Enloe, W.S.; Sparks, R.G.; Paesler, M.A.

    1988-12-01

    Knowledge of the variation of residual stress is a very important factor in understanding the properties of machined surfaces. The nature of the residual stress can determine a part`s susceptibility to wear deformation, and cracking. Raman spectroscopy is known to be a very useful technique for measuring residual stress in many materials. These measurements are routinely made with a lateral resolution of 1{mu}m and an accuracy of 0.1 kbar. The variation of stress with depth; however, has not received much attention in the past. A novel technique has been developed that allows quantitative measurement of the variation of the residual stress with depth with an accuracy of 10nm in the z direction. Qualitative techniques for determining whether the stress is varying with depth are presented. It is also demonstrated that when the stress is changing over the volume sampled, errors can be introduced if the variation of the stress with depth is ignored. Computer aided data analysis is used to determine the depth dependence of the residual stress.

  18. Bioenergy residues as novel sorbents to clean up pesticide pollution

    NASA Astrophysics Data System (ADS)

    Mukherjee, Santanu

    2016-04-01

    Worldwide, water contamination from agricultural use of pesticides has received increasing attention within the last decades. In general, sources of pesticide water pollution are categorized into diffuse (stemming from treated fields) and point sources (stemming from farmyards and spillages). Research has demonstrated that 40 to 90% of surface water pesticide contamination is due to point source pollution. To reduce point pollution from farm yards, where the spray equipment is washed, biobed or biofilter systems are used to treat the washing water. The organic material usually used in these systems is often not environmentally sustainable (e.g. peat) and incorporated organic material such as straw leads to a highly heterogeneous water flow, with negative effects on the retention and degradation behavior of the pesticides. Therefore, the objective of this study was to assess the suitability of alternative materials based on bioenergy residues (biochar and digestate) for use in biofilters. To this aim the sorption-desorption potential of three contrasting pesticides (bentazone, boscalid, and pyrimethanil) on mixtures of soil with digestate and/or biochar were investigated in laboratory batch equilibrium experiments. The results indicate that the mixture of digestate and biochar increased pesticide sorption potential, whereby in all cases, the Kd des / Kf des values were lower than the Kd ads / Kf ads values indicating that the retention of the pesticides was weak. Thus, as Kf des were lower than the Kf ads values and H values were below 1, it can be concluded that the biomixtures presented negative desorption (higher hysteresis) in those cases. A higher Kd (>78 L kg-1), Kf (>400 μM1-1/nf L1/nfkg-1) and KL (>40 L kg-1) was obtained for all pesticides for the digestate and biochar based mixtures, which had a higher organic matter content. However, lower sorption of the pesticides was observed in blank soil compared to the other biomixtures, which was attributed to the

  19. Attentional bias modification facilitates attentional control mechanisms: evidence from eye tracking.

    PubMed

    Chen, Nigel T M; Clarke, Patrick J F; Watson, Tamara L; MacLeod, Colin; Guastella, Adam J

    2015-01-01

    Social anxiety is thought to be maintained by biased attentional processing towards threatening information. Research has further shown that the experimental attenuation of this bias, through the implementation of attentional bias modification (ABM), may serve to reduce social anxiety vulnerability. However, the mechanisms underlying ABM remain unclear. The present study examined whether inhibitory attentional control was associated with ABM. A non-clinical sample of participants was randomly assigned to receive either ABM or a placebo task. To assess pre-post changes in attentional control, participants were additionally administered an emotional antisaccade task. ABM participants exhibited a subsequent shift in attentional bias away from threat as expected. ABM participants further showed a subsequent decrease in antisaccade cost, indicating a general facilitation of inhibitory attentional control. Mediational analysis revealed that the shift in attentional bias following ABM was independent to the change in attentional control. The findings suggest that the mechanisms of ABM are multifaceted. PMID:25527400

  20. Americium recovery from reduction residues

    DOEpatents

    Conner, W.V.; Proctor, S.G.

    1973-12-25

    A process for separation and recovery of americium values from container or bomb'' reduction residues comprising dissolving the residues in a suitable acid, adjusting the hydrogen ion concentration to a desired level by adding a base, precipitating the americium as americium oxalate by adding oxalic acid, digesting the solution, separating the precipitate, and thereafter calcining the americium oxalate precipitate to form americium oxide. (Official Gazette)