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Sample records for residual attentional capacity

  1. Perioperative functional residual capacity.

    PubMed

    Wahba, R W

    1991-04-01

    The literature dealing with the magnitude, mechanism and effects of reduced FRC in the perioperative period is reviewed. During general anaesthesia FRC is reduced by approximately 20%. The reduction is greater in the obese and in patients with COPD. The most likely mechanism is the loss of inspiratory muscle tone of the muscles acting on the rib cage. Gas trapping is an additional mechanism. Lung compliance decreases and airways resistance increases, in large part, due to decreased FRC. The larynx is displaced anteriorly and elongated, making laryngoscopy and intubation more difficult. The change in FRC creates or increases intrapulmonary shunt and areas of low ventilation to perfusion. This is due to the occurrence of compression atelectasis, and to regional changes in mechanics and airway closure which tend to reduce ventilation to dependent lung zones which are still well perfused. Abdominal and thoracic operations tend to increase shunting further. Large tidal volume but not PEEP will improve oxygenation, although both increase FRC. Both FRC and vital capacity are reduced following abdominal and thoracic surgery in a predictable pattern. The mechanism is the combined effect of incisional pain and reflex dysfunction of the diaphragm. Additional effects of thoracic surgery include pleural effusion, cooling of the phrenic nerve and mediastinal widening. Postoperative hypoxaemia is a function of reduced FRC and airway closure. There is no real difference among the various methods of active lung expansion in terms of the speed of restoration of lung function, or in preventing postoperative atelectasis/pneumonia. Epidural analgesia does not influence the rate of recovery of lung function, nor does it prevent atelectasis/pneumonia. PMID:2036700

  2. 20 CFR 416.945 - Your residual functional capacity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Your residual functional capacity. 416.945... Your residual functional capacity. (a) General—(1) Residual functional capacity assessment. Your... what you can do in a work setting. Your residual functional capacity is the most you can still...

  3. 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…

  4. Individual differences in working memory capacity and attentional control.

    PubMed

    Hiebel, Nina; Zimmer, Hubert D

    2015-03-01

    Visual working memory (WM) has a very limited online capacity making it considerably important to control the gating of encoding into WM. Recent studies have suggested that attention control is of importance in doing so, especially the time needed to disengage. However, the disengagement mechanism operates on a later stage of processing after the initial selection of information has already been initiated. We assume that individual differences in WM capacity are also driven by individual variations in the voluntary engagement of attention. In 2 experiments we investigated whether individuals with high- and low-WM capacity differ in the efficiency and speed of this attention control process. We realised different versions of the task in which different amounts of attention control were necessary, a more automatically triggered allocation of attention and a voluntary initiation of attention engagement, respectively. We further manipulated the time course to look for differences in the latency of attention control. The results revealed that participants with low-WM capacity were less effective to exhibit voluntary attention control processes and they were also slower in doing so compared with high-WM capacity individuals. However, this effect seems to be partly moderated by the ability to update the current task set. If the trial structure did not require task set updating smaller individual differences involving WM capacity could be found. PMID:25730638

  5. 20 CFR 404.1545 - Your residual functional capacity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Your residual functional capacity. 404.1545 Section 404.1545 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Residual Functional Capacity §...

  6. 20 CFR 404.1545 - Your residual functional capacity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Your residual functional capacity. 404.1545 Section 404.1545 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Residual Functional Capacity §...

  7. 20 CFR 404.1545 - Your residual functional capacity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Your residual functional capacity. 404.1545 Section 404.1545 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Residual Functional Capacity §...

  8. 20 CFR 404.1545 - Your residual functional capacity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Your residual functional capacity. 404.1545 Section 404.1545 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Residual Functional Capacity §...

  9. Restricted attentional capacity within but not between sensory modalities.

    PubMed

    Duncan, J; Martens, S; Ward, R

    1997-06-19

    Restrictions to attentional capacity are revealed by the interference that commonly results when two sensory inputs must be identified at the same time. To investigate this phenomenon within and between modalities, we presented streams of visual and/or auditory inputs, containing occasional targets to be identified and recalled. For two visual or two auditory streams, identification of one target produced a sustained reduction in the ability to identify a second, the period of interference lasting for several hundred milliseconds. Subjectively, when attention was assigned to one target it was temporarily unavailable for another. In contrast, there was no such time-locked interference between targets in different modalities. The results suggest a modality-specific restriction to concurrent attention and awareness; visual attention to one simple target does not restrict concurrent auditory attention to another.

  10. Working memory capacity as controlled attention in tactical decision making.

    PubMed

    Furley, Philip A; Memmert, Daniel

    2012-06-01

    The controlled attention theory of working memory capacity (WMC, Engle 2002) suggests that WMC represents a domain free limitation in the ability to control attention and is predictive of an individual's capability of staying focused, avoiding distraction and impulsive errors. In the present paper we test the predictive power of WMC in computer-based sport decision-making tasks. Experiment 1 demonstrated that high-WMC athletes were better able at focusing their attention on tactical decision making while blocking out irrelevant auditory distraction. Experiment 2 showed that high-WMC athletes were more successful at adapting their tactical decision making according to the situation instead of relying on prepotent inappropriate decisions. The present results provide additional but also unique support for the controlled attention theory of WMC by demonstrating that WMC is predictive of controlling attention in complex settings among different modalities and highlight the importance of working memory in tactical decision making.

  11. 20 CFR 416.945 - Your residual functional capacity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Section 416.945 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE... deciding your residual functional capacity. (e) Total limiting effects. When you have a severe impairment(s... appendix 1 of subpart P of part 404 of this chapter, we will consider the limiting effects of all...

  12. 20 CFR 416.945 - Your residual functional capacity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Section 416.945 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE... residual functional capacity. (e) Total limiting effects. When you have a severe impairment(s), but your... subpart P of part 404 of this chapter, we will consider the limiting effects of all your...

  13. 20 CFR 416.945 - Your residual functional capacity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Section 416.945 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE... deciding your residual functional capacity. (e) Total limiting effects. When you have a severe impairment(s... appendix 1 of subpart P of part 404 of this chapter, we will consider the limiting effects of all...

  14. 20 CFR 404.1545 - Your residual functional capacity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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, neighbors... that are not severe, in determining your residual functional capacity. Pain or other symptoms may...

  15. 20 CFR 416.945 - Your residual functional capacity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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, or...), even those that are not severe, in determining your residual functional capacity. Pain or...

  16. 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... Capacity § 416.946 Responsibility for assessing your residual functional capacity. (a) Responsibility for...) is responsible for assessing your residual functional capacity. (b) Responsibility for...

  17. 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

  18. 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.

  19. 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.

  20. Stereotype Strength and Attentional Bias: Preference for Confirming versus Disconfirming Information Depends on Processing Capacity

    PubMed Central

    Allen, Thomas J.; Sherman, Jeffrey W.; Conrey, Frederica R.; Stroessner, Steven J.

    2009-01-01

    In two experiments, we investigated the relationships among stereotype strength, processing capacity, and the allocation of attention to stereotype-consistent versus stereotype-inconsistent information describing a target person. The results of both experiments showed that, with full capacity, greater stereotype strength was associated with increased attention toward stereotype-consistent versus stereotype-inconsistent information. However, when capacity was diminished, greater stereotype strength was associated with increased attention toward inconsistent versus consistent information. Thus, strong stereotypes may act as self-confirming filters when processing capacity is plentiful, but as efficient information gathering devices that maximize the acquisition of novel (disconfirming) information when capacity is depleted. Implications for models of stereotyping and stereotype change are discussed. PMID:20161043

  1. Measurement of functional residual capacity by sulfur hexafluoride washout.

    PubMed

    Jonmarker, C; Jansson, L; Jonson, B; Larsson, A; Werner, O

    1985-07-01

    Measurement of functional residual capacity (FRC) by the open-circuit multiple breath tracer gas washout technique is an established method. A system based upon washout of sulfur hexafluoride (SF6) during mechanical ventilation is described. The central unit in the system is a sensitive and rapid-response infrared SF6 analyzer. SF6 is washed in until the alveolar concentration of SF6 is 0.5%, a concentration so low that the supply of other gases is hardly influenced. During washout, the flow of SF6 from the lungs is calculated by a computer every 10 ms from signals representing expiratory flow and SF6 concentration. The total volume of SF6, washed out, is calculated by integration of SF6 flow. Since the alveolar concentration at the end of washin is known, the lung volume may be obtained. The measurement procedure is highly automated and the result is presented by the computer immediately after washout. Accurate and reproducible results in model lung tests were obtained during air and N2O/O2 ventilation. Comparison with body plethysmography (FRCBOX) in eight sitting healthy subjects gave the following: FRCSF6 = 7 ml + 0.98 X FRCBOX, r = 0.99. Comparison with nitrogen washout (FRCN2) in five postoperative patients gave the following: FRCSF6 = 59 ml + 0.97 X FRCN2, r = 0.97. FRCSF6 during N2O/O2 ventilation was the same as during air/O2 ventilation in a group of paralyzed patients. The measurement system has not been tested in patients with obstructive lung disease.

  2. 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…

  3. The Relationship Between Working Memory Capacity and Executive Functioning: Evidence for a Common Executive Attention Construct

    PubMed Central

    McCabe, David P.; Roediger, Henry L.; McDaniel, Mark A.; Balota, David A.; Hambrick, David Z.

    2010-01-01

    Attentional control has been conceptualized as executive functioning by neuropsychologists and as working memory capacity by experimental psychologists. We examined the relationship between these constructs using a factor analytic approach in an adult lifespan sample. Several tests of working memory capacity and executive function were administered to over 200 subjects between the ages of 18-90 years old, along with tests of processing speed and episodic memory. The correlation between working memory capacity and executive functioning constructs was very strong (r = .97), but correlations between these constructs and processing speed were considerably weaker (r's ≈ .79). Controlling for working memory capacity or executive function eliminated age effects on episodic memory, and working memory capacity or executive function accounted for variance in episodic memory beyond that accounted for by processing speed. We conclude that tests of working memory capacity and executive function share a common underlying executive attention component that is strongly predictive of higher-level cognition. PMID:20230116

  4. Improving residual vision by attentional cueing in patients with brain lesions.

    PubMed

    Poggel, Dorothe A; Kasten, Erich; Müller-Oehring, Eva M; Bunzenthal, Ulrike; Sabel, Bernhard A

    2006-06-30

    Visual attention is crucial for almost all processes of visual perception, particularly when perception is difficult. We were interested in the effects of cueing spatial attention in patients with cerebral lesions who face difficulties in visual perception in areas of residual vision at the border of visual field defects. In 23 patients with visual field loss due to post-geniculate brain lesions, stimulus detection performance and reaction times were mapped with high-resolution computer-based perimetry. A cueing procedure using Gestalt completion to attract attention to areas of residual vision was implemented in this test and performance compared in attended and unattended conditions. Stimulus detection and reaction times in areas of residual vision improved significantly under attended conditions. The extent of this effect depended on the size of areas of residual vision within the cued field. Unexpectedly, facilitation was also observed, though to a lesser extent, in invalid cueing conditions, suggesting an unspecific increase of alertness in unattended areas. Our findings show that top-down influences are relevant for visual field testing. Visuo-spatial attention may change patterns of neural activation and induce short-term plasticity not only in the intact visual system but also in the presence of visual field loss after brain lesions. Attentional cueing induces a co-activation of the lesioned visual system and (intact) attentional networks in the brain inducing immediate facilitation of visual perception. This effect may be relevant for designing new strategies to permanently improve vision during neuropsychological rehabilitation. PMID:16777076

  5. Working memory capacity, intelligence, and the magnitude of the attentional blink revisited.

    PubMed

    Martens, Sander; Johnson, Addie

    2009-01-01

    The attentional blink (AB) is a well-established phenomenon in the study of attention. This deficit in reporting the second of two targets presented in rapid serial visual presentation when it occurs 200-500 ms after the first is considered to reflect a fundamental limitation in attentional processing. However, we recently reported that some individuals do not show an AB, and presented psychophysiological evidence that target processing differs between blinkers and non-blinkers. One possibility is that non-blinkers may have a larger WM capacity, allowing better attentional control. Here we explore the relation between the magnitude of the AB, general intelligence, and different measures of working memory (WM) and short-term memory (STM) capacity. Surprisingly, no correlation was found between memory capacity measures and AB magnitude, raising doubts about the generalizability of earlier findings of such a relationship.

  6. Attention and working memory capacity: insights from blocking, highlighting, and knowledge restructuring.

    PubMed

    Sewell, David K; Lewandowsky, Stephan

    2012-08-01

    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 and working memory. Experiment 1 examined blocking and highlighting effects in an associative learning paradigm, which are widely thought to be attentionally mediated. No relationship between attentional performance indicators and working memory capacity (WMC) was observed, despite the fact that WMC was strongly associated with overall learning performance. Experiment 2 used a knowledge restructuring paradigm, which is known to require recoordination of partial category knowledge using representational attention. We found that the extent to which people successfully recoordinated their knowledge was related to WMC. The results illustrate a link between WMC and representational-but not dimensional-attention in category learning.

  7. The contribution of attentional lapses to individual differences in visual working memory capacity.

    PubMed

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

    2015-08-01

    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.

  8. 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.

  9. The impact of attentional allocation capacities on nonword repetition in children with specific language impairment.

    PubMed

    Leclercq, Anne-Lise; Maillart, Christelle; Lange, Manon; Majerus, Steve

    2015-01-01

    This study aimed at directly assessing the hypothesis that attentional allocation capacity influences poor nonword repetition (NWR) performances in children with specific language impairment (SLI), using an attention demanding visual search task given concurrently with the NWR task. Twenty-one children with SLI, 21 typically developing children matched on age and 21 typically developing children matched on nonword span performed an immediate serial recall task of nonwords. The nonword lists were presented either alone or concurrently with the visual search task. Overall, results revealed a resource-sharing trade-off between the two tasks. Children with SLI were affected to the same extent as their span-matched controls by the necessity to allocate their attentional resources between the two tasks. Interestingly, nonword processing strategies seemed to differ among groups: age-matched controls allocated a larger part of their attentional resources to the encoding stage, whereas nonword recall was more attention demanding in children with SLI and younger controls.

  10. Reduced attentional capacity, but normal processing speed and shifting of attention in developmental dyslexia: evidence from a serial task.

    PubMed

    Romani, Cristina; Tsouknida, Effie; di Betta, Anna M; Olson, Andrew

    2011-06-01

    We report the performance of a group of adult dyslexics and matched controls in an array-matching task where two strings of either consonants or symbols are presented side by side and have to be judged to be the same or different. The arrays may differ either in the order or identity of two adjacent characters. This task does not require naming - which has been argued to be the cause of dyslexics' difficulty in processing visual arrays - but, instead, has a strong serial component as demonstrated by the fact that, in both groups, Reaction times (RTs) increase monotonically with position of a mismatch. The dyslexics are clearly impaired in all conditions and performance in the identity conditions predicts performance across orthographic tasks even after age, performance IQ and phonology are partialled out. Moreover, the shapes of serial position curves are revealing of the underlying impairment. In the dyslexics, RTs increase with position at the same rate as in the controls (lines are parallel) ruling out reduced processing speed or difficulties in shifting attention. Instead, error rates show a catastrophic increase for positions which are either searched later or more subject to interference. These results are consistent with a reduction in the attentional capacity needed in a serial task to bind together identity and positional information. This capacity is best seen as a reduction in the number of spotlights into which attention can be split to process information at different locations rather than as a more generic reduction of resources which would also affect processing the details of single objects.

  11. 20 CFR 220.120 - The claimant's residual functional capacity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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 of.... Pain or other symptoms may cause a limitation of function beyond that which can be determined on...

  12. 20 CFR 220.120 - The claimant's residual functional capacity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 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 of.... Pain or other symptoms may cause a limitation of function beyond that which can be determined on...

  13. 20 CFR 220.120 - The claimant's residual functional capacity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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 of.... Pain or other symptoms may cause a limitation of function beyond that which can be determined on...

  14. 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...

  15. 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...

  16. Working memory and fluid intelligence: capacity, attention control, and secondary memory retrieval.

    PubMed

    Unsworth, Nash; Fukuda, Keisuke; Awh, Edward; Vogel, Edward K

    2014-06-01

    Several theories have been put forth to explain the relation between working memory (WM) and gF. Unfortunately, no single factor has been shown to fully account for the relation between these two important constructs. In the current study we tested whether multiple factors (capacity, attention control, and secondary memory) would collectively account for the relation. A large number of participants performed multiple measures of each construct and latent variable analyses were used to examine the data. The results demonstrated that capacity, attention control, and secondary memory were uniquely related to WM storage, WM processing, and gF. Importantly, the three factors completely accounted for the relation between WM (both processing and storage) and gF. Thus, although storage and processing make independent contributions to gF, both of these contributions are accounted for by variation in capacity, attention control and secondary memory. These results are consistent with the multifaceted view of WM, suggesting that individual differences in capacity, attention control, and secondary memory jointly account for individual differences in WM and its relation with gF.

  17. 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…

  18. 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…

  19. 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

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... assessing residual functional capacity at the State agency. When a State agency medical or psychological...(c)(1), a State agency medical or psychological consultant(s) (or a medical or psychological expert... functional capacity in the disability hearings process. If your case involves a disability hearing...

  1. Neural correlates of age-related decline and compensation in visual attention capacity.

    PubMed

    Wiegand, Iris; Töllner, Thomas; Dyrholm, Mads; Müller, Hermann J; Bundesen, Claus; Finke, Kathrin

    2014-09-01

    We identified neural correlates of declined and preserved basic visual attention functions in aging individuals based on Bundesen "Theory of Visual Attention". In an interindividual difference approach, we contrasted electrophysiology of higher- and lower-performing younger and older participants. In both age groups, the same distinct components indexed performance levels of parameters visual processing speed C and visual short-term memory storage capacity K. The posterior N1 marked interindividual differences in C and the contralateral delay activity marked interindividual differences in K. Moreover, both parameters were selectively related to 2 further event-related potential waves in older age. The anterior N1 was reduced for older participants with lower processing speed, indicating that age-related loss of attentional resources slows encoding. An enhanced right-central positivity was found only for older participants with high storage capacity, suggesting compensatory recruitment for retaining visual short-term memory performance. Together, our results demonstrate that attentional capacity in older age depends on both preservation and successful reorganization of the underlying brain circuits.

  2. 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.

  3. Early Auditory Evoked Potential Is Modulated by Selective Attention and Related to Individual Differences in Visual Working Memory Capacity

    PubMed Central

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

    2015-01-01

    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

  4. Age-related changes in attentional control across adolescence: how does this impact emotion regulation capacities?

    PubMed Central

    Cohen Kadosh, Kathrin; Heathcote, Lauren C.; Lau, Jennifer Y. F.

    2014-01-01

    This study set out to establish the novel use of the go/no-go Overlap task for investigating the role of attentional control capacities in the processing of emotional expressions across different age-groups within adolescence: at the onset of adolescence (11–12 year-olds) and toward the end of adolescence (17–18 year-olds). We also looked at how attentional control in the processing of fearful, happy, and neutral expressions relates to individual differences in trait anxiety in these adolescent groups. We were able to show that younger adolescents, but not older adolescents had more difficulties with attention control in the presence of all faces, but particularly in the presence of fearful faces. Moreover, we found that across all groups, adolescents with higher trait anxiety exhibited attentional avoidance of all faces, which facilitated relatively better performance on the primary task. These differences in reaction time emerged in the context of comparable accuracy level in the primary task across age-groups. Our results contribute to our understanding of how attentional control abilities to faces but in particular fearful expressions may mature across adolescence. This may affect learning about the environment and the acquisition of behavioral response patterns in the social world. PMID:24575077

  5. 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

  6. 20 CFR 416.946 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... assessing residual functional capacity at the State agency. When a State agency medical or psychological...(c)(1) of this part, a State agency medical or psychological consultant(s) is responsible for... disability hearings process. If your case involves a disability hearing under § 416.1414, a...

  7. 20 CFR 416.946 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... assessing residual functional capacity at the State agency. When a State agency medical or psychological...(c)(1) of this part, a State agency medical or psychological consultant(s) is responsible for... disability hearings process. If your case involves a disability hearing under § 416.1414, a...

  8. 20 CFR 416.946 - Responsibility for assessing your residual functional capacity.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... assessing residual functional capacity at the State agency. When a State agency medical or psychological...(c)(1) of this part, a State agency medical or psychological consultant(s) is responsible for... disability hearings process. If your case involves a disability hearing under § 416.1414, a...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. How do selective attentional processes contribute to maintenance and recall in children's working memory capacity?

    PubMed

    Roome, Hannah E; Towse, John N; Jarrold, Chris

    2014-01-01

    The development of working memory capacity is considered from the perspective of the active maintenance of items in primary memory (PM) and a cue-dependent search component, secondary memory (SM). Using free recall, plus a more novel serial interleaved items task, age-related increases in PM estimates were evident in both paradigms. In addition to this, age-related improvements in attentional selectivity were observed, indexed by the recall of target and non-target information respectively. To further characterize PM, presentation modality was varied in the serial interleaved items task (auditory, visual and dual presentation). Developmental differences were found in the effectiveness of presentation formats. Older children's recall was enhanced by the combination of labeled visual items and enduring auditory information, whilst the same format was detrimental to younger children's recall of target information. The present results show how estimates of PM and SM in children relate to the development of working memory capacity, but measurement of these constructs in children is not straightforward. Data also points to age-related changes in selective attention, which in turn contributes to children's ability to process and maintain information in working memory.

  15. How do selective attentional processes contribute to maintenance and recall in children's working memory capacity?

    PubMed

    Roome, Hannah E; Towse, John N; Jarrold, Chris

    2014-01-01

    The development of working memory capacity is considered from the perspective of the active maintenance of items in primary memory (PM) and a cue-dependent search component, secondary memory (SM). Using free recall, plus a more novel serial interleaved items task, age-related increases in PM estimates were evident in both paradigms. In addition to this, age-related improvements in attentional selectivity were observed, indexed by the recall of target and non-target information respectively. To further characterize PM, presentation modality was varied in the serial interleaved items task (auditory, visual and dual presentation). Developmental differences were found in the effectiveness of presentation formats. Older children's recall was enhanced by the combination of labeled visual items and enduring auditory information, whilst the same format was detrimental to younger children's recall of target information. The present results show how estimates of PM and SM in children relate to the development of working memory capacity, but measurement of these constructs in children is not straightforward. Data also points to age-related changes in selective attention, which in turn contributes to children's ability to process and maintain information in working memory. PMID:25566031

  16. 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.

  17. 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

  18. 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.

  19. 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…

  20. Optimal path choice in railway passenger travel network based on residual train capacity.

    PubMed

    Dou, Fei; Yan, Kai; Huang, Yakun; Wang, Li; Jia, Limin

    2014-01-01

    Passenger's optimal path choice is one of the prominent research topics in the field of railway passenger transport organization. More and more different train types are available, increasing path choices from departure to destination for travelers are unstoppable. However, travelers cannot avoid being confused when they hope to choose a perfect travel plan based on various travel time and cost constraints before departure. In this study, railway passenger travel network is constructed based on train timetable. Both the generalized cost function we developed and the residual train capacity are considered to be the foundation of path searching procedure. The railway passenger travel network topology is analyzed based on residual train capacity. Considering the total travel time, the total travel cost, and the total number of passengers, we propose an optimal path searching algorithm based on residual train capacity in railway passenger travel network. Finally, the rationale of the railway passenger travel network and the optimal path generation algorithm are verified positively by case study.

  1. Optimal Path Choice in Railway Passenger Travel Network Based on Residual Train Capacity

    PubMed Central

    Dou, Fei; Yan, Kai; Huang, Yakun; Jia, Limin

    2014-01-01

    Passenger's optimal path choice is one of the prominent research topics in the field of railway passenger transport organization. More and more different train types are available, increasing path choices from departure to destination for travelers are unstoppable. However, travelers cannot avoid being confused when they hope to choose a perfect travel plan based on various travel time and cost constraints before departure. In this study, railway passenger travel network is constructed based on train timetable. Both the generalized cost function we developed and the residual train capacity are considered to be the foundation of path searching procedure. The railway passenger travel network topology is analyzed based on residual train capacity. Considering the total travel time, the total travel cost, and the total number of passengers, we propose an optimal path searching algorithm based on residual train capacity in railway passenger travel network. Finally, the rationale of the railway passenger travel network and the optimal path generation algorithm are verified positively by case study. PMID:25097867

  2. 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

  3. 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.

  4. 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…

  5. Influence of the inherent properties of drinking water treatment residuals on their phosphorus adsorption capacities.

    PubMed

    Bai, Leilei; Wang, Changhui; He, Liansheng; Pei, Yuansheng

    2014-12-01

    Batch experiments were conducted to investigate the phosphorus (P) adsorption and desorption on five drinking water treatment residuals (WTRs) collected from different regions in China. The physical and chemical characteristics of the five WTRs were determined. Combined with rotated principal component analysis, multiple regression analysis was used to analyze the relationship between the inherent properties of the WTRs and their P adsorption capacities. The results showed that the maximum P adsorption capacities of the five WTRs calculated using the Langmuir isotherm ranged from 4.17 to 8.20mg/g at a pH of 7 and further increased with a decrease in pH. The statistical analysis revealed that a factor related to Al and 200 mmol/L oxalate-extractable Al (Alox) accounted for 36.5% of the variations in the P adsorption. A similar portion (28.5%) was attributed to an integrated factor related to the pH, Fe, 200 mmol/L oxalate-extractable Fe (Feox), surface area and organic matter (OM) of the WTRs. However, factors related to other properties (Ca, P and 5 mmol/L oxalate-extractable Fe and Al) were rejected. In addition, the quantity of P desorption was limited and had a significant negative correlation with the (Feox+Alox) of the WTRs (p<0.05). Overall, WTRs with high contents of Alox, Feox and OM as well as large surface areas were proposed to be the best choice for P adsorption in practical applications.

  6. Why does working memory capacity predict variation in reading comprehension? On the influence of mind wandering and executive attention.

    PubMed

    McVay, Jennifer C; Kane, Michael J

    2012-05-01

    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 3 WMC span tasks, 7 varied reading-comprehension tasks, and 3 attention-control tasks. Mind wandering was assessed using experimenter-scheduled thought probes during 4 different tasks (2 reading, 2 attention-control). The results support the executive-attention theory of WMC. Mind wandering across the 4 tasks loaded onto a single latent factor, reflecting a stable individual difference. Most important, 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.

  7. 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

  8. 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…

  9. [Measurement of functional residual capacity by nitrogen washout during mechanical ventilation].

    PubMed

    Nomura, T; Saito, Y; Ogawa, H; Akata, N; Nishino, Y; Kosaka, Y

    1998-02-01

    A medical gas analyzer AMIS 2000 SP, which is a mass spectrometer, incorporating a fractional residual capacity (FRC) measuring program based on a nitrogen washout method, has been introduced recently. The purpose of this study was to assess the reliability and the reproductivity of the FRC measuring system in a clinical situation. FRC was measured by this system connected to a ventilator (Bennet 7200ae). Our study examined; 1) the accuracy of the measurement using a syringe. 2) the difference in two consecutive measurements in the same subject during mechanical ventilation, and 3) the correlation between the measured and the predicted value calculated with Gorldman's formula in 18 subjects during ventilation. The first study has showed an excellent correlation (y = 0.953x + 0.092, r = 0.996, P < 0.001) or y = 0.909x + 0.132 (r = 0.999, P < 0.001) with a tidal volume of 400 ml or 500 ml, respectively) between the measured value and the syringe capacity. Reproductivity was proved by the linear regression (y = 0.977x + 0.024, r = 0.998, P < 0.001) between the two consecutive measurements. A good correlation was shown between the measured values and the predicted values (y = 0.656x - 0.415, r = 0.849, P < 0.0001). These results showed good reliability and reproductivity of our FRC measuring system. It is concluded that the FRC measurements using AMIS2000SP system can be used in clinical respiratory managements in ICU.

  10. 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.

  11. A system to measure functional residual capacity in critically ill patients.

    PubMed

    Paloski, W H; Newell, J C; Gisser, D G; Stratton, H H; Annest, S J; Gottlieb, M E; Shah, D M

    1981-04-01

    The use of continuous positive airway pressure (CPAP) and intermittent mandatory ventilation (IMV) in spontaneously breathing, intubated patients has prompted the development of new procedures for measuring functional residual capacity (FRC). The authors have developed a system for measuring FRC by the multiple breath nitrogen washout technique, which is suitable for use on intubated patients breathing with CPAP, IMV, or intermittent positive pressure ventilation (CONTROL) and on nonintubated patients. This system uses a pair of synchronized volume ventilators to permit a step change in inspired N2 fraction while providing therapeutic ventilatory support. A rapid-response nitrogen analyzer and a modified bellows spirometer are used for continuous measurement of airway nitrogen concentration and expired gas flow rate. FRC is calculated on-line by a digital computer. The system accuracy was tested on a mechanical lung simulator in the CPAP and CONTROL modes. The measured volume was found to agree within 58 +/- 52 ml of the actual volume in the CONTROL mode and within 104 +/- 22 ml in the CPAP mode. The system was also tested for repeatability by making duplicate FRC determinations in patients with respiratory insufficiency. In the 18 patients studied, the correlation coefficient of these duplicate measurements was r = 0.987 and the mean difference between measurements was 49 +/- 24 ml. This noninvasive system also provides data used to calculate anatomical deadspace by Fowler's method (VSDS) and uniformity of ventilation (V/V) for multicompartment lung models.

  12. Effects of sustained proNGF blockade on attentional capacities in aged rats with compromised cholinergic system.

    PubMed

    Yegla, B; Parikh, V

    2014-03-01

    Disruption in nerve growth factor (NGF) signaling via tropomyosin-related kinase A (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 acetylcholine (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

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

    PubMed Central

    Cowan, Nelson; Elliott, Emily M.; Saults, J. Scott; Morey, Candice C.; Mattox, Sam; Hismjatullina, Anna; Conway, Andrew R.A.

    2008-01-01

    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 components, on the assumption that WM involves both storage and processing. We argue that the critical aspect of successful WM measures is that rehearsal and grouping processes are prevented, allowing a clearer estimate of how many separate chunks of information the focus of attention circumscribes at once. Storage-and-processing tasks correlate with aptitudes, according to this view, largely because the processing task prevents rehearsal and grouping of items to be recalled. In a developmental study, we document that several scope-of-attention measures that do not include a separate processing component, but nevertheless prevent efficient rehearsal or grouping, also correlate well with aptitudes and with storage-and-processing measures. So does digit span in children too young to rehearse. PMID:16039935

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. Working memory capacity and visual-verbal cognitive load modulate auditory-sensory gating in the brainstem: toward a unified view of attention.

    PubMed

    Sörqvist, Patrik; Stenfelt, Stefan; Rönnberg, Jerker

    2012-11-01

    Two fundamental research questions have driven attention research in the past: One concerns whether selection of relevant information among competing, irrelevant, information takes place at an early or at a late processing stage; the other concerns whether the capacity of attention is limited by a central, domain-general pool of resources or by independent, modality-specific pools. In this article, we contribute to these debates by showing that the auditory-evoked brainstem response (an early stage of auditory processing) to task-irrelevant sound decreases as a function of central working memory load (manipulated with a visual-verbal version of the n-back task). Furthermore, individual differences in central/domain-general working memory capacity modulated the magnitude of the auditory-evoked brainstem response, but only in the high working memory load condition. The results support a unified view of attention whereby the capacity of a late/central mechanism (working memory) modulates early precortical sensory processing.

  19. Decreased binding capacity (Bmax) of muscarinic acetylcholine receptors in fibroblasts from boys with attention-deficit/hyperactivity disorder (ADHD).

    PubMed

    Johansson, Jessica; Landgren, Magnus; Fernell, Elisabeth; Lewander, Tommy; Venizelos, Nikolaos

    2013-09-01

    Monoaminergic dysregulation is implicated in attention-deficit/hyperactivity disorder (ADHD), and methylphenidate and amphetamines are the most frequently prescribed pharmacological agents for treating ADHD. However, it has recently been proposed that the core symptoms of the disorder might be due to an imbalance between monoaminergic and cholinergic systems. In this study, we used fibroblast cell homogenates from boys with and without ADHD as an extraneural cell model to examine the cholinergic receptor density, that is, muscarinic acetylcholine receptors (mAChRs). We found that the binding capacity (Bmax) of [³H] Quinuclidinyl benzilate (³H-QNB) to mAChRs was decreased by almost 50 % in the children with ADHD (mean = 30.6 fmol/mg protein, SD = 25.6) in comparison with controls [mean = 63.1 fmol/mg protein, SD = 20.5, p ≤ 0.01 (Student's unpaired t test)]. The decreased Bmax indicates a reduced cholinergic receptor density, which might constitute a biomarker for ADHD. However, these preliminary findings need to be replicated in larger ADHD and comparison cohorts.

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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)…

  5. 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…

  6. 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

  7. The influence of sleeping position on functional residual capacity and effective pulmonary blood flow in healthy neonates.

    PubMed

    Aiton, N R; Fox, G F; Alexander, J; Ingram, D M; Milner, A D

    1996-12-01

    Variation in body position has been shown to affect respiratory function in adults and neonates with and without respiratory illness. At present it remains unclear why respiratory function should be affected by different body positions. We hypothesized that the effect of body weight on the relatively compliant chest wall of the newborn infant in the prone position would cause a reduction in functional residual capacity (FRC) and a compensatory improvement in ventilation/perfusion matching as measured by effective pulmonary blood flow. To evaluate this, a paired crossover study was performed on 12 normal newborn infants. The inert gas (argon) rebreathing method adapted for neonates was used to measure FRC. Simultaneously effective pulmonary blood flow (Qpeff) was determined using Freon 22 and a mass spectrometer with computerized analysis. The babies were studied in three different positions in random order: prone, supine and right lateral decubitus. The means (95% confidence intervals) of the three groups of FRC were 23.8 (19.2 to 28.4), 23.8 (20.2 to 27.5), and 24.3 (19.5 to 29.2) ml/kg, respectively (P = 0.59) and for Qpeff were 104 (91 to 116), 108 (95 to 122), 109 (97 to 122) ml/ kg-min, respectively (P = 0.11). Thus no significant differences were demonstrated. In nine of the babies, a repeat supine measurement was taken at the end of the study to assess repeatability of the method. In these nine babies alone the results were 22.7 (19.1 to 26.3) and 22.1 (18.6 to 25.6) ml/kg for FRC, and 102 (89 to 116) and 98 (90 to 107) ml/kg-min for Qpeff. The coefficients of repeatability were 4.7 ml/kg for FRC (21%) and 30 ml/kg-min for Qpeff (30%).

  8. Modification of the open circuit N2 washout technique for measurement of functional residual capacity in premature infants.

    PubMed

    Hentschel, R; Suska, A; Volbracht, A; Brune, T; Jorch, G

    1997-06-01

    We compared the standard nitrogen (N2) washout technique for measuring functional residual capacity (FRC) with a modified technique that uses a helium/oxygen mixture (heliox) at different ratio instead of pure oxygen. The tests were made with a standard lung function system equipped with an ultraviolet (UV) analyzer for measurement of N2 concentrations in the expired gas. We examined models of "spontaneous breathing" and "mechanical ventilation," each with volumes of FRC in the range of a premature and a newborn lung (20-80 ml), using both techniques at different baseline inspired oxygen concentrations (FIO2). Correlations between known and measured volumes were high and identical for the two techniques (r = 0.996), and the mean error was not significantly different from zero (P = 0.111). Measurements of FRC in 6 infants gave a correlation coefficient of r = 0.989 between the two techniques; reproducibility, as measured by the coefficient of variation, was high, showing no significant differences between both techniques (P = 0.792). However, values of individual infants were different (P = 0.011), and the slope of the regression line relating measurements by the 2 techniques was 1.04, with an intercept on the y-axis at 1.46. We conclude that FRC can be measured with the modified N2 washout technique, using heliox as a washout gas. Volumes can be measured with high precision and reproducibility, even in premature infants with low lung volumes and/or high baseline FIO2. A correction factor may be necessary to equate FRC measurements made by oxygen-N2 vs. heliox-N2 washouts. Hyperoxemia and hypoxemia can be avoided by admixing different flows of oxygen to a standard heliox mixture.

  9. 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

  10. Working memory capacity in a go/no-go task: age differences in interference, processing speed, and attentional control.

    PubMed

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

    2013-09-01

    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) was simultaneously fitted to the data of all groups. In addition to the 3 main model parameters (feature overlap, noise, and processing rate), we estimated the time for switching between go and no-go steps as a new model parameter. In this study, we examined the IM parameters across the life span. The IM parameter estimates show that (a) conditions were not different in interference by feature overlap and interference by confusion; (b) switching costs time; (c) young adults and children were less susceptible than old adults to interference due to feature overlap; (d) noise was highest for children, followed by old and young adults; (e) old adults differed from children and young adults in lower processing rate; and (f) children and old adults had a larger switch cost between go steps and no-go steps. Thus, the results of this study indicated that across age, the IM parameters contribute distinctively for explaining the limits of WMC.

  11. Getting the hang of it: preferential gist over verbatim story recall and the roles of attentional capacity and the episodic buffer in Alzheimer disease.

    PubMed

    Foldi, Nancy S

    2011-01-01

    Story recall in Alzheimer disease (AD) is typically used as a measure of episodic memory, but the degree to which recall is dependent on available attentional resources is not fully understood. The current study investigated how measures of attention were associated to verbatim recall (exact reproduction) or gist recall (relevant semantic meaning). Sixteen participants with AD and 16 age-matched healthy older adults recalled a story on immediate free recall and recognition. Controls recalled more units overall than AD. A group X response interaction revealed more gist than verbatim recall in AD, but those with mild disease generated approximately the same number gist responses as controls. For each group, qualitatively different attentional resources were associated with recall units. In controls, verbatim units correlated positively with primacy serial position items of the California Verbal Learning Test II (CVLTII), suggesting that episodic buffer resources may be associated with story recall. In AD, gist units were positively correlated with digits forward, but inversely related to the CVLTII primacy region items, suggesting reliance on low-level capacity resources. Possible explanations of the impaired performance in AD may be a bias in favor of gist processing, poor verbatim encoding, and/or processing failure at the level of the episodic buffer.

  12. Getting the hang of it: preferential gist over verbatim story recall and the roles of attentional capacity and the episodic buffer in Alzheimer disease.

    PubMed

    Foldi, Nancy S

    2011-01-01

    Story recall in Alzheimer disease (AD) is typically used as a measure of episodic memory, but the degree to which recall is dependent on available attentional resources is not fully understood. The current study investigated how measures of attention were associated to verbatim recall (exact reproduction) or gist recall (relevant semantic meaning). Sixteen participants with AD and 16 age-matched healthy older adults recalled a story on immediate free recall and recognition. Controls recalled more units overall than AD. A group X response interaction revealed more gist than verbatim recall in AD, but those with mild disease generated approximately the same number gist responses as controls. For each group, qualitatively different attentional resources were associated with recall units. In controls, verbatim units correlated positively with primacy serial position items of the California Verbal Learning Test II (CVLTII), suggesting that episodic buffer resources may be associated with story recall. In AD, gist units were positively correlated with digits forward, but inversely related to the CVLTII primacy region items, suggesting reliance on low-level capacity resources. Possible explanations of the impaired performance in AD may be a bias in favor of gist processing, poor verbatim encoding, and/or processing failure at the level of the episodic buffer. PMID:21122189

  13. 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

    Nielsen, Simon; Wilms, L Inge

    2014-01-01

    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.

  14. 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.

  15. 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

  16. 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

  17. Impaired metabolic capacity in the perirhinal and posterior parietal cortex lead to dissociation between attentional, motivational and spatial components of exploration in the Naples High-Excitability rat.

    PubMed

    Gallo, A; Gonzalez-Lima, F; Sadile, A G

    2002-03-10

    This study aimed at investigating the neural substrates of spatial and non-spatial Behavioural components of exploration to novelty by a neurogenetic approach. Thus, functional imaging and Behavioural analysis were carried out in the Naples High-Excitability (NHE) rats, a model of hyperactivity and attention-deficit. Quantitative cytochrome oxidase (C.O.) histochemistry was used to measure the basal metabolic capacity of different forebrain structures. In parallel experiments, exploration in an 8-arm radial maze (Olton-maze) with extra-maze cues was used to measure attentional, motivational and spatial components of Behaviour after feeding rats' ad-libitum or at a reduced diet. Functional imaging analysis: brains from naive rats were stained for quantitative C.O. histochemistry along with standards. NHE rats showed lower C.O. activity in perirhinal and posterior-parietal cortex (all layers) and cortical amygdala, and greater activity in entorhinal cortex (superficial layers). The outer granular cell layer of the dentate gyrus had greater activity in NHE. Behavioural analysis: at low and high motivational level, maze exploration was reinforced during shaping throughout and then only a single arm. The Behaviour was monitored by a CCD camera and videotaped. (i) There was no line difference in working memory during non reinforced maze exploration, independent of the motivational level; (ii) during shaping with all baited arms, there was no line difference in working memory, but NHE rats showed a very low or lower food consumption at low and high motivational level, respectively; (iii) rats showed a higher working memory in finding the single baited arm at high motivational level; (iv) NHE rats paid little attention towards reinforcement upon visiting the baited arm only at low motivational level. Thus, Behavioural and functional neuroimaging analysis suggests the neural substrates of spatial and non-spatial components of exploration to be underlined by different

  18. 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

  19. Use of Fe/Al drinking water treatment residuals as amendments for enhancing the retention capacity of glyphosate in agricultural soils.

    PubMed

    Zhao, Yuanyuan; Wendling, Laura A; Wang, Changhui; Pei, Yuansheng

    2015-08-01

    Fe/Al drinking water treatment residuals (WTRs), ubiquitous and non-hazardous by-products of drinking water purification, are cost-effective adsorbents for glyphosate. Given that repeated glyphosate applications could significantly decrease glyphosate retention by soils and that the adsorbed glyphosate is potentially mobile, high sorption capacity and stability of glyphosate in agricultural soils are needed to prevent pollution of water by glyphosate. Therefore, we investigated the feasibility of reusing Fe/Al WTR as a soil amendment to enhance the retention capacity of glyphosate in two agricultural soils. The results of batch experiments showed that the Fe/Al WTR amendment significantly enhanced the glyphosate sorption capacity of both soils (p<0.001). Up to 30% of the previously adsorbed glyphosate desorbed from the non-amended soils, and the Fe/Al WTR amendment effectively decreased the proportion of glyphosate desorbed. Fractionation analyses further demonstrated that glyphosate adsorbed to non-amended soils was primarily retained in the readily labile fraction (NaHCO3-glyphosate). The WTR amendment significantly increased the relative proportion of the moderately labile fraction (HCl-glyphosate) and concomitantly reduced that of the NaHCO3-glyphosate, hence reducing the potential for the release of soil-adsorbed glyphosate into the aqueous phase. Furthermore, Fe/Al WTR amendment minimized the inhibitory effect of increasing solution pH on glyphosate sorption by soils and mitigated the effects of increasing solution ionic strength. The present results indicate that Fe/Al WTR is suitable for use as a soil amendment to prevent glyphosate pollution of aquatic ecosystems by enhancing the glyphosate retention capacity in soils.

  20. 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.

  1. 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

  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.

  3. 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…

  4. 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…

  5. 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

  6. 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.

  7. Priming to promote fluent motor skill execution: exploring attentional demands.

    PubMed

    Adams, Danielle; Ashford, Kelly J; Jackson, Robin C

    2014-08-01

    The effect of priming on the speed and accuracy of skilled performance and on a probe-reaction time task designed to measure residual attentional capacity, was assessed. Twenty-four skilled soccer players completed a dribbling task under three prime conditions (fluency, skill-focus, and neutral) and a control condition. Results revealed changes in trial completion time and secondary task performance in line with successfully priming autonomous and skill-focused attention. Retention test data for task completion time and probe-reaction time indicated a linear decrease in the priming effect such that the effect was nonsignificant after 30 min. Results provide further support for the efficacy of priming and provide the first evidence of concurrent changes in attentional demands, consistent with promoting or disrupting automatic skill execution.

  8. 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

  9. 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…

  10. Attention deficits in stroke patients with aphasia.

    PubMed

    Korda, R J; Douglas, J M

    1997-08-01

    Attentional capacity and sustained attention were investigated in 21 aphasic stroke patients and 21 non-brain-damaged patients. Attentional capacity was assessed using a series of reaction time (RT) tasks. The aphasic patients demonstrated impaired attentional capacity as shown by slower processing speed than the non-brain-damaged group (p < .01) and greater increases in RT with increased processing load (p < .05). Similar patterns were found for both verbal and spatial material. There was no significant relationship between severity of auditory comprehension deficits and attentional capacity. Sustained attention was assessed using a cognitive vigilance task requiring identification of a target letter presented infrequently over 32 minutes. Both the aphasic and the non-brain-damaged group demonstrated a decline in performance with time on task as shown by a steady increase in RTs (p < .0001), but the decline was equivalent across the groups. Thus, the aphasic group did not show a specific deficit in the ability to sustain attention. PMID:9342688

  11. Individual differences in recovery time from attentional capture.

    PubMed

    Fukuda, Keisuke; Vogel, Edward K

    2011-03-01

    Working memory capacity reflects a core ability of the individual that affects performance on many cognitive tasks. Recent work has suggested that an important covariate of memory capacity is attentional control, and specifically that low-capacity individuals are more susceptible to attentional capture by distractors than high-capacity individuals are, with the latter being able to resist capture. Here, we tested an alternative account according to which all individuals are equally susceptible to attentional capture, but high-capacity individuals recover more quickly than low-capacity individuals. Using psychophysical and electrophysiological methods, we measured recovery time from attentional capture. In two experiments, we found that high- and low-capacity individuals showed equivalent attentional capture effects in the initial moments following capture, but that low-capacity individuals took much longer to recover than high-capacity individuals did. These results suggest that the poor attentional control associated with low capacity is due to slow disengagement from distractors. PMID:21310945

  12. 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

  13. 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…

  14. Everyday attention failures: an individual differences investigation.

    PubMed

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

    2012-11-01

    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 contexts (in class or while studying). Latent variable techniques were used to perform analyses, and the results suggested that individual differences in working memory capacity and attention control were related to some but not all everyday attention failures. Furthermore, everyday attention failures predicted SAT scores and partially accounted for the relation between cognitive abilities and SAT scores. These results provide important evidence for individual differences in everyday attention failures as well as for the ecological validity of laboratory measures of working memory capacity and attention control.

  15. Affective modulation of attentional switching.

    PubMed

    Heerebout, Bram T; Todorović, Ana; Smedinga, Hilde E; Phaf, R Hans

    2013-01-01

    Affective modulation of attentional switching may have developed early in evolution and may therefore have primacy over other affective influences. This behavioral study investigated the influence of affect on attentional switching between emotionally neutral stimuli, whether limited-capacity control processes are involved, and whether attentional flexibility should be distinguished from attentional broadening. Experiment 1 showed that suboptimally presented happy faces facilitated switching from an automatized response routine, whereas angry faces had the opposite effect. In Experiment 2, participants with a dominant global (i.e., broad) or local (i.e., narrow) spatial bias switched more easily to the opposite bias after suboptimal happy faces than after neutral primes but less easily after angry faces. Affective modulation of attentional switching was probably incorporated during evolution in many more complex forms of information processing.

  16. 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.

  17. 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…

  18. Delayed Attentional Engagement in the Attentional Blink

    ERIC Educational Resources Information Center

    Nieuwenstein, Mark R.; Chun, Marvin M.; van der Lubbe, Rob H. J.; Hooge, Ignace T. C.

    2005-01-01

    Observers often miss the 2nd of 2 visual targets (first target [T1] and second target [T2]) when these targets are presented closely in time; the attentional blink (AB). The authors hypothesized that the AB occurs because the attentional response to T2 is delayed by T1 processing, causing T2 to lose a competition for attention to the item that…

  19. 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,…

  20. Disentangling the adult attention-deficit hyperactivity disorder endophenotype: parametric measurement of attention.

    PubMed

    Finke, Kathrin; Schwarzkopf, Wolfgang; Müller, Ulrich; Frodl, Thomas; Müller, Hermann J; Schneider, Werner X; Engel, Rolf R; Riedel, Michael; Möller, Hans-Jürgen; Hennig-Fast, Kristina

    2011-11-01

    Attention deficit hyperactivity disorder (ADHD) persists frequently into adulthood. The decomposition of endophenotypes by means of experimental neuro-cognitive assessment has the potential to improve diagnostic assessment, evaluation of treatment response, and disentanglement of genetic and environmental influences. We assessed four parameters of attentional capacity and selectivity derived from simple psychophysical tasks (verbal report of briefly presented letter displays) and based on a "theory of visual attention." These parameters are mathematically independent, quantitative measures, and previous studies have shown that they are highly sensitive for subtle attention deficits. Potential reductions of attentional capacity, that is, of perceptual processing speed and working memory storage capacity, were assessed with a whole report paradigm. Furthermore, possible pathologies of attentional selectivity, that is, selection of task-relevant information and bias in the spatial distribution of attention, were measured with a partial report paradigm. A group of 30 unmedicated adult ADHD patients and a group of 30 demographically matched healthy controls were tested. ADHD patients showed significant reductions of working memory storage capacity of a moderate to large effect size. Perceptual processing speed, task-based, and spatial selection were unaffected. The results imply a working memory deficit as an important source of behavioral impairments. The theory of visual attention parameter working memory storage capacity might constitute a quantifiable and testable endophenotype of ADHD.

  1. Attention and Olfactory Consciousness

    PubMed Central

    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

  2. Mindfulness training affects attention--or is it attentional effort?

    PubMed

    Jensen, Christian Gaden; Vangkilde, Signe; Frokjaer, Vibe; Hasselbalch, Steen G

    2012-02-01

    Improvements in attentional performance are at the core of proposed mechanisms for stress reduction in mindfulness meditation practices. However, this claim can be questioned because no previous studies have actively manipulated test effort in control groups and controlled for effects of stress reduction per se. In a blinded design, 48 young, healthy meditation novices were randomly assigned to a mindfulness-based stress reduction (MBSR), nonmindfulness stress reduction (NMSR), or inactive control group. At posttest, inactive controls were randomly split into nonincentive and incentive controls, the latter receiving a financial reward to improve attentional performance. Pre- and postintervention, 5 validated attention paradigms were employed along with self-report scales on mindfulness and perceived stress and saliva cortisol samples to measure physiological stress. Attentional effects of MBSR, NMSR, and the financial incentive were comparable or significantly larger in the incentive group on all reaction-time-based measures. However, selective attention in the MBSR group improved significantly more than in any other group. Similarly, only the MBSR intervention improved the threshold for conscious perception and visual working memory capacity. Furthermore, stress-reducing effects of MBSR were supported because those in the MBSR group showed significantly less perceived and physiological stress while increasing their mindfulness levels significantly. We argue that MBSR may contribute uniquely to attentional improvements but that further research focusing on non-reaction-time-based measures and outcomes less confounded by test effort is needed. Critically, our data demonstrate that previously observed improvements of attention after MBSR may be seriously confounded by test effort and nonmindfulness stress reduction.

  3. 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.

  4. Emotion regulation, attention to emotion, and the ventral attentional network

    PubMed Central

    Viviani, Roberto

    2013-01-01

    Accounts of the effect of emotional information on behavioral response and current models of emotion regulation are based on two opposed but interacting processes: automatic bottom-up processes (triggered by emotionally arousing stimuli) and top-down control processes (mapped to prefrontal cortical areas). Data on the existence of a third attentional network operating without recourse to limited-capacity processes but influencing response raise the issue of how it is integrated in emotion regulation. We summarize here data from attention to emotion, voluntary emotion regulation, and on the origin of biases against negative content suggesting that the ventral network is modulated by exposure to emotional stimuli when the task does not constrain the handling of emotional content. In the parietal lobes, preferential activation of ventral areas associated with “bottom-up” attention by ventral network theorists is strongest in studies of cognitive reappraisal. In conditions when no explicit instruction is given to change one's response to emotional stimuli, control of emotionally arousing stimuli is observed without concomitant activation of the dorsal attentional network, replaced by a shift of activation toward ventral areas. In contrast, in studies where emotional stimuli are placed in the role of distracter, the observed deactivation of these ventral semantic association areas is consistent with the existence of proactive control on the role emotional representations are allowed to take in generating response. It is here argued that attentional orienting mechanisms located in the ventral network constitute an intermediate kind of process, with features only partially in common with effortful and automatic processes, which plays an important role in handling emotion by conveying the influence of semantic networks, with which the ventral network is co-localized. Current neuroimaging work in emotion regulation has neglected this system by focusing on a bottom

  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.

  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. 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…

  8. Attention Breaks in Lectures

    ERIC Educational Resources Information Center

    Johnstone, A. H.; Percival, F.

    1976-01-01

    Describes research into student attention patterns during lectures that suggests that student attention declines steadily during a lecture, and that the rate of decrease is dependent upon several variables including subject difficulty. (MLH)

  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. [Assessment of legal capacity and testamentary capacity].

    PubMed

    Dreßing, H; Foerster, K; Leygraf, J; Schneider, F

    2014-11-01

    The assessment of legal capacity and testamentary capacity require thorough knowledge of the legal framework and the relevant case law. This paper explains the concept of the legal capacity to contract and the concept of testamentary capacity with respect to German civil law. The relevance of major mental disorders for the assessment of legal capacity and testamentary capacity is discussed.

  11. Plant intelligence and attention

    PubMed Central

    Marder, Michael

    2013-01-01

    This article applies the phenomenological model of attention to plant monitoring of environmental stimuli and signal perception. Three complementary definitions of attention as selectivity, modulation and perdurance are explained with reference to plant signaling and behaviors, including foraging, ramet placement and abiotic stress communication. Elements of animal and human attentive attitudes are compared with plant attention at the levels of cognitive focus, context and margin. It is argued that the concept of attention holds the potential of becoming a cornerstone of plant intelligence studies. PMID:23425923

  12. 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

  13. 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

  14. 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.

  15. Attention is necessary for subliminal instrumental conditioning

    PubMed Central

    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

  16. Attentional functions of parietal and frontal cortex.

    PubMed

    Peers, Polly V; Ludwig, Casimir J H; Rorden, Chris; Cusack, Rhodri; Bonfiglioli, Claudia; Bundesen, Claus; Driver, Jon; Antoun, Nagui; Duncan, John

    2005-10-01

    A model of normal attentional function, based on the concept of competitive parallel processing, is used to compare attentional deficits following parietal and frontal lobe lesions. Measurements are obtained for visual processing speed, capacity of visual short-term memory (VSTM), spatial bias (bias to left or right hemifield) and top-down control (selective attention based on task relevance). The results show important differences, but also surprising similarities, in parietal and frontal lobe patients. For processing speed and VSTM, deficits are selectively associated with parietal lesions, in particular lesions of the temporoparietal junction. We discuss explanations based on either grey matter or white matter lesions. In striking contrast, measures of attentional weighting (spatial bias and top-down control) are predicted by simple lesion volume. We suggest that attentional weights reflect competition between broadly distributed object representations. Parietal and frontal mechanisms work together, both in weighting by location and weighting by task context.

  17. Attention and autonomic self-regulation.

    PubMed

    Cohen, J; Sedlacek, K

    1983-06-01

    To examine how various aspects of attentional functioning are affected by autonomic self-regulation procedures, this study compared the effect of two treatment programs (EMG and thermal biofeedback used in conjunction with various somatic and cognitive relaxation/self-regulation strategies, and Benson's Relaxation Response procedure) and a Waiting List control group for essential hypertensive adults on three, perhaps overlapping, attentional dimensions: the capacity to disembed figure from ground (Embedded Figures Test, Block Design, and Picture Completion WAIS subtests); the capacity to voluntarily deploy attention (Digit Span subtest of the WAIS), and capacity to sustain attention or become absorbed (as measured by the Tellegen Absorption Scale). Thirty essential hypertensive men and women were randomly placed in one of the three groups. Attentional dimensions were assessed before and after the 10-week treatment program (or waiting period) and the relationship between blood pressure and attentional changes were assessed. The only group to evidence significant blood pressure reduction, the "Biofeedback Group," became significantly more Field Independent as measured by the EFT (p less than 0.001) and the Block Design measure (p less than 0.01) and evidenced a strong trend in the same direction on the Picture Completion measure (p less than 0.052, NS). No other significant pre-post attentional changes were found. A Pearson product correlation revealed that changes in diastolic blood pressure were significantly correlated with changes in EFT (r = 0.54, p less than 0.0001) and the Picture Completion measure (r = 0.32, p less than 0.05). The cognitive effect of autonomic self-regulation is discussed. In addition, the possible role of attention in autonomic self-regulation is examined.

  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. 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…

  20. 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…

  1. Rethinking Attention Deficit Disorders.

    ERIC Educational Resources Information Center

    Cherkes-Julkowski, Miriam; And Others

    This book reviews issues concerning attention deficit disorders (ADDs) in the context of a systems perspective. ADDs are viewed as resulting from dynamic interactions of behavior, cognition, and affect, out of which emerge distinct and idiosyncratic ways of coping. Chapter 1 looks at the interaction of attention and behavior. In chapter 2, the…

  2. Attention Attenuates Metacontrast Masking

    ERIC Educational Resources Information Center

    Boyer, Jennifer; Ro, Tony

    2007-01-01

    The influence of attention on perceptual awareness was examined using metacontrast masking. Attention was manipulated with endogenous cues to assess the effects on the temporal and spatial parameters of target visibility. Experiment 1 examined the time course of effective masking when the target and mask set were presented at an attended vs. an…

  3. Attentional processes and meditation.

    PubMed

    Hodgins, Holley S; Adair, Kathryn C

    2010-12-01

    Visual attentional processing was examined in adult meditators and non-meditators on behavioral measures of change blindness, concentration, perspective-shifting, selective attention, and sustained inattentional blindness. Results showed that meditators (1) noticed more changes in flickering scenes and noticed them more quickly, (2) counted more accurately in a challenging concentration task, (3) identified a greater number of alternative perspectives in multiple perspectives images, and (4) showed less interference from invalid cues in a visual selective attention task, but (5) did not differ on a measure of sustained inattentional blindness. Together, results show that regular meditation is associated with more accurate, efficient, and flexible visual attentional processing across diverse tasks that have high face validity outside of the laboratory. Furthermore, effects were assessed in a context separate from actual meditation practice, suggesting that meditators' better visual attention is not just immediate, but extends to contexts separate from meditation practice.

  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. Attention, reading and dyslexia.

    PubMed

    Skottun, Bernt C; Skoyles, John R

    2006-07-01

    It has been proposed that magnocellular deficits cause dyslexia through reduced attention. According to one model (Vidyasagar, Clinical and Experimental Optometry 2004; 87: 4-10), attention is shifted from letter to letter during fixations and magnocellular deficits are hypothesised to cause reading problems by interfering with the ability to control the attention. The present report points out several problems in this model. 1. It requires dissociation of eye movements and attention, which may be problematic within the framework of reading. 2. There is direct evidence to indicate that reading is not carried out in a letter-to-letter manner during fixations. 3. There are aspects of the visual performance of dyslexic readers, which are difficult to attribute to inattention. 4. There are indications that attentional deficiencies of dyslexic readers are not associated with magnocellular deficits. 5. The evidence for linking magnocellular deficits to dyslexia in general is weak.

  6. Infant Joint Attention, Neural Networks and Social Cognition

    PubMed Central

    Mundy, Peter; Jarrold, William

    2010-01-01

    Neural network models of attention can provide a unifying approach to the study of human cognitive and emotional development (Posner & Rothbart, 2007). This paper we argue that a neural networks approach to the infant development of joint attention can inform our understanding of the nature of human social learning, symbolic thought process and social cognition. At its most basic, joint attention involves the capacity to coordinate one’s own visual attention with that of another person. We propose that joint attention development involves increments in the capacity to engage in simultaneous or parallel processing of information about one’s own attention and the attention of other people. Infant practice with joint attention is both a consequence and organizer of the development of a distributed and integrated brain network involving frontal and parietal cortical systems. This executive distributed network first serves to regulate the capacity of infants to respond to and direct the overt behavior of other people in order to share experience with others through the social coordination of visual attention. In this paper we describe this parallel and distributed neural network model of joint attention development and discuss two hypotheses that stem from this model. One is that activation of this distributed network during coordinated attention enhances to depth of information processing and encoding beginning in the first year of life. We also propose that with development joint attention becomes internalized as the capacity to socially coordinate mental attention to internal representations. As this occurs the executive joint attention network makes vital contributions to the development of human symbolic thinking and social cognition. PMID:20884172

  7. Infant joint attention, neural networks and social cognition.

    PubMed

    Mundy, Peter; Jarrold, William

    2010-01-01

    Neural network models of attention can provide a unifying approach to the study of human cognitive and emotional development (Posner & Rothbart, 2007). In this paper we argue that a neural network approach to the infant development of joint attention can inform our understanding of the nature of human social learning, symbolic thought process and social cognition. At its most basic, joint attention involves the capacity to coordinate one's own visual attention with that of another person. We propose that joint attention development involves increments in the capacity to engage in simultaneous or parallel processing of information about one's own attention and the attention of other people. Infant practice with joint attention is both a consequence and an organizer of the development of a distributed and integrated brain network involving frontal and parietal cortical systems. This executive distributed network first serves to regulate the capacity of infants to respond to and direct the overt behavior of other people in order to share experience with others through the social coordination of visual attention. In this paper we describe this parallel and distributed neural network model of joint attention development and discuss two hypotheses that stem from this model. One is that activation of this distributed network during coordinated attention enhances the depth of information processing and encoding beginning in the first year of life. We also propose that with development, joint attention becomes internalized as the capacity to socially coordinate mental attention to internal representations. As this occurs the executive joint attention network makes vital contributions to the development of human symbolic thinking and social cognition. PMID:20884172

  8. Prefrontal contributions to visual selective attention.

    PubMed

    Squire, Ryan F; Noudoost, Behrad; Schafer, Robert J; Moore, Tirin

    2013-07-01

    The faculty of attention endows us with the capacity to process important sensory information selectively while disregarding information that is potentially distracting. Much of our understanding of the neural circuitry underlying this fundamental cognitive function comes from neurophysiological studies within the visual modality. Past evidence suggests that a principal function of the prefrontal cortex (PFC) is selective attention and that this function involves the modulation of sensory signals within posterior cortices. In this review, we discuss recent progress in identifying the specific prefrontal circuits controlling visual attention and its neural correlates within the primate visual system. In addition, we examine the persisting challenge of precisely defining how behavior should be affected when attentional function is lost.

  9. 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

  10. 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 ...

  11. Nicotinic receptors and attention.

    PubMed

    Hahn, Britta

    2015-01-01

    Facilitation of different attentional functions by nicotinic acetylcholine receptor (nAChR) agonists may be of therapeutic potential in disease conditions such as Alzheimer's disease or schizophrenia. For this reason, the neuronal mechanisms underlying these effects have been the focus of research in humans and in preclinical models. Attention-enhancing effects of the nonselective nAChR agonist nicotine can be observed in human nonsmokers and in laboratory animals, suggesting that benefits go beyond a reversal of withdrawal deficits in smokers. The ultimate aim is to develop compounds acting with greater selectivity than nicotine at a subset of nAChRs, with an effects profile narrowly matching the targeted cognitive deficits and minimizing unwanted effects. To date, compounds tested clinically target the nAChR subtypes most abundant in the brain. To help pinpoint more selectively expressed subtypes critical for attention, studies have aimed at identifying the secondary neurotransmitter systems whose stimulation mediates the attention-enhancing properties of nicotine. Evidence indicates that noradrenaline and glutamate, but not dopamine release, are critical mediators. Thus, attention-enhancing nAChR agents could spare the system central to nicotine dependence. Neuroimaging studies suggest that nAChR agonists act on a variety of brain systems by enhancing activation, reducing activation, and enhancing deactivation by attention tasks. This supports the notion that effects on different attentional functions may be mediated by distinct central mechanisms, consistent with the fact that nAChRs interact with a multitude of brain sites and neurotransmitter systems. The challenge will be to achieve the optimal tone at the right subset of nAChR subtypes to modulate specific attentional functions, employing not just direct agonist properties, but also positive allosteric modulation and low-dose antagonism.

  12. Unmasking the Attentional Blink

    ERIC Educational Resources Information Center

    Nieuwenstein, Mark R.; Potter, Mary C.; Theeuwes, Jan

    2009-01-01

    When asked to identify 2 visual targets (T1 and T2 for the 1st and 2nd targets, respectively) embedded in a sequence of distractors, observers will often fail to identify T2 when it appears within 200-500 ms of T1--an effect called the "attentional blink". Recent work shows that attention does not blink when the task is to encode a sequence of…

  13. 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.

  14. Can Rhesus Monkey Learn Executive Attention?

    PubMed Central

    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

  15. 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.

  16. 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

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. Attention, communication, and schizophrenia.

    PubMed Central

    Rund, B. R.

    1985-01-01

    The paper starts by drawing the historical lines for and giving an account of the main methods and results from an empirical investigation of cognitive disorders in schizophrenics and communication deviances in their parents. The focus of the report is on the significant correlations that were found between some aspects of parents' style of communication and offsprings' cognitive functioning. On the basis of the empirical study, the relationship between attention and communication is discussed, and the issue of whether attentional processes "change identity" by being embedded in a social context is considered. Furthermore, the influence of deviant communication in parents on attentional processes in offspring is discussed in relation to a main postulate in Vygotsky's theory; namely, that higher mental functions are internalized social relations. PMID:4049909

  3. Conscious attention, meditation, and bilateral information transfer.

    PubMed

    Bob, Petr; Zimmerman, Elizabeth M; Hamilton, Elizabeth A; Sheftel, Jenna G; Bajo, Stephanie D; Raboch, Jiri; Golla, Megan; Konopka, Lukasz M

    2013-01-01

    Recent findings indicate that conscious attention is related to large-scale information integration of various brain regions, including both hemispheres, that enables integration of parallel distributed modalities of processed information. There is also evidence that the level of information transference related to integration or splitting among brain regions, and between hemispheres, establishes a certain level of efficiency of the information processing. The level of information transference also may have modulatory influences on attentional capacity that are closely linked to the emotional arousal and autonomic response related to a stimulus. These findings suggest a hypothesis that changes in conscious attention, specifically during meditation could be reflected in the autonomic activity as the left-right information transference calculated from bilateral electrodermal activity (EDA). With the aim to compare conscious attention during meditation with other attentional states (resting state, Stroop task, and memory task), we performed bilateral EDA measurement in 7 healthy persons during resting state, Stroop task, neurofeedback memory test, and meditation. The results indicate that the information transference (ie, transinformation) is able to distinguish those attentional states, and that the highest level of the transinformation has been found during attentional processing related to meditation, indicating higher level of connectivity between left and right sides. Calculations other than pointwise transinformation (PTI) performed on EDA records, such as mean skin conductance level or laterality index, were not able to distinguish attentional states. The results suggest that PTI may present an interesting method useful for the assessment of information flow, related to neural functioning, that in the case of meditation may reflect typical integrative changes in the autonomic nervous system related to brain functions and focused attentional processing.

  4. 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.

  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. Attention: Moral-Cognitive Geography.

    ERIC Educational Resources Information Center

    Tuan, Yi-Fu

    1987-01-01

    This article is an essay on the importance of attention as a personal trait. Offers a definition of attention, reviews symptoms of inattention, and identifies the categories of objects which typically hold a person's attention. (JDH)

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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

  12. Disentangling gaze shifts from preparatory ERP effects during spatial attention.

    PubMed

    Kennett, Steffan; van Velzen, José; Eimer, Martin; Driver, Jon

    2007-01-01

    After a cue directing attention to one side, anterior event-related potentials (ERPs) show contralateral negativity (anterior directing attention negativity, ADAN). It is unclear whether ADAN effects are contaminated by contralateral negativity arising from residual gaze shifts. Conversely, it is possible that ADAN-related potentials contaminate the horizontal electrooculogram (HEOG), via volume conduction. To evaluate these possibilities, we used high-resolution infrared eye tracking while recording EEG and HEOG in a cued spatial-attention task. We found that, after conventional ERP and HEOG preprocessing exclusions, small but systematic residual gaze shifts in the cued direction can remain, as revealed by the infrared measure. Nevertheless, by using this measure for more stringent exclusion of small gaze shifts, we confirmed that reliable ADAN components remain for preparatory spatial attention in the absence of any systematic gaze shifts toward the cued side.

  13. Mental training enhances attentional stability: neural and behavioral evidence.

    PubMed

    Lutz, Antoine; Slagter, Heleen A; Rawlings, Nancy B; Francis, Andrew D; Greischar, Lawrence L; Davidson, Richard J

    2009-10-21

    The capacity to stabilize the content of attention over time varies among individuals, and its impairment is a hallmark of several mental illnesses. Impairments in sustained attention in patients with attention disorders have been associated with increased trial-to-trial variability in reaction time and event-related potential deficits during attention tasks. At present, it is unclear whether the ability to sustain attention and its underlying brain circuitry are transformable through training. Here, we show, with dichotic listening task performance and electroencephalography, that training attention, as cultivated by meditation, can improve the ability to sustain attention. Three months of intensive meditation training reduced variability in attentional processing of target tones, as indicated by both enhanced theta-band phase consistency of oscillatory neural responses over anterior brain areas and reduced reaction time variability. Furthermore, those individuals who showed the greatest increase in neural response consistency showed the largest decrease in behavioral response variability. Notably, we also observed reduced variability in neural processing, in particular in low-frequency bands, regardless of whether the deviant tone was attended or unattended. Focused attention meditation may thus affect both distracter and target processing, perhaps by enhancing entrainment of neuronal oscillations to sensory input rhythms, a mechanism important for controlling the content of attention. These novel findings highlight the mechanisms underlying focused attention meditation and support the notion that mental training can significantly affect attention and brain function.

  14. 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

  15. Attention: the claustrum.

    PubMed

    Goll, Yael; Atlan, Gal; Citri, Ami

    2015-08-01

    The claustrum is a mysterious thin sheet of neurons lying between the insular cortex and the striatum. It is reciprocally connected with almost all cortical areas, including motor, somatosensory, visual, auditory, limbic, associative, and prefrontal cortices. In addition, it receives neuromodulatory input from subcortical structures. A decade ago, Sir Francis Crick and Christof Koch published an influential review proposing the claustrum as the 'seat of consciousness', spurring a revival of interest in the claustrum. We review the literature on the claustrum, emphasizing recent discoveries, and develop a detailed hypothesis describing a role for the claustrum in the segregation of attention.

  16. 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…

  17. 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

  18. Joint attention and language evolution

    NASA Astrophysics Data System (ADS)

    Kwisthout, Johan; Vogt, Paul; Haselager, Pim; Dijkstra, Ton

    2008-06-01

    This study investigates how more advanced joint attentional mechanisms, rather than only shared attention between two agents and an object, can be implemented and how they influence the results of language games played by these agents. We present computer simulations with language games showing that adding constructs that mimic the three stages of joint attention identified in children's early development (checking attention, following attention, and directing attention) substantially increase the performance of agents in these language games. In particular, the rates of improved performance for the individual attentional mechanisms have the same ordering as that of the emergence of these mechanisms in infants' development. These results suggest that language evolution and joint attentional mechanisms have developed in a co-evolutionary way, and that the evolutionary emergence of the individual attentional mechanisms is ordered just like their developmental emergence.

  19. How the deployment of attention determines what we see

    PubMed Central

    Treisman, Anne

    2007-01-01

    Attention is a tool to adapt what we see to our current needs. It can be focused narrowly on a single object or spread over several or distributed over the scene as a whole. In addition to increasing or decreasing the number of attended objects, these different deployments may have different effects on what we see. This chapter describes some research both on focused attention and its use in binding features, and on distributed attention and the kinds of information we gain and lose with the attention window opened wide. One kind of processing that we suggest occurs automatically with distributed attention results in a statistical description of sets of similar objects. Another gives the gist of the scene, which may be inferred from sets of features registered in parallel. Flexible use of these different modes of attention allows us to reconcile sharp capacity limits with a richer understanding of the visual scene. PMID:17387378

  20. 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

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

    PubMed

    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

  2. Geotechnical characteristics of residual soils

    SciTech Connect

    Townsend, F.C.

    1985-01-01

    Residual soils are products of chemical weathering and thus their characteristics are dependent upon environmental factors of climate, parent material, topography and drainage, and age. These conditions are optimized in the tropics where well-drained regions produce reddish lateritic soils rich in iron and aluminum sesquioxides and kaolinitic clays. Conversely, poorly drained areas tend towards montmorillonitic expansive black clays. Andosols develop over volcanic ash and rock regions and are rich in allophane (amorphous silica) and metastable halloysite. The geological origins greatly affect the resulting engineering characteristics. Both lateritic soils and andosols are susceptible to property changes upon drying, and exhibit compaction and strength properties not indicative of their classification limits. Both soils have been used successfully in earth dam construction, but attention must be given to seepage control through the weathered rock. Conversely, black soils are unpopular for embankments. Lateritic soils respond to cement stabilization and, in some cases, lime stabilization. Andosols should also respond to lime treatment and cement treatments if proper mixing can be achieved. Black expansive residual soils respond to lime treatment by demonstrating strength gains and decreased expansiveness. Rainfall induced landslides are typical of residual soil deposits.

  3. Attention deficit hyperactivity disorder.

    PubMed

    Matthews, Marguerite; Nigg, Joel T; Fair, Damien A

    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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Culture, attention, and emotion.

    PubMed

    Grossmann, Igor; Ellsworth, Phoebe C; Hong, Ying-yi

    2012-02-01

    This research provides experimental evidence for cultural influence on one of the most basic elements of emotional processing: attention to positive versus negative stimuli. To this end, we focused on Russian culture, which is characterized by brooding and melancholy. In Study 1, Russians spent significantly more time looking at negative than positive pictures, whereas Americans did not show this tendency. In Study 2, Russian Latvians were randomly primed with symbols of each culture, after which we measured the speed of recognition for positive versus negative trait words. Biculturals were significantly faster in recognizing negative words (as compared with baseline) when primed with Russian versus Latvian cultural symbols. Greater identification with Russian culture facilitated this effect. We provide a theoretical discussion of mental processes underlying cultural differences in emotion research.

  9. Attentional inertia and delayed orienting of spatial attention in task-switching.

    PubMed

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

    2014-08-01

    Among the potential, but neglected, sources of task-switch costs is the need to reallocate attention to different attributes or objects. Even theorists who recognize the importance of attentional resetting in task-switching sometimes think it too efficient to result in significant behavioral costs. We examined the dynamics of spatial attention in a task-cuing paradigm using eye-tracking. Digits appeared simultaneously at 3 locations. A cue preceded this display by a variable interval, instructing the performance of 1 of 3 classification tasks (odd-even, low-high, inner-outer) each consistently associated with a location, so that task preparation could be tracked via fixation of the task-relevant location. Task-switching led to a delay in selecting the relevant location and a tendency to misallocate attention; the previously relevant location attracted attention much more than the other irrelevant location on switch trials, indicating "inertia" in attentional parameters rather than mere distractibility. These effects predicted reaction time switch costs within and over participants. The switch-induced delay was not confined to trials with slow/late orienting, but characteristic of most switch trials. The attentional pull of the previously relevant location was substantially reduced, but not eliminated, by extending the preparation interval to more than 1 sec, suggesting that attentional inertia contributes to the "residual" switch cost. A control condition, using identical displays but only 1 task, showed that these effects could not be attributed to the (small and transient) delays or inertia observed when the required orientation changed between trials in the absence of a task change.

  10. Selection History Modulates Working Memory Capacity

    PubMed Central

    Kuo, Bo-Cheng

    2016-01-01

    Recent studies have shown that past selection history affects the allocation of attention on target selection. However, it is unclear whether context-driven selection history can modulate the efficacy of attention allocation on working memory (WM) representations. This study tests the influences of selection history on WM capacity. A display of one item (low load) or three/four items (high load) was shown for the participants to hold in WM in a delayed response task. Participants then judged whether a probe item was in the memory display or not. Selection history was defined as the number of items attended across trials in the task context within a block, manipulated by the stimulus set-size in the contexts with fewer possible stimuli (4-item or 5-item context) or more possible stimuli (8-item or 9-item context) from which the memorized content was selected. The capacity measure (i.e., the K measure) was estimated to reflect the number of items that can be held in WM. Across four behavioral experiments, the results revealed that the capacity was significantly reduced in the context with more possible stimuli relative to the context with fewer possible stimuli. Moreover, the reduction in capacity was significant for high WM load and not observed when the focus was on only a single item. Together, these findings indicate that context-driven selection history and focused attention influence WM capacity. PMID:27774082

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. In competition for the attentional template: can multiple items within visual working memory guide attention?

    PubMed

    van Moorselaar, Dirk; Theeuwes, Jan; Olivers, Christian N L

    2014-08-01

    Recent studies have revealed that the deployment of attention can be biased by the content of visual working memory (VWM), but that stored memories do not always interact with attention. This has led to a model which proposes a division within VWM between a single active template that interacts with perception and multiple accessory representations that do not. The present study was designed to study whether multiple memory representations are able to bias attention. Participants performed a visual search task while maintaining a variable number of colors in VWM. Consistent with earlier findings, we observed increased attentional capture by memory related distractors when VWM was filled with a single item. However, memory related capture was no longer present for memory loads beyond a single item. The absence of memory related capture at higher VWM loads was independent of individual VWM capacity, nor was it attributable to weaker encoding, forgetting, or reduced precision of memory representations. When analyses were limited to those trials in which participants had a relatively precise memory, there was still no sign of attentional guidance at higher loads. However, when observers were cued toward a specific memory item after encoding, interference with search returned. These results are consistent with a distinction within VWM between representations that interact with perception and those that do not, and show that only a single VWM representation at a time can interact with visual attention.

  17. In competition for the attentional template: can multiple items within visual working memory guide attention?

    PubMed

    van Moorselaar, Dirk; Theeuwes, Jan; Olivers, Christian N L

    2014-08-01

    Recent studies have revealed that the deployment of attention can be biased by the content of visual working memory (VWM), but that stored memories do not always interact with attention. This has led to a model which proposes a division within VWM between a single active template that interacts with perception and multiple accessory representations that do not. The present study was designed to study whether multiple memory representations are able to bias attention. Participants performed a visual search task while maintaining a variable number of colors in VWM. Consistent with earlier findings, we observed increased attentional capture by memory related distractors when VWM was filled with a single item. However, memory related capture was no longer present for memory loads beyond a single item. The absence of memory related capture at higher VWM loads was independent of individual VWM capacity, nor was it attributable to weaker encoding, forgetting, or reduced precision of memory representations. When analyses were limited to those trials in which participants had a relatively precise memory, there was still no sign of attentional guidance at higher loads. However, when observers were cued toward a specific memory item after encoding, interference with search returned. These results are consistent with a distinction within VWM between representations that interact with perception and those that do not, and show that only a single VWM representation at a time can interact with visual attention. PMID:24730738

  18. 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…

  19. Object file continuity predicts attentional blink magnitude.

    PubMed

    Kellie, Frances J; Shapiro, Kimron L

    2004-05-01

    When asked to identify targets embedded within a rapid consecutive stream of visual stimuli, observers are less able to identify the second target (T2) when it is presented within half a second of the first (T1); this deficit has been termed the attentional blink (AB). Rapid serial visual presentation methodology was used to investigate the relationship between the AB and object files (episodic representations implicated in object identification and perceptual constancy). An inverse linear relationship was found between the degree of object file continuity and AB magnitude. An important locus of object file continuity was the intervening stream items between T1 and T2. The results are discussed in terms of the heuristic of the object file to preserve limited attentional capacity.

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

    PubMed Central

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

    2013-01-01

    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

  1. Attentional orienting towards smoking-related stimuli.

    PubMed

    Hogarth, L C; Mogg, K; Bradley, B P; Duka, T; Dickinson, A

    2003-03-01

    According to incentive salience theory, conditioned stimuli (CS+) associated with drug reinforcement acquire the capacity to elicit a conditioned attentional orienting response, which controls drug-seeking and drug-taking behaviour. We sought evidence for this proposal by measuring visual attentional orienting towards smoking pictures presented briefly in the periphery of the visual field, versus control pictures likewise presented, in smokers versus non-smokers. In each trial, smokers and non-smokers responded manually to a dot probe stimulus that appeared in a location previously occupied by either a smoking picture or a control picture. Attentional bias scores were calculated by subtracting the median reaction time (RT) in the former condition from the median RT in the latter condition. In two experiments, light-smokers (smokers of fewer than 20 cigarettes/day) produced a mean bias score that was significantly greater than that of heavy-smokers (smokers of 20 or more cigarettes/day) and non-smokers. In addition, when smokers from the two experiments were pooled, a significant quadratic relationship was found between cigarettes/day and the attentional bias for the smoking stimuli. These findings are consistent with incentive salience theories and dual-process theories of addiction.

  2. 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

  3. 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.

  4. 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

  5. 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 ...

  6. Assessment of attention in preschoolers.

    PubMed

    Mahone, E M; Schneider, H E

    2012-12-01

    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.

  7. Attentional but not Pre-Attentive Neural Measures of Auditory Discrimination are Atypical in Children with Developmental Language Disorder

    PubMed Central

    Kornilov, Sergey A.; Landi, Nicole; Rakhlin, Natalia; Fang, Shin-Yi; Grigorenko, Elena L.; Magnuson, James S.

    2015-01-01

    We examined neural indices of pre-attentive phonological and attentional auditory discrimination in children with developmental language disorder (DLD, n=23) and typically developing (n=16) peers from a geographically isolated Russian-speaking population with an elevated prevalence of DLD. Pre-attentive phonological MMN components were robust and did not differ in two groups. Children with DLD showed attenuated P3 and atypically distributed P2 components in the attentional auditory discrimination task; P2 and P3 amplitudes were linked to working memory capacity, development of complex syntax, and vocabulary. The results corroborate findings of reduced processing capacity in DLD and support a multifactorial view of the disorder. PMID:25350759

  8. Connectivity supporting attention in children with attention deficit hyperactivity disorder.

    PubMed

    Barber, Anita D; Jacobson, Lisa A; Wexler, Joanna L; Nebel, Mary Beth; Caffo, Brian S; Pekar, James J; Mostofsky, Stewart H

    2015-01-01

    Intra-subject variability (ISV) is the most consistent behavioral deficit in Attention Deficit Hyperactivity Disorder (ADHD). ISV may be associated with networks involved in sustaining task control (cingulo-opercular network: CON) and self-reflective lapses of attention (default mode network: DMN). The current study examined whether connectivity supporting attentional control is atypical in children with ADHD. Group differences in full-brain connection strength and brain-behavior associations with attentional control measures were examined for the late-developing CON and DMN in 50 children with ADHD and 50 typically-developing (TD) controls (ages 8-12 years). Children with ADHD had hyper-connectivity both within the CON and within the DMN. Full-brain behavioral associations were found for a number of between-network connections. Across both groups, more anti-correlation between DMN and occipital cortex supported better attentional control. However, in the TD group, this brain-behavior association was stronger and occurred for a more extensive set of DMN-occipital connections. Differential support for attentional control between the two groups occurred with a number of CON-DMN connections. For all CON-DMN connections identified, increased between-network anti-correlation was associated with better attentional control for the ADHD group, but worse attentional control in the TD group. A number of between-network connections with the medial frontal cortex, in particular, showed this relationship. Follow-up analyses revealed that these associations were specific to attentional control and were not due to individual differences in working memory, IQ, motor control, age, or scan motion. While CON-DMN anti-correlation is associated with improved attention in ADHD, other circuitry supports improved attention in TD children. Greater CON-DMN anti-correlation supported better attentional control in children with ADHD, but worse attentional control in TD children. On the other

  9. [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.

  10. [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

  11. Exogenous attention to unseen objects?

    PubMed

    Norman, Liam J; Heywood, Charles A; Kentridge, Robert W

    2015-09-01

    Attention and awareness are closely related phenomena, but recent evidence has shown that not all attended stimuli give rise to awareness. Controversy still remains over whether, and the extent to which, a dissociation between attention and awareness encompasses all forms of attention. For example, it has been suggested that attention without awareness is more readily demonstrated for voluntary, endogenous attention than its reflexive, exogenous counterpart. Here we examine whether exogenous attentional cueing can have selective behavioural effects on stimuli that nevertheless remain unseen. Using a task in which object-based attention has been shown in the absence of awareness, we remove all possible contingencies between cues and target stimuli to ensure that any cueing effects must be under purely exogenous control, and find evidence of exogenous object-based attention without awareness. In a second experiment we address whether this dissociation crucially depends on the method used to establish that the objects indeed remain unseen. Specifically, to confirm that objects are unseen we adopt appropriate signal detection task procedures, including those that retain parity with the primary attentional task (by requiring participants to discriminate the two types of trial that are used to measure an effect of attention). We show a significant object-based attention effect is apparent under conditions where the selected object indeed remains undetectable.

  12. 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

  13. 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.

  14. Early Social Attention Impairments in Autism: Social Orienting, Joint Attention, and Attention to Distress

    ERIC Educational Resources Information Center

    Dawson, Geraldine; Toth, Karen; Abbott, Robert; Osterling, Julie; Munson, Jeff; Estes, Annette; Liaw, Jane

    2004-01-01

    This study investigated social attention impairments in autism (social orienting, joint attention, and attention to another's distress) and their relations to language ability. Three- to four-year-old children with autism spectrum disorder (ASD; n = 72), 3- to 4-year-old developmentally delayed children (n = 34), and 12- to 46-month-old typically…

  15. 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.

  16. Pesticide residues in eagles

    USGS Publications Warehouse

    Reichel, W.L.; Cromartie, E.; Lamont, T.G.; Mulhern, B.M.; Prouty, R.M.

    1969-01-01

    Bald and golden eagles found sick or dead in 18 States and Canada during 1964-1965 were analyzed for pesticide residues. Residues in bald eagles were considerably higher than in golden eagles. Residues of DDE, DDD, and dieldrin were detected in all samples of bald eagle carcasses; other compounds found, less frequently were heptachlor epoxide, endrin, and DCBP, a metabolite of DDT. DDE was detected in all samples of golden eagle carcasses; DDD, DDT, dieldrin, and heptachlor epoxide were detected less frequently.

  17. 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

  18. Attentional bias temporal dynamics in remitted depression.

    PubMed

    Zvielli, Ariel; Vrijsen, Janna N; Koster, Ernst H W; Bernstein, Amit

    2016-08-01

    Theory implicates attentional bias (AB) or dysregulated attentional processing of emotional information in the recurrence of major depressive episodes. However, empirical study of AB among remitted depressed patients is limited in scope and has yielded mixed findings. Mixed findings may be accounted for by how the field has conceptualized and thereby studied AB. We propose that a novel temporal dynamic process perspective on AB may help disambiguate extant findings and elucidate the nature of AB in remitted depression. Thus, we reexamined Dot Probe data among remitted depressed patients (RMD; n = 328) and nondepressed controls (NDC; n = 82) that previously yielded null effects when AB was quantified by means of the traditional aggregated mean bias score (Vrijsen et al., 2014). We reanalyzed data using a novel computational approach that extracts a series of bias estimations from trial to trial (Zvielli, Bernstein, & Koster, 2015). Key features of these dynamic process signals revealed moderate to excellent reliability relative to the traditional aggregated mean bias scores. These features of AB dynamics-specifically temporal variability in AB including AB toward and away from emotional stimuli-were significantly elevated among RMDs relative to NDCs. Moreover, among RMDs, a greater number of past depressive episodes were associated with elevation in these features of AB dynamics. Effects were not accounted for by residual depressive symptoms or social anxiety symptoms. Findings indicate that dysregulation in attentional processing of emotional information reflected in AB dynamics may be key to depression vulnerability. (PsycINFO Database Record PMID:27505407

  19. From behavior to neural dynamics: An integrated theory of attention

    PubMed Central

    Buschman, Timothy J.; Kastner, Sabine

    2015-01-01

    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

  20. Attention and joint attention in preschool children with autism.

    PubMed

    Leekam, S R; López, B; Moore, C

    2000-03-01

    Three experiments examined the role of attention in explaining dyadic (child-adult) and triadic (child-adult-object) joint attention difficulties in autism. Experiments 1 and 2 investigated children's ability to orient to an adult's attention bid and to follow the direction of a human or nonhuman cue. Experiment 3 tested ability to disengage and shift attention to objects. Results showed autism-specific difficulties at both dyadic and triadic levels. Children with autism were less responsive than developmentally delayed controls in orienting to attention bids and in following a human head-turn cue yet had no difficulty in shifting attention and were faster overall in orienting to targets. Results suggest a specific developmental delay in which children with autism rely on the presence of objects in the visual field to guide action. The relation between this problem and autistic children's difficulties with human communicative signals is discussed. PMID:10749083

  1. 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...

  2. 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

  3. 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.

  4. Foundational tuning: how infants' attention to speech predicts language development.

    PubMed

    Vouloumanos, Athena; Curtin, Suzanne

    2014-01-01

    Orienting biases for speech may provide a foundation for language development. Although human infants show a bias for listening to speech from birth, the relation of a speech bias to later language development has not been established. Here, we examine whether infants' attention to speech directly predicts expressive vocabulary. Infants listened to speech or non-speech in a preferential listening procedure. Results show that infants' attention to speech at 12 months significantly predicted expressive vocabulary at 18 months, while indices of general development did not. No predictive relationships were found for infants' attention to non-speech, or overall attention to sounds, suggesting that the relationship between speech and expressive vocabulary was not a function of infants' general attentiveness. Potentially ancient evolutionary perceptual capacities such as biases for conspecific vocalizations may provide a foundation for proficiency in formal systems such language, much like the approximate number sense may provide a foundation for formal mathematics.

  5. 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.

  6. 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

  7. 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…

  8. The interplay of attention and consciousness in visual search, attentional blink and working memory consolidation.

    PubMed

    Raffone, Antonino; Srinivasan, Narayanan; van Leeuwen, Cees

    2014-05-01

    Despite the acknowledged relationship between consciousness and attention, theories of the two have mostly been developed separately. Moreover, these theories have independently attempted to explain phenomena in which both are likely to interact, such as the attentional blink (AB) and working memory (WM) consolidation. Here, we make an effort to bridge the gap between, on the one hand, a theory of consciousness based on the notion of global workspace (GW) and, on the other, a synthesis of theories of visual attention. We offer a theory of attention and consciousness (TAC) that provides a unified neurocognitive account of several phenomena associated with visual search, AB and WM consolidation. TAC assumes multiple processing stages between early visual representation and conscious access, and extends the dynamics of the global neuronal workspace model to a visual attentional workspace (VAW). The VAW is controlled by executive routers, higher-order representations of executive operations in the GW, without the need for explicit saliency or priority maps. TAC leads to newly proposed mechanisms for illusory conjunctions, AB, inattentional blindness and WM capacity, and suggests neural correlates of phenomenal consciousness. Finally, the theory reconciles the all-or-none and graded perspectives on conscious representation.

  9. The interplay of attention and consciousness in visual search, attentional blink and working memory consolidation.

    PubMed

    Raffone, Antonino; Srinivasan, Narayanan; van Leeuwen, Cees

    2014-05-01

    Despite the acknowledged relationship between consciousness and attention, theories of the two have mostly been developed separately. Moreover, these theories have independently attempted to explain phenomena in which both are likely to interact, such as the attentional blink (AB) and working memory (WM) consolidation. Here, we make an effort to bridge the gap between, on the one hand, a theory of consciousness based on the notion of global workspace (GW) and, on the other, a synthesis of theories of visual attention. We offer a theory of attention and consciousness (TAC) that provides a unified neurocognitive account of several phenomena associated with visual search, AB and WM consolidation. TAC assumes multiple processing stages between early visual representation and conscious access, and extends the dynamics of the global neuronal workspace model to a visual attentional workspace (VAW). The VAW is controlled by executive routers, higher-order representations of executive operations in the GW, without the need for explicit saliency or priority maps. TAC leads to newly proposed mechanisms for illusory conjunctions, AB, inattentional blindness and WM capacity, and suggests neural correlates of phenomenal consciousness. Finally, the theory reconciles the all-or-none and graded perspectives on conscious representation. PMID:24639586

  10. Comparative ecotoxicology of halogenated hydrocarbon residues.

    PubMed

    Winteringham, F P

    1977-12-01

    The term ecotoxicology is adopted in the sense of a comparative and integrated study of the undesirable effects of trace contaminants on the range of fauna and flora of an "ecosystem" or of a defined part or unit thereof. The importance of population changes over long periods of time is stressed. Sources, usage, and global trends of representative halogenated hydrocarbon (HHC) residues which appear as trace contaminants of environment, food, and living organisms are briefly compared: industrial solvents and intermediates, chlorofluoromethanes as an atmospheric pollutant, methyl bromide as a food and soil residue, HCH (hexachlorobenzene) as a fungicide residue, DDT, lindane (gamma-hexachlorocyclohexane), and dieldrin as insecticide residues, and polychlorinated biphenyls (PCBs) as industrial contaminants. A simple mathematical approach to the problem of relating inputs, persistence, and steady-state residue levels is explained. Persistence and biodegradation of representative compounds are compared. Attention is drawn to the persistence of hexachlorobenzene, the p,p'-dichlorodiphenyl- and hexachlorocyclopentadiene-derived moities of HHC residues. Ecotoxicological effects and their implications are discussed comparatively under the indirect effects of atmospheric pollutants and direct and indirect effects of trace contaminants of soil and aquatic ecosystems. Some conclusions related to research and "impact monitoring" are drawn.

  11. 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

  12. Attentional priority determines working memory precision.

    PubMed

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

    2014-12-01

    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.

  13. Attentional priority determines working memory precision.

    PubMed

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

    2014-12-01

    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

  14. 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

  15. 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.…

  16. 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…

  17. 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…

  18. Attention function after childhood stroke.

    PubMed

    Max, Jeffrey E; Robin, Donald A; Taylor, H Gerry; Yeates, Keith O; Fox, Peter T; Lancaster, Jack L; Manes, Facundo F; Mathews, Katherine; Austermann, Shannon

    2004-11-01

    We investigated attentional outcome after childhood stroke and orthopedic diagnosis in medical controls. Twenty-nine children with focal stroke lesions and individually matched children with clubfoot or scoliosis were studied with standardized attention and neuroimaging assessments. Stroke lesions were quite varied in location and commonly involved regions implicated in Posner's model of attention networks. Children with stroke lesions performed significantly more poorly regarding attention function compared with controls. Performance on the Starry Night, a test demanding alerting and sensory-orienting but not executive attention function, was significantly associated with lesion size in the alerting and sensory-orienting networks but not the executive attention network. Furthermore, earlier age at lesion acquisition was significantly associated with poorer attention function even when lesion size was controlled. These findings support the theory of dissociable networks of attention and add to evidence from studies of children with diffuse and focal brain damage that early insults are associated with worse long-term outcomes in many domains of neuropsychological function. In addition, these results may provide clues towards the understanding of mechanisms underlying attention in children.

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. Connectivity supporting attention in children with attention deficit hyperactivity disorder

    PubMed Central

    Barber, Anita D.; Jacobson, Lisa A.; Wexler, Joanna L.; Nebel, Mary Beth; Caffo, Brian S.; Pekar, James J.; Mostofsky, Stewart H.

    2014-01-01

    Intra-subject variability (ISV) is the most consistent behavioral deficit in Attention Deficit Hyperactivity Disorder (ADHD). ISV may be associated with networks involved in sustaining task control (cingulo-opercular network: CON) and self-reflective lapses of attention (default mode network: DMN). The current study examined whether connectivity supporting attentional control is atypical in children with ADHD. Group differences in full-brain connection strength and brain–behavior associations with attentional control measures were examined for the late-developing CON and DMN in 50 children with ADHD and 50 typically-developing (TD) controls (ages 8–12 years). Children with ADHD had hyper-connectivity both within the CON and within the DMN. Full-brain behavioral associations were found for a number of between-network connections. Across both groups, more anti-correlation between DMN and occipital cortex supported better attentional control. However, in the TD group, this brain–behavior association was stronger and occurred for a more extensive set of DMN–occipital connections. Differential support for attentional control between the two groups occurred with a number of CON–DMN connections. For all CON–DMN connections identified, increased between-network anti-correlation was associated with better attentional control for the ADHD group, but worse attentional control in the TD group. A number of between-network connections with the medial frontal cortex, in particular, showed this relationship. Follow-up analyses revealed that these associations were specific to attentional control and were not due to individual differences in working memory, IQ, motor control, age, or scan motion. While CON–DMN anti-correlation is associated with improved attention in ADHD, other circuitry supports improved attention in TD children. Greater CON–DMN anti-correlation supported better attentional control in children with ADHD, but worse attentional control in TD

  4. 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.

  5. 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

  6. Shifting Attentional Priorities: Control of Spatial Attention through Hemispheric Competition

    PubMed Central

    Szczepanski, Sara M.; Kastner, Sabine

    2013-01-01

    Regions of frontal and posterior parietal cortex are known to control the allocation of spatial attention across the visual field. However, the neural mechanisms underlying attentional control in the intact human brain remain unclear, with some studies supporting a hemispatial theory emphasizing a dominant function of the right hemisphere and others supporting an interhemispheric competition theory. We previously found neural evidence to support the latter account, in which topographically organized frontoparietal areas each generate a spatial bias, or “attentional weight,” toward the contralateral hemifield, with the sum of the weights constituting the overall bias that can be exerted across visual space. Here, we used a multimodal approach consisting of functional magnetic resonance imaging (fMRI) of spatial attention signals, behavioral measures of spatial bias, and fMRI-guided single-pulse transcranial magnetic stimulation (TMS) to causally test this interhemispheric competition account. Across the group of fMRI subjects, we found substantial individual differences in the strengths of the frontoparietal attentional weights in each hemisphere, which predicted subjects’ respective behavioral preferences when allocating spatial attention, as measured by a landmark task. Using TMS to interfere with attentional processing within specific topographic frontoparietal areas, we then demonstrated that the attentional weights of individual subjects, and thus their spatial attention behavior, could be predictably shifted toward one visual field or the other, depending on the site of interference. The results of our multimodal approach, combined with an emphasis on neural and behavioral individual differences, provide compelling evidence that spatial attention is controlled through competitive interactions between hemispheres rather than a dominant right hemisphere in the intact human brain. PMID:23516306

  7. Divided attention limits perception of 3-D object shapes.

    PubMed

    Scharff, Alec; Palmer, John; Moore, Cathleen M

    2013-01-01

    Can one perceive multiple object shapes at once? We tested two benchmark models of object shape perception under divided attention: an unlimited-capacity and a fixed-capacity model. Under unlimited-capacity models, shapes are analyzed independently and in parallel. Under fixed-capacity models, shapes are processed at a fixed rate (as in a serial model). To distinguish these models, we compared conditions in which observers were presented with simultaneous or sequential presentations of a fixed number of objects (The extended simultaneous-sequential method: Scharff, Palmer, & Moore, 2011a, 2011b). We used novel physical objects as stimuli, minimizing the role of semantic categorization in the task. Observers searched for a specific object among similar objects. We ensured that non-shape stimulus properties such as color and texture could not be used to complete the task. Unpredictable viewing angles were used to preclude image-matching strategies. The results rejected unlimited-capacity models for object shape perception and were consistent with the predictions of a fixed-capacity model. In contrast, a task that required observers to recognize 2-D shapes with predictable viewing angles yielded an unlimited capacity result. Further experiments ruled out alternative explanations for the capacity limit, leading us to conclude that there is a fixed-capacity limit on the ability to perceive 3-D object shapes.

  8. 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

  9. 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…

  10. 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…

  11. Joint Attention and Early Language.

    ERIC Educational Resources Information Center

    Tomasello, Michael; Farrar, Michael Jeffrey

    1986-01-01

    Findings from studies exploring role of joint attentional focus in children's acquisition of language indicated that language of 24 mothers and their 15- to 21-month-olds inside episodes of joint attentional focus involved more utterances, shorter sentences, more comments, and longer conversations than outside of episodes. Also, object references…

  12. Nonequilibrium heat capacity.

    PubMed

    Mandal, Dibyendu

    2013-12-01

    Development of steady state thermodynamics and statistical mechanics depends crucially on our ability to extend the notions of equilibrium thermodynamics to nonequilibrium steady states (NESS). The present paper considers the extension of heat capacity. A modified definition is proposed which continues to maintain the same relation to steady state Shannon entropy as in equilibrium, thus providing a thermodynamically consistent treatment of NESS heat capacity.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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

  19. Extending the Simultaneous-Sequential Paradigm to Measure Perceptual Capacity for Features and Words

    ERIC Educational Resources Information Center

    Scharff, Alec; Palmer, John; Moore, Cathleen M.

    2011-01-01

    In perception, divided attention refers to conditions in which multiple stimuli are relevant to an observer. To measure the effect of divided attention in terms of perceptual capacity, we introduce an extension of the simultaneous-sequential paradigm. The extension makes predictions for fixed-capacity models as well as for unlimited-capacity…

  20. Implications of ERP data for psychological theories of attention.

    PubMed

    Näätänen, R

    1988-06-01

    The contribution of the event-related potential (ERP) research to understanding human selective attention will be evaluated. A closely related issue, the starting point of the present treatment, involves the nature and extent of automaticity in information processing. The mismatch-negativity component of the ERP suggests that the basic, obligatory, processing of the physical features of auditory stimuli is unaffected by the direction of attention. These data also reveal a possible mechanism for attention switching to stimulus change occurring in the unattended input, observed by cognitive psychologists. The N1 wave of the ERP might in turn provide a data base for explaining similar attention switches to stimulus onsets after breaks in stimulation and to offsets of long-duration stimuli. With regard to selective attention, the processing negativity might make it possible to delineate the central principle of stimulus selection in attention, a goal probably inaccessible to non-physiological attention research. In the visual modality, cognitive psychologists have found that spatial attention is more fundamental and powerful in stimulus selection than any other form of visual selective attention. Consistently, ERP data show that the exogenous components in vision are enhanced by spatial selective attention but not when attended and unattended stimuli are not spatially separated. Also, ERP data (the P3 wave) give support to certain forms of resource-allocation theories of attention. In addition, with regard to the currently popular distinction between automatic versus controlled processing, these data strongly suggest that extended consistent-mapping training does not lead to a "genuine" automatization of a search process in the sense of independence of a limited-capacity system. PMID:3061477

  1. 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.

  2. Attention modulates visual size adaptation.

    PubMed

    Kreutzer, Sylvia; Fink, Gereon R; Weidner, Ralph

    2015-01-01

    The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance detection task. When attention was directed toward the small as compared to the large adapter, the perceived size of the subsequent target was significantly increased. Data suggest that different size adaptation effects can be induced by one and the same stimulus depending on the current allocation of attention. This indicates that size adaptation is subject to attentional modulation. These findings are in line with previous research showing that transient as well as sustained attention modulates visual features, such as contrast sensitivity and spatial frequency, and influences adaptation in other contexts, such as motion adaptation (Alais & Blake, 1999; Lankheet & Verstraten, 1995). Based on a recently suggested model (Pooresmaeili, Arrighi, Biagi, & Morrone, 2013), according to which perceptual adaptation is based on local excitation and inhibition in V1, we conclude that guiding attention can boost these local processes in one or the other direction by increasing the weight of the attended adapter. In sum, perceptual adaptation, although reflected in changes of neural activity at early levels (as shown in the aforementioned study), is nevertheless subject to higher-order modulation.

  3. Adaptive allocation of attentional gain

    PubMed Central

    Scolari, Miranda; Serences, John T.

    2009-01-01

    Humans are adept at distinguishing between stimuli that are very similar, an ability that is particularly crucial when the outcome is of serious consequence (e.g. for a surgeon or air traffic controller). Traditionally, selective attention was thought to facilitate perception by increasing the gain of sensory neurons tuned to the defining features of a behaviorally relevant object (e.g. color, orientation, etc.). In contrast, recent mathematical models counter-intuitively suggest that in many cases attentional gain should be applied to neurons that are tuned away from relevant features, especially when discriminating highly similar stimuli. Here we used psychophysical methods to critically evaluate these ‘ideal observer’ models. The data demonstrate that attention enhances the gain of the most informative sensory neurons, even when these neurons are tuned away from the behaviorally relevant target feature. Moreover, the degree to which an individual adopted optimal attentional gain settings by the end of testing predicted success rates on a difficult visual discrimination task, as well as the amount of task improvement that occurred across repeated testing sessions (learning). Contrary to most traditional accounts, these observations suggest that the primary function of attentional gain is not simply to enhance the representation of target features, but to optimize performance on the current perceptual task. Additionally, individual differences in gain suggest that the operating characteristics of low-level attentional phenomena are not stable trait-like attributes and that variability in how attention is deployed may play an important role in determining perceptual abilities. PMID:19776279

  4. Residue chemistry guidelines.

    PubMed

    Olinger, C L; Schmitt, R D; Zager, E

    1993-01-01

    Residue chemistry guidelines are designed to determine what the potential residues in food are and how much may be present as a result of pesticide application, so that a tolerance level may be established. Some requirements are established to assist in the enforcement of tolerances by the USDA, FDA, and the states. I realize I have given you a quick overview of the residue chemistry requirements. There are many documents which are available if you should require more information, such as the Subdivision O Residue Chemistry Guidelines, Standard Evaluation Procedures (which are used by reviewers when evaluating the studies), the Data Reporting Guidelines (which provide guidance on preparing final reports), and the Technical Guidance from Phase III of Reregistration. We have also released various papers on studies when additional guidance is required. Most of these documents are available from NTIS. I hope you will consider this information when auditing residue chemistry studies. As I see the efforts that you, the QA professionals, have made to educate yourselves on residue chemistry studies through programs such as this meeting, I have a little more confidence in answering the question "Do you trust them?" with a "Yes." Thank you.

  5. [Neuropsychological approach to visual attention].

    PubMed

    Suzuki, Kyoko

    2007-01-01

    Visual experience depends critically on visual attention, which selects a particular aspect of a visual display. Recent clinical, neuroimaging, and animal studies revealed that visual attention was divided into active and passive or top-down and bottom-up attention. Although these dichotomies are clear-cut in definition, visual attention could be modulated by many factors. Detailed observation of brain-injured patients provides with evidence for dynamic and fine control of visual attention. We observed patients with dorsal simultanagnosia and that with callosal disconnection syndrome. Patients with dorsal simultanagnosia demonstrated that extent of visual attention was dynamically changed depending on the level of visual processing. Despite the ability to read a kanji character and to describe its components correctly, a patient could not notice a component that he had just written and could not assemble individual components to make up a correct kanji character. He could point to an overlapping area of two figures. But once he started to color the overlapping area, he missed the margin of the area and colored much larger area. Another patient with dorsal simultanagnosia missed borderlines between columns of a newspaper and read letters continuously across columns. In contrast, he could point to lines between figures or meaningless patterns easily. These findings indicated that visual attention was directed automatically to meaningful characters. A patients with callosal disconnection syndrome demonstrated left unilateral spatial neglect only when he used his right hand to draw figures. Right hand movement, controlled by the left hemisphere, elicited visual attention to the right hemispace, resulting in the left unilateral spatial neglect. Thus visual attention is not simply top-down or bottom up, but is implicitly affected by the visual recognition as well as motor component of the task. PMID:17354375

  6. [Neuropsychological approach to visual attention].

    PubMed

    Suzuki, Kyoko

    2007-01-01

    Visual experience depends critically on visual attention, which selects a particular aspect of a visual display. Recent clinical, neuroimaging, and animal studies revealed that visual attention was divided into active and passive or top-down and bottom-up attention. Although these dichotomies are clear-cut in definition, visual attention could be modulated by many factors. Detailed observation of brain-injured patients provides with evidence for dynamic and fine control of visual attention. We observed patients with dorsal simultanagnosia and that with callosal disconnection syndrome. Patients with dorsal simultanagnosia demonstrated that extent of visual attention was dynamically changed depending on the level of visual processing. Despite the ability to read a kanji character and to describe its components correctly, a patient could not notice a component that he had just written and could not assemble individual components to make up a correct kanji character. He could point to an overlapping area of two figures. But once he started to color the overlapping area, he missed the margin of the area and colored much larger area. Another patient with dorsal simultanagnosia missed borderlines between columns of a newspaper and read letters continuously across columns. In contrast, he could point to lines between figures or meaningless patterns easily. These findings indicated that visual attention was directed automatically to meaningful characters. A patients with callosal disconnection syndrome demonstrated left unilateral spatial neglect only when he used his right hand to draw figures. Right hand movement, controlled by the left hemisphere, elicited visual attention to the right hemispace, resulting in the left unilateral spatial neglect. Thus visual attention is not simply top-down or bottom up, but is implicitly affected by the visual recognition as well as motor component of the task. PMID:17228775

  7. 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.

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

    PubMed

    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

  9. 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

  10. Effects of target enhancement and distractor suppression on multiple object tracking capacity.

    PubMed

    Bettencourt, Katherine C; Somers, David C

    2009-07-14

    Mounting evidence suggests that visual attention may be simultaneously deployed to multiple distinct object locations, but the constraints upon this multi-object attentional system are still debated. Results from multiple object tracking (MOT) experiments have been interpreted as revealing a fixed attentional capacity limit of 4 objects, while other evidence has suggested that attentional capacity may be more fluid. Here, we investigated the influence of target stimulus factors, such as speed and size, and of distractor filtering factors, such as number of distractors and screen density, on MOT performance. Each factor had significant effects on capacity, producing values that ranged from above 6 objects down to one object, depending on the task demands. Although our results support the view that crowding effects modulate the effective capacity of attention, we also find evidence that central processes related to distractor suppression and target enhancement modulate capacity.

  11. Tips for Beginners: Attention Getters.

    ERIC Educational Resources Information Center

    Moldavan, Carla

    1993-01-01

    Proposes the use of humor and the personalization of word problems by inserting students' names in the problem statement as methods of gaining students' attention. Illustrates their use in a mixture problem and the Tower of Hanoi problem. (MDH)

  12. 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.

  13. 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.

  14. 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).

  15. 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.

  16. Testing attention: comparing the ANT with TVA-based assessment.

    PubMed

    Habekost, Thomas; Petersen, Anders; Vangkilde, Signe

    2014-03-01

    Posner's attention network model and Bundesen's theory of visual attention (TVA) are two influential accounts of attention. Each model has led to the development of a test method: the attention network test (ANT) and TVA-based assessment, respectively. Both tests have been widely used to investigate attentional function in normal and clinical populations. Here we report on the first direct comparison of the ANT to TVA-based assessment. A group of 68 young healthy participants were tested in three consecutive sessions that each contained standard versions of the two tests. The parameters derived from TVA-based assessment had better internal reliability and retest reliability than did those of the standard version of the ANT, where only the executive network score reached comparable levels. However, when corrected for differences in test length, the retest reliability of the orienting network score equaled the least reliable TVA parameters. Both tests were susceptible to practice effects, which improved performance for some parameters while leaving others constant. All pairwise correlations between the eight attention parameters measured by the two tests were small and nonsignificant, with one exception: A strong correlation (r = 0.72) was found between two parameters of TVA-based assessment, visual processing speed and the capacity of visual short-term memory. We conclude that TVA-based assessment and the ANT measure complementary aspects of attention, but the scores derived from TVA-based assessment are more reliable.

  17. 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

  18. Attentional biases in geometric form perception.

    PubMed

    Latimer, C; Stevens, C; Irish, M; Webber, L

    2000-08-01

    This paper reports the operation of robust attentional bias to the top and right during perception of small, single geometric forms. Same/different judgements of successively presented standard and comparison forms are faster when local differences are located at top and right rather than in other regions of the forms. The bias persists when form size is reduced to approximately one degree of visual angle, and it is unaffected by saccadic eye movements and by instructions to attend to other reliably differentiating regions of the forms. Results lend support in various degrees to two of the possible explanations of the bias: (1) a static, skewed distribution of attentional resources around eye fixation; and (2) biased, covert scanning that commences invariably at the top and right of stimulus forms. Origins of the bias in terms of possible left-hemispheric capacity for constructing representations of visual stimuli from parts, as well as in terms of reading experience and prevailing optic flow during locomotion through space are considered. Recent investigations of conditions under which the bias can be maintained or reduced are mentioned.

  19. 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

  20. 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…

  1. 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…

  2. 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…

  3. Psychophysiological Studies of Attention During Infancy and Early Childhood. Final Report.

    ERIC Educational Resources Information Center

    Porges, Stephen W.

    Reports on research conducted to asses the utility of physiological responses for both the prediction of individual differences in attentional capacity and the monitoring of developmental changes in attentional responsivity. Specifically the experiments assessed: (1) Heart rate variability and newborn heart rate responses to illumination changes,…

  4. Spatial separation between targets constrains maintenance of attention on multiple objects.

    PubMed

    Shim, Won Mok; Alvarez, George A; Jiang, Yuhong V

    2008-04-01

    Humans are limited in their ability to maintain multiple attentional foci. In attentive tracking of moving objects, performance declines as the number of tracked targets increases. Previous studies have interpreted such reduction in terms of a limit in the number of attentional foci. However, increasing the number of targets usually reduces spatial separation among different targets. In this study, we examine the role of target spatial separation in maintaining multiple attentional foci. Results from a multiple-object tracking task show that tracking accuracy deteriorates as the spatial separation between targets decreases. We propose that local interaction between nearby attentional foci modulates the resolution of attention, and that capacity limitation from attentive tracking originates in part from limitations in maintaining critical spacing among multiple attentional foci. These findings are consistent with the hypothesis that tracking performance is limited not primarily by a number of locations, but by factors such as the spacing and speed of the targets and distractors.

  5. 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).

  6. 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.

  7. 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…

  8. 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

  9. Pay Attention! Demonstrating the Role of Attention in Learning.

    ERIC Educational Resources Information Center

    Larsen, Janet D.

    1991-01-01

    Describes a demonstration to illustrate the importance of knowing what is supposed to be learned before studying begins. Suggests that the exercise may be used to show the basic elements of a scientific experiment. Explains that attention's effect upon memory is shown by students' tendency to remember best what they are told to remember. (DK)

  10. 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)…

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Proteomics: capacity versus utility.

    PubMed

    Harry, J L; Wilkins, M R; Herbert, B R; Packer, N H; Gooley, A A; Williams, K L

    2000-04-01

    Until recently scientists studied genes or proteins one at a time. With improvements in technology, new tools have become available to study the complex interactions that occur in biological systems. Global studies are required to do this, and these will involve genomic and proteomic approaches. High-throughput methods are necessary in each case because the number of genes and proteins in even the simplest of organisms are immense. In the developmental phase of genomics, the emphasis was on the generation and assembly of large amounts of nucleic acid sequence data. Proteomics is currently in a phase of technological development and establishment, and demonstrating the capacity for high throughput is a major challenge. However, funding bodies (both in the public and private sector) are increasingly focused on the usefulness of this capacity. Here we review the current state of proteome research in terms of capacity and utility.

  16. 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

  17. 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

  18. Local capacity for groundwater protection in Ontario.

    PubMed

    De Loë, Rob C; Di Giantomasso, Sandra E; Kreutzwiser, Reid D

    2002-02-01

    Preventing groundwater contamination is vastly cheaper than remediation. Recognizing this, attention in water and land management agencies in North America increasingly turn to groundwater protection. Local agencies, such as municipalities and watershed management districts, are vital to successful groundwater protection, but they face daunting challenges. In the United States, senior governments have recognized these challenges and provide considerable support for local agencies. In Ontario, Canada, local agencies are, to a much greater extent, on their own. The aims in this paper are to analyze factors that shape local capacity for groundwater protection, focusing on Ontario, and to recommend avenues for capacity building. Interrelationships among five dimensions of capacity (technical, financial, institutional, social, and political) are explored through an analysis of three smaller Ontario communities: City of Guelph (population 93,400), Town of Orangeville (population 22,188), and Town of Erin (population 11,000). Size clearly influences capacity for groundwater protection. However, other considerations unrelated to size appear to be as important. These other factors include the ability to form horizontal and vertical linkages with external agencies, political leadership and commitment, and citizen involvement. Thus, smaller communities in Ontario (and other jurisdictions with limited senior government support) would do well to focus on these areas at the same time as they develop their technical, financial, and institutional capacity.

  19. 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

  20. 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

  1. 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.

  2. 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…

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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…

  8. 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…

  9. 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…

  10. 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.

  11. 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

  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. 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

  14. 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

  15. 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…

  16. 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

  17. 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.

  18. Field dependence-independence (FDI) cognitive style: an analysis of attentional functioning.

    PubMed

    Guisande, M Adelina; Páramo, M Fernanda; Tinajero, Carolina; Almeida, Leandro S

    2007-11-01

    Previous research has indicated that field-dependent children display poorer performance than field-independent children in almost all academic subjects and cognitive tasks. However, the processes underlying this poorer performance remain unclear. The present study aimed to assess whether children with different FDI cognitive styles show differences in performance of tasks measuring aspects of attentional functioning. Specifically, 149 children aged 8 - 11 years were classified according to FDI cognitive style (field-dependent, intermediate, or field-independent), and to storage capacity (Digits Forward Test), verbal working memory (Digits Backward Test), capacity to focus, shift, and maintain attention (Digit Symbol Test), and capacity for sustained attention (Visual Search and Attention Test). Field-independent children displayed better performance than intermediate and field-dependent children on all tests except the Digits Forward Test. Theoretical and practical implications of these results are discussed.

  19. Motor recovery after stroke depends on intact sustained attention: a 2-year follow-up study.

    PubMed

    Robertson, I H; Ridgeway, V; Greenfield, E; Parr, A

    1997-04-01

    The functional recovery of 47 right-brain-damaged stroke patients was studied over a 2-year period. The researchers hypothesized that sustained attention capacity should predict the degree of motor and functional recovery over this period because of a proposed privileged role of sustained attention in learning-based recovery of function. As predicted, significant correlations were found between sustained attention capacity at 2 months and functional status (including the Barthel Index) at 2 years. This relationship was shown to exist independently of 2-month functional status. Furthermore, compared with a left-brain-damaged group of cerebrovascular accident (CVA) patients, the right-brain CVA group did not recover functional ability as well over the 2-year period. This increasing difference in functional status over a 2-year period was mirrored by an emerging difference in sustained attention capacity, in favor of the left-brain CVA group.

  20. 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 ...

  1. Pesticide residues in birds and mammals

    USGS Publications Warehouse

    Stickel, L.F.; Edwards, C.A.

    1973-01-01

    SUMMARY: Residues of organochlorine pesticides and their breakdown products are present in the tissues of essentially all wild birds throughout the world. These chemicals accumulate in fat from a relatively small environmental exposure. DDE and dieldrin are most prevalent. Others, such as heptachlor epoxide, chlordane, endrin, and benzene hexachloride also occur, the quantities and kinds generally reflecting local or regional use. Accumulation may be sufficient to kill animals following applications for pest control. This has occurred in several large-scale programmes in the United States. Mortality has also resulted from unintentional leakage of chemical from commercial establishments. Residues may persist in the environment for many years, exposing successive generations of animals. In general, birds that eat other birds, or fish, have higher residues than those that eat seeds and vegetation. The kinetic processes of absorption, metabolism, storage, and output differ according to both kind of chemical and species of animal. When exposure is low and continuous, a balance between intake and excretion may be achieved. Residues reach a balance at an approximate animal body equilibrium or plateau; the storage is generally proportional to dose. Experiments with chickens show that dieldrin and heptachlor epoxide have the greatest propensity for storage, endrin next, then DDT, then lindane. The storage of DDT was complicated by its metabolism to DDE and DDD, but other studies show that DDE has a much greater propensity for storage than either DDD or DDT. Methoxychlor has little cumulative capacity in birds. Residues in eggs reflect and parallel those in the parent bird during accumulation, equilibrium, and decline when dosage is discontinued. Residues with the greatest propensity for storage are also lost most slowly. Rate of loss of residues can be modified by dietary components and is speeded by weight loss of the animal. Under sublethal conditions of continuous

  2. Reduced insular volume in attention deficit hyperactivity disorder

    PubMed Central

    Lopez-Larson, Melissa Patricia; King, Jace Bradford; Terry, Janine; McGlade, Erin Catherine; Yurgelun-Todd, Deborah

    2014-01-01

    The aim of this study was to evaluate whether structural differences in the insula and anterior cingulate (ACC), two critical areas of the “salience network,” co-exist in adolescents with ADHD compared to healthy controls (HC). In addition we aimed to determine if structural changes within these regions correlate with attention and inhibitory function. Nineteen adolescents with ADHD and 25 HC received MRI scans on a 3T magnet. Morphometric analysis was performed with FreeSurfer. Youths with ADHD were found to have a bilateral reduction in anterior insular (AIC) gray matter volumes compared to HC. Furthermore, the left AIC was found to positively correlate with oppositional symptoms, while the right AIC was found to associate with both attention problems and inhibition. To our knowledge this is the first report of a bilateral reduction in AIC volumes in ADHD. Our findings suggest a role for the insula in modulating attention and inhibitory capacity in ADHD. PMID:23142193

  3. 40 CFR 180.127 - Piperonyl butoxide; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... paper bags of 50 pounds or more capacity. (C) Food treated in accordance with 21 CFR 178.3730. (D) Food... established on both raw agricultural commodities and processed food made therefrom, the total residues of piperonyl butoxide in or on the processed food shall not be greater than that permitted by the larger of...

  4. 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.

  5. 40 CFR 1065.705 - Residual and intermediate residual fuel.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... specifications for fuels meeting the definition of residual fuel in 40 CFR 80.2, including fuels marketed as... for Residual Fuel Characteristic Unit Category ISO-F- RMA 30 RMB 30 RMD 80 RME 180 RMF 180 RMG 380...

  6. 40 CFR 1065.705 - Residual and intermediate residual fuel.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... specifications for fuels meeting the definition of residual fuel in 40 CFR 80.2, including fuels marketed as... for Residual Fuel Characteristic Unit Category ISO-F- RMA 30 RMB 30 RMD 80 RME 180 RMF 180 RMG 380...

  7. Effect of Chinese traditional cooking on eight pesticides residue during cowpea processing.

    PubMed

    Huan, Zhibo; Xu, Zhi; Jiang, Wayne; Chen, Zhiqiang; Luo, Jinhui

    2015-03-01

    Thermal processing can concentrate residues or convert residues to more toxic metabolites in food. Chinese traditional cooking pays more attention to thermal processing and more vegetables were eaten after thermal processing. In this study, the effect of Chinese traditional cooking (washing, blanching, stir-frying, frying and combined operations) on eight pesticides residues (pyridaben, procymidone, chlorothalonil, difenoconazole, α-cypermethrin, bifenthrin, S-fenvalerate and λ-cyhalothrin) in cowpea which was one of the most important legume crops in China was examined. Result showed washing and blanching could reduce residues with low Kow while stir-frying and frying were more effective to residues with high Kow; stir-frying and frying could concentrate residues with low Kow; the residue levels in oil increased following increasing frying time and frequency especially the residues with high Kow; one metabolite studied in this paper was not detected. Blanching (5 min) followed by stir-frying (3 min) was the most effective combined operation.

  8. 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.

  9. Water treatment residuals

    SciTech Connect

    Billings, C.H.

    1994-01-01

    Solutions to an environmental problem often create other environmental problems. That surely is the case in the water supply field. By providing new or expanded water treatment systems to comply with the maximum contaminant levels and treatment mandates of the Safe Drinking Water Act, water purveyors are generating large volumes of residuals that must be managed, ultimately disposed of, or recycled. Numerous federal, state, and local laws govern the management, transport, disposal, and recycling of wastes produced by water treatment systems. Because these laws can result in exorbitant waste disposal costs, restricting some projects entirely, water suppliers need to consider residual disposal early in the siting, selection, and design of treatment projects. To inform water suppliers about residual laws, AWWA commissioned a study published as a Water Industry Technical Action Fund report. In addition to identifying and describing applicable laws at the federal level and in six of the states, the study revealed a series of findings as to the consequences of those laws to water suppliers. This article is a brief overview of the findings of the report.

  10. 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.

  11. 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

  12. 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.

  13. Community Capacity Building:

    PubMed Central

    Goytia, Crispin N.; Todaro-Rivera, Lea; Brenner, Barbara; Shepard, Peggy; Piedras, Veronica; Horowitz, Carol

    2013-01-01

    Background: Successful community–academic research partnerships require building the capacity of both community-based organizations (CBOs) and academics to conduct collaborative research of mutual interest and benefit. Yet, information about the needs and goals of research-interested CBOs is lacking. Our partnership aimed to conduct a community research needs assessment and to use results to develop future capacity-building programs for CBOs. Methods: Based on our review of the literature, informal interviews with research-interested CBOs and community-engaged research groups locally and nationally, we developed a needs assessment survey. Key domains of this survey included history and experience with research collaboration, interest in specific research topics, and preference for learning format and structure. We trained community health workers (CHWs) to recruit senior leaders from CBOs in New York City (NYC) and encourage them to complete an on-line survey. Results: Fully 54% (33/61) of CBOs completed the needs assessment. Most (69%) reported involvement with research or evaluation in the last 2 years and 33% had some funding for research. Although 75% had collaborated with academic institutions in the past, 58% did not rate this experience well. The four areas respondents prioritized for skills building were program evaluation, developing needs assessments, building surveys, and understanding statistical analyses. They were less interested in learning to build collaborations with academics. Conclusions: A formal needs assessment of research training and educational needs of CBOs revealed that most had experience, albeit negative, with academic collaborations. CBO leaders wanted to build skills to conduct and analyze assessments and program evaluations. Our community–academic partnership is using these findings to develop a research capacity-building course. Other partnerships should consider conducting such assessments to transform the capacity of CBOs to

  14. Long-term memory guidance of visuospatial attention in a change-detection paradigm.

    PubMed

    Rosen, Maya L; Stern, Chantal E; Somers, David C

    2014-01-01

    Visual task performance is generally stronger in familiar environments. One reason for this familiarity benefit is that we learn where to direct our visual attention and effective attentional deployment enhances performance. Visual working memory plays a central role in supporting long-term memory guidance of visuospatial attention. We modified a change detection task to create a new paradigm for investigating long-term memory guidance of attention. During the training phase, subjects viewed images in a flicker paradigm and were asked to detect between one and three changes in the images. The test phase required subjects to detect a single change in a one-shot change detection task in which they held all possible locations of changes in visual working memory and deployed attention to those locations to determine if a change occurred. Subjects detected significantly more changes in images for which they had been trained to detect the changes, demonstrating that memory of the images guided subjects in deploying their attention. Moreover, capacity to detect changes was greater for images that had multiple changes during the training phase. In Experiment 2, we observed that capacity to detect changes for the 3-studied change condition increased significantly with more study exposures and capacity was significantly higher than 1, indicating that subjects were able to attend to more than one location. Together, these findings suggest memory and attentional systems interact via working memory such that long-term memory can be used to direct visual spatial attention to multiple locations based on previous experience.

  15. 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.

  16. 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.

  17. 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).

  18. Capacity for visual features in mental rotation

    PubMed Central

    Xu, Yangqing; Franconeri, Steven L.

    2015-01-01

    Although mental rotation is a core component of scientific reasoning, we still know little about its underlying mechanism. For instance - how much visual information can we rotate at once? Participants rotated a simple multi-part shape, requiring them to maintain attachments between features and moving parts. The capacity of this aspect of mental rotation was strikingly low – only one feature could remain attached to one part. Behavioral and eyetracking data showed that this single feature remained ‘glued’ via a singular focus of attention, typically on the object’s top. We argue that the architecture of the human visual system is not suited for keeping multiple features attached to multiple parts during mental rotation. Such measurement of the capacity limits may prove to be a critical step in dissecting the suite of visuospatial tools involved in mental rotation, leading to insights for improvement of pedagogy in science education contexts. PMID:26174781

  19. 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

  20. Visual attention: the past 25 years.

    PubMed

    Carrasco, Marisa

    2011-07-01

    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.

  1. Emotional attention in acquired prosopagnosia.

    PubMed

    Peelen, Marius V; Lucas, Nadia; Mayer, Eugene; Vuilleumier, Patrik

    2009-09-01

    The present study investigated whether emotionally expressive faces guide attention and modulate fMRI activity in fusiform gyrus in acquired prosopagnosia. Patient PS, a pure case of acquired prosopagnosia with intact right middle fusiform gyrus, performed two behavioral experiments and a functional imaging experiment to address these questions. In a visual search task involving face stimuli, PS was faster to select the target face when it was expressing fear or happiness as compared to when it was emotionally neutral. In a change detection task, PS detected significantly more changes when the changed face was fearful as compared to when it was neutral. Finally, an fMRI experiment showed enhanced activation to emotionally expressive faces and bodies in right fusiform gyrus. In addition, PS showed normal body-selective activation in right fusiform gyrus, partially overlapping the fusiform face area. Together these behavioral and neuroimaging results show that attention was preferentially allocated to emotional faces in patient PS, as observed in healthy subjects. We conclude that systems involved in the emotional guidance of attention by facial expression can function normally in acquired prosopagnosia, and can thus be dissociated from systems involved in face identification.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  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. 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)

  11. 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…

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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.

  17. 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

  18. "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.)

  19. "Hitting Paydirt": Capacity Theory and Sports Announcers' Use of Cliches.

    ERIC Educational Resources Information Center

    Wanta, Wayne; Leggett, Dawn

    1988-01-01

    Analyzes the frequency of cliches used by television sports announcers in order to understand better how the mind processes information under stressful situations. Finds some support for capacity theory and asserts that, under pressure, sports announcers may divert some of their attention away from communication and toward processing information.…

  20. 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.

  1. Quantum reading capacity

    NASA Astrophysics Data System (ADS)

    Pirandola, Stefano; Lupo, Cosmo; Giovannetti, Vittorio; Mancini, Stefano; Braunstein, Samuel L.

    2011-11-01

    The readout of a classical memory can be modelled as a problem of quantum channel discrimination, where a decoder retrieves information by distinguishing the different quantum channels encoded in each cell of the memory (Pirandola 2011 Phys. Rev. Lett. 106 090504). In the case of optical memories, such as CDs and DVDs, this discrimination involves lossy bosonic channels and can be remarkably boosted by the use of nonclassical light (quantum reading). Here we generalize these concepts by extending the model of memory from single-cell to multi-cell encoding. In general, information is stored in a block of cells by using a channel-codeword, i.e. a sequence of channels chosen according to a classical code. Correspondingly, the readout of data is realized by a process of ‘parallel’ channel discrimination, where the entire block of cells is probed simultaneously and decoded via an optimal collective measurement. In the limit of a large block we define the quantum reading capacity of the memory, quantifying the maximum number of readable bits per cell. This notion of capacity is nontrivial when we suitably constrain the physical resources of the decoder. For optical memories (encoding bosonic channels), such a constraint is energetic and corresponds to fixing the mean total number of photons per cell. In this case, we are able to prove a separation between the quantum reading capacity and the maximum information rate achievable by classical transmitters, i.e. arbitrary classical mixtures of coherent states. In fact, we can easily construct nonclassical transmitters that are able to outperform any classical transmitter, thus showing that the advantages of quantum reading persist in the optimal multi-cell scenario.

  2. 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

  3. 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.

  4. Heat Capacity in Proteins

    NASA Astrophysics Data System (ADS)

    Prabhu, Ninad V.; Sharp, Kim A.

    2005-05-01

    Heat capacity (Cp) is one of several major thermodynamic quantities commonly measured in proteins. With more than half a dozen definitions, it is the hardest of these quantities to understand in physical terms, but the richest in insight. There are many ramifications of observed Cp changes: The sign distinguishes apolar from polar solvation. It imparts a temperature (T) dependence to entropy and enthalpy that may change their signs and which of them dominate. Protein unfolding usually has a positive ΔCp, producing a maximum in stability and sometimes cold denaturation. There are two heat capacity contributions, from hydration and protein-protein interactions; which dominates in folding and binding is an open question. Theoretical work to date has dealt mostly with the hydration term and can account, at least semiquantitatively, for the major Cp-related features: the positive and negative Cp of hydration for apolar and polar groups, respectively; the convergence of apolar group hydration entropy at T ≈ 112°C; the decrease in apolar hydration Cp with increasing T; and the T-maximum in protein stability and cold denaturation.

  5. 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

  6. Working memory's workload capacity.

    PubMed

    Heathcote, Andrew; Coleman, James R; Eidels, Ami; Watson, Jason M; Houpt, Joseph; Strayer, David L

    2015-10-01

    We examined the role of dual-task interference in working memory using a novel dual two-back task that requires a redundant-target response (i.e., a response that neither the auditory nor the visual stimulus occurred two back versus a response that one or both occurred two back) on every trial. Comparisons with performance on single two-back trials (i.e., with only auditory or only visual stimuli) showed that dual-task demands reduced both speed and accuracy. Our task design enabled a novel application of Townsend and Nozawa's (Journal of Mathematical Psychology 39: 321-359, 1995) workload capacity measure, which revealed that the decrement in dual two-back performance was mediated by the sharing of a limited amount of processing capacity. Relative to most other single and dual n-back tasks, performance measures for our task were more reliable, due to the use of a small stimulus set that induced a high and constant level of proactive interference. For a version of our dual two-back task that minimized response bias, accuracy was also more strongly correlated with complex span than has been found for most other single and dual n-back tasks.

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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.

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

    PubMed

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

    2016-03-17

    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.

  13. 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

  14. 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.

  15. The effects of selective and divided attention on sensory precision and integration.

    PubMed

    Odegaard, Brian; Wozny, David R; Shams, Ladan

    2016-02-12

    In our daily lives, our capacity to selectively attend to stimuli within or across sensory modalities enables enhanced perception of the surrounding world. While previous research on selective attention has studied this phenomenon extensively, two important questions still remain unanswered: (1) how selective attention to a single modality impacts sensory integration processes, and (2) the mechanism by which selective attention improves perception. We explored how selective attention impacts performance in both a spatial task and a temporal numerosity judgment task, and employed a Bayesian Causal Inference model to investigate the computational mechanism(s) impacted by selective attention. We report three findings: (1) in the spatial domain, selective attention improves precision of the visual sensory representations (which were relatively precise), but not the auditory sensory representations (which were fairly noisy); (2) in the temporal domain, selective attention improves the sensory precision in both modalities (both of which were fairly reliable to begin with); (3) in both tasks, selective attention did not exert a significant influence over the tendency to integrate sensory stimuli. Therefore, it may be postulated that a sensory modality must possess a certain inherent degree of encoding precision in order to benefit from selective attention. It also appears that in certain basic perceptual tasks, the tendency to integrate crossmodal signals does not depend significantly on selective attention. We conclude with a discussion of how these results relate to recent theoretical considerations of selective attention.

  16. 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.

  17. 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…

  18. 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.

  19. 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…

  20. Experimental determination of residual stress

    NASA Technical Reports Server (NTRS)

    Ferguson, Milton W.

    1991-01-01

    Residual stresses in finished parts have often been regarded as factors contributing to premature part failure and geometric distortions. Currently, residual stresses in welded structures and railroad components are being investigated. High residual stresses formed in welded structures due primarily to the differential contractions of the weld material as it cools and solidifies can have a profound effect on the surface performance of the structure. In railroad wheels, repeated use of the brakes causes high residual stresses in the rims which may lead to wheel failure and possible derailment. The goals of the study were: (1) to develop strategies for using x-ray diffraction to measure residual stress; (2) to subject samples of Inconel 718 to various mechanical and heat treatments and to measure the resulting stress using x-ray diffraction; and (3) to measure residual stresses in ferromagnetic alloys using magnetoacoustics.

  1. 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.

  2. Water leaching of titanium from ore flotation residue

    SciTech Connect

    Jaworska, Malgorzata M.; Guibal, Eric

    2003-07-01

    Copper ore tailings were tested for the stability of titanium submitted to water leaching in three different reactor systems (agitated vessel, bioreactor and percolated fixed-bed column). For each of these systems, titanium extraction did not exceed 1% of the available metal. Biomass removed from ore residue adsorbed a small part of the titanium with sorption capacities below 20-30 mg g{sup -1}, but most of this biomass was sequestered in the ore residue. Oxygen and carbon dioxide concentrations were monitored and changes in concentration correlated with bacteria development at the initial stage of the process and to fungal development in the latter stages.

  3. 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:…

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Superior Colliculus and Visual Spatial Attention

    PubMed Central

    Krauzlis, Richard J.; Lovejoy, Lee P.; Zénon, Alexandre

    2013-01-01

    The superior colliculus (SC) has long been known to be part of the network of brain areas involved in spatial attention, but recent findings have dramatically refined our understanding of its functional role. The SC both implements the motor consequences of attention and plays a crucial role in the process of target selection that precedes movement. Moreover, even in the absence of overt orienting movements, SC activity is related to shifts of covert attention and is necessary for the normal control of spatial attention during perceptual judgments. The neuronal circuits that link the SC to spatial attention may include attention-related areas of the cerebral cortex, but recent results show that the SC's contribution involves mechanisms that operate independently of the established signatures of attention in visual cortex. These findings raise new issues and suggest novel possibilities for understanding the brain mechanisms that enable spatial attention. PMID:23682659

  9. 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

  10. 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

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

    PubMed

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

    2014-04-01

    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.

  12. Symbiosis of executive and selective attention in working memory.

    PubMed

    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.

  13. 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

  14. 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

  15. 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

  16. 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.…

  17. 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…

  18. 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)…

  19. 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…

  20. 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…

  1. 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;…

  2. 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…

  3. 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…

  4. 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…

  5. 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…

  6. The What and Where of Visual Attention.

    PubMed

    Moore, Tirin; Zirnsak, Marc

    2015-11-18

    The selective processing of sensory input during attention is known to take many forms, and different forms of attention likely reflect varying underlying neural mechanisms. Bichot and colleagues (2015) identify neurons that appear specialized for the control of feature-based visual attention. PMID:26590339

  7. An Operant Analysis of Joint Attention Skills

    ERIC Educational Resources Information Center

    Holth, Per

    2005-01-01

    Joint attention, a synchronizing of the attention of two or more persons, has been an increasing focus of research in cognitive developmental psychology. Research in this area has progressed mainly outside of behavior analysis, and behavior-analytic research and theory has tended to ignore the work on joint attention. It is argued here, on the one…

  8. 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…

  9. 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…

  10. Measuring Evaluation Capacity--Results and Implications of a Danish Study

    ERIC Educational Resources Information Center

    Nielsen, Steffen Bohni; Lemire, Sebastian; Skov, Majbritt

    2011-01-01

    Evaluation capacity building (ECB) has become an area in the evaluation field that is attracting both scholarly attention and the practical work of evaluators. Despite some recent contributions, differing conceptions still exist concerning what constitutes ECB, let alone the nature of the capacity being built. Responding to an earlier call on the…

  11. 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…

  12. 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

  13. 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.

  14. Attention deficit and attention training in early twentieth-century Japan.

    PubMed

    Takeda, Toshinobu; Ando, Mizuho; Kumagai, Keiko

    2015-06-01

    Yuzero Motora (1856-1912), regarded as the first professional Japanese psychologist, tried to address students' attention difficulties through attention training methods of his own design. His reports contain the first description of ADHD-like symptoms in the history of Japan. Motora viewed "distractibility" as the irregular transition of attention. Students with low scores and attention difficulties who participated in Motora's exercises showed improvement in arithmetic, psychological testing, and certain aspects of daily life. This article describes Motora's theoretical conception of attention and attention training methodology, the history of attention deficit and attention training, and the significance of Motora's experiments.

  15. Attention-deficit/hyperactivity disorder.

    PubMed

    Faraone, Stephen V; Asherson, Philip; Banaschewski, Tobias; Biederman, Joseph; Buitelaar, Jan K; Ramos-Quiroga, Josep Antoni; Rohde, Luis Augusto; Sonuga-Barke, Edmund J S; Tannock, Rosemary; Franke, Barbara

    2015-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is a persistent neurodevelopmental disorder that affects 5% of children and adolescents and 2.5% of adults worldwide. Throughout an individual's lifetime, ADHD can increase the risk of other psychiatric disorders, educational and occupational failure, accidents, criminality, social disability and addictions. No single risk factor is necessary or sufficient to cause ADHD. In most cases ADHD arises from several genetic and environmental risk factors that each have a small individual effect and act together to increase susceptibility. The multifactorial causation of ADHD is consistent with the heterogeneity of the disorder, which is shown by its extensive psychiatric co-morbidity, its multiple domains of neurocognitive impairment and the wide range of structural and functional brain anomalies associated with it. The diagnosis of ADHD is reliable and valid when evaluated with standard criteria for psychiatric disorders. Rating scales and clinical interviews facilitate diagnosis and aid screening. The expression of symptoms varies as a function of patient developmental stage and social and academic contexts. Although there are no curative treatments for ADHD, evidenced-based treatments can markedly reduce its symptoms and associated impairments. For example, medications are efficacious and normally well tolerated, and various non-pharmacological approaches are also valuable. Ongoing clinical and neurobiological research holds the promise of advancing diagnostic and therapeutic approaches to ADHD. For an illustrated summary of this Primer, visit: http://go.nature.com/J6jiwl. PMID:27189265

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. Selective attention skills of experienced sonar operators.

    PubMed

    Merrill, L L; Lewandowski, L J; Kobus, D A

    1994-06-01

    This study investigated the influence of sonar training and experience on the selective attention of experienced and inexperienced operators. The Stroop task was selected as a measure of general selective attention, similar in certain task requirements (attentional allocation) to sonar operation. Across two samples (ns = 32 and 36) and four repeated test sessions groups did not differ significantly in speed or accuracy of Stroop performance. The data suggest that experienced operators do not seem to have developed extraordinary attentional skills and that any attentional skills developed through sonar experience do not generalize to other tasks such as the Stroop.

  1. [Transfer of pesticide residues to crops via cardboard boxes].

    PubMed

    Iwakoshi, Keiko; Takano, Ichiro; Kobayashi, Maki; Ohtsuka, Kenji; Tamura, Yasuhiro; Tomizawa, Sanae; Kamijo, Kyoko; Kageyama, Yuriko; Nagayama, Toshihiro

    2009-10-01

    Cardboard boxes used to transport crops are often reused in the distribution process, and therefore transfer of pesticides between crops might occur. So, we designed model experiments to investigate whether or not transfer of pesticide residues from crops to other crops via cardboard boxes occurs. Under severe experimental conditions, 6.2% of the pesticide residues of grapefruit was found to be transferred to spinach via cardboard boxes. In the case of the mandarin orange, 0.57% was transferred. The actual amount of transferred pesticides in the market may be less than that in these model experiments, but it is clear that transfer of pesticide residues to other crops via cardboard boxes can occur. Therefore more attention must be given to reuse of cardboard boxes in the distribution process. PMID:19897948

  2. Fungicide residues in strawberry processing.

    PubMed

    Will, F; Krüger, E

    1999-03-01

    The fate of three fungicides (dichlofluanid, procymidone, and iprodione) applied under field conditions was studied during strawberry processing to juice, wine, and jam. An untreated control was compared to raw material treated with fungicides according to recommended doses and to a sample with 6-fold higher application rates. The highest residue values were found in the pomace after pressing. Residue values in readily produced juices and fruit wines were very low and did not exceed legally required maximum residue levels. Generally, processing steps such as pressing and clarification diminished fungicide residues from 50 to 100%. If the whole fruit is processed, as in fruit preparations or jam, the residue levels remain higher due to missing processing steps. PMID:10552381

  3. 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

  4. Feature- and category-specific attentional control settings are differently affected by attentional engagement in contingent attentional capture.

    PubMed

    Wu, Xia; Liu, Xiaoyue; Fu, Shimin

    2016-07-01

    A distractor can capture attention and impair target processing when it shares a target-defining property and matches specific attentional control settings (ACS). We studied how feature-specific ACS (fACS) and category-specific ACS (cACS) operate in a conjunction search task and how they are influenced by attentional engagement. The feature- and category-matching level and temporal lags between the distractor and target were manipulated in a rapid serial visual presentation (RSVP) task. The N2pc component and impairment of target identification, which are associated with attentional allocation at an earlier stage and response selection at a later stage, respectively, were measured as markers of attentional capture. The interaction of two ACSs was observed in behavioral data, but disappeared in N2pc data, suggesting two-stage processing of multiple ACSs during a conjunction search, including an early independent and a late integrated stage. Moreover, a reliable N2pc was observed for fACS regardless of the sufficiency of attentional engagement, whereas the N2pc for cACS was only observed with sufficient attentional engagement, but disappeared when the attentional engagement was insufficient. This suggests that cACS demands sufficient attentional engagement, while fACS does not. In conclusion, fACS and cACS can be activated independently at an earlier stage, but they are integrated at a later stage during a conjunction search task and are differently influenced by attentional engagement.

  5. CHP Installed Capacity Optimizer Software

    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

  6. 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.

  7. Relationships, autonomy and legal capacity: Mental capacity and support paradigms.

    PubMed

    Series, Lucy

    2015-01-01

    Within law and legal scholarship there are different models of legal personality and legal capacity. The most well known of these emphasises individual rationality, and is distilled into the medico-legal concept of 'mental capacity'. In connection with the UN Convention on the Rights of Persons with Disabilities (CRPD) a new approach to legal personality is being developed, emphasising relationships of support and recognition of universal legal capacity. Recent scholarship on both 'mental capacity' and CRPD approaches to legal capacity has drawn from feminist writings on relational autonomy. In this paper, I use this scholarship on relational autonomy to explore the differences between these approaches to legal capacity. I argue that the approach connected with the CRPD offers a refreshing take on the importance of relationships of support in exercising legal capacity. However, despite their pronounced differences, especially in relation to the legitimacy of coercion, there are remarkable similarities in the underlying challenges for each approach: the extent to which others can 'know' our authentic and autonomous selves, and the inextricable relationships of power that all forms of legal capacity are embedded within. PMID:25982964

  8. 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.

  9. Mutagenesis of essential functional residues in acetylcholinesterase.

    PubMed Central

    Gibney, G; Camp, S; Dionne, M; MacPhee-Quigley, K; Taylor, P

    1990-01-01

    The cholinesterases are serine hydrolases that show no global similarities in sequence with either the trypsin or the subtilisin family of serine proteases. The cholinesterase superfamily includes several esterases with distinct functions and other proteins devoid of the catalytic serine and known esterase activity. To identify the residues involved in catalysis and conferring specificity on the enzyme, we have expressed wild-type Torpedo acetylcholinesterase (EC 3.1.1.7) and several site-directed mutants in a heterologous system. Mutation of serine-200 to cysteine results in diminished activity, while its mutation to valine abolishes detectable activity. Two conserved histidines can be identified at positions 425 and 440 in the cholinesterase family; glutamine replacement at position 440 eliminates activity whereas the mutation at 425 reduces activity only slightly. The assignment of the catalytic histidine to position 440 defines a rank ordering of catalytic residues in cholinesterases distinct from trypsin and subtilisin and suggests a convergence of a catalytic triad to form a third, distinct family of serine hydrolases. Mutation of glutamate-199 to glutamine yields an enzyme with a higher Km and without the substrate-inhibition behavior characteristic of acetylcholinesterase. Hence, modification of the acidic amino acid adjacent to the serine influences substrate association and the capacity of a second substrate molecule to affect catalysis. Images PMID:2217185

  10. 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.

  11. Encoding attentional states during visuomotor adaptation

    PubMed Central

    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

  12. Voluntary attention increases perceived spatial frequency.

    PubMed

    Abrams, Jared; Barbot, Antoine; Carrasco, Marisa

    2010-08-01

    Voluntary covert attention selects relevant sensory information for prioritized processing. The behavioral and neural consequences of such selection have been extensively documented, but its phenomenology has received little empirical investigation. Involuntary attention increases perceived spatial frequency (Gobell & Carrasco, 2005), but involuntary attention can differ from voluntary attention in its effects on performance in tasks mediated by spatial resolution (Yeshurun, Montagna, & Carrasco, 2008). Therefore, we ask whether voluntary attention affects the subjective appearance of spatial frequency--a fundamental dimension of visual perception underlying spatial resolution. We used a demanding rapid serial visual presentation task to direct voluntary attention and measured perceived spatial frequency at the attended and unattended locations. Attention increased the perceived spatial frequency of suprathreshold stimuli and also improved performance on a concurrent orientation discrimination task. In the control experiment, we ruled out response bias as an alternative account by using a lengthened interstimulus interval, which allows observers to disengage attention from the cued location. In contrast to the main experiment, the observers showed neither increased perceived spatial frequency nor improved orientation discrimination at the attended location. Thus, this study establishes that voluntary attention increases perceived spatial frequency. This phenomenological consequence links behavioral and neurophysiological studies on the effects of attention.

  13. 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

  14. Object continuity enhances selective auditory attention.

    PubMed

    Best, Virginia; Ozmeral, Erol J; Kopco, Norbert; Shinn-Cunningham, Barbara G

    2008-09-01

    In complex scenes, the identity of an auditory object can build up across seconds. Given that attention operates on perceptual objects, this perceptual buildup may alter the efficacy of selective auditory attention over time. Here, we measured identification of a sequence of spoken target digits presented with distracter digits from other directions to investigate the dynamics of selective attention. Performance was better when the target location was fixed rather than changing between digits, even when listeners were cued as much as 1 s in advance about the position of each subsequent digit. Spatial continuity not only avoided well known costs associated with switching the focus of spatial attention, but also produced refinements in the spatial selectivity of attention across time. Continuity of target voice further enhanced this buildup of selective attention. Results suggest that when attention is sustained on one auditory object within a complex scene, attentional selectivity improves over time. Similar effects may come into play when attention is sustained on an object in a complex visual scene, especially in cases where visual object formation requires sustained attention.

  15. 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

  16. Low attentional engagement makes attention network activity susceptible to emotional interference.

    PubMed

    Mäki-Marttunen, Verónica; Pickard, Natasha; Solbakk, Anne-Kristin; Ogawa, Keith H; Knight, Robert T; Hartikainen, Kaisa M

    2014-09-10

    The aim of this study was to investigate whether emotion-attention interaction depends on attentional engagement. To investigate emotional modulation of attention network activation, we used a functional MRI paradigm consisting of a visuospatial attention task with either frequent (high-engagement) or infrequent (low-engagement) targets and intermittent emotional or neutral distractors. The attention task recruited a bilateral frontoparietal network with no emotional interference on network activation when the attentional engagement was high. In contrast, when the attentional engagement was low, the unpleasant stimuli interfered with the activation of the frontoparietal attention network, especially in the right hemisphere. This study provides novel evidence for low attentional engagement making attention control network activation susceptible to emotional interference.

  17. 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.

  18. 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

  19. 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

  20. 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…

  1. 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.

  2. Peptidoglycan diversity and anti-inflammatory capacity in Lactobacillus strains.

    PubMed

    Wu, Zhen; Pan, Daodong; Guo, Yuxing; Sun, Yangying; Zeng, Xiaoqun

    2015-09-01

    Lactobacillus species are potential probiotic bacteria for humans because of their capacity to improve certain biological functions in the host's immune system. In this study, we focused on three peptidoglycans (PGNs) derived from different Lactobacillus strains and investigated each PGN's anti-inflammatory capacity. Each PGN was analyzed using HPLC, MALDI-TOF/TOF MS and FTIR. All three PGNs displayed a β-1,4-linked N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) structure with some modifications in the polypeptides at the end of the MurNAc residue. In a new insight, we found that PGNs inhibit the release of inflammatory cytokines in LPS-induced RAW 264.7 cells; a capacity that may be related to the TLR-4 pathway. The goal for exploring PGN diversity in Lactobacillus strains is to better understand the potential use of Lactobacillus PGNs in food and pharmaceutical applications.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. Attention alters the appearance of motion coherence.

    PubMed

    Liu, Taosheng; Fuller, Stuart; Carrasco, Marisa

    2006-12-01

    Selective attention enhances visual information processing, as measured by behavioral performance and neural activity. However, little is known about its effects on subjective experience. Here, we investigated the effect of transient (exogenous) attention on the appearance of visual motion, using a psychophysical procedure that directly measures appearance and controls for response bias. Observers viewed pairs of moving dot patterns and reported the motion direction of the more coherent pattern. Directing attention (via a peripheral precue) to a stimulus location increased its perceived coherence level and improved performance on a direction discrimination task. In a control experiment, we ruled out response bias by lengthening the time interval between the cue and the stimuli, so that the effect of transient attention could no longer be exerted. Our results are consistent with those of neurophysiological studies showing that attention modulates motion processing and provide evidence of a subjective perceptual correlate of attention, with a concomitant effect on performance.

  9. 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.

  10. 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

  11. 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

  12. Long-term memory guidance of visuospatial attention in a change-detection paradigm

    PubMed Central

    Rosen, Maya L.; Stern, Chantal E.; Somers, David C.

    2014-01-01

    Visual task performance is generally stronger in familiar environments. One reason for this familiarity benefit is that we learn where to direct our visual attention and effective attentional deployment enhances performance. Visual working memory plays a central role in supporting long-term memory guidance of visuospatial attention. We modified a change detection task to create a new paradigm for investigating long-term memory guidance of attention. During the training phase, subjects viewed images in a flicker paradigm and were asked to detect between one and three changes in the images. The test phase required subjects to detect a single change in a one-shot change detection task in which they held all possible locations of changes in visual working memory and deployed attention to those locations to determine if a change occurred. Subjects detected significantly more changes in images for which they had been trained to detect the changes, demonstrating that memory of the images guided subjects in deploying their attention. Moreover, capacity to detect changes was greater for images that had multiple changes during the training phase. In Experiment 2, we observed that capacity to detect changes for the 3-studied change condition increased significantly with more study exposures and capacity was significantly higher than 1, indicating that subjects were able to attend to more than one location. Together, these findings suggest memory and attentional systems interact via working memory such that long-term memory can be used to direct visual spatial attention to multiple locations based on previous experience. PMID:24744744

  13. Synthetic computational models of selective attention.

    PubMed

    Raffone, Antonino

    2006-11-01

    Computational modeling plays an important role to understand the mechanisms of attention. In this framework, synthetic computational models can uniquely contribute to integrate different explanatory levels and neurocognitive findings, with special reference to the integration of attention and awareness processes. Novel combined experimental and computational investigations can lead to important insights, as in the revived domain of neural correlates of attention- and awareness-related meditation states and traits.

  14. 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.

  15. Attention in schizophrenia and in epileptic psychosis.

    PubMed

    Kairalla, I C J; Mattos, P E L; Hoexter, M Q; Bressan, R A; Mari, J J; Shirakawa, I

    2008-01-01

    The adaptive behavior of human beings is usually supported by rapid monitoring of outstanding events in the environment. Some investigators have suggested that a primary attention deficit might trigger symptoms of schizophrenia. In addition, researchers have long discussed the relationship between schizophrenia and the schizophrenia-like psychosis of epilepsy (SLPE). On the basis of these considerations, the objective of the present study was to investigate attention performance of patients with both disorders. Patient age was 18 to 60 years, and all patients had received formal schooling for at least four years. Patients were excluded if they had any systemic disease with neurologic or psychiatric comorbidity, or a history of brain surgery. The computer-assisted TAVIS-2R test was applied to all patients and to a control group to evaluate and discriminate between selective, alternating and sustained attention. The TAVIS-2R test is divided into three parts: one for selective attention (5 min), the second for alternating attention (5 min), and the third for the evaluation of vigilance or sustained attention (10 min). The same computer software was used for statistical analysis of reaction time, omission errors, and commission errors. The sample consisted of 36 patients with schizophrenia, 28 with interictal SLPE, and 47 healthy controls. The results of the selective attention tests for both patient groups were significantly lower than that for controls. The patients with schizophrenia and SLPE performed differently in the alternating and sustained attention tests: patients with SLPE had alternating attention deficits, whereas patients with schizophrenia showed deficits in sustained attention. These quantitative results confirmed the qualitative clinical observations for both patient groups, that is, that patients with schizophrenia had difficulties in focusing attention, whereas those with epilepsy showed perseveration in attention focus.

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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

  1. 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.

  2. Attention regulation and monitoring in meditation.

    PubMed

    Lutz, Antoine; Slagter, Heleen A; Dunne, John D; Davidson, Richard J

    2008-04-01

    Meditation can be conceptualized as a family of complex emotional and attentional regulatory training regimes developed for various ends, including the cultivation of well-being and emotional balance. Among these various practices, there are two styles that are commonly studied. One style, focused attention meditation, entails the voluntary focusing of attention on a chosen object. The other style, open monitoring meditation, involves nonreactive monitoring of the content of experience from moment to moment. The potential regulatory functions of these practices on attention and emotion processes could have a long-term impact on the brain and behavior.

  3. Attentional processes and choking under pressure.

    PubMed

    Schücker, Linda; Hagemann, Norbert; Strauss, Bernd

    2013-04-01

    The self-focus theory of choking under pressure explains decreases in performance of well-learned motor tasks with an increase in skill-focused attention. This shift in attentional focus has been demonstrated; however, specific propositions about the processes in pressure-induced attentional shift are yet to be developed. This study assesses whether specific aspects of movement execution attract more attention than others when movements are executed under pressure. Such elements are important in conscious movement control before execution becomes automated through practice; under pressure, attention may be redirected to these elements. Basketball free throws were executed by 22 junior national team members in a low and high pressure situation. Two dual task/focus conditions (related to different aspects of the movement) were implemented in each pressure condition. This dual task paradigm was used as a direct and detailed measure of skill focused attention, suitable to show specific pressure induced shifts of attention that lead to performance decrements. Pressure was induced by telling players that their performance would be evaluated by coaches. Players were defined as chokers if their performance decreased under this pressure. Chokers showed differences with regard to their attentional focus on movement execution in the pressure conditions compared to the players defined as non-chokers. The findings suggest that attentional shifts during choking can be related to specific aspects of movement execution.

  4. 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.

  5. Rhythm and Attention: Does the Beat Position of a Visual or Auditory Regular Pulse Modulate T2 Detection in the Attentional Blink?

    PubMed

    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

  6. 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

  7. 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

  8. 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)

  9. 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

  10. 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

  11. Training of attention functions in children with attention deficit hyperactivity disorder.

    PubMed

    Tucha, Oliver; Tucha, Lara; Kaumann, Gesa; König, Sebastian; Lange, Katharina M; Stasik, Dorota; Streather, Zoe; Engelschalk, Tobias; Lange, Klaus W

    2011-09-01

    Pharmacological treatment of children with ADHD has been shown to be successful; however, medication may not normalize attention functions. The present study was based on a neuropsychological model of attention and assessed the effect of an attention training program on attentional functioning of children with ADHD. Thirty-two children with ADHD and 16 healthy children participated in the study. Children with ADHD were randomly assigned to one of the two conditions, i.e., an attention training program which trained aspects of vigilance, selective attention and divided attention, or a visual perception training which trained perceptual skills, such as perception of figure and ground, form constancy and position in space. The training programs were applied in individual sessions, twice a week, for a period of four consecutive weeks. Healthy children did not receive any training. Alertness, vigilance, selective attention, divided attention, and flexibility were examined prior to and following the interventions. Children with ADHD were assessed and trained while on ADHD medications. Data analysis revealed that the attention training used in the present study led to significant improvements of various aspects of attention, including vigilance, divided attention, and flexibility, while the visual perception training had no specific effects. The findings indicate that attention training programs have the potential to facilitate attentional functioning in children with ADHD treated with ADHD drugs. PMID:21597880

  12. The role of selective attention and action selection in the development of multiple action capabilities

    NASA Astrophysics Data System (ADS)

    Simione, Luca; Nolfi, Stefano

    2014-10-01

    In this paper we illustrate how the capacity to select the most appropriate actions when handling contexts affording multiple conflicting actions can be solved either through a selective attention strategy (in which the stimuli affording alternative actions are filtered out at the perceptual level through top-down regulation) or at later processing stages through an action selection strategy (through the suppression of the premotor information eliciting alternative actions). By carrying out a series of experiments in which a neuro-robot develops an ability to choose between conflicting actions, we were able to identify the conditions that lead to the development of solutions based on one strategy or another. Overall, the results indicate that the selective attention strategy constitutes the most simple and straightforward mechanism enabling the acquisition of such capacities. Moreover, the characteristics of the adaptive/learning process influence whether the adaptive robot converges towards a selective attention and/or action selection strategy.

  13. 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.

  14. Policy Capacity for Health Reform: Necessary but Insufficient: Comment on "Health Reform Requires Policy Capacity".

    PubMed

    Adams, Owen

    2015-09-04

    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.

  15. 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

  16. DISSOLUTION OF NEPTUNIUM OXIDE RESIDUES

    SciTech Connect

    Kyser, E

    2009-01-12

    This report describes the development of a dissolution flowsheet for neptunium (Np) oxide (NpO{sub 2}) residues (i.e., various NpO{sub 2} sources, HB-Line glovebox sweepings, and Savannah River National Laboratory (SRNL) thermogravimetric analysis samples). Samples of each type of materials proposed for processing were dissolved in a closed laboratory apparatus and the rate and total quantity of off-gas were measured. Samples of the off-gas were also analyzed. The quantity and type of solids remaining (when visible) were determined after post-dissolution filtration of the solution. Recommended conditions for dissolution of the NpO{sub 2} residues are: Solution Matrix and Loading: {approx}50 g Np/L (750 g Np in 15 L of dissolver solution), using 8 M nitric acid (HNO{sub 3}), 0.025 M potassium fluoride (KF) at greater than 100 C for at least 3 hours. Off-gas: Analysis of the off-gas indicated nitric oxide (NO), nitrogen dioxide (NO{sub 2}) and nitrous oxide (N{sub 2}O) as the only identified components. No hydrogen (H{sub 2}) was detected. The molar ratio of off-gas produced per mole of Np dissolved ranged from 0.25 to 0.4 moles of gas per mole of Np dissolved. A peak off-gas rate of {approx}0.1 scfm/kg bulk oxide was observed. Residual Solids: Pure NpO{sub 2} dissolved with little or no residue with the proposed flowsheet but the NpCo and both sweepings samples left visible solid residue after dissolution. For the NpCo and Part II Sweepings samples the residue amounted to {approx}1% of the initial material, but for the Part I Sweepings sample, the residue amounted to {approx}8 % of the initial material. These residues contained primarily aluminum (Al) and silicon (Si) compounds that did not completely dissolve under the flowsheet conditions. The residues from both sweepings samples contained minor amounts of plutonium (Pu) particles. Overall, the undissolved Np and Pu particles in the residues were a very small fraction of the total solids.

  17. 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…

  18. 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…

  19. A New Approach to Attention Deficit Disorder

    ERIC Educational Resources Information Center

    Brown, Thomas E.

    2007-01-01

    A recent study conducted by the U.S. Centers for Disease Control estimated that approximately 7.8 percent of U.S. children ages 4-17 are currently diagnosed with Attention Deficit Disorder (ADD) or Attention Deficit/Hyperactivity Disorder (ADHD). For decades, most educators, physicians, psychologists, and parents have thought of ADD/ADHD as…

  20. 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,…

  1. An Economics of Attention: The Pure State.

    ERIC Educational Resources Information Center

    Lanham, Richard A.

    2001-01-01

    Discusses the need for human attention in an information economy to shift from data to information, or information to knowledge, and suggests it be called an economics of attention. Considers implications for higher education and how it will change the history of American higher education. (LRW)

  2. 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…

  3. 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…

  4. 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…

  5. Categorically Defined Targets Trigger Spatiotemporal Visual Attention

    ERIC Educational Resources Information Center

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

    2009-01-01

    Transient attention to a visually salient cue enhances processing of a subsequent target in the same spatial location between 50 to 150 ms after cue onset (K. Nakayama & M. Mackeben, 1989). Do stimuli from a categorically defined target set, such as letters or digits, also generate transient attention? Participants reported digit targets among…

  6. 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…

  7. 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

  8. 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…

  9. 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…

  10. 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.

  11. 28 CFR 301.104 - Medical attention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 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...

  12. Noise and Attentional Selectivity: A Reproducible Phenomenon?

    ERIC Educational Resources Information Center

    Forster, Peter M.; Grierson, Arthur T.

    1978-01-01

    Four pursuit-tracking experiments were conducted in an attempt to replicate with adults, Hockey's findings that loud noise increases attentional selectivity. Neither attentional selectivity nor masking of auditory feedback was found to be significant. For Hockey's reply and the authors' rejoinder, see p499-506 of this issue. (SJL)

  13. Attention, Scholastic Achievement and Timing of Lessons.

    ERIC Educational Resources Information Center

    Klein, Joseph

    2001-01-01

    Studied the time of day of optimal attention for 204 5th graders and 202 10th graders who varied in their aptitude for mathematics. Attention levels of fifth graders were especially high in the afternoon, but 10th graders reported increased concentration in the morning hours. Among 10th graders, there was significant interaction between…

  14. 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…

  15. 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…

  16. 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…

  17. 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

  18. 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...

  19. 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 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...

  20. 28 CFR 301.104 - Medical attention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 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...