Bright ideas. Some rules of thumb for interior lighting design and selection.

PubMed

Hunter, Claudia M

2002-07-01

Interior lighting design and selection can be a demanding assignment for a health facilities manager or department head. It requires a balance between conflicting needs, such as providing good task lighting for a nursing station while also shielding luminaires that are visible from patients' rooms to avoid glare.

Increased cognitive control after task conflict? Investigating the N-3 effect in task switching.

PubMed

Schuch, Stefanie; Grange, James A

2018-05-25

Task inhibition is considered to facilitate switching to a new task and is assumed to decay slowly over time. Hence, more persisting inhibition needs to be overcome when returning to a task after one intermediary trial (ABA task sequence) than when returning after two or more intermediary trials (CBA task sequence). Schuch and Grange (J Exp Psychol Learn Mem Cogn 41:760-767, 2015) put forward the hypothesis that there is higher task conflict in ABA than CBA sequences, leading to increased cognitive control in the subsequent trial. They provided evidence that performance is better in trials following ABA than following CBA task sequences. Here, this effect of the previous task sequence ("N-3 effect") is further investigated by varying the cue-stimulus interval (CSI), allowing for short (100 ms) or long (900 ms) preparation time for the upcoming task. If increased cognitive control after ABA involves a better preparation for the upcoming task, the N-3 effect should be larger with long than short CSI. The results clearly show that this is not the case. In Experiment 1, the N-3 effect was smaller with long than short CSI; in Experiment 2, the N-3 effect was not affected by CSI. Diffusion model analysis confirmed previous results in the literature (regarding the effect of CSI and of the ABA-CBA difference); however, the N-3 effect was not unequivocally associated with any of the diffusion model parameters. In exploratory analysis, we also tested the alternative hypothesis that the N-3 effect involves more effective task shielding, which would be reflected in reduced congruency effects in trials following ABA, relative to trials following CBA; congruency effects did not differ between these conditions. Taken together, we can rule out two potential explanations of the N-3 effect: Neither is this effect due to enhanced task preparation, nor to more effective task shielding.

Accounting for sequential trial effects in the flanker task: conflict adaptation or associative priming?

PubMed

Nieuwenhuis, Sander; Stins, John F; Posthuma, Danielle; Polderman, Tinca J C; Boomsma, Dorret I; de Geus, Eco J

2006-09-01

The conflict-control loop theory proposes that the detection of conflict in information processing triggers an increase in cognitive control, resulting in improved performance on the subsequent trial. This theory seems consistent with the robust finding that conflict susceptibility is reduced following correct trials associated with high conflict: the conflict adaptation effect. However, despite providing favorable conditions for eliciting and detecting conflict-triggered performance adjustments, none of the five experiments reported here provide unequivocal evidence of such adjustments. Instead, the results corroborate and extend earlier findings by demonstrating that the conflict adaptation effect, at least in the flanker task, is only present for a specific subset of trial sequences that is characterized by a response repetition. This pattern of results provides strong evidence that the conflict adaptation effect reflects associative stimulus-response priming instead of conflict-driven adaptations in cognitive control.

The neural dynamics of stimulus and response conflict processing as a function of response complexity and task demands

PubMed Central

Donohue, Sarah E.; Appelbaum, Lawrence G.; McKay, Cameron C.; Woldorff, Marty G.

2016-01-01

Both stimulus and response conflict can disrupt behavior by slowing response times and decreasing accuracy. Although several neural activations have been associated with conflict processing, it is unclear how specific any of these are to the type of stimulus conflict or the amount of response conflict. Here, we recorded electrical brain activity, while manipulating the type of stimulus conflict in the task (spatial [Flanker] versus semantic [Stroop]) and the amount of response conflict (two versus four response choices). Behaviorally, responses were slower to incongruent versus congruent stimuli across all task and response types, along with overall slowing for higher response-mapping complexity. The earliest incongruency-related neural effect was a short-duration frontally-distributed negativity at ~200 ms that was only present in the Flanker spatial-conflict task. At longer latencies, the classic fronto-central incongruency-related negativity ‘Ninc’ was observed for all conditions, which was larger and ~100 ms longer in duration with more response options. Further, the onset of the motor-related lateralized readiness potential (LRP) was earlier for the two vs. four response sets, indicating that smaller response sets enabled faster motor-response preparation. The late positive complex (LPC) was present in all conditions except the two-response Stroop task, suggesting this late conflict-related activity is not specifically related to task type or response-mapping complexity. Importantly, across tasks and conditions, the LRP onset at or before the conflict-related Ninc, indicating that motor preparation is a rapid, automatic process that interacts with the conflict-detection processes after it has begun. Together, these data highlight how different conflict-related processes operate in parallel and depend on both the cognitive demands of the task and the number of response options. PMID:26827917

The neural dynamics of stimulus and response conflict processing as a function of response complexity and task demands.

PubMed

Donohue, Sarah E; Appelbaum, Lawrence G; McKay, Cameron C; Woldorff, Marty G

2016-04-01

Both stimulus and response conflict can disrupt behavior by slowing response times and decreasing accuracy. Although several neural activations have been associated with conflict processing, it is unclear how specific any of these are to the type of stimulus conflict or the amount of response conflict. Here, we recorded electrical brain activity, while manipulating the type of stimulus conflict in the task (spatial [Flanker] versus semantic [Stroop]) and the amount of response conflict (two versus four response choices). Behaviorally, responses were slower to incongruent versus congruent stimuli across all task and response types, along with overall slowing for higher response-mapping complexity. The earliest incongruency-related neural effect was a short-duration frontally-distributed negativity at ~200 ms that was only present in the Flanker spatial-conflict task. At longer latencies, the classic fronto-central incongruency-related negativity 'N(inc)' was observed for all conditions, but was larger and ~100 ms longer in duration with more response options. Further, the onset of the motor-related lateralized readiness potential (LRP) was earlier for the two vs. four response sets, indicating that smaller response sets enabled faster motor-response preparation. The late positive complex (LPC) was present in all conditions except the two-response Stroop task, suggesting this late conflict-related activity is not specifically related to task type or response-mapping complexity. Importantly, across tasks and conditions, the LRP onset at or before the conflict-related N(inc), indicating that motor preparation is a rapid, automatic process that interacts with the conflict-detection processes after it has begun. Together, these data highlight how different conflict-related processes operate in parallel and depend on both the cognitive demands of the task and the number of response options. Copyright © 2016 Elsevier Ltd. All rights reserved.

Contextual within-trial adaptation of cognitive control: Evidence from the combination of conflict tasks.

PubMed

Rey-Mermet, Alodie; Gade, Miriam

2016-10-01

It is assumed that we recruit cognitive control (i.e., attentional adjustment and/or inhibition) to resolve 2 conflicts at a time, such as driving toward a red traffic light and taking care of a near-by ambulance car. A few studies have addressed this issue by combining a Simon task (that required responding with left or right key-press to a stimulus presented on the left or right side of the screen) with either a Stroop task (that required identifying the color of color words) or a Flanker task (that required identifying the target character among flankers). In most studies, the results revealed no interaction between the conflict tasks. However, these studies include a small stimulus set, and participants might have learned the stimulus-response mappings for each stimulus. Thus, it is possible that participants have more relied on episodic memory than on cognitive control to perform the task. In 5 experiments, we combined the 3 tasks pairwise, and we increased the stimulus set size to circumvent episodic memory contributions. The results revealed an interaction between the conflict tasks: Irrespective of task combination, the congruency effect of 1 task was smaller when the stimulus was incongruent for the other task. This suggests that when 2 conflicts are presented concurrently, the control processes induced by 1 conflict source can affect the control processes induced by the other conflict source. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Inhibition, interference, and conflict in task switching.

PubMed

Costa, Russell E; Friedrich, Frances J

2012-12-01

The role of inhibition in the task-switching process has received increased empirical and theoretical attention in the literature on cognitive control. Many accounts have suggested that inhibition occurs when a conflict must be resolved-for example, when a target stimulus contains features of more than one task. In the two experiments reported here, we used variants of backward inhibition, or N - 2 repetition, designs to examine (1) whether inhibition occurs in the absence of conflict at the stimulus or response level, (2) when in the task-switching process such inhibition may occur, and (3) the potential consequences of inhibition. In Experiment 1, we demonstrate that neither stimulus- nor response-level conflict is necessary for inhibition to occur, while the results of Experiment 2 suggest that inhibition may be associated with a reduction of proactive interference (PI) from a previously performed task. Evidence of inhibition and the reduction of PI both occurred at the task-set level. However, inhibition of specific stimulus values can also occur, but this is clearly separable from task-set inhibition. Both experiments also provided evidence that task-set inhibition can be applied at the time of the new task cue, as opposed to at the onset of the target or at the response stage of the trial. Taken together, the results from these experiments provide insight into when and where in the task-switching process inhibition may occur, as well as into the potential functional benefits that inhibition of task sets may provide.

Dissociating Stimulus-Set and Response-Set in the Context of Task-Set Switching

ERIC Educational Resources Information Center

Kieffaber, Paul D.; Kruschke, John K.; Cho, Raymond Y.; Walker, Philip M.; Hetrick, William P.

2013-01-01

The primary aim of the present research was to determine how "stimulus-set" and "response-set" components of task-set contribute to switch costs and conflict processing. Three experiments are described wherein participants completed an explicitly cued task-switching procedure. Experiment 1 established that task switches requiring a reconfiguration…

When Task Conflict Becomes Personal: The Impact of Perceived Team Performance.

PubMed

Guenter, Hannes; van Emmerik, Hetty; Schreurs, Bert; Kuypers, Tom; van Iterson, Ad; Notelaers, Guy

2016-10-01

Although potentially beneficial, task conflict may threaten teams because it often leads to relationship conflict. Prior research has identified a set of interpersonal factors (e.g., team communication, team trust) that help attenuate this association. The purpose of this article is to provide an alternative perspective that focuses on the moderating role of performance-related factors (i.e., perceived team performance). Using social identity theory, we build a model that predicts how task conflict associates with growth in relationship conflict and how perceived team performance influences this association. We test a three-wave longitudinal model by means of random coefficient growth modeling, using data from 60 ongoing teams working in a health care organization. Results provide partial support for our hypotheses. Only when perceived team performance is low, do task conflicts relate with growth in relationship conflict. We conclude that perceived team performance seems to enable teams to uncouple task from relationship conflict.

When Task Conflict Becomes Personal

PubMed Central

Guenter, Hannes; van Emmerik, Hetty; Schreurs, Bert; Kuypers, Tom; van Iterson, Ad; Notelaers, Guy

2016-01-01

Although potentially beneficial, task conflict may threaten teams because it often leads to relationship conflict. Prior research has identified a set of interpersonal factors (e.g., team communication, team trust) that help attenuate this association. The purpose of this article is to provide an alternative perspective that focuses on the moderating role of performance-related factors (i.e., perceived team performance). Using social identity theory, we build a model that predicts how task conflict associates with growth in relationship conflict and how perceived team performance influences this association. We test a three-wave longitudinal model by means of random coefficient growth modeling, using data from 60 ongoing teams working in a health care organization. Results provide partial support for our hypotheses. Only when perceived team performance is low, do task conflicts relate with growth in relationship conflict. We conclude that perceived team performance seems to enable teams to uncouple task from relationship conflict. PMID:28190944

How Important is Conflict Detection to the Conflict Resolution Task?

NASA Technical Reports Server (NTRS)

Mercer, Joey; Gabets, Cynthia; Gomez, Ashley; Edwards, Tamsyn; Bienert, Nancy; Claudatos, Lauren; Homola, Jeffrey R.

2016-01-01

To determine the capabilities and limitations of human operators and automation in separation assurance roles, the second of three Human-in-the-Loop (HITL) part-task studies investigates air traffic controllers ability to detect and resolve conflicts under varying task sets, traffic densities, and run lengths. Operations remained within a single sector, staffed by a single controller, and explored, among other things, the controllers conflict resolution performance in conditions with or without their involvement in the conflict detection task. Whereas comparisons of conflict resolution performance between these two conditions are available in a prior publication, this paper explores whether or not other subjective measures display a relationship to that data. Analyses of controller workload and situation awareness measures attempt to quantify their contribution to controllers ability to resolve traffic conflicts.

Impact of Automation Support on the Conflict Resolution Task in a Human-in-the-Loop Air Traffic Control Simulation

NASA Technical Reports Server (NTRS)

Mercer, Joey; Gomez, Ashley; Gabets, Cynthia; Bienert, Nancy; Edwards, Tamsyn; Martin, Lynne; Gujral, Vimmy; Homola, Jeffrey

2016-01-01

To determine the capabilities and limitations of human operators and automation in separation assurance roles, the second of three Human-in-the-Loop (HITL) part-task studies investigated air traffic controllers ability to detect and resolve conflicts under varying task sets, traffic densities, and run lengths. Operations remained within a single sector, staffed by a single controller, and explored, among other things, the controllers responsibility for conflict resolution with or without their involvement in the conflict detection task. Furthermore, these conditions were examined across two different traffic densities; 1x (current-day traffic) and a 20 increase above current-day traffic levels (1.2x). Analyses herein offer an examination of the conflict resolution strategies employed by controllers. In particular, data in the form of elapsed time between conflict detection and conflict resolution are used to assess if, and how, the controllers involvement in the conflict detection task affected the way in which they resolved traffic conflicts.

Emotional body-word conflict evokes enhanced n450 and slow potential.

PubMed

Ma, Jianling; Liu, Chang; Zhong, Xin; Wang, Lu; Chen, Xu

2014-01-01

Emotional conflict refers to the influence of task irrelevant affective stimuli on current task set. Previously used emotional face-word tasks have produced certain electrophysiological phenomena, such as an enhanced N450 and slow potential; however, it remains unknown whether these effects emerge in other tasks. The present study used an emotional body-word conflict task to investigate the neural dynamics of emotional conflict as reflected by response time, accuracy, and event-related potentials, which were recorded with the aim of replicating the previously observed N450 and slow potential effect. Results indicated increased response time and decreased accuracy in the incongruent condition relative to the congruent condition, indicating a robust interference effect. Furthermore, the incongruent condition evoked pronounced N450 amplitudes and a more positive slow potential, which might be associated with conflict-monitoring and conflict resolution. The present findings extend our understanding of emotional conflict to the body-word domain.

Cue response dissociates inhibitory processes: task identity information is related to backward inhibition but not to competitor rule suppression.

PubMed

Regev, Shirley; Meiran, Nachshon

2017-01-01

In task switching, a conflict between competing task-sets is resolved by inhibiting the interfering task-set. Recent models have proposed a framework of the task-set as composed of two hierarchical components: abstract task identity (e.g., respond to quantity) and more concrete task rules (e.g., category-response rules mapping the categories "one" and "three" to the left and right keys, respectively). The present study explored whether task-set inhibition is the outcome of a general control process or whether it reflects multiple inhibitory processes, each targeting a different component of the competing task-set. To this end, two effects of task-set inhibition were examined: backward inhibition (BI), reflecting the suppression of a just-performed task-set that is no longer relevant; and, competitor rule suppression (CRS), reflecting the suppression of an irrelevant task-set that generates a response conflict. In two task switching experiments, each involving three tasks, we asked participants to make two responses: a cue response, indicating the identity of the relevant task (e.g., "Color"), and a target response requiring the implementation of the task rule (e.g., "Red"). The results demonstrate that BI, but not CRS, appears in cue responses, and thus, suggests that BI reflects inhibition that influences representations related to abstract task identity, rather than (just) competing responses or response rules. These results support a dissociation between inhibitory processes in task switching. The current findings also provide further evidence for a multi-component conceptualization of task-set and task-set inhibition.

Exploring conflict- and target-related movement of visual attention.

PubMed

Wendt, Mike; Garling, Marco; Luna-Rodriguez, Aquiles; Jacobsen, Thomas

2014-01-01

Intermixing trials of a visual search task with trials of a modified flanker task, the authors investigated whether the presentation of conflicting distractors at only one side (left or right) of a target stimulus triggers shifts of visual attention towards the contralateral side. Search time patterns provided evidence for lateral attention shifts only when participants performed the flanker task under an instruction assumed to widen the focus of attention, demonstrating that instruction-based control settings of an otherwise identical task can impact performance in an unrelated task. Contrasting conditions with response-related and response-unrelated distractors showed that shifting attention does not depend on response conflict and may be explained as stimulus-conflict-related withdrawal or target-related deployment of attention.

Distinct Effects of Trial-Driven and Task Set-Related Control in Primary Visual Cortex

PubMed Central

Vaden, Ryan J.; Visscher, Kristina M.

2015-01-01

Task sets are task-specific configurations of cognitive processes that facilitate task-appropriate reactions to stimuli. While it is established that the trial-by-trial deployment of visual attention to expected stimuli influences neural responses in primary visual cortex (V1) in a retinotopically specific manner, it is not clear whether the mechanisms that help maintain a task set over many trials also operate with similar retinotopic specificity. Here, we address this question by using BOLD fMRI to characterize how portions of V1 that are specialized for different eccentricities respond during distinct components of an attention-demanding discrimination task: cue-driven preparation for a trial, trial-driven processing, task-initiation at the beginning of a block of trials, and task-maintenance throughout a block of trials. Tasks required either unimodal attention to an auditory or a visual stimulus or selective intermodal attention to the visual or auditory component of simultaneously presented visual and auditory stimuli. We found that while the retinotopic patterns of trial-driven and cue-driven activity depended on the attended stimulus, the retinotopic patterns of task-initiation and task-maintenance activity did not. Further, only the retinotopic patterns of trial-driven activity were found to depend on the presence of intermodal distraction. Participants who performed well on the intermodal selective attention tasks showed strong task-specific modulations of both trial-driven and task-maintenance activity. Importantly, task-related modulations of trial-driven and task-maintenance activity were in opposite directions. Together, these results confirm that there are (at least) two different processes for top-down control of V1: One, working trial-by-trial, differently modulates activity across different eccentricity sectors—portions of V1 corresponding to different visual eccentricities. The second process works across longer epochs of task performance, and does not differ among eccentricity sectors. These results are discussed in the context of previous literature examining top-down control of visual cortical areas. PMID:26163806

Deep Thinking Increases Task-Set Shielding and Reduces Shifting Flexibility in Dual-Task Performance

ERIC Educational Resources Information Center

Fischer, Rico; Hommel, Bernhard

2012-01-01

Performing two tasks concurrently is difficult, which has been taken to imply the existence of a structural processing bottleneck. Here we sought to assess whether and to what degree one's multitasking abilities depend on the cognitive-control style one engages in. Participants were primed with creativity tasks that either called for divergent…

Sleep-Driven Computations in Speech Processing.

PubMed

Frost, Rebecca L A; Monaghan, Padraic

2017-01-01

Acquiring language requires segmenting speech into individual words, and abstracting over those words to discover grammatical structure. However, these tasks can be conflicting-on the one hand requiring memorisation of precise sequences that occur in speech, and on the other requiring a flexible reconstruction of these sequences to determine the grammar. Here, we examine whether speech segmentation and generalisation of grammar can occur simultaneously-with the conflicting requirements for these tasks being over-come by sleep-related consolidation. After exposure to an artificial language comprising words containing non-adjacent dependencies, participants underwent periods of consolidation involving either sleep or wake. Participants who slept before testing demonstrated a sustained boost to word learning and a short-term improvement to grammatical generalisation of the non-adjacencies, with improvements after sleep outweighing gains seen after an equal period of wake. Thus, we propose that sleep may facilitate processing for these conflicting tasks in language acquisition, but with enhanced benefits for speech segmentation.

Common and Distinct Neural Mechanisms of Attentional Switching and Response Conflict

PubMed Central

Kim, Chobok; Johnson, Nathan F.; Gold, Brian T.

2012-01-01

The human capacities for overcoming prepotent actions and flexibly switching between tasks represent cornerstones of cognitive control. Functional neuroimaging has implicated a diverse set of brain regions contributing to each of these cognitive control processes. However, the extent to which attentional switching and response conflict draw on shared or distinct neural mechanisms remains unclear. The current study examined the neural correlates of response conflict and attentional switching using event-related functional magnetic resonance imaging (fMRI) and a fully randomized 2×2 design. We manipulated an arrow-word version of the Stroop task to measure conflict and switching in the context of a single task decision, in response to a common set of stimuli. Under these common conditions, both behavioral and imaging data showed significant main effects of conflict and switching but no interaction. However, conjunction analyses identified frontal regions involved in both switching and response conflict, including the dorsal anterior cingulate cortex (dACC) and left inferior frontal junction. In addition, connectivity analyses demonstrated task-dependent functional connectivity patterns between dACC and inferior temporal cortex for attentional switching and between dACC and posterior parietal cortex for response conflict. These results suggest that the brain makes use of shared frontal regions, but can dynamically modulate the connectivity patterns of some of those regions, to deal with attentional switching and response conflict. PMID:22750124

Common and distinct neural mechanisms of attentional switching and response conflict.

PubMed

Kim, Chobok; Johnson, Nathan F; Gold, Brian T

2012-08-21

The human capacities for overcoming prepotent actions and flexibly switching between tasks represent cornerstones of cognitive control. Functional neuroimaging has implicated a diverse set of brain regions contributing to each of these cognitive control processes. However, the extent to which attentional switching and response conflict draw on shared or distinct neural mechanisms remains unclear. The current study examined the neural correlates of response conflict and attentional switching using event-related functional magnetic resonance imaging (fMRI) and a fully randomized 2×2 design. We manipulated an arrow-word version of the Stroop task to measure conflict and switching in the context of a single task decision, in response to a common set of stimuli. Under these common conditions, both behavioral and imaging data showed significant main effects of conflict and switching but no interaction. However, conjunction analyses identified frontal regions involved in both switching and response conflict, including the dorsal anterior cingulate cortex (dACC) and left inferior frontal junction. In addition, connectivity analyses demonstrated task-dependent functional connectivity patterns between dACC and inferior temporal cortex for attentional switching and between dACC and posterior parietal cortex for response conflict. These results suggest that the brain makes use of shared frontal regions, but can dynamically modulate the connectivity patterns of some of those regions, to deal with attentional switching and response conflict. Copyright © 2012 Elsevier B.V. All rights reserved.

Conflict and bias in heuristic judgment.

PubMed

Bhatia, Sudeep

2017-02-01

Conflict has been hypothesized to play a key role in recruiting deliberative processing in reasoning and judgment tasks. This claim suggests that changing the task so as to add incorrect heuristic responses that conflict with existing heuristic responses can make individuals less likely to respond heuristically and can increase response accuracy. We tested this prediction in experiments involving judgments of argument strength and word frequency, and found that participants are more likely to avoid heuristic bias and respond correctly in settings with 2 incorrect heuristic response options compared with similar settings with only 1 heuristic response option. Our results provide strong evidence for conflict as a mechanism influencing the interaction between heuristic and deliberative thought, and illustrate how accuracy can be increased through simple changes to the response sets offered to participants. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Functional imaging of decision conflict.

PubMed

Pochon, Jean-Baptiste; Riis, Jason; Sanfey, Alan G; Nystrom, Leigh E; Cohen, Jonathan D

2008-03-26

Decision conflict occurs when people feel uncertain as to which option to choose from a set of similarly attractive (or unattractive) options, with many studies demonstrating that this conflict can lead to suboptimal decision making. In this article, we investigate the neurobiological underpinnings of decision conflict, in particular, the involvement of the anterior cingulate cortex (ACC). Previous studies have implicated the ACC in conflict monitoring during perceptual tasks, but there is considerable controversy as to whether the ACC actually indexes conflict related to choice, or merely conflict related to selection of competing motor responses. In a functional magnetic resonance imaging study, we dissociate the decision and response phases of a decision task, and show that the ACC does indeed index conflict at the decision stage. Furthermore, we show that it does so for a complex decision task, one that requires the integration of beliefs and preferences and not just perceptual judgments.

Meditation-induced cognitive-control states regulate response-conflict adaptation: Evidence from trial-to-trial adjustments in the Simon task.

PubMed

Colzato, Lorenza S; Sellaro, Roberta; Samara, Iliana; Hommel, Bernhard

2015-09-01

Here we consider the possibility that meditation has an immediate impact on information processing. Moreover, we were interested to see whether this impact affects attentional input control, as previous observations suggest, or the handling of response conflict. Healthy adults underwent a brief single session of either focused attention meditation (FAM), which is assumed to increase top-down control, or open monitoring meditation (OMM), which is assumed to weaken top-down control, before performing a Simon task-which assesses conflict-resolution efficiency. While the size of the Simon effect (reflecting the efficiency of handling response conflict) was unaffected by type of meditation, the amount of dynamic behavioral adjustments (i.e., trial-to-trial variability of the Simon effect: the Gratton effect) was considerably smaller after OMM than after FAM. Our findings suggest that engaging in meditation instantly creates a cognitive-control state that has a specific impact on conflict-driven control adaptations. Copyright © 2015 Elsevier Inc. All rights reserved.

The cerebellum mediates conflict resolution.

PubMed

Schweizer, Tom A; Oriet, Chris; Meiran, Nachshon; Alexander, Michael P; Cusimano, Michael; Stuss, Donald T

2007-12-01

Regions within the frontal and parietal cortex have been implicated as important neural correlates for cognitive control during conflict resolution. Despite the extensive reciprocal connectivity between the cerebellum and these putatively critical cortical areas, a role for the cerebellum in conflict resolution has never been identified. We used a task-switching paradigm that separates processes related to task-set switching and the management of response conflict independent of motor processing. Eleven patients with chronic, focal lesions to the cerebellum and 11 healthy controls were compared. Patients were slower and less accurate in conditions involving conflict resolution. In the absence of response conflict, however, tasks-witching abilities were not impaired in our patients. The cerebellum may play an important role in coordinating with other areas of cortex to modulate active response states. These results are the first demonstration of impaired conflict resolution following cerebellar lesions in the presence of an intact prefrontal cortex.

Cognitive and affective control in a flanker word task: common and dissociable brain mechanisms.

PubMed

Alguacil, Sonia; Tudela, Pío; Ruz, María

2013-08-01

In the present study we compared the nature of cognitive and affective conflict modulations at different stages of information processing using electroencephalographic recordings. Participants performed a flanker task in which they had to focus on a central word target and indicate its semantic category (cognitive version) or its valence (affective version). Targets were flanked by congruent or incongruent words in both versions. Although tasks were equivalent at the behavioral level, event-related potentials (ERPs) showed common and dissociable cognitive and emotional conflict modulations. At early stages of information processing, both tasks generated parallel sequential conflict effects in the P1 and N170 potentials. Later, the N2 and the first part of the P3 wave were exclusively modulated by cognitive conflict, whereas the last section of the P3 deflection/Late Positive Component (LPC) was only involved in affective current conflict processing. Therefore, the whole data set suggests the existence of early common mechanisms that are equivalent for cognitive and affective materials and later task-specific conflict processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

The use of the long modular diagnostics shield module to mitigate shutdown dose rates in the ITER diagnostics equatorial ports

NASA Astrophysics Data System (ADS)

Juárez, R.; Guirao, J.; Kolsek, A.; Lopez, A.; Pedroche, G.; Bertalot, L.; Udintsev, V. S.; Walsh, M. J.; Sauvan, P.; Sanz, J.

2018-05-01

The ITER equatorial port plugs are submitted to a drained weight limit of 45 T. This limitation can conflict with their radiation shielding demands, although some weight margin is being discussed. The port interspaces are subject to a shutdown dose rate limit of 100 µSv h‑1 after 106 s of cooling time. To meet it, the port plugs must show a neutron flux attenuation comparable to their neighborhood, despite considering penetrations to host systems. Most of this task relies on the drawer shield module (DSM). In this work, two DSM concepts are analyzed with this perspective: the box-based DSM and the modular DSM. Regardless the penetrations, the box-based DSM leads to unsatisfactory port plugs to meet both weight and SDDR requirements. On the contrary, the modular DSM shows a performance which allows for the adoption of such DSM concept, or equivalent, a port may comply with both requirements at the same time, provided the penetrations are well designed.

Congruency sequence effect in cross-task context: evidence for dimension-specific modulation.

PubMed

Lee, Jaeyong; Cho, Yang Seok

2013-11-01

The congruency sequence effect refers to a reduced congruency effect after incongruent trials relative to congruent trials. This modulation is thought to be, at least in part, due to the control mechanisms resolving conflict. The present study examined the nature of the control mechanisms by having participants perform two different tasks in an alternating way. When participants performed horizontal and vertical Simon tasks in Experiment 1A, and horizontal and vertical spatial Stroop task in Experiment 1B, no congruency sequence effect was obtained between the task congruencies. When the Simon task and spatial Stroop task were performed with different response sets in Experiment 2, no congruency sequence effect was obtained. However, in Experiment 3, in which the participants performed the horizontal Simon and spatial Stroop tasks with an identical response set, a significant congruency sequence effect was obtained between the task congruencies. In Experiment 4, no congruency sequence effect was obtained when participants performed two tasks having different task-irrelevant dimensions with the identical response set. The findings suggest inhibitory processing between the task-irrelevant dimension and response mode after conflict. © 2013 Elsevier B.V. All rights reserved.

The relationship between conflict awareness and behavioral and oscillatory signatures of immediate and delayed cognitive control.

PubMed

Jiang, Jun; Correa, Camile M; Geerts, Jesse; van Gaal, Simon

2018-08-15

Cognitive control over conflict, mediated by the prefrontal cortex, is an important skill for successful decision-making. Although it has been shown that cognitive control may operate unconsciously, it has recently been proposed that control operations may be driven by the metacognitive awareness of conflict, e.g. arising from the feeling of task difficulty or the ease of action selection, and therefore crucially depends on conflict awareness. Behavioral and electroencephalography (EEG) data are presented from 64 subjects performing a masked priming paradigm to test this hypothesis. Although the subjective experience of conflict elicited behavioral adaptation, this was also the case when conflict was present, but not experienced. In EEG, typical oscillatory markers of conflict processing in the theta-, alpha- and beta-band were observed (relative broadband), but these were differentially modulated by conflict experience. This demonstrates that conflict adaptation does not depend on conflict experience, but that conflict experience is associated with increased cognitive control. Copyright © 2018 Elsevier Inc. All rights reserved.

The benefit of expecting no conflict--Stronger influence of self-generated than cue-induced conflict expectations on Stroop performance.

PubMed

Kemper, Maike; Gaschler, Robert; Schwager, Sabine; Schubert, Torsten

2016-01-01

The role of expectations in sequential adaptation to cognitive conflict has been debated controversially in prior studies. On the one hand, a sequential congruency effect (SCE) has been reported for trials in which participants expect a repetition of conflict level. On the other hand, conflict level expectations vs. the SCE have been shown to develop differentially across runs of trials with the same conflict level, arguing against the theory that the SCE is purely driven by expectation. The current verbal Stroop experiment addresses this controversy by two means. First, we tested which specific type of expectation (cue-induced expectations vs. self-generated predictions) might affect the SCE. Second, we assessed the impact of expectation on the SCE as well as the development of SCE and expectation with congruency level run length in one design. We observed a dissociation between expectations and SCE, demonstrating that the SCE is not exclusively driven by expectations. At the same time, we found evidence that (self-generated) expectations do have an impact on the SCE. Our data document especially high performance for one specific combination of task events: congruent trial accompanied by congruent prediction and conflict level repetition. Our results are in line with theories attributing conflict adaptation effects to the "adaption to the lack of conflict". We discuss our results in a broader context of theories about conflict monitoring. Copyright © 2015. Published by Elsevier B.V.

Heightened Conflict in Cue-Target Translation Increases Backward Inhibition in Set Switching

ERIC Educational Resources Information Center

Grange, James A.; Houghton, George

2010-01-01

Backward inhibition (BI) is a performance cost that occurs when an individual returns to a task after 1 (vs. more than 1) intervening trial, and it may reflect the inhibition of task-set components during switching. In 3 experiments, we support the theory that inhibition can target cue-based preparatory stages of a task. Participants performed a…

General proactive interference and the N450 response.

PubMed

Tays, William J; Dywan, Jane; Segalowitz, Sidney J

2009-10-25

Strategic repetition of verbal stimuli can effectively produce proactive interference (PI) effects in the Sternberg working memory task. Unique fronto-cortical activation to PI-eliciting letter probes has been interpreted as reflecting brain responses to PI. However, the use of only a small set of stimuli (e.g., letters and digits) requires constant repetition of stimuli in both PI and baseline trials, potentially creating a general PI effect in all conditions. We used event-related potentials to examine general PI effects by contrasting the interference-related frontal N450 response in two Sternberg tasks using a small versus large set size. We found that the N450 response differed significantly from baseline during the small set-size task only for response-conflict PI trials but not when PI was created solely from stimulus repetition. During the large set-size task N450 responses in both the familiarity-based and response-conflict PI conditions differed from baseline but not from each other. We conclude that the general stimulus repetition inherent in small set-size conditions can mask effects of familiarity-based PI and complicate the interpretation of any associated neural response.

Members' needs, intragroup conflict, and group performance.

PubMed

Chun, Jinseok S; Choi, Jin Nam

2014-05-01

Focusing on "what people want in their group" as a critical antecedent of intragroup conflict, the present study theorizes and empirically investigates the relationships among the psychological needs of group members, intragroup conflict, and group performance. It attends to the within-group average and dispersion of members' psychological needs and examines the effects stemming from group composition of needs on multiple types of conflict. The analyses based on multisource data from 145 organizational teams revealed significant relationships between the groups' composition with respect to the members' need for achievement and task conflict, need for affiliation and relationship conflict, and need for power and status conflict. Some of these relationships were moderated by open communication among members. The analyses also demonstrated that when the 3 types of conflict were considered together, task conflict was a positive predictor of group performance, whereas relationship conflict was a negative predictor. The findings highlight the motivational aspects of intragroup conflict, revealing the multilevel dynamics of the psychological needs in social settings. (c) 2014 APA, all rights reserved.

Conflict effects without conflict in anterior cingulate cortex: multiple response effects and context specific representations

PubMed Central

Brown, Joshua W.

2009-01-01

The error likelihood computational model of anterior cingulate cortex (ACC) (Brown & Braver, 2005) has successfully predicted error likelihood effects, risk prediction effects, and how individual differences in conflict and error likelihood effects vary with trait differences in risk aversion. The same computational model now makes a further prediction that apparent conflict effects in ACC may result in part from an increasing number of simultaneously active responses, regardless of whether or not the cued responses are mutually incompatible. In Experiment 1, the model prediction was tested with a modification of the Eriksen flanker task, in which some task conditions require two otherwise mutually incompatible responses to be generated simultaneously. In that case, the two response processes are no longer in conflict with each other. The results showed small but significant medial PFC effects in the incongruent vs. congruent contrast, despite the absence of response conflict, consistent with model predictions. This is the multiple response effect. Nonetheless, actual response conflict led to greater ACC activation, suggesting that conflict effects are specific to particular task contexts. In Experiment 2, results from a change signal task suggested that the context dependence of conflict signals does not depend on error likelihood effects. Instead, inputs to ACC may reflect complex and task specific representations of motor acts, such as bimanual responses. Overall, the results suggest the existence of a richer set of motor signals monitored by medial PFC and are consistent with distinct effects of multiple responses, conflict, and error likelihood in medial PFC. PMID:19375509

Conflict-driven adaptive control is enhanced by integral negative emotion on a short time scale.

PubMed

Yang, Qian; Pourtois, Gilles

2018-02-05

Negative emotion influences cognitive control, and more specifically conflict adaptation. However, discrepant results have often been reported in the literature. In this study, we broke down negative emotion into integral and incidental components using a modern motivation-based framework, and assessed whether the former could change conflict adaptation. In the first experiment, we manipulated the duration of the inter-trial-interval (ITI) to assess the actual time-scale of this effect. Integral negative emotion was induced by using loss-related feedback contingent on task performance, and measured at the subjective and physiological levels. Results showed that conflict-driven adaptive control was enhanced when integral negative emotion was elicited, compared to a control condition without changes in defensive motivation. Importantly, this effect was only found when a short, as opposed to long ITI was used, suggesting that it had a short time scale. In the second experiment, we controlled for effects of feature repetition and contingency learning, and replicated an enhanced conflict adaptation effect when integral negative emotion was elicited and a short ITI was used. We interpret these new results against a standard cognitive control framework assuming that integral negative emotion amplifies specific control signals transiently, and in turn enhances conflict adaptation.

Sleep-Driven Computations in Speech Processing

PubMed Central

Frost, Rebecca L. A.; Monaghan, Padraic

2017-01-01

Acquiring language requires segmenting speech into individual words, and abstracting over those words to discover grammatical structure. However, these tasks can be conflicting—on the one hand requiring memorisation of precise sequences that occur in speech, and on the other requiring a flexible reconstruction of these sequences to determine the grammar. Here, we examine whether speech segmentation and generalisation of grammar can occur simultaneously—with the conflicting requirements for these tasks being over-come by sleep-related consolidation. After exposure to an artificial language comprising words containing non-adjacent dependencies, participants underwent periods of consolidation involving either sleep or wake. Participants who slept before testing demonstrated a sustained boost to word learning and a short-term improvement to grammatical generalisation of the non-adjacencies, with improvements after sleep outweighing gains seen after an equal period of wake. Thus, we propose that sleep may facilitate processing for these conflicting tasks in language acquisition, but with enhanced benefits for speech segmentation. PMID:28056104

Mood states determine the degree of task shielding in dual-task performance.

PubMed

Zwosta, Katharina; Hommel, Bernhard; Goschke, Thomas; Fischer, Rico

2013-01-01

Current models of multitasking assume that dual-task performance and the degree of multitasking are affected by cognitive control strategies. In particular, cognitive control is assumed to regulate the amount of shielding of the prioritised task from crosstalk from the secondary task. We investigated whether and how task shielding is influenced by mood states. Participants were exposed to two short film clips, one inducing high and one inducing low arousal, of either negative or positive content. Negative mood led to stronger shielding of the prioritised task (i.e., less crosstalk) than positive mood, irrespective of arousal. These findings support the assumption that emotional states determine the parameters of cognitive control and play an important role in regulating dual-task performance.

Resolving task rule incongruence during task switching by competitor rule suppression.

PubMed

Meiran, Nachshon; Hsieh, Shulan; Dimov, Eduard

2010-07-01

Task switching requires maintaining readiness to execute any task of a given set of tasks. However, when tasks switch, the readiness to execute the now-irrelevant task generates interference, as seen in the task rule incongruence effect. Overcoming such interference requires fine-tuned inhibition that impairs task readiness only minimally. In an experiment involving 2 object classification tasks and 2 location classification tasks, the authors show that irrelevant task rules that generate response conflicts are inhibited. This competitor rule suppression (CRS) is seen in response slowing in subsequent trials, when the competing rules become relevant. CRS is shown to operate on specific rules without affecting similar rules. CRS and backward inhibition, which is another inhibitory phenomenon, produced additive effects on reaction time, suggesting their mutual independence. Implications for current formal theories of task switching as well as for conflict monitoring theories are discussed. (c) 2010 APA, all rights reserved

Emotional and Nonemotional Conflict Processing in Pediatric and Adult Anxiety Disorders

PubMed Central

Gold, Andrea L.; Jarcho, Johanna M.; Rosen, Dana K.; Pine, Daniel S.; Ernst, Monique

2015-01-01

Abstract Objective: Perturbations in emotional conflict adaptation, an implicit regulatory process, have been observed in adult anxiety disorders. However, findings remain inconsistent and restricted to adults. The current study compares conflict adaptation in youth and adults, with and without anxiety disorders. We predicted conflict adaptation would be present in the healthy but not the anxious groups. Methods: In a clinic setting, 111 participants (27 healthy youth, 22 anxious youth, 41 healthy adults, and 21 anxious adults) completed emotional and nonemotional conflict tasks. Groups did not differ (all p's >0.1) on intelligence quotient (IQ), gender, and socioeconomic status; age did not differ between healthy and anxious subjects in either age cohort. Separate four way mixed-design analyses of variance were conducted to test hypotheses regarding the influence of diagnosis, age group, and task type on accuracy (percent correct) and reaction time (RT) for conflict adaptation (incongruent trials preceded by incongruent vs. congruent trials) and conflict detection (incongruent vs. congruent trials). Results: Measures of conflict adaptation did not interact with diagnosis or age. There was a significant main effect of conflict adaptation across the overall sample in the expected direction for accuracy, but not RT. The well-replicated conflict detection effect also did emerge across tasks, with slower RT and lower accuracy for incongruent than for congruent trials. These effects were greater for the emotional than for nonemotional tasks. Finally, there were age differences in accuracy-based conflict detection specific to the emotional task, for which the size of the effect was larger for youth than for adults. Conclusions: The current study of youth and adults did not replicate prior behavioral findings of failure to engage conflict adaptation in anxiety disorders. Therefore, more work is needed before widely adopting conflict adaptation paradigms as a standard neurocognitive marker for anxiety disorders. PMID:26544668

Two Independent Frontal Midline Theta Oscillations during Conflict Detection and Adaptation in a Simon-Type Manual Reaching Task.

PubMed

Töllner, Thomas; Wang, Yijun; Makeig, Scott; Müller, Hermann J; Jung, Tzyy-Ping; Gramann, Klaus

2017-03-01

One of the most firmly established factors determining the speed of human behavioral responses toward action-critical stimuli is the spatial correspondence between the stimulus and response locations. If both locations match, the time taken for response production is markedly reduced relative to when they mismatch, a phenomenon called the Simon effect. While there is a consensus that this stimulus-response (S-R) conflict is associated with brief (4-7 Hz) frontal midline theta (fmθ) complexes generated in medial frontal cortex, it remains controversial (1) whether there are multiple, simultaneously active theta generator areas in the medial frontal cortex that commonly give rise to conflict-related fmθ complexes; and if so, (2) whether they are all related to the resolution of conflicting task information. Here, we combined mental chronometry with high-density electroencephalographic measures during a Simon-type manual reaching task and used independent component analysis and time-frequency domain statistics on source-level activities to model fmθ sources. During target processing, our results revealed two independent fmθ generators simultaneously active in or near anterior cingulate cortex, only one of them reflecting the correspondence between current and previous S-R locations. However, this fmθ response is not exclusively linked to conflict but also to other, conflict-independent processes associated with response slowing. These results paint a detailed picture regarding the oscillatory correlates of conflict processing in Simon tasks, and challenge the prevalent notion that fmθ complexes induced by conflicting task information represent a unitary phenomenon related to cognitive control, which governs conflict processing across various types of response-override tasks. SIGNIFICANCE STATEMENT Humans constantly monitor their environment for and adjust their cognitive control settings in response to conflicts, an ability that arguably paves the way for survival in ever-changing situations. Anterior cingulate-generated frontal midline theta (fmθ) complexes have been hypothesized to play a role in this conflict-monitoring function. However, it remains a point of contention whether fmθ complexes govern conflict processing in a unitary, paradigm-nonspecific manner. Here, we identified two independent fmθ oscillations triggered during a Simon-type task, only one of them reflecting current and previous conflicts. Importantly, this signal differed in various respects (cortical origin, intertrial history) from fmθ phenomena in other response-override tasks, challenging the prevalent notion of conflict-induced fmθ as a unitary phenomenon associated with the resolution of conflict. Copyright © 2017 the authors 0270-6474/17/372505-12$15.00/0.

Task representation in individual and joint settings

PubMed Central

Prinz, Wolfgang

2015-01-01

This paper outlines a framework for task representation and discusses applications to interference tasks in individual and joint settings. The framework is derived from the Theory of Event Coding (TEC). This theory regards task sets as transient assemblies of event codes in which stimulus and response codes interact and shape each other in particular ways. On the one hand, stimulus and response codes compete with each other within their respective subsets (horizontal interactions). On the other hand, stimulus and response code cooperate with each other (vertical interactions). Code interactions instantiating competition and cooperation apply to two time scales: on-line performance (i.e., doing the task) and off-line implementation (i.e., setting the task). Interference arises when stimulus and response codes overlap in features that are irrelevant for stimulus identification, but relevant for response selection. To resolve this dilemma, the feature profiles of event codes may become restructured in various ways. The framework is applied to three kinds of interference paradigms. Special emphasis is given to joint settings where tasks are shared between two participants. Major conclusions derived from these applications include: (1) Response competition is the chief driver of interference. Likewise, different modes of response competition give rise to different patterns of interference; (2) The type of features in which stimulus and response codes overlap is also a crucial factor. Different types of such features give likewise rise to different patterns of interference; and (3) Task sets for joint settings conflate intraindividual conflicts between responses (what), with interindividual conflicts between responding agents (whom). Features of response codes may, therefore, not only address responses, but also responding agents (both physically and socially). PMID:26029085

Determinants of Quality Perception in Educational Administration: Potential Conflict between the Requirements of Internal and External Customers.

ERIC Educational Resources Information Center

Galloway, R. L.; Wearn, Katrina

1998-01-01

Attempts to measure perceived quality, based on customers' views within the context of a (British) university faculty office, using a modified SERVQUAL instrument. Internal customers demonstrated that perceived quality is driven by task-focused issues, stressing clarity, accuracy, and reliability. External customers, whose usage is more casual,…

Nova-driven winds in globular clusters

NASA Technical Reports Server (NTRS)

Scott, E. H.; Durisen, R. H.

1978-01-01

Recent sensitive searches for H-alpha emission from ionized intracluster gas in globular clusters have set upper limits that conflict with theoretical predictions. It is suggested that nova outbursts heat the gas, producing winds that resolve this discrepancy. The incidence of novae in globular clusters, the conversion of kinetic energy of the nova shell to thermal energy of the intracluster gas, and the characteristics of the resultant winds are discussed. Calculated emission from the nova-driven models does not conflict with any observations to date. Some suggestions are made concerning the most promising approaches for future detection of intracluster gas on the basis of these models. The possible relationship of nova-driven winds to globular cluster X-ray sources is also considered.

Task set persistence modulates word reading following resolution of picture-word interference.

PubMed

Masson, Michael E J; Bub, Daniel N; Ishigami, Yoko

2007-12-01

We extend the finding that word reading slows following successful responses to a color-word Stroop interference task (Masson, Bub, Woodward, & Chan, 2003). Word reading was assessed in a picture-word interference task in which subjects alternated between naming a picture (with either a word or a row of Xs superimposed on it) and reading a word. For the word-reading task, words were presented either in isolation or superimposed on a picture. Word reading was slower after subjects responded to a bivalent stimulus that required resolution of conflict (naming a picture with a word superimposed on it) than after they responded to a stimulus that involved no conflict (naming a picture with Xs superimposed on it), indicating modulation of dominant task performance. This effect was found when word-reading targets were superimposed on pictures but not when those targets were presented in isolation. Modulation of word reading, therefore, appears to be the result of interference from a persistent picture-naming task set, cued by a stimulus configuration that invites execution of both competing tasks.

Switches of stimulus tagging frequencies interact with the conflict-driven control of selective attention, but not with inhibitory control.

PubMed

Scherbaum, Stefan; Frisch, Simon; Dshemuchadse, Maja

2016-01-01

Selective attention and its adaptation by cognitive control processes are considered a core aspect of goal-directed action. Often, selective attention is studied behaviorally with conflict tasks, but an emerging neuroscientific method for the study of selective attention is EEG frequency tagging. It applies different flicker frequencies to the stimuli of interest eliciting steady state visual evoked potentials (SSVEPs) in the EEG. These oscillating SSVEPs in the EEG allow tracing the allocation of selective attention to each tagged stimulus continuously over time. The present behavioral investigation points to an important caveat of using tagging frequencies: The flicker of stimuli not only produces a useful neuroscientific marker of selective attention, but interacts with the adaptation of selective attention itself. Our results indicate that RT patterns of adaptation after response conflict (so-called conflict adaptation) are reversed when flicker frequencies switch at once. However, this effect of frequency switches is specific to the adaptation by conflict-driven control processes, since we find no effects of frequency switches on inhibitory control processes after no-go trials. We discuss the theoretical implications of this finding and propose precautions that should be taken into account when studying conflict adaptation using frequency tagging in order to control for the described confounds. Copyright © 2015 Elsevier B.V. All rights reserved.

Task conflict effect in task switching.

PubMed

Braverman, Ami; Meiran, Nachshon

2010-11-01

A part of action preparation is deciding what the relevant task is. This task-decision process is conceptually separate from response selection. To show this, the authors manipulated task conflict in a spatial task-switching paradigm, using conflict stimuli that appeared during trials with univalent targets (affording 1 task). The conflict stimuli afforded task identity because they were used as task cues with bivalent targets (affording 2 tasks) that were intermixed with the univalent targets. Thus, for univalent targets, irrelevant stimuli either caused low task conflict or high task conflict. In three experiments, the authors found poorer performance in high task conflict trials than in low task conflict trials. Task conflict was introduced during target appearance (Experiment 1) or task preparation (Experiments 2 and 3). In the latter case, the task conflict effect decreased with increasing task preparation time showing that task preparation involves task decision.

Small Engine Technology (SET) - Task 13 ANOPP Noise Prediction for Small Engines: Jet Noise Prediction Module, Wing Shielding Module, and System Studies Results

NASA Technical Reports Server (NTRS)

Lieber, Lysbeth; Golub, Robert (Technical Monitor)

2000-01-01

This Final Report has been prepared by AlliedSignal Engines and Systems, Phoenix, Arizona, documenting work performed during the period May 1997 through June 1999, under the Small Engines Technology Program, Contract No. NAS3-27483, Task Order 13, ANOPP Noise Prediction for Small Engines. The report specifically covers the work performed under Subtasks 4, 5 and 6. Subtask 4 describes the application of a semi-empirical procedure for jet noise prediction, subtask 5 describes the development of a procedure to predict the effects of wing shielding, and subtask 6 describes the results of system studies of the benefits of the new noise technology on business and regional aircraft.

Activation of context-specific attentional control sets by exogenous allocation of visual attention to the context?

PubMed

Gottschalk, Caroline; Fischer, Rico

2017-03-01

Different contexts with high versus low conflict frequencies require a specific attentional control involvement, i.e., strong attentional control for high conflict contexts and less attentional control for low conflict contexts. While it is assumed that the corresponding control set can be activated upon stimulus presentation at the respective context (e.g., upper versus lower location), the actual features that trigger control set activation are to date not described. Here, we ask whether the perceptual priming of the location context by an abrupt onset of irrelevant stimuli is sufficient in activating the context-specific attentional control set. For example, the mere onset of a stimulus might disambiguate the relevant location context and thus, serve as a low-level perceptual trigger mechanism that activates the context-specific attentional control set. In Experiment 1 and 2, the onsets of task-relevant and task-irrelevant (distracter) stimuli were manipulated at each context location to compete for triggering the activation of the appropriate control set. In Experiment 3, a prior training session enabled distracter stimuli to establish contextual control associations of their own before entering the test session. Results consistently showed that the mere onset of a task-irrelevant stimulus (with or without a context-control association) is not sufficient to activate the context-associated attentional control set by disambiguating the relevant context location. Instead, we argue that the identification of the relevant stimulus at the respective context is a precondition to trigger the activation of the context-associated attentional control set.

Task conflict and relationship conflict in top management teams: the pivotal role of intragroup trust.

PubMed

Simons, T L; Peterson, R S

2000-02-01

Task conflict is usually associated with effective decisions, and relationship conflict is associated with poor decisions. The 2 conflict types are typically correlated in ongoing groups, however, which creates a prescriptive dilemma. Three explanations might account for this relationship--misattribution of task conflict as relationship conflict, harsh task conflict tactics triggering relationship conflict, and misattribution of relationship conflict as task conflict. The authors found that intragroup trust moderates the relationship between task conflict and relationship conflict in 70 top management teams. This result supports the "misattribution of task conflict" explanation. The authors also found a weak effect that is consistent with the argument that tactical choices drive the association between the 2 conflict types. We infer that trust is a key to gaining the benefits of task conflict without suffering the costs of relationship conflict.

Multiple Cognitive Control Effects of Error Likelihood and Conflict

PubMed Central

Brown, Joshua W.

2010-01-01

Recent work on cognitive control has suggested a variety of performance monitoring functions of the anterior cingulate cortex, such as errors, conflict, error likelihood, and others. Given the variety of monitoring effects, a corresponding variety of control effects on behavior might be expected. This paper explores whether conflict and error likelihood produce distinct cognitive control effects on behavior, as measured by response time. A change signal task (Brown & Braver, 2005) was modified to include conditions of likely errors due to tardy as well as premature responses, in conditions with and without conflict. The results discriminate between competing hypotheses of independent vs. interacting conflict and error likelihood control effects. Specifically, the results suggest that the likelihood of premature vs. tardy response errors can lead to multiple distinct control effects, which are independent of cognitive control effects driven by response conflict. As a whole, the results point to the existence of multiple distinct cognitive control mechanisms and challenge existing models of cognitive control that incorporate only a single control signal. PMID:19030873

Actively driven thermal radiation shield

DOEpatents

Madden, Norman W.; Cork, Christopher P.; Becker, John A.; Knapp, David A.

2002-01-01

A thermal radiation shield for cooled portable gamma-ray spectrometers. The thermal radiation shield is located intermediate the vacuum enclosure and detector enclosure, is actively driven, and is useful in reducing the heat load to mechanical cooler and additionally extends the lifetime of the mechanical cooler. The thermal shield is electrically-powered and is particularly useful for portable solid-state gamma-ray detectors or spectrometers that dramatically reduces the cooling power requirements. For example, the operating shield at 260K (40K below room temperature) will decrease the thermal radiation load to the detector by 50%, which makes possible portable battery operation for a mechanically cooled Ge spectrometer.

Preparatory neural activity predicts performance on a conflict task.

PubMed

Stern, Emily R; Wager, Tor D; Egner, Tobias; Hirsch, Joy; Mangels, Jennifer A

2007-10-24

Advance preparation has been shown to improve the efficiency of conflict resolution. Yet, with little empirical work directly linking preparatory neural activity to the performance benefits of advance cueing, it is not clear whether this relationship results from preparatory activation of task-specific networks, or from activity associated with general alerting processes. Here, fMRI data were acquired during a spatial Stroop task in which advance cues either informed subjects of the upcoming relevant feature of conflict stimuli (spatial or semantic) or were neutral. Informative cues decreased reaction time (RT) relative to neutral cues, and cues indicating that spatial information would be task-relevant elicited greater activity than neutral cues in multiple areas, including right anterior prefrontal and bilateral parietal cortex. Additionally, preparatory activation in bilateral parietal cortex and right dorsolateral prefrontal cortex predicted faster RT when subjects responded to spatial location. No regions were found to be specific to semantic cues at conventional thresholds, and lowering the threshold further revealed little overlap between activity associated with spatial and semantic cueing effects, thereby demonstrating a single dissociation between activations related to preparing a spatial versus semantic task-set. This relationship between preparatory activation of spatial processing networks and efficient conflict resolution suggests that advance information can benefit performance by leading to domain-specific biasing of task-relevant information.

Long-Term Memory and the Control of Attentional Control

PubMed Central

Mayr, Ulrich; Kuhns, David; Hubbard, Jason

2014-01-01

Task-switch costs and in particular the switch-cost asymmetry (i.e., the larger costs of switching to a dominant than a non-dominant task) are usually explained in terms of trial-to-trial carry-over of task-specific control settings. Here we argue that task switches are just one example of situations that trigger a transition from working-memory maintenance to updating, thereby opening working memory to interference from long-term memory. We used a new paradigm that requires selecting a spatial location either on the basis of a central cue (i.e., endogenous control of attention) or a peripheral, sudden onset (i.e., exogenous control of attention). We found a strong cost asymmetry that occurred even after short interruptions of otherwise single-task blocks (Exp. 1-3), but that was much stronger when participants had experienced the competing task under conditions of conflict (Exp. 1-2). Experiment 3 showed that the asymmetric costs were due to interruptions per se, rather than to associative interference tied to specific interruption activities. Experiment 4 generalized the basic pattern across interruptions varying in length or control demands and Experiment 5 across primary tasks with response-selection conflict rather than attentional conflict. Combined, the results support a model in which costs of selecting control settings arise when (a) potentially interfering memory traces have been encoded in long-term memory and (b) working-memory is forced from a maintenance mode into an updating mode (e.g., through task interruptions), thereby allowing unwanted retrieval of the encoded memory traces. PMID:24650696

Teaching operating room conflict management to surgeons: clarifying the optimal approach.

PubMed

Rogers, David; Lingard, Lorelei; Boehler, Margaret L; Espin, Sherry; Klingensmith, Mary; Mellinger, John D; Schindler, Nancy

2011-09-01

Conflict management has been identified as an essential competence for surgeons as they work in operating room (OR) teams; however, the optimal approach is unclear. Social science research offers two alternatives, the first of which recommends that task-related conflict be managed using problem-solving techniques while avoiding relationship conflict. The other approach advocates for the active management of relationship conflict as it almost always accompanies task-related conflict. Clarity about the optimal management strategy can be gained through a better understanding of conflict transformation, or the inter-relationship between conflict types, in this specific setting. The purpose of this study was to evaluate conflict transformation in OR teams in order to clarify the approach most appropriate for an educational conflict management programme for surgeons. A constructivist grounded theory approach was adopted to explore the phenomenon of OR team conflict. Narratives were collected from focus groups of OR nurses and surgeons at five participating centres. A subset of these narratives involved transformation between and within conflict types. This dataset was analysed. The results confirm that misattribution and the use of harsh language cause conflict transformation in OR teams just as they do in stable work teams. Negative emotionality was found to make a substantial contribution to responses to and consequences of conflict, notably in the swiftness with which individuals terminated their working relationships. These findings contribute to a theory of conflict transformation in the OR team. There are a number of behaviours that activate conflict transformation in the OR team and a conflict management education programme should include a description of and alternatives to these behaviours. The types of conflict are tightly interwoven in this setting and thus the most appropriate management strategy is one that assumes that both types of conflict will exist and should be managed actively. © Blackwell Publishing Ltd 2011.

Distinguishing response conflict and task conflict in the Stroop task: evidence from ex-Gaussian distribution analysis.

PubMed

Steinhauser, Marco; Hübner, Ronald

2009-10-01

It has been suggested that performance in the Stroop task is influenced by response conflict as well as task conflict. The present study investigated the idea that both conflict types can be isolated by applying ex-Gaussian distribution analysis which decomposes response time into a Gaussian and an exponential component. Two experiments were conducted in which manual versions of a standard Stroop task (Experiment 1) and a separated Stroop task (Experiment 2) were performed under task-switching conditions. Effects of response congruency and stimulus bivalency were used to measure response conflict and task conflict, respectively. Ex-Gaussian analysis revealed that response conflict was mainly observed in the Gaussian component, whereas task conflict was stronger in the exponential component. Moreover, task conflict in the exponential component was selectively enhanced under task-switching conditions. The results suggest that ex-Gaussian analysis can be used as a tool to isolate different conflict types in the Stroop task. PsycINFO Database Record (c) 2009 APA, all rights reserved.

Exploring relations between task conflict and informational conflict in the Stroop task.

PubMed

Entel, Olga; Tzelgov, Joseph; Bereby-Meyer, Yoella; Shahar, Nitzan

2015-11-01

In this study, we tested the proposal that the Stroop task involves two conflicts--task conflict and informational conflict. Task conflict was defined as the latency difference between color words and non-letter neutrals, and manipulated by varying the proportion of color words versus non-letter neutrals. Informational conflict was defined as the latency difference between incongruent and congruent trials and manipulated by varying the congruent-to-incongruent trial ratio. We replicated previous findings showing that increasing the ratio of incongruent-to-congruent trials reduces the latency difference between the incongruent and congruent condition (i.e., informational conflict), as does increasing the proportion of color words (i.e., task conflict). A significant under-additive interaction between the two proportion manipulations (congruent vs. incongruent and color words vs. neutrals) indicated that the effects of task conflict and informational conflict were not additive. By assessing task conflict as the contrast between color words and neutrals, we found that task conflict existed in all of our experimental conditions. Under specific conditions, when task conflict dominated behavior by explaining most of the variability between congruency conditions, we also found negative facilitation, thus demonstrating that this effect is a special case of task conflict.

Mixed Initiative Visual Analytics Using Task-Driven Recommendations

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

Cook, Kristin A.; Cramer, Nicholas O.; Israel, David

2015-12-07

Visual data analysis is composed of a collection of cognitive actions and tasks to decompose, internalize, and recombine data to produce knowledge and insight. Visual analytic tools provide interactive visual interfaces to data to support tasks involved in discovery and sensemaking, including forming hypotheses, asking questions, and evaluating and organizing evidence. Myriad analytic models can be incorporated into visual analytic systems, at the cost of increasing complexity in the analytic discourse between user and system. Techniques exist to increase the usability of interacting with such analytic models, such as inferring data models from user interactions to steer the underlying modelsmore » of the system via semantic interaction, shielding users from having to do so explicitly. Such approaches are often also referred to as mixed-initiative systems. Researchers studying the sensemaking process have called for development of tools that facilitate analytic sensemaking through a combination of human and automated activities. However, design guidelines do not exist for mixed-initiative visual analytic systems to support iterative sensemaking. In this paper, we present a candidate set of design guidelines and introduce the Active Data Environment (ADE) prototype, a spatial workspace supporting the analytic process via task recommendations invoked by inferences on user interactions within the workspace. ADE recommends data and relationships based on a task model, enabling users to co-reason with the system about their data in a single, spatial workspace. This paper provides an illustrative use case, a technical description of ADE, and a discussion of the strengths and limitations of the approach.« less

System for solving diagnosis and hitting set problems

NASA Technical Reports Server (NTRS)

Vatan, Farrokh (Inventor); Fijany, Amir (Inventor)

2007-01-01

The diagnosis problem arises when a system's actual behavior contradicts the expected behavior, thereby exhibiting symptoms (a collection of conflict sets). System diagnosis is then the task of identifying faulty components that are responsible for anomalous behavior. To solve the diagnosis problem, the present invention describes a method for finding the minimal set of faulty components (minimal diagnosis set) that explain the conflict sets. The method includes acts of creating a matrix of the collection of conflict sets, and then creating nodes from the matrix such that each node is a node in a search tree. A determination is made as to whether each node is a leaf node or has any children nodes. If any given node has children nodes, then the node is split until all nodes are leaf nodes. Information gathered from the leaf nodes is used to determine the minimal diagnosis set.

Factors responsible for performance on the day-night task: response set or semantics?

PubMed

Simpson, Andrew; Riggs, Kevin J

2005-07-01

In a recent study Diamond, Kirkham and Amso (2002) obtained evidence consistent with the claim that the day-night task requires inhibition because the picture and its corresponding conflicting response are semantically related. In their study children responded more accurately in a dog-pig condition (see /day picture/ say "dog"; see /night picture/ say "pig") than the standard day-night condition (see /day picture/ say "night"; see /night picture/ say "day"). However, there is another effect that may have made the day-night condition harder than the dog-pig condition: the response set effect. In the day-night condition the names of the two stimuli ("day" and "night") and the two corresponding conflicting responses ("night" and "day") are from the same response set: both "day" and "night". In the dog-pig condition the names of the stimuli ("day", "night") and the corresponding responses ("dog", "pig") are from a different response set. In two experiments (Experiment 1 with 4-year-olds (n = 25); Experiment 2 with , 4-, 5-, 7- and 11-year-olds (n = 81)) children were tested on four experimental conditions that enabled the effects of semantics and response set to be separated. Overall, our data suggest that response set is a major factor in creating the inhibitory demands of the day-night task in children of all ages. Results are discussed in relation to other inhibitory tasks.

Conflict control in task conflict and response conflict.

PubMed

Braverman, Ami; Meiran, Nachshon

2015-03-01

Studies have suggested that conflict control can modulate conflict effects in response to differing levels of conflict context. The current study probed, in two experiments of proportion congruence, the relevance of both task conflict (between a currently relevant task and irrelevant task alternatives) and response conflict (between a currently relevant response and irrelevant response alternatives) to conflict control. In Experiment 1, proportion congruence between blocks was manipulated and in Experiment 2, proportion congruence was manipulated between items. The response conflict effect was smaller when proportion of incongruence was high, regardless if task conflict or response conflict proportions were manipulated. These findings suggest that both task conflict and response conflict are monitored but that only response conflict is being influenced by this monitoring process. Theoretical implications are discussed.

Executive control over unconscious cognition: attentional sensitization of unconscious information processing

PubMed Central

Kiefer, Markus

2012-01-01

Unconscious priming is a prototypical example of an automatic process, which is initiated without deliberate intention. Classical theories of automaticity assume that such unconscious automatic processes occur in a purely bottom-up driven fashion independent of executive control mechanisms. In contrast to these classical theories, our attentional sensitization model of unconscious information processing proposes that unconscious processing is susceptible to executive control and is only elicited if the cognitive system is configured accordingly. It is assumed that unconscious processing depends on attentional amplification of task-congruent processing pathways as a function of task sets. This article provides an overview of the latest research on executive control influences on unconscious information processing. I introduce refined theories of automaticity with a particular focus on the attentional sensitization model of unconscious cognition which is specifically developed to account for various attentional influences on different types of unconscious information processing. In support of the attentional sensitization model, empirical evidence is reviewed demonstrating executive control influences on unconscious cognition in the domains of visuo-motor and semantic processing: subliminal priming depends on attentional resources, is susceptible to stimulus expectations and is influenced by action intentions and task sets. This suggests that even unconscious processing is flexible and context-dependent as a function of higher-level executive control settings. I discuss that the assumption of attentional sensitization of unconscious information processing can accommodate conflicting findings regarding the automaticity of processes in many areas of cognition and emotion. This theoretical view has the potential to stimulate future research on executive control of unconscious processing in healthy and clinical populations. PMID:22470329

Executive control over unconscious cognition: attentional sensitization of unconscious information processing.

PubMed

Kiefer, Markus

2012-01-01

Unconscious priming is a prototypical example of an automatic process, which is initiated without deliberate intention. Classical theories of automaticity assume that such unconscious automatic processes occur in a purely bottom-up driven fashion independent of executive control mechanisms. In contrast to these classical theories, our attentional sensitization model of unconscious information processing proposes that unconscious processing is susceptible to executive control and is only elicited if the cognitive system is configured accordingly. It is assumed that unconscious processing depends on attentional amplification of task-congruent processing pathways as a function of task sets. This article provides an overview of the latest research on executive control influences on unconscious information processing. I introduce refined theories of automaticity with a particular focus on the attentional sensitization model of unconscious cognition which is specifically developed to account for various attentional influences on different types of unconscious information processing. In support of the attentional sensitization model, empirical evidence is reviewed demonstrating executive control influences on unconscious cognition in the domains of visuo-motor and semantic processing: subliminal priming depends on attentional resources, is susceptible to stimulus expectations and is influenced by action intentions and task sets. This suggests that even unconscious processing is flexible and context-dependent as a function of higher-level executive control settings. I discuss that the assumption of attentional sensitization of unconscious information processing can accommodate conflicting findings regarding the automaticity of processes in many areas of cognition and emotion. This theoretical view has the potential to stimulate future research on executive control of unconscious processing in healthy and clinical populations.

Functional brain and age-related changes associated with congruency in task switching

PubMed Central

Eich, Teal S.; Parker, David; Liu, Dan; Oh, Hwamee; Razlighi, Qolamreza; Gazes, Yunglin; Habeck, Christian; Stern, Yaakov

2016-01-01

Alternating between completing two simple tasks, as opposed to completing only one task, has been shown to produce costs to performance and changes to neural patterns of activity, effects which are augmented in old age. Cognitive conflict may arise from factors other than switching tasks, however. Sensorimotor congruency (whether stimulus-response mappings are the same or different for the two tasks) has been shown to behaviorally moderate switch costs in older, but not younger adults. In the current study, we used fMRI to investigate the neurobiological mechanisms of response-conflict congruency effects within a task switching paradigm in older (N=75) and younger (N=62) adults. Behaviorally, incongruency moderated age-related differences in switch costs. Neurally, switch costs were associated with greater activation in the dorsal attention network for older relative to younger adults. We also found that older adults recruited an additional set of brain areas in the ventral attention network to a greater extent than did younger adults to resolve congruency-related response-conflict. These results suggest both a network and an age-based dissociation between congruency and switch costs in task switching. PMID:27520472

Mixed signals: The effect of conflicting reward- and goal-driven biases on selective attention.

PubMed

Preciado, Daniel; Munneke, Jaap; Theeuwes, Jan

2017-07-01

Attentional selection depends on the interaction between exogenous (stimulus-driven), endogenous (goal-driven), and selection history (experience-driven) factors. While endogenous and exogenous biases have been widely investigated, less is known about their interplay with value-driven attention. The present study investigated the interaction between reward-history and goal-driven biases on perceptual sensitivity (d') and response time (RT) in a modified cueing paradigm presenting two coloured cues, followed by sinusoidal gratings. Participants responded to the orientation of one of these gratings. In Experiment 1, one cue signalled reward availability but was otherwise task irrelevant. In Experiment 2, the same cue signalled reward, and indicated the target's most likely location at the opposite side of the display. This design introduced a conflict between reward-driven biases attracting attention and goal-driven biases directing it away. Attentional effects were examined comparing trials in which cue and target appeared at the same versus opposite locations. Two interstimulus interval (ISI) levels were used to probe the time course of attentional effects. Experiment 1 showed performance benefits at the location of the reward-signalling cue and costs at the opposite for both ISIs, indicating value-driven capture. Experiment 2 showed performance benefits only for the long ISI when the target was at the opposite to the reward-associated cue. At the short ISI, only performance costs were observed. These results reveal the time course of these biases, indicating that reward-driven effects influence attention early but can be overcome later by goal-driven control. This suggests that reward-driven biases are integrated as attentional priorities, just as exogenous and endogenous factors.

Flexible conflict management: conflict avoidance and conflict adjustment in reactive cognitive control.

PubMed

Dignath, David; Kiesel, Andrea; Eder, Andreas B

2015-07-01

Conflict processing is assumed to serve two crucial, yet distinct functions: Regarding task performance, control is adjusted to overcome the conflict. Regarding task choice, control is harnessed to bias decision making away from the source of conflict. Despite recent theoretical progress, until now two lines of research addressed these conflict-management strategies independently of each other. In this research, we used a voluntary task-switching paradigm in combination with response interference tasks to study both strategies in concert. In Experiment 1, participants chose between two univalent tasks on each trial. Switch rates increased following conflict trials, indicating avoidance of conflict. Furthermore, congruency effects in reaction times and error rates were reduced following conflict trials, demonstrating conflict adjustment. In Experiment 2, we used bivalent instead of univalent stimuli. Conflict adjustment in task performance was unaffected by this manipulation, but conflict avoidance was not observed. Instead, task switches were reduced after conflict trials. In Experiment 3, we used tasks comprising univalent or bivalent stimuli. Only tasks with univalent revealed conflict avoidance, whereas conflict adjustment was found for all tasks. On the basis of established theories of cognitive control, an integrative process model is described that can account for flexible conflict management. (c) 2015 APA, all rights reserved.

Observations of Children’s Interactions with Teachers, Peers, and Tasks across Preschool Classroom Activity Settings

PubMed Central

Booren, Leslie M.; Downer, Jason T.; Vitiello, Virginia E.

2014-01-01

This descriptive study examined classroom activity settings in relation to children’s observed behavior during classroom interactions, child gender, and basic teacher behavior within the preschool classroom. 145 children were observed for an average of 80 minutes during 8 occasions across 2 days using the inCLASS, an observational measure that conceptualizes behavior into teacher, peer, task, and conflict interactions. Findings indicated that on average children’s interactions with teachers were higher in teacher-structured settings, such as large group. On average, children’s interactions with peers and tasks were more positive in child-directed settings, such as free choice. Children experienced more conflict during recess and routines/transitions. Finally, gender differences were observed within small group and meals. The implications of these findings might encourage teachers to be thoughtful and intentional about what types of support and resources are provided so children can successfully navigate the demands of particular settings. These findings are not meant to discourage certain teacher behaviors or imply value of certain classroom settings; instead, by providing an evidenced-based picture of the conditions under which children display the most positive interactions, teachers can be more aware of choices within these settings and have a powerful way to assist in professional development and interventions. PMID:25717282

Observations of Children's Interactions with Teachers, Peers, and Tasks across Preschool Classroom Activity Settings.

PubMed

Booren, Leslie M; Downer, Jason T; Vitiello, Virginia E

2012-07-01

This descriptive study examined classroom activity settings in relation to children's observed behavior during classroom interactions, child gender, and basic teacher behavior within the preschool classroom. 145 children were observed for an average of 80 minutes during 8 occasions across 2 days using the inCLASS, an observational measure that conceptualizes behavior into teacher, peer, task, and conflict interactions. Findings indicated that on average children's interactions with teachers were higher in teacher-structured settings, such as large group. On average, children's interactions with peers and tasks were more positive in child-directed settings, such as free choice. Children experienced more conflict during recess and routines/transitions. Finally, gender differences were observed within small group and meals. The implications of these findings might encourage teachers to be thoughtful and intentional about what types of support and resources are provided so children can successfully navigate the demands of particular settings. These findings are not meant to discourage certain teacher behaviors or imply value of certain classroom settings; instead, by providing an evidenced-based picture of the conditions under which children display the most positive interactions, teachers can be more aware of choices within these settings and have a powerful way to assist in professional development and interventions.

Conflict in medical teams: opportunity or danger?

PubMed

Greer, Lindred L; Saygi, Ozum; Aaldering, Hillie; de Dreu, Carsten K W

2012-10-01

  Intragroup conflicts often occur when people are called upon to collaborate in the accomplishment of a task. For example, when surgeons and nurses work together during an operation, conflicts may emerge because of differences in functional understanding. Whether these conflicts are beneficial or detrimental to team outcomes has been the source of much debate. From one perspective, a conflict that stems from differences in members' functional understanding may enhance team members' understanding and performance of the task at hand. By contrast, such a conflict may cause hostility, emotionality and distraction from actual task accomplishment.   This study reviews findings on the relationships between intragroup conflict and team outcomes, discusses potential conflict resolution strategies for intragroup conflicts and explores how these link to the field of medical education.   Three primary types of conflict have been distinguished, involving, respectively, task-, process- and relationship-associated conflict. Both process conflict, or conflict about the logistics of task accomplishment, and relationship conflict, or conflict about interpersonal incompatibilities, have been shown to detract from effective team functioning. Task conflict, or conflict about the content of the task itself, is also generally negative for team functioning, but under certain conditions its negative effects may be minimised. For example, when teams can clearly separate task issues from relationship issues, task conflicts are less destructive for team outcomes. However, achieving such a separation in practice, and thereby realising the benefits of task conflict, is quite difficult to achieve.   Intragroup conflicts pose a challenge to effective team functioning. In the education of medical professionals, effective training in conflict management skills and their application to specific team conflict dynamics, such as with reference to how to resolve task as opposed to relationship conflict, is critical. © Blackwell Publishing Ltd 2012.

An FMRI study of self-regulatory control and conflict resolution in adolescents with bulimia nervosa.

PubMed

Marsh, Rachel; Horga, Guillermo; Wang, Zhishun; Wang, Pengwei; Klahr, Kristin W; Berner, Laura A; Walsh, B Timothy; Peterson, Bradley S

2011-11-01

The authors examined functional activity in the frontostriatal systems that mediate self-regulatory capacities and conflict resolution in adolescents with bulimia nervosa. Functional magnetic resonance imaging was used to compare blood-oxygen-level-dependent response in 18 female adolescents with bulimia nervosa and 18 healthy female age-matched subjects during performance on a Simon spatial incompatibility task. Bayesian analyses were used to compare the two groups on patterns of brain activation during correct responses to conflict stimuli and to explore the effects of antecedent stimulus context on group differences in self-regulation and conflict resolution. Adolescents with and without bulimia nervosa performed similarly on the task. During correct responses in conflict trials, frontostriatal circuits-including the right inferolateral and dorsolateral prefrontal cortices and putamen-failed to activate to the same degree in adolescents with bulimia nervosa as in healthy comparison subjects. Instead, deactivation was seen in the left inferior frontal gyrus as well as a neural system encompassing the posterior cingulate cortex and superior frontal gyrus. Group differences in cortical and striatal regions were driven by the differential responses to stimuli preceded by conflict and nonconflict stimuli, respectively. When engaging the self-regulatory control processes necessary to resolve conflict, adolescents with bulimia nervosa displayed abnormal patterns of activation in frontostriatal and default-mode systems. Their abnormal processing of the antecedent stimulus context conditioned their brain response to conflict differently from that of healthy comparison subjects, specifically in frontal regions. It is suspected that functional disturbances in frontal portions of frontostriatal systems may release feeding behaviors from regulatory control, thereby perpetuating the conflicting desires to consume fattening foods and avoid weight gain that characterize bulimia nervosa.

An fMRI Study of Self-Regulatory Control and Conflict Resolution in Adolescents With Bulimia Nervosa

PubMed Central

Marsh, Rachel; Horga, Guillermo; Wang, Zhishun; Wang, Pengwei; Klahr, Kristin W.; Berner, Laura A.; Walsh, B. Timothy; Peterson, Bradley S.

2012-01-01

Objective The authors examined functional activity in the frontostriatal systems that mediate self-regulatory capacities and conflict resolution in adolescents with bulimia nervosa. Method Functional magnetic resonance imaging was used to compare blood-oxygen-level-dependent response in 18 female adolescents with bulimia nervosa and 18 healthy female age-matched subjects during performance on a Simon spatial incompatibility task. Bayesian analyses were used to compare the two groups on patterns of brain activation during correct responses to conflict stimuli and to explore the effects of antecedent stimulus context on group differences in self-regulation and conflict resolution. Results Adolescents with and without bulimia nervosa performed similarly on the task. During correct responses in conflict trials, frontostriatal circuits—including the right inferolateral and dorsolateral prefrontal cortices and putamen—failed to activate to the same degree in adolescents with bulimia nervosa as in healthy comparison subjects. Instead, deactivation was seen in the left inferior frontal gyrus as well as a neural system encompassing the posterior cingulate cortex and superior frontal gyrus. Group differences in cortical and striatal regions were driven by the differential responses to stimuli preceded by conflict and nonconflict stimuli, respectively. Conclusions When engaging the self-regulatory control processes necessary to resolve conflict, adolescents with bulimia nervosa displayed abnormal patterns of activation in frontostriatal and default-mode systems. Their abnormal processing of the antecedent stimulus context conditioned their brain response to conflict differently from that of healthy comparison subjects, specifically in frontal regions. It is suspected that functional disturbances in frontal portions of frontostriatal systems may release feeding behaviors from regulatory control, thereby perpetuating the conflicting desires to consume fattening foods and avoid weight gain that characterize bulimia nervosa. PMID:21676991

Linking Theoretical Decision-making Mechanisms in the Simon Task with Electrophysiological Data: A Model-based Neuroscience Study in Humans.

PubMed

Servant, Mathieu; White, Corey; Montagnini, Anna; Burle, Borís

2016-10-01

A current challenge for decision-making research is in extending models of simple decisions to more complex and ecological choice situations. Conflict tasks (e.g., Simon, Stroop, Eriksen flanker) have been the focus of much interest, because they provide a decision-making context representative of everyday life experiences. Modeling efforts have led to an elaborated drift diffusion model for conflict tasks (DMC), which implements a superimposition of automatic and controlled decision activations. The DMC has proven to capture the diversity of behavioral conflict effects across various task contexts. This study combined DMC predictions with EEG and EMG measurements to test a set of linking propositions that specify the relationship between theoretical decision-making mechanisms involved in the Simon task and brain activity. Our results are consistent with a representation of the superimposed decision variable in the primary motor cortices. The decision variable was also observed in the EMG activity of response agonist muscles. These findings provide new insight into the neurophysiology of human decision-making. In return, they provide support for the DMC model framework.

UpSet: Visualization of Intersecting Sets

PubMed Central

Lex, Alexander; Gehlenborg, Nils; Strobelt, Hendrik; Vuillemot, Romain; Pfister, Hanspeter

2016-01-01

Understanding relationships between sets is an important analysis task that has received widespread attention in the visualization community. The major challenge in this context is the combinatorial explosion of the number of set intersections if the number of sets exceeds a trivial threshold. In this paper we introduce UpSet, a novel visualization technique for the quantitative analysis of sets, their intersections, and aggregates of intersections. UpSet is focused on creating task-driven aggregates, communicating the size and properties of aggregates and intersections, and a duality between the visualization of the elements in a dataset and their set membership. UpSet visualizes set intersections in a matrix layout and introduces aggregates based on groupings and queries. The matrix layout enables the effective representation of associated data, such as the number of elements in the aggregates and intersections, as well as additional summary statistics derived from subset or element attributes. Sorting according to various measures enables a task-driven analysis of relevant intersections and aggregates. The elements represented in the sets and their associated attributes are visualized in a separate view. Queries based on containment in specific intersections, aggregates or driven by attribute filters are propagated between both views. We also introduce several advanced visual encodings and interaction methods to overcome the problems of varying scales and to address scalability. UpSet is web-based and open source. We demonstrate its general utility in multiple use cases from various domains. PMID:26356912

Cue-type manipulation dissociates two types of task set inhibition: backward inhibition and competitor rule suppression.

PubMed

Regev, Shirley; Meiran, Nachshon

2016-07-01

Backward inhibition (BI) reflects the suppression of a recently abandoned task set to allow for smooth transition to a new task even when the rules do not generate a response conflict. Competitor rule suppression (CRS) reflects the inhibition/suppression of irrelevant task rules when these rules generate a response conflict even if they have not recently been abandoned. We assessed whether BI and CRS are differentially affected by the difficulty in retrieving category-response mappings from memory. Retrieval demands were manipulated via the information provided by the task cues, which either indicated the relevant dimension (dimension cues; "color") or the relevant dimension with its category-to-key mapping (mapping cues; "red green", indicating that "red" and "green" go with the left/right responses, respectively). CRS was larger with dimension compared to mapping cues when cue-type varied between groups and was larger after trials involving dimension cues when cue-type varied on a trial-by-trial basis. In contrast, BI was not influenced by cue-type. These results suggest that task switching involve at least two distinct inhibitory processes, with CRS being related to the ease of retrieval of category-response mappings from memory.

Development, social norms, and assignment to task

PubMed Central

Fafchamps, Marcel

2011-01-01

Economic development involves a structural transformation in the way people are allocated to tasks. There is a shift from self-provision to market exchange, facilitating specialization. There is also a shift from self-employment to wage employment in large firms and organizations, driven by innovation and increasing returns to scale. Changes in allocation mechanisms require changes in norms and attitudes. Because different labor assignment domains coexist, conflicts arise among norms that apply to different domains, possibly resulting in dysfunctional outcomes. I argue that religion, humanism, and schools have all played an important historical role in fostering the changes in social norms and attitudes that are needed to accompany structural changes in the way economies allocate workers to tasks. PMID:22198757

Combining environment-driven adaptation and task-driven optimisation in evolutionary robotics.

PubMed

Haasdijk, Evert; Bredeche, Nicolas; Eiben, A E

2014-01-01

Embodied evolutionary robotics is a sub-field of evolutionary robotics that employs evolutionary algorithms on the robotic hardware itself, during the operational period, i.e., in an on-line fashion. This enables robotic systems that continuously adapt, and are therefore capable of (re-)adjusting themselves to previously unknown or dynamically changing conditions autonomously, without human oversight. This paper addresses one of the major challenges that such systems face, viz. that the robots must satisfy two sets of requirements. Firstly, they must continue to operate reliably in their environment (viability), and secondly they must competently perform user-specified tasks (usefulness). The solution we propose exploits the fact that evolutionary methods have two basic selection mechanisms-survivor selection and parent selection. This allows evolution to tackle the two sets of requirements separately: survivor selection is driven by the environment and parent selection is based on task-performance. This idea is elaborated in the Multi-Objective aNd open-Ended Evolution (monee) framework, which we experimentally validate. Experiments with robotic swarms of 100 simulated e-pucks show that monee does indeed promote task-driven behaviour without compromising environmental adaptation. We also investigate an extension of the parent selection process with a 'market mechanism' that can ensure equitable distribution of effort over multiple tasks, a particularly pressing issue if the environment promotes specialisation in single tasks.

Effects of shields on cables

NASA Technical Reports Server (NTRS)

1977-01-01

Aircraft wiring subjected to rapidly changing electromagnetic fields was considered. The ways in which shielded cables reduce surge voltages were studied along with the ways in which common practice regarding the use of shields may be at variance with the use required for the control of lightning effects. Courses in which this apparent conflict of use may be resolved were suggested. Noise currents flowing on shields of cables related to the noise signals coupled onto signal conductors were also investigated.

An integrated utility-based model of conflict evaluation and resolution in the Stroop task.

PubMed

Chuderski, Adam; Smolen, Tomasz

2016-04-01

Cognitive control allows humans to direct and coordinate their thoughts and actions in a flexible way, in order to reach internal goals regardless of interference and distraction. The hallmark test used to examine cognitive control is the Stroop task, which elicits both the weakly learned but goal-relevant and the strongly learned but goal-irrelevant response tendencies, and requires people to follow the former while ignoring the latter. After reviewing the existing computational models of cognitive control in the Stroop task, its novel, integrated utility-based model is proposed. The model uses 3 crucial control mechanisms: response utility reinforcement learning, utility-based conflict evaluation using the Festinger formula for assessing the conflict level, and top-down adaptation of response utility in service of conflict resolution. Their complex, dynamic interaction led to replication of 18 experimental effects, being the largest data set explained to date by 1 Stroop model. The simulations cover the basic congruency effects (including the response latency distributions), performance dynamics and adaptation (including EEG indices of conflict), as well as the effects resulting from manipulations applied to stimulation and responding, which are yielded by the extant Stroop literature. (c) 2016 APA, all rights reserved).

Relationship and task conflict at work: interactive short-term effects on angry mood and somatic complaints.

PubMed

Meier, Laurenz L; Gross, Sven; Spector, Paul E; Semmer, Norbert K

2013-04-01

Our research examined short-term within-person effects of relationship and task conflict on angry mood and somatic complaints. We assumed that conflicts of both kinds would be prospectively related to both indicators of impaired well-being, that the effect of relationship conflict would be stronger than the effect of task conflict, and that the effect of relationship conflict would be stronger when task conflict is low than when it is high. We tested our hypotheses with a daily diary study with ratings made 3 times/day for 2 weeks, involving 131 participants. We found a prospective main effect of relationship conflict on angry mood, but not on somatic complaints. In contrast, controlling for relationship conflict, task conflict was unrelated to both angry mood and somatic complaints. Supporting our assumption, task conflict moderated the effect of relationship conflict. Relationship conflict had a prospective effect on angry mood and somatic complaints that lasted until the next day if, and only if, task conflict was low.

Context Specificity of Post-Error and Post-Conflict Cognitive Control Adjustments

PubMed Central

Forster, Sarah E.; Cho, Raymond Y.

2014-01-01

There has been accumulating evidence that cognitive control can be adaptively regulated by monitoring for processing conflict as an index of online control demands. However, it is not yet known whether top-down control mechanisms respond to processing conflict in a manner specific to the operative task context or confer a more generalized benefit. While previous studies have examined the taskset-specificity of conflict adaptation effects, yielding inconsistent results, control-related performance adjustments following errors have been largely overlooked. This gap in the literature underscores recent debate as to whether post-error performance represents a strategic, control-mediated mechanism or a nonstrategic consequence of attentional orienting. In the present study, evidence of generalized control following both high conflict correct trials and errors was explored in a task-switching paradigm. Conflict adaptation effects were not found to generalize across tasksets, despite a shared response set. In contrast, post-error slowing effects were found to extend to the inactive taskset and were predictive of enhanced post-error accuracy. In addition, post-error performance adjustments were found to persist for several trials and across multiple task switches, a finding inconsistent with attentional orienting accounts of post-error slowing. These findings indicate that error-related control adjustments confer a generalized performance benefit and suggest dissociable mechanisms of post-conflict and post-error control. PMID:24603900

Task inhibition, conflict, and the n-2 repetition cost: A combined computational and empirical approach.

PubMed

Sexton, Nicholas J; Cooper, Richard P

2017-05-01

Task inhibition (also known as backward inhibition) is an hypothesised form of cognitive inhibition evident in multi-task situations, with the role of facilitating switching between multiple, competing tasks. This article presents a novel cognitive computational model of a backward inhibition mechanism. By combining aspects of previous cognitive models in task switching and conflict monitoring, the model instantiates the theoretical proposal that backward inhibition is the direct result of conflict between multiple task representations. In a first simulation, we demonstrate that the model produces two effects widely observed in the empirical literature, specifically, reaction time costs for both (n-1) task switches and n-2 task repeats. Through a systematic search of parameter space, we demonstrate that these effects are a general property of the model's theoretical content, and not specific parameter settings. We further demonstrate that the model captures previously reported empirical effects of inter-trial interval on n-2 switch costs. A final simulation extends the paradigm of switching between tasks of asymmetric difficulty to three tasks, and generates novel predictions for n-2 repetition costs. Specifically, the model predicts that n-2 repetition costs associated with hard-easy-hard alternations are greater than for easy-hard-easy alternations. Finally, we report two behavioural experiments testing this hypothesis, with results consistent with the model predictions. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

The effects of a sportsmanship curriculum intervention on generalized positive social behavior of urban elementary school students

PubMed Central

Sharpe, Tom; Brown, Marty; Crider, Kim

1995-01-01

This study evaluated the effects of an elementary physical education curriculum in which development of positive social skills, including leadership and conflict-resolution behaviors, was the primary focus. A second goal was to determine possible generalization effects beyond the primary intervention setting. Students in two urban elementary physical education classes served as subjects, with a third class used as a comparison. The effects of the curriculum intervention were evaluated in the training setting and in the students' regular education classrooms using a multiple baseline across classrooms design. Results showed (a) an immediate increase in student leadership and independent conflict-resolution behaviors, (b) an increase in percentage of class time devoted to activity participation, and (c) decreases in the frequency of student off-task behavior and percentage of class time that students devoted to organizational tasks. Similar changes in student behavior were also observed in the regular classroom settings. PMID:16795872

Cognitive and brain consequences of conflict.

PubMed

Fan, Jin; Flombaum, Jonathan I; McCandliss, Bruce D; Thomas, Kathleen M; Posner, Michael I

2003-01-01

Tasks involving conflict between stimulus dimensions have been shown to activate dorsal anterior cingulate and prefrontal areas. It has been proposed that the dorsal anterior cingulate is involved a domain general process of monitoring conflict, while prefrontal areas are involved in resolving conflict. We examine three tasks that all require people to respond based on one stimulus dimension while ignoring another conflicting dimension, but which vary in the source of conflict. One of the tasks uses language stimuli (Stroop effect) and two use nonlanguage spatial conflicts appropriate for children and nonhuman animals. In Experiment 1, 12 participants were studied with event-related functional magnetic resonance imaging (fMRI) while performing each of the three tasks. Reaction times for each of the three tasks were significantly longer in the incongruent condition compared with the congruent condition, demonstrating that each task elicits a conflict. By studying the same people in the same session, we test the hypothesis that conflict activates a similar brain network in the three tasks. Significant activations were found in the anterior cingulate and left prefrontal cortex for all three conflict tasks. Within these regions, the conflict component demonstrated evidence for significant common activation across the three tasks, although the peak activation point and spatial extent were not identical. Other areas demonstrated activation unique to each task. Experiments 2-4 provide behavioral evidence indicating considerable independence between conflict operations involved in the tasks. The behavioral and fMRI results taken together seem to argue against a single unified network for processing conflict, but instead support either distinct networks for each conflict task or a single network that monitors conflict with different sites used to resolve the conflict.

Formalized Conflicts Detection Based on the Analysis of Multiple Emails: An Approach Combining Statistics and Ontologies

NASA Astrophysics Data System (ADS)

Zakaria, Chahnez; Curé, Olivier; Salzano, Gabriella; Smaïli, Kamel

In Computer Supported Cooperative Work (CSCW), it is crucial for project leaders to detect conflicting situations as early as possible. Generally, this task is performed manually by studying a set of documents exchanged between team members. In this paper, we propose a full-fledged automatic solution that identifies documents, subjects and actors involved in relational conflicts. Our approach detects conflicts in emails, probably the most popular type of documents in CSCW, but the methods used can handle other text-based documents. These methods rely on the combination of statistical and ontological operations. The proposed solution is decomposed in several steps: (i) we enrich a simple negative emotion ontology with terms occuring in the corpus of emails, (ii) we categorize each conflicting email according to the concepts of this ontology and (iii) we identify emails, subjects and team members involved in conflicting emails using possibilistic description logic and a set of proposed measures. Each of these steps are evaluated and validated on concrete examples. Moreover, this approach's framework is generic and can be easily adapted to domains other than conflicts, e.g. security issues, and extended with operations making use of our proposed set of measures.

Achieving reutilization of scheduling software through abstraction and generalization

NASA Technical Reports Server (NTRS)

Wilkinson, George J.; Monteleone, Richard A.; Weinstein, Stuart M.; Mohler, Michael G.; Zoch, David R.; Tong, G. Michael

1995-01-01

Reutilization of software is a difficult goal to achieve particularly in complex environments that require advanced software systems. The Request-Oriented Scheduling Engine (ROSE) was developed to create a reusable scheduling system for the diverse scheduling needs of the National Aeronautics and Space Administration (NASA). ROSE is a data-driven scheduler that accepts inputs such as user activities, available resources, timing contraints, and user-defined events, and then produces a conflict-free schedule. To support reutilization, ROSE is designed to be flexible, extensible, and portable. With these design features, applying ROSE to a new scheduling application does not require changing the core scheduling engine, even if the new application requires significantly larger or smaller data sets, customized scheduling algorithms, or software portability. This paper includes a ROSE scheduling system description emphasizing its general-purpose features, reutilization techniques, and tasks for which ROSE reuse provided a low-risk solution with significant cost savings and reduced software development time.

New shielding material development for compact accelerator-driven neutron source

NASA Astrophysics Data System (ADS)

Hu, Guang; Hu, Huasi; Wang, Sheng; Han, Hetong; Otake, Y.; Pan, Ziheng; Taketani, A.; Ota, H.; Hashiguchi, Takao; Yan, Mingfei

2017-04-01

The Compact Accelerator-driven Neutron Source (CANS), especially the transportable neutron source is longing for high effectiveness shielding material. For this reason, new shielding material is researched in this investigation. The component of shielding material is designed and many samples are manufactured. Then the attenuation detection experiments were carried out. In the detections, the dead time of the detector appeases when the proton beam is too strong. To grasp the linear range and nonlinear range of the detector, two currents of proton are employed in Pb attenuation detections. The transmission ratio of new shielding material, polyethylene (PE), PE + Pb, BPE + Pb is detected under suitable current of proton. Since the results of experimental neutrons and γ-rays appear as together, the MCNP and PHITS simulations are applied to assisting the analysis. The new shielding material could reduce of the weight and volume compared with BPE + Pb and PE + Pb.

On the role of conflict and control in social cognition: event-related brain potential investigations.

PubMed

Bartholow, Bruce D

2010-03-01

Numerous social-cognitive models posit that social behavior largely is driven by links between constructs in long-term memory that automatically become activated when relevant stimuli are encountered. Various response biases have been understood in terms of the influence of such "implicit" processes on behavior. This article reviews event-related potential (ERP) studies investigating the role played by cognitive control and conflict resolution processes in social-cognitive phenomena typically deemed automatic. Neurocognitive responses associated with response activation and conflict often are sensitive to the same stimulus manipulations that produce differential behavioral responses on social-cognitive tasks and that often are attributed to the role of automatic associations. Findings are discussed in the context of an overarching social cognitive neuroscience model in which physiological data are used to constrain social-cognitive theories.

Rethinking intractable conflict: the perspective of dynamical systems.

PubMed

Vallacher, Robin R; Coleman, Peter T; Nowak, Andrzej; Bui-Wrzosinska, Lan

2010-01-01

Intractable conflicts are demoralizing. Beyond destabilizing the families, communities, or international regions in which they occur, they tend to perpetuate the very conditions of misery and hate that contributed to them in the first place. Although the common factors and processes associated with intractable conflicts have been identified through research, they represent an embarrassment of riches for theory construction. Thus, the current task in this area is integrating these diverse factors into an account that provides a coherent perspective yet allows for prediction and a basis for conflict resolution in specific conflict settings. We suggest that the perspective of dynamical systems provides such an account. This article outlines the key concepts and hypotheses associated with this approach. It is organized around a set of basic questions concerning intractable conflict for which the dynamical perspective offers fresh insight and testable propositions. The questions and answers are intended to provide readers with basic concepts and principles of complexity and dynamical systems that are useful for rethinking the nature of intractable conflict and the means by which such conflict can be transformed. Copyright 2010 APA, all rights reserved.

Task versus relationship conflict, team performance, and team member satisfaction: a meta-analysis.

PubMed

De Dreu, Carsten K W; Weingart, Laurie R

2003-08-01

This study provides a meta-analysis of research on the associations between relationship conflict, task conflict, team performance, and team member satisfaction. Consistent with past theorizing, results revealed strong and negative correlations between relationship conflict, team performance, and team member satisfaction. In contrast to what has been suggested in both academic research and introductory textbooks, however, results also revealed strong and negative (instead of the predicted positive) correlations between task conflict team performance, and team member satisfaction. As predicted, conflict had stronger negative relations with team performance in highly complex (decision making, project, mixed) than in less complex (production) tasks. Finally, task conflict was less negatively related to team performance when task conflict and relationship conflict were weakly, rather than strongly, correlated.

Evidence for interaction between the stop signal and the Stroop task conflict.

PubMed

Kalanthroff, Eyal; Goldfarb, Liat; Henik, Avishai

2013-04-01

Performance of the Stroop task reflects two conflicts--informational (between the incongruent word and ink color) and task (between relevant color naming and irrelevant word reading). The task conflict is usually not visible, and is only seen when task control is damaged. Using the stop-signal paradigm, a few studies demonstrated longer stop-signal reaction times for incongruent trials than for congruent trials. This indicates interaction between stopping and the informational conflict. Here we suggest that "zooming in" on task-control failure trials will reveal another interaction--between stopping and task conflict. To examine this suggestion, we combined stop-signal and Stroop tasks in the same experiment. When participants' control failed and erroneous responses to a stop signal occurred, a reverse facilitation emerged in the Stroop task (Experiment 1) and this was eliminated using methods that manipulated the emergence of the reverse facilitation (Experiment 2). Results from both experiments were replicated when all stimuli were used in the same task (Experiment 3). In erroneous response trials, only the task conflict increased, not the informational conflict. These results indicate that task conflict and stop-signal inhibition share a common control mechanism that is dissociable from the control mechanism activated by the informational conflict.

Skewed task conflicts in teams: What happens when a few members see more conflict than the rest?

PubMed

Sinha, Ruchi; Janardhanan, Niranjan S; Greer, Lindred L; Conlon, Donald E; Edwards, Jeffery R

2016-07-01

Task conflict has been the subject of a long-standing debate in the literature-when does task conflict help or hurt team performance? We propose that this debate can be resolved by taking a more precise view of how task conflicts are perceived in teams. Specifically, we propose that in teams, when a few team members perceive a high level of task disagreement while a majority of others perceive low levels of task disagreement-that is, there is positively skewed task conflict, task conflict is most likely to live up to its purported benefits for team performance. In our first study of student teams engaged in a business decision game, we find support for the positive relationship between skewed task conflict and team performance. In our second field study of teams in a financial corporation, we find that the relationship between positively skewed task conflict and supervisor ratings of team performance is mediated by reflective communication within the team. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Using neural pattern classifiers to quantify the modularity of conflict-control mechanisms in the human brain.

PubMed

Jiang, Jiefeng; Egner, Tobias

2014-07-01

Resolving conflicting sensory and motor representations is a core function of cognitive control, but it remains uncertain to what degree control over different sources of conflict is implemented by shared (domain general) or distinct (domain specific) neural resources. Behavioral data suggest conflict-control to be domain specific, but results from neuroimaging studies have been ambivalent. Here, we employed multivoxel pattern analyses that can decode a brain region's informational content, allowing us to distinguish incidental activation overlap from actual shared information processing. We trained independent sets of "searchlight" classifiers on functional magnetic resonance imaging data to decode control processes associated with stimulus-conflict (Stroop task) and ideomotor-conflict (Simon task). Quantifying the proportion of domain-specific searchlights (capable of decoding only one type of conflict) and domain-general searchlights (capable of decoding both conflict types) in each subject, we found both domain-specific and domain-general searchlights, though the former were more common. When mapping anatomical loci of these searchlights across subjects, neural substrates of stimulus- and ideomotor-specific conflict-control were found to be anatomically consistent across subjects, whereas the substrates of domain-general conflict-control were not. Overall, these findings suggest a hybrid neural architecture of conflict-control that entails both modular (domain specific) and global (domain general) components. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Stop interfering: Stroop task conflict independence from informational conflict and interference.

PubMed

Kalanthroff, Eyal; Goldfarb, Liat; Usher, Marius; Henik, Avishai

2013-01-01

Performance of the Stroop task reflects two conflicts-informational (between the incongruent word and ink colour) and task (between relevant colour naming and irrelevant word reading). This is supported by findings showing that the anterior cingulate cortex is more activated by congruent and incongruent stimuli than by nonword neutral stimuli. Previously, researchers demonstrated behavioural evidence for task conflict-a reverse facilitation effect under a reduced task conflict control condition. The boundary conditions of this Stroop reverse facilitation effect are not yet clear. The current study aimed to investigate whether task conflict arises, and task control is needed, whenever there are two possible tasks, even if the irrelevant task cannot mislead one to give erroneous responses (i.e., stimuli do not contain an informational conflict). To this end, in both experiments no incongruent stimuli were presented. In Experiment 1, participants conducted a Stroop task with a high proportion of nonword neutrals and with a neutral/congruent cue in 50% of the trials. In Experiment 2, the nonword neutral was replaced by a real non-colour-word. We found the reverse facilitation effect in the noncued trials of Experiment 1. Moreover, as expected, this effect was eliminated when a noncolour neutral word that induced task conflict was used (Experiment 2). We conclude that task conflict control is reactively activated whenever there are at least two possible tasks, even in the absence of any possibility of informational conflict.

Grin and Bear It?: Employees' Use of Surface Acting During Co-worker Conflict.

PubMed

Nixon, Ashley E; Bruk-Lee, Valentina; Spector, Paul E

2017-04-01

Using survey data from 459 employed individuals, the conditional indirect effects of three types of interpersonal conflict at work on strains and performance through surface acting were tested. Results indicated that task, relationship and non-task organizational conflict were positively related to depressive and physical symptoms and negatively related to performance. Task conflict had a significantly weaker association with employee outcomes than either relationship or non-task organizational conflict. Surface acting negatively related to all types of conflict, although it had a weaker association with relationship conflict than task or non-task organizational conflict. Support was found for moderated mediation relationships whereby surface acting mediated the associations between all types of conflict with depressive symptoms, as well as the association between relationship and non-task organizational conflict with physical symptoms, when conflict was infrequent. Surface acting also mediated the associations between all types of conflict and performance when conflict was frequent. Future research directions are discussed that can advance our theoretical understanding of how emotional labour and interpersonal conflict interact to affect employees, as well as further our ability to improve employee well-being and organizational functioning. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Using Shared Models of Activity for Coalition Task-Driven Cooperation

DTIC Science & Technology

2003-08-01

of Binni Region of the Red Sea A conflict has developed between two countries in the area. To the north is Gao , which has expansionist...and fundamentalist country. Gao has managed to annex an area of land, called it Binni, and has put in its own puppet...5 See http://www.aiai.ed.ac.uk/project/coax/ 16 government. This action has come under fierce attack from Agadez. Gao has

Two-to-one color-response mapping and the presence of semantic conflict in the Stroop task.

PubMed

Hasshim, Nabil; Parris, Benjamin A

2014-01-01

A series of recent studies have utilized the two-to-one mapping paradigm in the Stroop task. In this paradigm, the word red might be presented in blue when both red and blue share the same-response key (same-response trials). This manipulation has been used to show the separate contributions of (within) semantic category conflict and response conflict to Stroop interference. Such results evidencing semantic category conflict are incompatible with models of the Stroop task that are based on response conflict only. However, the nature of same-response trials is unclear since they are also likely to involve response facilitation given that both dimensions of the stimulus provide evidence toward the same-response. In this study we explored this possibility by comparing them with three other trial types. We report strong (Bayesian) evidence for no statistical difference between same-response and non-color word neutral trials, faster responses to same-response trials than to non-response set incongruent trials, and no differences between same-response vs. congruent trials when contingency is controlled. Our results suggest that same-response trials are not different from neutral trials indicating that they cannot be used reliably to determine the presence or absence of semantic category conflict. In light of these results, the interpretation of a series of recent studies might have to be reassessed.

Control processes through the suppression of the automatic response activation triggered by task-irrelevant information in the Simon-type tasks.

PubMed

Kim, Sanga; Lee, Sang Ho; Cho, Yang Seok

2015-11-01

The congruency sequence effect, one of the indices of cognitive control, refers to a smaller congruency effect after an incongruent than congruent trial. Although the effect has been found across a variety of conflict tasks, there is not yet agreement on the underlying mechanism. The present study investigated the mechanism underlying cognitive control by using a cross-task paradigm. In Experiments 1, 2, and 3, participants performed a modified Simon task and a spatial Stroop task alternately in a trial-by-trial manner. The task-irrelevant dimension of the two tasks was perceptually and conceptually identical in Experiment 1, whereas it was perceptually different but conceptually identical in Experiment 2. The response sets for both tasks were different in Experiment 3. In Experiment 4, participants performed two Simon tasks with different task-relevant dimensions. In all experiments in which the task-irrelevant dimension and response mode were shared, significant congruency sequence effects were found between the two different congruencies, indicating that Simon-type conflicts were resolved by a control mechanism, which is specific to an abstract task-irrelevant stimulus spatial dimension. Copyright © 2015 Elsevier B.V. All rights reserved.

Demonstrating the Viability and Affordability of Nuclear Surface Power Systems

NASA Technical Reports Server (NTRS)

Vandyke, Melissa K.

2006-01-01

A set of tasks have been identified to help demonstrate the viability, performance, and affordability of surface fission systems. Completion of these tasks will move surface fission systems closer to reality by demonstrating affordability and performance potential. Tasks include fabrication and test of a 19-pin section of a Surface Power Unit Demonstrator (SPUD); design, fabrication, and utilization of thermal simulators optimized for surface fission' applications; design, fabrication, and utilization of GPHS module thermal simulators; design, fabrication, and test of a fission surface power system shield; and work related to potential fission surface power fuel/clad systems. Work on the SPUD will feed directly into joint NASA MSFC/NASA GRC fabrication and test of a surface power plant Engineering Development Unit (EDU). The goal of the EDU will be to perform highly realistic thermal, structural, and electrical testing on an integrated fission surface power system. Fission thermal simulator work will help enable high fidelity non-nuclear testing of pumped NaK surface fission power systems. Radioisotope thermal simulator work will help enable design and development of higher power radioisotope systems (power ultimately limited by Pu-238 availability). Shield work is designed to assess the potential of using a water neutron shield on the surface of the moon. Fuels work is geared toward assessing the current potential of using fuels that have already flown in space.

Contingency learning is not affected by conflict experience: Evidence from a task conflict-free, item-specific Stroop paradigm.

PubMed

Levin, Yulia; Tzelgov, Joseph

2016-02-01

A contingency learning account of the item-specific proportion congruent effect has been described as an associative stimulus-response learning process that has nothing to do with controlling the Stroop conflict. As supportive evidence, contingency learning has been demonstrated with response conflict-free stimuli, such as neutral words. However, what gives rise to response conflict and to Stroop interference in general is task conflict. The present study investigated whether task conflict can constitute a trigger or, alternatively, a booster to the contingency learning process. This was done by employing a "task conflict-free" condition (i.e., geometric shapes) and comparing it with a "task conflict" condition (i.e., neutral words). The results showed a significant contingency learning effect in both conditions, refuting the possibility that contingency learning is triggered by the presence of a task conflict. Contingency learning was also not enhanced by the task conflict experience, indicating its complete insensitivity to Stroop conflict(s). Thus, the results showed no evidence that performance optimization as a result of contingency learning is greater under conflict, implying that contingency learning is not recruited to assist the control system to overcome conflict. Copyright © 2015 Elsevier B.V. All rights reserved.

Toward Developing Laboratory-Based Parent-Adolescent Conflict Discussion Tasks that Consistently Elicit Adolescent Conflict-Related Stress Responses: Support from Physiology and Observed Behavior.

PubMed

Thomas, Sarah A; Wilson, Tristan; Jain, Anjali; Deros, Danielle E; Um, Miji; Hurwitz, Joanna; Jacobs, Irene; Myerberg, Lindsay; Ehrlich, Katherine B; Dunn, Emily J; Aldao, Amelia; Stadnik, Ryan; De Los Reyes, Andres

2017-12-01

Parent-adolescent conflict poses risk for youth maladjustment. One potential mechanism of this risk is that stress in the form of increased arousal during conflict interactions results in adolescents' impaired decision-making. However, eliciting consistent adolescent stress responses within laboratory-based tasks of parent-adolescent conflict (i.e., conflict discussion tasks) is hindered by task design. This limitation may stem from how conflict topics are assessed and selected for discussion. Within a sample of 47 adolescents (ages 14-17) and parents, we investigated whether a modified version of a conflict discussion task could elicit physiological (i.e., arousal) and behavioral (i.e., hostility) displays of adolescents' conflict-related stress responses. We assessed parent-adolescent conflict via structured interview to identify topics for dyads to discuss during the task. We randomly assigned dyads to complete a 5-minute task to discuss either a putatively benign topic (i.e., control condition) or a conflict topic while undergoing direct assessments of continuous arousal. Trained raters coded dyad members' hostile behavior during the task. Adolescents in the conflict condition exhibited significantly greater levels of arousal than adolescents in the control condition. We observed an interaction between discussion condition and baseline conflict. Specifically, higher baseline conflict predicted greater hostile behavior for adolescents in the conflict condition, yet we observed the inverse relation for adolescents in the control condition. Our modified laboratory discussion task successfully elicited both physiological and behavioral displays of adolescent conflict-related stress. These findings have important implications for leveraging experimental paradigms to understand causal links between parent-adolescent conflict and adolescent psychopathology, and their underlying mechanisms.

Can conflict be energizing? a study of task conflict, positive emotions, and job satisfaction.

PubMed

Todorova, Gergana; Bear, Julia B; Weingart, Laurie R

2014-05-01

Scholars have assumed that the presence of negative emotions during task conflict implies the absence of positive emotions. However, emotions researchers have shown that positive and negative emotions are not 2 ends of a bipolar continuum; rather, they represent 2 separate, orthogonal dimensions. Drawing on affective events theory, we develop and test hypotheses about the effects of task conflict on positive emotions and job satisfaction. To this end, we distinguish among the frequency, intensity, and information gained from task conflict. Using field data from 232 employees in a long-term health care organization, we find that more frequent mild task conflict expression engenders more information acquisition, but more frequent intense task conflict expression hinders it. Because of the information gains from mild task conflict expression, employees feel more active, energized, interested, and excited, and these positive active emotions increase job satisfaction. The information gained during task conflict, however, is not always energizing: It depends on the extent to which the behavioral context involves active learning and whether the conflict is cross-functional. We discuss theoretical implications for conflict, emotions, and job satisfaction in organizations. (c) 2014 APA, all rights reserved.

Factors Responsible for Performance on the Day-Night Task: Response Set or Semantics?

ERIC Educational Resources Information Center

Simpson, Andrew; Riggs, Kevin J.

2005-01-01

In a recent study Diamond, Kirkham and Amso (2002) obtained evidence consistent with the claim that the day-night task requires inhibition because the picture and its corresponding conflicting response are semantically related. In their study children responded more accurately in a dog-pig condition (see /day picture/ say "dog"; see /night…

Multiple Language Use Influences Oculomotor Task Performance: Neurophysiological Evidence of a Shared Substrate between Language and Motor Control

PubMed Central

Heidlmayr, Karin; Doré-Mazars, Karine; Aparicio, Xavier; Isel, Frédéric

2016-01-01

In the present electroencephalographical study, we asked to which extent executive control processes are shared by both the language and motor domain. The rationale was to examine whether executive control processes whose efficiency is reinforced by the frequent use of a second language can lead to a benefit in the control of eye movements, i.e. a non-linguistic activity. For this purpose, we administrated to 19 highly proficient late French-German bilingual participants and to a control group of 20 French monolingual participants an antisaccade task, i.e. a specific motor task involving control. In this task, an automatic saccade has to be suppressed while a voluntary eye movement in the opposite direction has to be carried out. Here, our main hypothesis is that an advantage in the antisaccade task should be observed in the bilinguals if some properties of the control processes are shared between linguistic and motor domains. ERP data revealed clear differences between bilinguals and monolinguals. Critically, we showed an increased N2 effect size in bilinguals, thought to reflect better efficiency to monitor conflict, combined with reduced effect sizes on markers reflecting inhibitory control, i.e. cue-locked positivity, the target-locked P3 and the saccade-locked presaccadic positivity (PSP). Moreover, effective connectivity analyses (dynamic causal modelling; DCM) on the neuronal source level indicated that bilinguals rely more strongly on ACC-driven control while monolinguals rely on PFC-driven control. Taken together, our combined ERP and effective connectivity findings may reflect a dynamic interplay between strengthened conflict monitoring, associated with subsequently more efficient inhibition in bilinguals. Finally, L2 proficiency and immersion experience constitute relevant factors of the language background that predict efficiency of inhibition. To conclude, the present study provided ERP and effective connectivity evidence for domain-general executive control involvement in handling multiple language use, leading to a control advantage in bilingualism. PMID:27832065

Gamma ray detector shield

DOEpatents

Ohlinger, R.D.; Humphrey, H.W.

1985-08-26

A gamma ray detector shield comprised of a rigid, lead, cylindrical-shaped vessel having upper and lower portions with an pneumatically driven, sliding top assembly. Disposed inside the lead shield is a gamma ray scintillation crystal detector. Access to the gamma detector is through the sliding top assembly.

Ready to rumble: how team personality composition and task conflict interact to improve performance.

PubMed

Bradley, Bret H; Klotz, Anthony C; Postlethwaite, Bennett E; Brown, Kenneth G

2013-03-01

Although prior work has proposed a number of conditions under which task conflict in teams may improve performance, composition variables have been left unexplored. Given the effects of personality traits on team processes and outcomes demonstrated in prior work, investigating whether specific personality compositions influence the effect of task conflict on team performance is critical to researchers' understanding of conflict in teams. Our results indicate that team-level averages of both openness to experience and emotional stability function as moderators of the relationship between task conflict and team performance. Specifically, task conflict had a positive impact on performance in teams with high levels of openness or emotional stability; in contrast, task conflict had a negative impact on performance in teams with low levels of openness or emotional stability. Thus, when task conflict emerges, teams composed of members who are open minded or emotionally stable are best able to leverage conflict to improve performance. Implications for theory and practice are discussed.

Distinguishing Response Conflict and Task Conflict in the Stroop Task: Evidence from Ex-Gaussian Distribution Analysis

ERIC Educational Resources Information Center

Steinhauser, Marco; Hubner, Ronald

2009-01-01

It has been suggested that performance in the Stroop task is influenced by response conflict as well as task conflict. The present study investigated the idea that both conflict types can be isolated by applying ex-Gaussian distribution analysis which decomposes response time into a Gaussian and an exponential component. Two experiments were…

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

ERIC Educational Resources Information Center

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

1999-01-01

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

Stimulus ambiguity elicits response conflict.

PubMed

Szmalec, Arnaud; Verbruggen, Frederick; Vandierendonck, André; De Baene, Wouter; Verguts, Tom; Notebaert, Wim

2008-04-18

Conflict monitoring theory [M.M. Botvinick, T. Braver, D. Barch, C. Carter, J.D. Cohen, Conflict monitoring and cognitive control, Psychol. Rev. 108 (2001) 625-652] assumes that perceptual ambiguity among choice stimuli elicits response conflict in choice reaction. It hence predicts that response conflict is also involved in elementary variants of choice reaction time (RT) tasks, i.e., those variants that, by contrast with the Stroop task or the Go/No-Go task for instance, are rarely associated with cognitive control. In order to test this prediction, an experiment was designed in which participants performed a simple RT task and a regular between-hand 2-choice RT task under three different levels of stimulus ambiguity. The data show that response conflict, as measured by the N2 component of the event-related brain potential (ERP), was elicited in the 2-choice RT task but not in the simple RT task and that the degree of response conflict in the 2-choice RT task was a function of stimulus ambiguity. These results show that response conflict is also present in a regular choice RT task which is traditionally not considered to be a measure of cognitive conflict.

Reaping the benefits of task conflict in teams: the critical role of team psychological safety climate.

PubMed

Bradley, Bret H; Postlethwaite, Bennett E; Klotz, Anthony C; Hamdani, Maria R; Brown, Kenneth G

2012-01-01

Past research suggests that task conflict may improve team performance under certain conditions; however, we know little about these specific conditions. On the basis of prior theory and research on conflict in teams, we argue that a climate of psychological safety is one specific context under which task conflict will improve team performance. Using evidence from 117 project teams, the present research found that psychological safety climate moderates the relationship between task conflict and performance. Specifically, task conflict and team performance were positively associated under conditions of high psychological safety. The results support the conclusion that psychological safety facilitates the performance benefits of task conflict in teams. Theoretical implications and suggestions for future research are discussed.

Evidence for task conflict in the Stroop effect.

PubMed

Goldfarb, Liat; Henik, Avishai

2007-10-01

C. M. MacLeod and P. A. MacDonald (2000) suggested that congruent and incongruent Stroop stimuli cause more task conflict than neutral stimuli because the anterior cingulate cortex is more activated with these stimuli. This study investigated behavioral expression for this pattern. Experiment 1 reduced task conflict control by increasing the proportion of nonword neutrals. Additionally, half the trials had conflict or neutral cues. The control reduction revealed the task conflict. For noncued trials, response time was longer for congruent stimuli than for neutral stimuli (reverse facilitation effect). In addition, response time for congruent stimuli was longer when stimuli were uncued vs. cued. Experiment 2 increased task conflict control by changing the neutral stimuli to noncolor words. Consequently, the task conflict expression disappeared. (c) 2007 APA

Post-conflict slowing after incongruent stimuli: from general to conflict-specific.

PubMed

Rey-Mermet, Alodie; Meier, Beat

2017-05-01

Encountering a cognitive conflict not only slows current performance, but it can also affect subsequent performance, in particular when the conflict is induced with bivalent stimuli (i.e., stimuli with relevant features for two different tasks) or with incongruent trials (i.e., stimuli with relevant features for two response alternatives). The post-conflict slowing following bivalent stimuli, called "bivalency effect", affects all subsequent stimuli, irrespective of whether the subsequent stimuli share relevant features with the conflict stimuli. To date, it is unknown whether the conflict induced by incongruent stimuli results in a similar post-conflict slowing. To investigate this, we performed six experiments in which participants switched between two tasks. In one task, incongruent stimuli appeared occasionally; in the other task, stimuli shared no feature with the incongruent trials. The results showed an initial performance slowing that affected all tasks after incongruent trials. On further trials, however, the slowing only affected the task sharing features with the conflict stimuli. Therefore, the post-conflict slowing following incongruent stimuli is first general and then becomes conflict-specific across trials. These findings are discussed within current task switching and cognitive control accounts.

Feature singletons attract spatial attention independently of feature priming

PubMed Central

Yashar, Amit; White, Alex L.; Fang, Wanghaoming; Carrasco, Marisa

2017-01-01

People perform better in visual search when the target feature repeats across trials (intertrial feature priming [IFP]). Here, we investigated whether repetition of a feature singleton's color modulates stimulus-driven shifts of spatial attention by presenting a probe stimulus immediately after each singleton display. The task alternated every two trials between a probe discrimination task and a singleton search task. We measured both stimulus-driven spatial attention (via the distance between the probe and singleton) and IFP (via repetition of the singleton's color). Color repetition facilitated search performance (IFP effect) when the set size was small. When the probe appeared at the singleton's location, performance was better than at the opposite location (stimulus-driven attention effect). The magnitude of this attention effect increased with the singleton's set size (which increases its saliency) but did not depend on whether the singleton's color repeated across trials, even when the previous singleton had been attended as a search target. Thus, our findings show that repetition of a salient singleton's color affects performance when the singleton is task relevant and voluntarily attended (as in search trials). However, color repetition does not affect performance when the singleton becomes irrelevant to the current task, even though the singleton does capture attention (as in probe trials). Therefore, color repetition per se does not make a singleton more salient for stimulus-driven attention. Rather, we suggest that IFP requires voluntary selection of color singletons in each consecutive trial. PMID:28800369

Feature singletons attract spatial attention independently of feature priming.

PubMed

Yashar, Amit; White, Alex L; Fang, Wanghaoming; Carrasco, Marisa

2017-08-01

People perform better in visual search when the target feature repeats across trials (intertrial feature priming [IFP]). Here, we investigated whether repetition of a feature singleton's color modulates stimulus-driven shifts of spatial attention by presenting a probe stimulus immediately after each singleton display. The task alternated every two trials between a probe discrimination task and a singleton search task. We measured both stimulus-driven spatial attention (via the distance between the probe and singleton) and IFP (via repetition of the singleton's color). Color repetition facilitated search performance (IFP effect) when the set size was small. When the probe appeared at the singleton's location, performance was better than at the opposite location (stimulus-driven attention effect). The magnitude of this attention effect increased with the singleton's set size (which increases its saliency) but did not depend on whether the singleton's color repeated across trials, even when the previous singleton had been attended as a search target. Thus, our findings show that repetition of a salient singleton's color affects performance when the singleton is task relevant and voluntarily attended (as in search trials). However, color repetition does not affect performance when the singleton becomes irrelevant to the current task, even though the singleton does capture attention (as in probe trials). Therefore, color repetition per se does not make a singleton more salient for stimulus-driven attention. Rather, we suggest that IFP requires voluntary selection of color singletons in each consecutive trial.

Conflict Management Strategies in the ICU Differ Between Palliative Care Specialists and Intensivists

PubMed Central

Chiarchiaro, Jared; White, Douglas B.; Ernecoff, Natalie C.; Buddadhumaruk, Praewpannarai; Schuster, Rachel A.; Arnold, Robert M.

2016-01-01

OBJECTIVE Conflict is common between physicians and surrogate decision makers around end-of-life care in intensive care units (ICU). Involving experts in conflict management improve outcomes, but little is known about what differences in conflict management styles may explain the benefit. We used simulation to examine potential differences in how palliative care specialists manage conflict with surrogates about end-of-life treatment decisions in ICUs compared with intensivists. DESIGN Subjects participated in a high-fidelity simulation of conflict with a surrogate in an ICU. In this simulation, a medical actor portrayed a surrogate decision maker during an ICU family meeting who refuses to follow an advance directive that clearly declines advanced life-sustaining therapies. We audio-recorded the simulation encounters and applied a coding framework to quantify conflict management behaviors, which was organized into two categories: task-focused communication and relationship-building. We used negative binomial modeling to determine whether there were differences between palliative care specialists’ and intensivists’ use of task-focused communication and relationship building. SETTING Single academic medical center ICU PARTICIPANTS Palliative care specialists and intensivists INTERVENTIONS none MEASUREMENTS and MAIN RESULTS We enrolled 11 palliative care specialists and 25 intensivists. The palliative care specialists were all attending physicians. The intensivist group consisted of 11 attending physicians, 9 pulmonary and critical care fellows, and 5 internal medicine residents rotating in the intensive care unit. We excluded the 5 residents from the primary analysis in order to reduce confounding due to training level. Physicians’ mean age was 37 years with a mean of 8 years in practice. Palliative care specialists used 55% fewer task-focused communication statements (Incidence Rate Ratio 0.55, 95% CI 0.36–0.83, p= 0.005) and 48% more relationship building statements (Incidence Rate Ratio 1.48, 95% CI 0.89–2.46, p=0.13) compared with intensivists. CONCLUSIONS We found that palliative care specialists engage in less task-focused communication when managing conflict with surrogates compared to intensivists. These differences may help explain the benefit of palliative care involvement in conflict and could be the focus of interventions to improve clinicians’ conflict resolution skills. PMID:26765500

Injury surveillance in construction: eye injuries.

PubMed

Welch, L S; Hunting, K L; Mawudeku, A

2001-07-01

Occupational eye injuries are both common and preventable. About 20% of occupational eye injuries occur in construction. To investigate the nature of eye injuries among construction workers, we analyzed a large data set of construction worker injuries. In addition, we interviewed 62 workers with eye injuries to further explore circumstances of eye injury and workers' attitudes and behavior toward the use of eye protection. Eleven percent (363 cases) of the 3,390 construction workers in our data set were treated for eye injuries. Welders, plumbers, insulators, painters/glaziers, supervisors, and electricians had a higher proportion of all injuries due to eye injuries than other trades. Nearly half of the diagnoses were abrasions (46%) followed by foreign objects or splash in the eye (29%), conjunctivitis (10%), and burns (5%). In the interviews with 62 workers, we found that employers very frequently required eye protection for all tasks or for high-risk tasks, and workers report wearing eye protection regularly. However, most did not wear eye protection with top and side shields; if we believe the injuries occurred because a particle or liquid passed between the glasses and the workers' faces, increased use of goggles or full shields would have prevented two-thirds of this group of injuries.

Task conflict and team creativity: a question of how much and when.

PubMed

Farh, Jiing-Lih; Lee, Cynthia; Farh, Crystal I C

2010-11-01

Bridging the task conflict, team creativity, and project team development literatures, we present a contingency model in which the relationship between task conflict and team creativity depends on the level of conflict and when it occurs in the life cycle of a project team. In a study of 71 information technology project teams in the greater China region, we found that task conflict had a curvilinear effect on team creativity, such that creativity was highest at moderate levels of task conflict. Additionally, we found this relationship to be moderated by team phase, such that the curvilinear effect was strongest at an early phase. In contrast, at later phases of the team life cycle, task conflict was found to be unrelated to team creativity. (c) 2010 APA, all rights reserved.

21 CFR 352.72 - General testing procedures.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., suntan, scars, active dermal lesions, and uneven skin tones on the areas of the back to be tested. The... immediate responses are noted, each subject shall shield the exposed area from further UV radiation for the... noncompliant (e.g., subject withdraws from the test due to illness or work conflicts, subject does not shield...

21 CFR 352.72 - General testing procedures.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., suntan, scars, active dermal lesions, and uneven skin tones on the areas of the back to be tested. The... immediate responses are noted, each subject shall shield the exposed area from further UV radiation for the... noncompliant (e.g., subject withdraws from the test due to illness or work conflicts, subject does not shield...

21 CFR 352.72 - General testing procedures.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., suntan, scars, active dermal lesions, and uneven skin tones on the areas of the back to be tested. The... immediate responses are noted, each subject shall shield the exposed area from further UV radiation for the... noncompliant (e.g., subject withdraws from the test due to illness or work conflicts, subject does not shield...

21 CFR 352.72 - General testing procedures.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., suntan, scars, active dermal lesions, and uneven skin tones on the areas of the back to be tested. The... immediate responses are noted, each subject shall shield the exposed area from further UV radiation for the... noncompliant (e.g., subject withdraws from the test due to illness or work conflicts, subject does not shield...

Dissociable neural mechanisms underlying response-based and familiarity-based conflict in working memory.

PubMed

Nelson, James K; Reuter-Lorenz, Patricia A; Sylvester, Ching-Yune C; Jonides, John; Smith, Edward E

2003-09-16

Cognitive control requires the resolution of interference among competing and potentially conflicting representations. Such conflict can emerge at different points between stimulus input and response generation, with the net effect being that of compromising performance. The goal of this article was to dissociate the neural mechanisms underlying different sources of conflict to elucidate the architecture of the neural systems that implement cognitive control. By using functional magnetic resonance imaging and a verbal working memory task (item recognition), we examined brain activity related to two kinds of conflict with comparable behavioral consequences. In a trial of our item-recognition task, participants saw four letters, followed by a retention interval, and a probe letter that did or did not match one of the letters held in working memory (positive probe and negative probe, respectively). On some trials, conflict arose solely because of the current negative probe having a high familiarity, due to its membership in the immediately preceding trial's target set. On other trials, additional conflict arose because of the current negative probe having also been a positive probe on the immediately preceding trial, producing response-level conflict. Consistent with previous work, conflict due to high familiarity was associated with left prefrontal activation, but not with anterior cingulate activation. The response-conflict condition, when compared with high-familiarity conflict trials, was associated with anterior cingulate cortex activation, but with no additional left prefrontal activation. This double dissociation points to differing contributions of specific cortical areas to cognitive control, which are based on the source of conflict.

Mechanisms underlying flexible adaptation of cognitive control: behavioral and neuroimaging evidence in a flanker task.

PubMed

Zurawska Vel Grajewska, Blandyna; Sim, Eun-Jin; Hoenig, Klaus; Herrnberger, Bärbel; Kiefer, Markus

2011-11-03

Cognitive control can be adapted flexibly according to the conflict level in a given situation. In the Eriksen flanker task, interference evoked by flankers is larger in conditions with a higher, rather than a lower proportion of compatible trials. Such compatibility ratio effects also occur for stimuli presented at two spatial locations suggesting that different cognitive control settings can be simultaneously maintained. However, the conditions and the neural correlates of this flexible adaptation of cognitive control are only poorly understood. In the present study, we further elucidated the mechanisms underlying the simultaneous maintenance of two cognitive control settings. In behavioral experiments, stimuli were presented centrally above and below fixation and hence processed by both hemispheres or lateralized to stimulate hemispheres differentially. The different compatibility ratio at two stimulus locations had a differential influence on the flanker effect in both experiments. In an fMRI experiment, blocks with an identical compatibility ratio at two central spatial locations elicited stronger activity in a network of prefrontal and parietal brain areas, which are known to be involved in conflict resolution and cognitive control, as compared with blocks with a different compatibility ratio at the same spatial locations. This demonstrates that the simultaneous maintenance of two conflicting control settings vs. one single setting does not recruit additional neural circuits suggesting the involvement of one single cognitive control system. Instead a crosstalk between multiple control settings renders adaptation of cognitive control more efficient when only one uniform rather than two different control settings has to be simultaneously maintained. Copyright © 2011 Elsevier B.V. All rights reserved.

Stimulus conflict triggers behavioral avoidance.

PubMed

Dignath, David; Eder, Andreas B

2015-12-01

According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance.

Sustained attention ability in schizophrenia: Investigation of conflict monitoring mechanisms.

PubMed

Hoonakker, Marc; Doignon-Camus, Nadège; Marques-Carneiro, José Eduardo; Bonnefond, Anne

2017-09-01

The main goal of the current study was to assess, with a time-on-task approach, sustained attention ability in schizophrenia, and to investigate conflict monitoring underlying this ability. Behavioral and event-related potentials data (N2 and P3a amplitudes) were recorded in a long-lasting sustained attention Go/NoGo task (sustained attention to response task, SART), over a period of 30min, in 29 patients with schizophrenia and 29 pair-matched healthy subjects. Our results revealed spared sustained attention ability in patients throughout the task. Impairment of conflict detection (N2) in patients was particularly significant at the end of the task. Furthermore, both schizophrenia and healthy subjects exhibited a decline in conflict detection from the beginning to the middle of the task. Whereas controls' conflict detection recovered in the last part of the task, patients' did not, suggesting a deficit in recovery processes reflecting a lack of additional resources sustained attention Go/NoGo task. Conflict resolution (P3a) was preserved throughout the task in both groups. Conflict monitoring processes are increasingly impaired in schizophrenia during a long-lasting sustained attention Go/NoGo task. This impairment at the end of the task may rely on deficit in recovery processes, rather than a deficit in conflict detection per se in schizophrenia. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

The dissociable neural dynamics of cognitive conflict and emotional conflict control: An ERP study.

PubMed

Xue, Song; Li, Yu; Kong, Xia; He, Qiaolin; Liu, Jia; Qiu, Jiang

2016-04-21

This study investigated differences in the neural time-course of cognitive conflict and emotional conflict control, using event-related potentials (ERPs). Although imaging studies have provided some evidence that distinct, dissociable neural systems underlie emotional and nonemotional conflict resolution, no ERP study has directly compared these two types of conflict. Therefore, the present study used a modified face-word Stroop task to explore the electrophysiological correlates of cognitive and emotional conflict control. The behavioral data showed that the difference in response time of congruency (incongruent condition minus the congruent condition) was larger in the cognitive conflict task than in the emotional conflict task, which indicated that cognitive conflict was stronger than the emotional conflict in the present tasks. Analysis of the ERP data revealed a main effect of task type on N2, which may be associated with top-down attention. The N450 results showed an interaction between cognitive and emotional conflict, which might be related to conflict detection. In addition, we found the incongruent condition elicited a larger SP than the congruent condition, which might be related to conflict resolution. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

N270 sensitivity to conflict strength and working memory: A combined ERP and sLORETA study.

PubMed

Scannella, Sébastien; Pariente, Jérémie; De Boissezon, Xavier; Castel-Lacanal, Evelyne; Chauveau, Nicolas; Causse, Mickaël; Dehais, Frédéric; Pastor, Josette

2016-01-15

The event-related potential N270 component is known to be an electrophysiological marker of the supramodal conflict processing. However little is know about the factors that may modulate its amplitude. In particular, among all studies that have investigated the N270, little or no control of the conflict strength and of the load in working memory have been done leaving a lack in the understanding of this component. We designed a spatial audiovisual conflict task with simultaneous target and cross-modal distractor to evaluate the N270 sensitivity to the conflict strength (i.e., visual target with auditory distractor or auditory target with visual distractor) and the load in working memory (goal task maintenance with frequent change in the target modality). In a first session, participants had to focus on one modality for the target position to be considered (left-hand or right-hand) while the distractor could be at the same side (compatible) or at opposite side (incompatible). In a second session, we used the same set of stimuli as in the first session with an additional distinct auditory signal that clued the participants to frequently switch between the auditory and the visual targets. We found that (1) reaction times and N270 amplitudes for conflicting situations were larger within the auditory target condition compared to the visual one, (2) the increase in target maintenance effort led to equivalent increase of both reaction times and N270 amplitudes within all conditions and (3) the right dorsolateral prefrontal cortex current density was higher for both conflicting and active maintenance of the target situations. These results provide new evidence that the N270 component is an electrophysiological marker of the supramodal conflict processing that is sensitive to the conflict strength and that conflict processing and active maintenance of the task goal are two functions of a common executive attention system. Copyright © 2015 Elsevier B.V. All rights reserved.

Leadership Skills.

ERIC Educational Resources Information Center

Hutchison, Cathleen; And Others

1988-01-01

Lists skills identified by the Leadership Development Task Force as being critical skills for a leader. Discussion focuses on information managing skills, including problem solving, decision making, setting goals and objectives; project management; and people managing skills, including interpersonal communications, conflict management, motivation,…

Focusing on task conflict in the Stroop effect.

PubMed

Entel, Olga; Tzelgov, Joseph

2018-03-01

Two types of conflict underlie performance in the Stroop task-informational (between the incongruent word and its ink color) and task (between the relevant color-naming task and the irrelevant word-reading task). We manipulated congruent-to-neutral trial ratio in an attempt to reveal whether task conflict can be monitored and controlled in the absence of an informational conflict. In our first experiment, no incongruent trials were included, thus allowing examination of a pure task conflict situation. The results revealed an impressively large facilitation when most of the stimuli were congruent and a smaller yet significant facilitation when most of the stimuli were neutrals. In Experiments 2, exposing participants to incongruent trials during pre-experimental practice (but not during the experimental blocks) slowed down the responses to congruent trials, resulting in a reduced facilitation effect in the mostly congruent condition, and in a negative facilitation in the mostly neutral condition. In our third experiment, we replicated our results, eliminating possible contingency and frequency biases. Overall, our findings show that experiencing, or at least expecting, informational conflict is essential to reveal conflict, while control is recruited through task demands. This challenges previous findings and points out that additional research is needed to clarify the necessity of informational conflict for conflict detection.

The hierarchy of task decision and response selection: a task-switching event related potentials study.

PubMed

Braverman, Ami; Berger, Andrea; Meiran, Nachshon

2014-07-01

According to "hierarchical" multi-step theories, response selection is preceded by a decision regarding which task rule should be executed. Other theories assume a "flat" single-step architecture in which task information and stimulus information are simultaneously considered. Using task switching, the authors independently manipulated two kinds of conflict: task conflict (with information that potentially triggers the relevant or the competing task rule/identity) and response conflict (with information that potentially triggers the relevant or the competing response code/motor response). Event related potentials indicated that the task conflict effect began before the response conflict effect and carried on in parallel with it. These results are more in line with the hierarchical view. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of Aging on Motor Inhibition during Action Preparation under Sensory Conflict.

PubMed

Duque, Julie; Petitjean, Charlotte; Swinnen, Stephan P

2016-01-01

Motor behaviors often require refraining from selecting options that may be part of the repertoire of natural response tendencies but that are in conflict with ongoing goals. The presence of sensory conflict has a behavioral cost but the latter can be attenuated in contexts where control processes are recruited because conflict is expected in advance, producing a behavioral gain compared to contexts where conflict occurs in a less predictable way. In the present study, we investigated the corticospinal correlates of these behavioral effects (both conflict-driven cost and context-related gain). To do so, we measured motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) over the primary motor cortex (M1) of young and healthy older adults performing the Eriksen Flanker Task. Subjects performed button-presses according to a central arrow, flanked by irrelevant arrows pointing in the same (congruent trial) or opposite direction (incongruent trial). Conflict expectation was manipulated by changing the probability of congruent and incongruent trials in a given block. It was either high (mostly incongruent blocks, MIB, 80% incongruent trials) or low (mostly congruent blocks, MCB, 80% congruent). The MEP data indicate that the conflict-driven behavioral cost is associated with a strong increase in inappropriate motor activity regardless of the age of individuals, as revealed by larger MEPs in the non-responding muscle in incongruent than in congruent trials. However, this aberrant facilitation disappeared in both groups of subjects when conflict could be anticipated (i.e., in the MIBs) compared to when it occurred in a less predictably way (MCBs), probably allowing the behavioral gain observed in both the young and the older individuals. Hence, the ability to overcome and anticipate conflict was surprisingly preserved in the older adults. Nevertheless, some control processes are likely to evolve with age because the behavioral gain observed in the MIB context was associated with an attenuated suppression of MEPs at the time of the imperative signal (i.e., before conflict is actually detected) in older individuals, suggesting altered motor inhibition, compared to young individuals. In addition, the behavioral analysis suggests that young and older adults rely on different strategies to cope with conflict, including a change in speed-accuracy tradeoff.

Effect of Aging on Motor Inhibition during Action Preparation under Sensory Conflict

PubMed Central

Duque, Julie; Petitjean, Charlotte; Swinnen, Stephan P.

2016-01-01

Motor behaviors often require refraining from selecting options that may be part of the repertoire of natural response tendencies but that are in conflict with ongoing goals. The presence of sensory conflict has a behavioral cost but the latter can be attenuated in contexts where control processes are recruited because conflict is expected in advance, producing a behavioral gain compared to contexts where conflict occurs in a less predictable way. In the present study, we investigated the corticospinal correlates of these behavioral effects (both conflict-driven cost and context-related gain). To do so, we measured motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) over the primary motor cortex (M1) of young and healthy older adults performing the Eriksen Flanker Task. Subjects performed button-presses according to a central arrow, flanked by irrelevant arrows pointing in the same (congruent trial) or opposite direction (incongruent trial). Conflict expectation was manipulated by changing the probability of congruent and incongruent trials in a given block. It was either high (mostly incongruent blocks, MIB, 80% incongruent trials) or low (mostly congruent blocks, MCB, 80% congruent). The MEP data indicate that the conflict-driven behavioral cost is associated with a strong increase in inappropriate motor activity regardless of the age of individuals, as revealed by larger MEPs in the non-responding muscle in incongruent than in congruent trials. However, this aberrant facilitation disappeared in both groups of subjects when conflict could be anticipated (i.e., in the MIBs) compared to when it occurred in a less predictably way (MCBs), probably allowing the behavioral gain observed in both the young and the older individuals. Hence, the ability to overcome and anticipate conflict was surprisingly preserved in the older adults. Nevertheless, some control processes are likely to evolve with age because the behavioral gain observed in the MIB context was associated with an attenuated suppression of MEPs at the time of the imperative signal (i.e., before conflict is actually detected) in older individuals, suggesting altered motor inhibition, compared to young individuals. In addition, the behavioral analysis suggests that young and older adults rely on different strategies to cope with conflict, including a change in speed-accuracy tradeoff. PMID:28082896

Using Neural Pattern Classifiers to Quantify the Modularity of Conflict–Control Mechanisms in the Human Brain

PubMed Central

Jiang, Jiefeng; Egner, Tobias

2014-01-01

Resolving conflicting sensory and motor representations is a core function of cognitive control, but it remains uncertain to what degree control over different sources of conflict is implemented by shared (domain general) or distinct (domain specific) neural resources. Behavioral data suggest conflict–control to be domain specific, but results from neuroimaging studies have been ambivalent. Here, we employed multivoxel pattern analyses that can decode a brain region's informational content, allowing us to distinguish incidental activation overlap from actual shared information processing. We trained independent sets of “searchlight” classifiers on functional magnetic resonance imaging data to decode control processes associated with stimulus-conflict (Stroop task) and ideomotor-conflict (Simon task). Quantifying the proportion of domain-specific searchlights (capable of decoding only one type of conflict) and domain-general searchlights (capable of decoding both conflict types) in each subject, we found both domain-specific and domain-general searchlights, though the former were more common. When mapping anatomical loci of these searchlights across subjects, neural substrates of stimulus- and ideomotor-specific conflict–control were found to be anatomically consistent across subjects, whereas the substrates of domain-general conflict–control were not. Overall, these findings suggest a hybrid neural architecture of conflict–control that entails both modular (domain specific) and global (domain general) components. PMID:23402762

Behavioral conflict, anterior cingulate cortex, and experiment duration: implications of diverging data.

PubMed

Erickson, Kirk I; Milham, Michael P; Colcombe, Stanley J; Kramer, Arthur F; Banich, Marie T; Webb, Andrew; Cohen, Neal J

2004-02-01

We investigated the relationship between behavioral measures of conflict and the degree of activity in the anterior cingulate cortex (ACC). We reanalyzed an existing data set that employed the Stroop task using functional magnetic resonance imaging [Milham et al., Brain Cogn 2002;49:277-296]. Although we found no changes in the behavioral measures of conflict from the first to the second half of task performance, we found a reliable reduction in the activity of the anterior cingulate cortex. This result suggests the lack of a strong relationship between behavioral measurements of conflict and anterior cingulate activity. A concomitant increase in dorsolateral prefrontal cortex activity was also found, which may reflect a tradeoff in the neural substrates involved in supporting conflict resolution, detection, or monitoring processes. A second analysis of the data revealed that the duration of an experiment can dramatically affect interpretations of the results, including the roles in which particular regions are thought to play in cognition. These results are discussed in relation to current conceptions of ACC's role in attentional control. In addition, we discuss the implication of our results with current conceptions of conflict and of its instantiation in the brain. Hum. Brain Mapping 21:96-105, 2004. Copyright 2003 Wiley-Liss, Inc.

Behavioral consequences of conflict-oriented health news coverage: the 2009 mammography guideline controversy and online information seeking.

PubMed

Weeks, Brian E; Friedenberg, Laura M; Southwell, Brian G; Slater, Jonathan S

2012-01-01

Building on channel complementarity theory and media-system dependency theory, this study explores the impact of conflict-oriented news coverage of health issues on information seeking online. Using Google search data as a measure of behavior, we demonstrate that controversial news coverage of the U.S. Preventive Services Task Force's November 2009 recommendations for changes in breast cancer screening guidelines strongly predicted the volume of same-day online searches for information about mammograms. We also found that this relationship did not exist 1 year prior to the coverage, during which mammography news coverage did not focus on the guideline controversy, suggesting that the controversy frame may have driven search behavior. We discuss the implications of these results for health communication scholars and practitioners.

How Do Children Deal With Conflict? A Developmental Study of Sequential Conflict Modulation

PubMed Central

Smulders, Silvan F. A.; Soetens, Eric L. L.; van der Molen, Maurits W.

2018-01-01

This study examined age-related differences in sequential conflict modulation (SCM), elicited in three tasks requiring the inhibition of pre-potent responses; a Simon task, an S-R compatibility (SRC) task and a hybrid Choice-reaction/NoGo task. The primary focus was on age-related changes in performance changes following a conflict trial. A secondary aim was to assess whether SCM follows different developmental trajectories depending on the type of conflict elicited by the tasks. The tasks were presented to three different groups of participants with an age range between 7- to 25-years—one group of participants for each task. For each task, the response-to-stimulus interval (RSI) was manipulated (50 vs. 500 ms) across trial blocks to assess time-dependent changes in conflict modulation. The results showed SCM for all three tasks, although the specific patterns differed between tasks and RSIs. Importantly, the magnitude of SCM decreased with advancing age, but this developmental trend did not survive when considering age-group differences in basic response speed. The current results contribute to the emerging evidence suggesting that patterns of SCM are task specific and were interpreted in terms of multiple bottom-up control mechanisms. PMID:29875718

Evidence for Interaction between the Stop Signal and the Stroop Task Conflict

ERIC Educational Resources Information Center

Kalanthroff, Eyal; Goldfarb, Liat; Henik, Avishai

2013-01-01

Performance of the Stroop task reflects two conflicts--informational (between the incongruent word and ink color) and task (between relevant color naming and irrelevant word reading). The task conflict is usually not visible, and is only seen when task control is damaged. Using the stop-signal paradigm, a few studies demonstrated longer…

Alpha power increases in right parietal cortex reflects focused internal attention

PubMed Central

Benedek, Mathias; Schickel, Rainer J.; Jauk, Emanuel; Fink, Andreas; Neubauer, Aljoscha C.

2014-01-01

This study investigated the functional significance of EEG alpha power increases, a finding that is consistently observed in various memory tasks and specifically during divergent thinking. It was previously shown that alpha power is increased when tasks are performed in mind—e.g., when bottom-up processing is prevented. This study aimed to examine the effect of task-immanent differences in bottom-up processing demands by comparing two divergent thinking tasks, one intrinsically relying on bottom-up processing (sensory-intake task) and one that is not (sensory-independence task). In both tasks, stimuli were masked in half of the trials to establish conditions of higher and lower internal processing demands. In line with the hypotheses, internal processing affected performance and led to increases in alpha power only in the sensory-intake task, whereas the sensory-independence task showed high levels of task-related alpha power in both conditions. Interestingly, conditions involving focused internal attention showed a clear lateralization with higher alpha power in parietal regions of the right hemisphere. Considering evidence from fMRI studies, right-parietal alpha power increases may correspond to a deactivation of the right temporoparietal junction, reflecting an inhibition of the ventral attention network. Inhibition of this region is thought to prevent reorienting to irrelevant stimulation during goal-driven, top-down behavior, which may serve the executive function of task shielding during demanding cognitive tasks such as idea generation and mental imagery. PMID:24561034

A Tentative Study on the Task-Based Teaching of Writing to English Majors in Chinese Settings

ERIC Educational Resources Information Center

Zhaochun, Sun

2015-01-01

Under task-based learning (TBL) framework, language learners engage in purposeful, problem-oriented, and outcome-driven tasks that are comparable to traditional teaching methods which focus only on the correctness of grammar. In this study, the author employs Jane Willis' TBL framework and examines its effects on the improvement of EFL learners'…

Across-Task Conflict Regulation: A Replication Failure

ERIC Educational Resources Information Center

Runger, Dennis; Schwager, Sabine; Frensch, Peter A.

2010-01-01

Fernandez-Duque and Knight (2008, Experiment 4) described an across-task effect of endogenously generated, anticipatory control: A cue that predicted conflict in an upcoming Eriksen flanker task modulated conflict regulation in a subsequent number Stroop task. In 3 experiments, 1 of which included an exact replication condition, we failed to…

The Stroop matching task presents conflict at both the response and nonresponse levels: an event-related potential and electromyography study.

PubMed

Caldas, A L; Machado-Pinheiro, W; Souza, L B; Motta-Ribeiro, G C; David, I A

2012-09-01

In the Stroop matching task, a Stroop word is compared to a colored bar. The origin of the conflict presented by this task is a topic of current debate. In an effort to disentangle nonresponse and response conflicts, we recorded electromyography (EMG) and event-related potentials (ERPs) while participants performed the task. The N450 component was sensitive to the relationship of color surfaces, regardless of the response, suggesting the participation of nonresponse conflict. Incompatible arrays (e.g., incongruent Stroop stimuli during "same" responses) presented a substantial amount of double EMG activation and slower EMG latencies, suggesting the participation of response conflict. We propose that both response and nonresponse conflicts are sources of these effects. The combined use of the EMG and ERP techniques played an important role in elucidating the conflicts immersed in the Stroop matching task. Copyright © 2012 Society for Psychophysiological Research.

OMOGENIA: A Semantically Driven Collaborative Environment

NASA Astrophysics Data System (ADS)

Liapis, Aggelos

Ontology creation can be thought of as a social procedure. Indeed the concepts involved in general need to be elicited from communities of domain experts and end-users by teams of knowledge engineers. Many problems in ontology creation appear to resemble certain problems in software design, particularly with respect to the setup of collaborative systems. For instance, the resolution of conceptual conflicts between formalized ontologies is a major engineering problem as ontologies move into widespread use on the semantic web. Such conflict resolution often requires human collaboration and cannot be achieved by automated methods with the exception of simple cases. In this chapter we discuss research in the field of computer-supported cooperative work (CSCW) that focuses on classification and which throws light on ontology building. Furthermore, we present a semantically driven collaborative environment called OMOGENIA as a natural way to display and examine the structure of an evolving ontology in a collaborative setting.

Positive emotion impedes emotional but not cognitive conflict processing.

PubMed

Zinchenko, Artyom; Obermeier, Christian; Kanske, Philipp; Schröger, Erich; Kotz, Sonja A

2017-06-01

Cognitive control enables successful goal-directed behavior by resolving a conflict between opposing action tendencies, while emotional control arises as a consequence of emotional conflict processing such as in irony. While negative emotion facilitates both cognitive and emotional conflict processing, it is unclear how emotional conflict processing is affected by positive emotion (e.g., humor). In 2 EEG experiments, we investigated the role of positive audiovisual target stimuli in cognitive and emotional conflict processing. Participants categorized either spoken vowels (cognitive task) or their emotional valence (emotional task) and ignored the visual stimulus dimension. Behaviorally, a positive target showed no influence on cognitive conflict processing, but impeded emotional conflict processing. In the emotional task, response time conflict costs were higher for positive than for neutral targets. In the EEG, we observed an interaction of emotion by congruence in the P200 and N200 ERP components in emotional but not in cognitive conflict processing. In the emotional conflict task, the P200 and N200 conflict effect was larger for emotional than neutral targets. Thus, our results show that emotion affects conflict processing differently as a function of conflict type and emotional valence. This suggests that there are conflict- and valence-specific mechanisms modulating executive control.

Dissociable neural systems resolve conflict from emotional versus nonemotional distracters.

PubMed

Egner, Tobias; Etkin, Amit; Gale, Seth; Hirsch, Joy

2008-06-01

The human brain protects the processing of task-relevant stimuli from interference ("conflict") by task-irrelevant stimuli via attentional biasing mechanisms. The lateral prefrontal cortex has been implicated in resolving conflict between competing stimuli by selectively enhancing task-relevant stimulus representations in sensory cortices. Conversely, recent data suggest that conflict from emotional distracters may be resolved by an alternative route, wherein the rostral anterior cingulate cortex inhibits amygdalar responsiveness to task-irrelevant emotional stimuli. Here we tested the proposal of 2 dissociable, distracter-specific conflict resolution mechanisms, by acquiring functional magnetic resonance imaging data during resolution of conflict from either nonemotional or emotional distracters. The results revealed 2 distinct circuits: a lateral prefrontal "cognitive control" system that resolved nonemotional conflict and was associated with enhanced processing of task-relevant stimuli in sensory cortices, and a rostral anterior cingulate "emotional control" system that resolved emotional conflict and was associated with decreased amygdalar responses to emotional distracters. By contrast, activations related to both emotional and nonemotional conflict monitoring were observed in a common region of the dorsal anterior cingulate. These data suggest that the neuroanatomical networks recruited to overcome conflict vary systematically with the nature of the conflict, but that they may share a common conflict-detection mechanism.

A contingency model of conflict and team effectiveness.

PubMed

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

2011-03-01

The authors develop and test theoretical extensions of the relationships of task conflict, relationship conflict, and 2 dimensions of team effectiveness (performance and team-member satisfaction) among 2 samples of work teams in Taiwan and Indonesia. Findings show that relationship conflict moderates the task conflict-team performance relationship. Specifically, the relationship is curvilinear in the shape of an inverted U when relationship conflict is low, but the relationship is linear and negative when relationship conflict is high. The results for team-member satisfaction are more equivocal, but the findings provide some evidence that relationship conflict exacerbates the negative relationship between task conflict and team-member satisfaction. PsycINFO Database Record (c) 2011 APA, all rights reserved.

The Influence of Reward Associations on Conflict Processing in the Stroop Task

ERIC Educational Resources Information Center

Krebs, Ruth M.; Boehler, Carsten N.; Woldorff, Marty G.

2010-01-01

Performance in a behavioral task can be facilitated by associating stimulus properties with reward. In contrast, conflicting information is known to impede task performance. Here we investigated how reward associations influence the within-trial processing of conflicting information using a color-naming Stroop task in which a subset of ink colors…

Learning tactile skills through curious exploration

PubMed Central

Pape, Leo; Oddo, Calogero M.; Controzzi, Marco; Cipriani, Christian; Förster, Alexander; Carrozza, Maria C.; Schmidhuber, Jürgen

2012-01-01

We present curiosity-driven, autonomous acquisition of tactile exploratory skills on a biomimetic robot finger equipped with an array of microelectromechanical touch sensors. Instead of building tailored algorithms for solving a specific tactile task, we employ a more general curiosity-driven reinforcement learning approach that autonomously learns a set of motor skills in absence of an explicit teacher signal. In this approach, the acquisition of skills is driven by the information content of the sensory input signals relative to a learner that aims at representing sensory inputs using fewer and fewer computational resources. We show that, from initially random exploration of its environment, the robotic system autonomously develops a small set of basic motor skills that lead to different kinds of tactile input. Next, the system learns how to exploit the learned motor skills to solve supervised texture classification tasks. Our approach demonstrates the feasibility of autonomous acquisition of tactile skills on physical robotic platforms through curiosity-driven reinforcement learning, overcomes typical difficulties of engineered solutions for active tactile exploration and underactuated control, and provides a basis for studying developmental learning through intrinsic motivation in robots. PMID:22837748

Flexible Conflict Management: Conflict Avoidance and Conflict Adjustment in Reactive Cognitive Control

ERIC Educational Resources Information Center

Dignath, David; Kiesel, Andrea; Eder, Andreas B.

2015-01-01

Conflict processing is assumed to serve two crucial, yet distinct functions: Regarding task performance, control is adjusted to overcome the conflict. Regarding task choice, control is harnessed to bias decision making away from the source of conflict. Despite recent theoretical progress, until now two lines of research addressed these…

Conflict-specific effects of accessory stimuli on cognitive control in the Stroop task and the Simon task.

PubMed

Soutschek, Alexander; Müller, Hermann J; Schubert, Torsten

2013-01-01

Both the Stroop and the Simon paradigms are often used in research on cognitive control, however, there is evidence that dissociable control processes are involved in these tasks: While conflicts in the Stroop task may be resolved mainly by enhanced task-relevant stimulus processing, conflicts in the Simon task may be resolved rather by suppressing the influence of task-irrelevant information on response selection. In the present study, we show that these control mechanisms interact in different ways with the presentation of accessory stimuli. Accessory stimuli do not affect cognitive control in the Simon task, but they impair the efficiency of cross-trial control processes in the Stroop task. Our findings underline the importance of differentiating between different types of conflicts and mechanisms of cognitive control.

Optimization of radiation shielding material aiming at compactness, lightweight, and low activation for a vehicle-mounted accelerator-driven D-T neutron source.

PubMed

Cai, Yao; Hu, Huasi; Lu, Shuangying; Jia, Qinggang

2018-05-01

To minimize the size and weight of a vehicle-mounted accelerator-driven D-T neutron source and protect workers from unnecessary irradiation after the equipment shutdown, a method to optimize radiation shielding material aiming at compactness, lightweight, and low activation for the fast neutrons was developed. The method employed genetic algorithm, combining MCNP and ORIGEN codes. A series of composite shielding material samples were obtained by the method step by step. The volume and weight needed to build a shield (assumed as a coaxial tapered cylinder) were adopted to compare the performance of the materials visually and conveniently. The results showed that the optimized materials have excellent performance in comparison with the conventional materials. The "MCNP6-ACT" method and the "rigorous two steps" (R2S) method were used to verify the activation grade of the shield irradiated by D-T neutrons. The types of radionuclide, the energy spectrum of corresponding decay gamma source, and the variation in decay gamma dose rate were also computed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Reaping the Benefits of Task Conflict in Teams: The Critical Role of Team Psychological Safety Climate

ERIC Educational Resources Information Center

Bradley, Bret H.; Postlethwaite, Bennett E.; Klotz, Anthony C.; Hamdani, Maria R.; Brown, Kenneth G.

2012-01-01

Past research suggests that task conflict may improve team performance under certain conditions; however, we know little about these specific conditions. On the basis of prior theory and research on conflict in teams, we argue that a climate of psychological safety is one specific context under which task conflict will improve team performance.…

A Contingency Model of Conflict and Team Effectiveness

ERIC Educational Resources Information Center

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

2011-01-01

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

The Conflict between On-Task and Off-Task Actions in the Classroom and Its Consequences for Motivation and Achievement

ERIC Educational Resources Information Center

Kilian, Britta; Hofer, Manfred; Fries, Stefan; Kuhnle, Claudia

2010-01-01

The relations between students' value orientations, decisions in conflicts between on-task and off-task actions in the classroom, and experiences of motivational interference following these conflicts were investigated. It was expected that well-being value orientation was positively linked and achievement value orientation was negatively linked…

Task conflicts and exclusive professionalism in nursing in South Korea.

PubMed

Jung, Minsoo

2014-01-01

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

Working with men to prevent intimate partner violence in a conflict-affected setting: a pilot cluster randomized controlled trial in rural Côte d’Ivoire

PubMed Central

2014-01-01

Background Evidence from armed conflict settings points to high levels of intimate partner violence (IPV) against women. Current knowledge on how to prevent IPV is limited—especially within war-affected settings. To inform prevention programming on gender-based violence in settings affected by conflict, we evaluated the impact of adding a targeted men’s intervention to a community-based prevention programme in Côte d’Ivoire. Methods We conducted a two-armed, non-blinded cluster randomized trial in Côte d’Ivoire among 12 pair-matched communities spanning government-controlled, UN buffer, and rebel–controlled zones. The intervention communities received a 16-week IPV prevention intervention using a men’s discussion group format. All communities received community-based prevention programmes. Baseline data were collected from couples in September 2010 (pre-intervention) and follow-up in March 2012 (one year post-intervention). The primary trial outcome was women’s reported experiences of physical and/or sexual IPV in the last 12 months. We also assessed men’s reported intention to use physical IPV, attitudes towards sexual IPV, use of hostility and conflict management skills, and participation in gendered household tasks. An adjusted cluster-level intention to treat analysis was used to compare outcomes between intervention and control communities at follow-up. Results At follow-up, reported levels of physical and/or sexual IPV in the intervention arm had decreased compared to the control arm (ARR 0.52, 95% CI 0.18-1.51, not significant). Men participating in the intervention reported decreased intentions to use physical IPV (ARR 0.83, 95% CI 0.66-1.06) and improved attitudes toward sexual IPV (ARR 1.21, 95% CI 0.77-1.91). Significant differences were found between men in the intervention and control arms’ reported ability to control their hostility and manage conflict (ARR 1.3, 95% CI 1.06-1.58), and participation in gendered household tasks (ARR 2.47, 95% CI 1.24-4.90). Conclusions This trial points to the value of adding interventions working with men alongside community activities to reduce levels of IPV in conflict-affected settings. The intervention significantly influenced men’s reported behaviours related to hostility and conflict management and gender equitable behaviours. The decreased mean level of IPV and the differences between intervention and control arms, while not statistically significant, suggest that IPV in conflict-affected areas can be reduced through concerted efforts to include men directly in violence prevention programming. A larger-scale trial is needed to replicate these findings and further understand the mechanisms of change. Trial registration clinicaltrials.gov NCT01803932 PMID:24716478

How Team-Level and Individual-Level Conflict Influences Team Commitment: A Multilevel Investigation.

PubMed

Lee, Sanghyun; Kwon, Seungwoo; Shin, Shung J; Kim, MinSoo; Park, In-Jo

2017-01-01

We investigate how two different types of conflict (task conflict and relationship conflict) at two different levels (individual-level and team-level) influence individual team commitment. The analysis was conducted using data we collected from 193 employees in 31 branch offices of a Korean commercial bank. The relationships at multiple levels were tested using hierarchical linear modeling (HLM). The results showed that individual-level relationship conflict was negatively related to team commitment while individual-level task conflict was not. In addition, both team-level task and relationship conflict were negatively associated with team commitment. Finally, only team-level relationship conflict significantly moderated the relationship between individual-level relationship conflict and team commitment. We further derive theoretical implications of these findings.

How Team-Level and Individual-Level Conflict Influences Team Commitment: A Multilevel Investigation

PubMed Central

Lee, Sanghyun; Kwon, Seungwoo; Shin, Shung J.; Kim, MinSoo; Park, In-Jo

2018-01-01

We investigate how two different types of conflict (task conflict and relationship conflict) at two different levels (individual-level and team-level) influence individual team commitment. The analysis was conducted using data we collected from 193 employees in 31 branch offices of a Korean commercial bank. The relationships at multiple levels were tested using hierarchical linear modeling (HLM). The results showed that individual-level relationship conflict was negatively related to team commitment while individual-level task conflict was not. In addition, both team-level task and relationship conflict were negatively associated with team commitment. Finally, only team-level relationship conflict significantly moderated the relationship between individual-level relationship conflict and team commitment. We further derive theoretical implications of these findings. PMID:29387033

Examining a supramodal network for conflict processing: a systematic review and novel functional magnetic resonance imaging data for related visual and auditory stroop tasks.

PubMed

Roberts, Katherine L; Hall, Deborah A

2008-06-01

Cognitive control over conflicting information has been studied extensively using tasks such as the color-word Stroop, flanker, and spatial conflict task. Neuroimaging studies typically identify a fronto-parietal network engaged in conflict processing, but numerous additional regions are also reported. Ascribing putative functional roles to these regions is problematic because some may have less to do with conflict processing per se, but could be engaged in specific processes related to the chosen stimulus modality, stimulus feature, or type of conflict task. In addition, some studies contrast activation on incongruent and congruent trials, even though a neutral baseline is needed to separate the effect of inhibition from that of facilitation. In the first part of this article, we report a systematic review of 34 neuroimaging publications, which reveals that conflict-related activity is reliably reported in the anterior cingulate cortex and bilaterally in the lateral prefrontal cortex, the anterior insula, and the parietal lobe. In the second part, we further explore these candidate "conflict" regions through a novel functional magnetic resonance imaging experiment, in which the same group of subjects perform related visual and auditory Stroop tasks. By carefully controlling for the same task (Stroop), the same to-be-ignored stimulus dimension (word meaning), and by separating out inhibitory processes from those of facilitation, we attempt to minimize the potential differences between the two tasks. The results provide converging evidence that the regions identified by the systematic review are reliably engaged in conflict processing. Despite carefully matching the Stroop tasks, some regions of differential activity remained, particularly in the parietal cortex. We discuss some of the task-specific processes which might account for this finding.

Distinct cognitive control mechanisms as revealed by modality-specific conflict adaptation effects.

PubMed

Yang, Guochun; Nan, Weizhi; Zheng, Ya; Wu, Haiyan; Li, Qi; Liu, Xun

2017-04-01

Cognitive control is essential to resolve conflict in stimulus-response compatibility (SRC) tasks. The SRC effect in the current trial is reduced after an incongruent trial as compared with a congruent trial, a phenomenon being termed conflict adaptation (CA). The CA effect is found to be domain-specific , such that it occurs when adjacent trials contain the same type of conflict, but disappears when the conflicts are of different types. Similar patterns have been observed when tasks involve different modalities, but the modality-specific effect may have been confounded by task switching. In the current study, we investigated whether or not cognitive control could transfer across auditory and visual conflicts when task-switching was controlled. Participants were asked to respond to a visual or auditory (Experiments 1A/B) stimulus, with conflict coming from either the same or a different modality. CA effects showed modality-specific patterns. To account for potential confounding effects caused by differences in task-irrelevant properties, we specifically examined the influence of task-irrelevant properties on CA effects within the visual modality (Experiments 2A/B). Significant CA effects were observed across different conflicts from distinct task-irrelevant properties, ruling out that the lack of cross-modal CA effects in Experiments 1A/B resulted from differences in task-irrelevant information. Task-irrelevant properties were further matched in Experiments 3A/B to examine the pure effect of modality. Results replicated Experiments 1A/B showing robust modality-specific CA effects. Taken together, we provide supporting evidences that modality affects cognitive control in conflict resolution, which should be taken into account in theories of cognitive control. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

In Support of a Distinction between Voluntary and Stimulus-Driven Control: A Review of the Literature on Proportion Congruent Effects.

PubMed

Bugg, Julie M; Crump, Matthew J C

2012-01-01

Cognitive control is by now a large umbrella term referring collectively to multiple processes that plan and coordinate actions to meet task goals. A common feature of paradigms that engage cognitive control is the task requirement to select relevant information despite a habitual tendency (or bias) to select goal-irrelevant information. At least since the 1970s, researchers have employed proportion congruent (PC) manipulations to experimentally establish selection biases and evaluate the mechanisms used to control attention. PC manipulations vary the frequency with which irrelevant information conflicts (i.e., is incongruent) with relevant information. The purpose of this review is to summarize the growing body of literature on PC effects across selective attention paradigms, beginning first with Stroop, and then describing parallel effects in flanker and task-switching paradigms. The review chronologically tracks the expansion of the PC manipulation from its initial implementation at the list-wide level, to more recent implementations at the item-specific and context-specific levels. An important theoretical aim is demonstrating that PC effects at different levels (e.g., list-wide vs. item or context-specific) support a distinction between voluntary forms of cognitive control, which operate based on anticipatory information, and relatively automatic or reflexive forms of cognitive control, which are rapidly triggered by the processing of particular stimuli or stimulus features. A further aim is to highlight those PC manipulations that allow researchers to dissociate stimulus-driven control from other stimulus-driven processes (e.g., S-R responding; episodic retrieval). We conclude by discussing the utility of PC manipulations for exploring the distinction between voluntary control and stimulus-driven control in other relevant paradigms.

In Support of a Distinction between Voluntary and Stimulus-Driven Control: A Review of the Literature on Proportion Congruent Effects

PubMed Central

Bugg, Julie M.; Crump, Matthew J. C.

2012-01-01

Cognitive control is by now a large umbrella term referring collectively to multiple processes that plan and coordinate actions to meet task goals. A common feature of paradigms that engage cognitive control is the task requirement to select relevant information despite a habitual tendency (or bias) to select goal-irrelevant information. At least since the 1970s, researchers have employed proportion congruent (PC) manipulations to experimentally establish selection biases and evaluate the mechanisms used to control attention. PC manipulations vary the frequency with which irrelevant information conflicts (i.e., is incongruent) with relevant information. The purpose of this review is to summarize the growing body of literature on PC effects across selective attention paradigms, beginning first with Stroop, and then describing parallel effects in flanker and task-switching paradigms. The review chronologically tracks the expansion of the PC manipulation from its initial implementation at the list-wide level, to more recent implementations at the item-specific and context-specific levels. An important theoretical aim is demonstrating that PC effects at different levels (e.g., list-wide vs. item or context-specific) support a distinction between voluntary forms of cognitive control, which operate based on anticipatory information, and relatively automatic or reflexive forms of cognitive control, which are rapidly triggered by the processing of particular stimuli or stimulus features. A further aim is to highlight those PC manipulations that allow researchers to dissociate stimulus-driven control from other stimulus-driven processes (e.g., S-R responding; episodic retrieval). We conclude by discussing the utility of PC manipulations for exploring the distinction between voluntary control and stimulus-driven control in other relevant paradigms. PMID:23060836

Conflict Management at School: An Unavoidable Task.

ERIC Educational Resources Information Center

Bondesio, Mike J.

Conflict management has become an integral part of a headmaster's tasks. Headmasters are not required to suppress or resolve conflict, but to manage it. Since 1976, conflict in black schools has increased, and headmasters have had to manage serious and dangerous situations. Unfortunately, there has been little research in conflict management in…

Cognitive conflict increases processing of negative, task-irrelevant stimuli.

PubMed

Ligeza, Tomasz S; Wyczesany, Miroslaw

2017-10-01

The detection of cognitive conflict is thought to trigger adjustments in executive control. It has been recently shown that cognitive conflict increases processing of stimuli that are relevant to the ongoing task and that these modulations are exerted by the dorsolateral prefrontal cortex (DLPFC). However, it is still unclear whether such control influences are unspecific and might also affect the processing of task-irrelevant stimuli. The aim of the study was to examine if cognitive conflict affects processing of neutral and negative, task-irrelevant pictures. Participants responded to congruent (non-conflict) or to incongruent (conflict-eliciting) trials of a modified flanker task. Each response was followed by a presentation of a neutral or negative picture. The late positive potential (LPP) in response to picture presentation was used to assess the level of picture processing after conflict vs non-conflict trials. Connectivity between the DLPFC and attentional and perceptual areas during picture presentation was analysed to check if the DLPFC might be a source of these modulations. ERP results showed an effect of cognitive conflict only on processing of negative pictures: LPP in response to negative pictures was increased after conflict trials, whereas LPP in response to neutral pictures remained unchanged. Cortical connectivity analysis showed that conflict trials intensified information flow from the DLPFC towards attentional and perceptual regions. Results suggest that cognitive conflict increases processing of task-irrelevant stimuli; however, they must display high biological salience. Increase in cognitive control exerted by the DLPFC over attentional and perceptual regions is a probable mechanism of the effect. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of positive affect on conflict resolution: Modulated by approach-motivational intensity.

PubMed

Liu, Ya; Wang, Zhenhong; Quan, Sixiang; Li, Mingjun

2017-01-01

The motivational dimensional model of affect proposes that the influence of positive affect on cognitive processing is modulated by approach-motivational intensity. The present research extended this model by examining the influence of positive affect varying in approach-motivational intensity on conflict resolution-the ability to resolve interference from task-irrelevant distractors in order to focus on the target. The global-local task (Experiment 1) and letter-Flanker task (Experiment 2) were used to measure conflict resolution. Additionally, the 4:2 mapping design that assigns two kinds of task-relevant stimuli to one response key and two more to another response key was used in these two tasks to dissociate stimulus and response conflict. Results showed that positive affect varying in approach motivation had opposite influences on conflict resolution. The opposite influences are primarily reflected in low approach-motivated positive affect impairing, while high approach-motivated positive affect facilitating the resolution of response conflict. Conversely, the stimulus conflict was slightly influenced. These findings highlight the utility of distinguishing stimulus and response conflict in future research.

Gender differences in brain activity toward unpleasant linguistic stimuli concerning interpersonal relationships: an fMRI study.

PubMed

Shirao, Naoko; Okamoto, Yasumasa; Okada, Go; Ueda, Kazutaka; Yamawaki, Shigeto

2005-10-01

Women are more vulnerable to psychosocial stressors such as interpersonal conflicts than men, and are more susceptible to some psychiatric disorders. We hypothesized that there are differences in the brain activity of men and women while perceiving unpleasant linguistic stimuli concerning interpersonal relationships, and that they underlie the different sensitivity toward these stressful stimuli. We carried out a functional magnetic resonance imaging (fMRI) study on 13 young female adults and 13 young male adults who performed an emotional decision task including sets of unpleasant words concerning interpersonal relationships and sets of neutral words. In the women, the unpleasant words more significantly activated the bilateral caudate nuclei and left putamen than the neutral words. However, among the men, there was no difference in the level of activation of any brain area induced by the unpleasant or neutral word stimuli. Upon performing the task, there was a significant gender difference in brain activation. Moreover, among the female subjects, the activation in the bilateral caudate nuclei and left thalamus was negatively correlated with the average rating of pleasantness of the words concerning interpersonal conflicts by the subject. These results demonstrate gender differences in brain activity in processing unpleasant linguistic stimuli related to interpersonal conflicts. Our data suggest that the bilateral caudate nuclei and left putamen play an important role in the perception of words concerning interpersonal conflicts in women. The bilateral caudate nuclei and left thalamus may regulate a woman's sensitivity to unpleasant information about interpersonal difficulties.

Transcranial direct current stimulation (tDCS) over the right dorsolateral prefrontal cortex affects stimulus conflict but not response conflict.

PubMed

Zmigrod, S; Zmigrod, L; Hommel, B

2016-05-13

When the human brain encounters a conflict, performance is often impaired. Two tasks that are widely used to induce and measure conflict-related interference are the Eriksen flanker task, whereby the visual target stimulus is flanked by congruent or incongruent distractors, and the Simon task, where the location of the required spatial response is either congruent or incongruent with the location of the target stimulus. Interestingly, both tasks share the characteristic of inducing response conflict but only the flanker task induces stimulus conflict. We used a non-invasive brain stimulation technique to explore the role of the right dorsolateral prefrontal cortex (DLPFC) in dealing with conflict in the Eriksen flanker and Simon tasks. In different sessions, participants received anodal, cathodal, or sham transcranial direct current stimulation (tDCS) (2 mA, 20 min) on the right DLPFC while performing these tasks. The results indicate that cathodal tDCS over the right DLPFC increased the flanker interference effect while having no impact on the Simon effect. This finding provides empirical support for the role of the right DLPFC in stimulus-stimulus rather than stimulus-response conflict, which suggests the existence of multiple, domain-specific control mechanisms underlying conflict resolution. In addition, methodologically, the study also demonstrates the way in which brain stimulation techniques can reveal subtle yet important differences between experimental paradigms that are often assumed to tap into a single process. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Hostile behavior during marital conflict alters pituitary and adrenal hormones.

PubMed

Malarkey, W B; Kiecolt-Glaser, J K; Pearl, D; Glaser, R

1994-01-01

We evaluated hormonal changes and problem-solving behaviors in 90 newlywed couples who were admitted to a hospital research unit for 24 hours. The subjects were selected on the basis of stringent mental and physical health criteria, and admissions were scheduled during the follicular phase of the woman's menstrual cycle. For frequent, unobtrusive endocrine sampling during the interaction tasks, a long polyethylene tube was attached to a heparin well, allowing nurses to draw blood samples at set intervals, out of subjects' sight. Five blood samples were obtained before, during, and after a 30-minute structured problem-solving or conflict task. The conflict session was recorded on videotapes that were later scored for problem-solving behaviors using the Marital Interaction Coding System (MICS). Marital conflict and MICS-coded hostile or negative behavior during conflict was closely linked to changes in serum hormonal levels across five of the six hormones we studied, in spite of the high marital satisfaction of our newlywed couples and the healthy lifestyles demanded by our exclusion criteria. Hostile behavior was associated with decreased levels of prolactin (PRL) and increases in epinephrine (EPI), norepinephrine (NEPI), ACTH, and growth hormone (GH), but not cortisol. These data suggest that the endocrine system may be an important mediator between personal relationships and health.

Double-driven shield capacitive type proximity sensor

NASA Technical Reports Server (NTRS)

Vranish, John M. (Inventor)

1993-01-01

A capacity type proximity sensor comprised of a capacitance type sensor, a capacitance type reference, and two independent and mutually opposing driven shields respectively adjacent to the sensor and reference and which are coupled in an electrical bridge circuit configuration and driven by a single frequency crystal controlled oscillator is presented. The bridge circuit additionally includes a pair of fixed electrical impedance elements which form adjacent arms of the bridge and which comprise either a pair of precision resistances or capacitors. Detection of bridge unbalance provides an indication of the mutual proximity between an object and the sensor. Drift compensation is also utilized to improve performance and thus increase sensor range and sensitivity.

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

PubMed

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

2018-04-23

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

Attentional Control of Task and Response in Lateral and Medial Frontal Cortex: Brain Activity and Reaction Time Distributions

ERIC Educational Resources Information Center

Aarts, Esther; Roelofs, Ardi; van Turennout, Miranda

2009-01-01

It is unclear whether task conflict is reflected in the anterior cingulate cortex (ACC) or in more dorsal regions of the medial frontal cortex (MFC). When participants switch between tasks involving incongruent, congruent, and neutral stimuli, it is possible to examine both response conflict (incongruent vs. congruent) and task conflict (congruent…

Impaired preparatory re-mapping of stimulus-response associations and rule-implementation in schizophrenic patients--the role for differences in early processing.

PubMed

Finke, Mareike; Barceló, Francisco; Garolera, Maite; Cortiñas, Miriam; Garrido, Gemma; Pajares, Marta; Escera, Carles

2011-07-01

An accurate representation of task-set information is needed for successful goal directed behavior. Recent studies point to disturbances in the early processing stages as plausible causes for task-switching deficits in schizophrenia. A task-cueing protocol was administered to a group of schizophrenic patients and compared with a sample of age-matched healthy controls. Patients responded slower and less accurate compared with controls in all conditions. The concurrent recording of event-related brain potentials to contextual cues and target events revealed abnormalities in the early processing of both cue-locked and target-locked N1 potentials. Abnormally enhanced target-locked P2 amplitudes were observed in schizophrenic patients for task-switch trials only, suggesting disrupted stimulus evaluation and memory retrieval processes. The endogenous P3 potentials discriminated between task conditions but without further differences between groups. These results suggest that the observed impairments in task-switching behavior were not specifically related to anticipatory set-shifting, but derived from a deficit in the implementation of task-set representations at target onset in the presence of irrelevant and conflicting information. Copyright © 2011 Elsevier B.V. All rights reserved.

What Klein's "Semantic Gradient" Does and Does Not Really Show: Decomposing Stroop Interference into Task and Informational Conflict Components.

PubMed

Levin, Yulia; Tzelgov, Joseph

2016-01-01

The present study suggests that the idea that Stroop interference originates from multiple components may gain theoretically from integrating two independent frameworks. The first framework is represented by the well-known notion of "semantic gradient" of interference and the second one is the distinction between two types of conflict - the task and the informational conflict - giving rise to the interference (MacLeod and MacDonald, 2000; Goldfarb and Henik, 2007). The proposed integration led to the conclusion that two (i.e., orthographic and lexical components) of the four theoretically distinct components represent task conflict, and the other two (i.e., indirect and direct informational conflict components) represent informational conflict. The four components were independently estimated in a series of experiments. The results confirmed the contribution of task conflict (estimated by a robust orthographic component) and of informational conflict (estimated by a strong direct informational conflict component) to Stroop interference. However, the performed critical review of the relevant literature (see General Discussion), as well as the results of the experiments reported, showed that the other two components expressing each type of conflict (i.e., the lexical component of task conflict and the indirect informational conflict) were small and unstable. The present analysis refines our knowledge of the origins of Stroop interference by providing evidence that each type of conflict has its major and minor contributions. The implications for cognitive control of an automatic reading process are also discussed.

What Klein’s “Semantic Gradient” Does and Does Not Really Show: Decomposing Stroop Interference into Task and Informational Conflict Components

PubMed Central

Levin, Yulia; Tzelgov, Joseph

2016-01-01

The present study suggests that the idea that Stroop interference originates from multiple components may gain theoretically from integrating two independent frameworks. The first framework is represented by the well-known notion of “semantic gradient” of interference and the second one is the distinction between two types of conflict – the task and the informational conflict – giving rise to the interference (MacLeod and MacDonald, 2000; Goldfarb and Henik, 2007). The proposed integration led to the conclusion that two (i.e., orthographic and lexical components) of the four theoretically distinct components represent task conflict, and the other two (i.e., indirect and direct informational conflict components) represent informational conflict. The four components were independently estimated in a series of experiments. The results confirmed the contribution of task conflict (estimated by a robust orthographic component) and of informational conflict (estimated by a strong direct informational conflict component) to Stroop interference. However, the performed critical review of the relevant literature (see General Discussion), as well as the results of the experiments reported, showed that the other two components expressing each type of conflict (i.e., the lexical component of task conflict and the indirect informational conflict) were small and unstable. The present analysis refines our knowledge of the origins of Stroop interference by providing evidence that each type of conflict has its major and minor contributions. The implications for cognitive control of an automatic reading process are also discussed. PMID:26955363

Task-Driven Evaluation of Aggregation in Time Series Visualization

PubMed Central

Albers, Danielle; Correll, Michael; Gleicher, Michael

2014-01-01

Many visualization tasks require the viewer to make judgments about aggregate properties of data. Recent work has shown that viewers can perform such tasks effectively, for example to efficiently compare the maximums or means over ranges of data. However, this work also shows that such effectiveness depends on the designs of the displays. In this paper, we explore this relationship between aggregation task and visualization design to provide guidance on matching tasks with designs. We combine prior results from perceptual science and graphical perception to suggest a set of design variables that influence performance on various aggregate comparison tasks. We describe how choices in these variables can lead to designs that are matched to particular tasks. We use these variables to assess a set of eight different designs, predicting how they will support a set of six aggregate time series comparison tasks. A crowd-sourced evaluation confirms these predictions. These results not only provide evidence for how the specific visualizations support various tasks, but also suggest using the identified design variables as a tool for designing visualizations well suited for various types of tasks. PMID:25343147

Small Group Conflict: A Look at Equity, Satisfaction, and Styles of Conflict Management.

ERIC Educational Resources Information Center

Wall, Victor D., Jr.; Nolan, Linda L.

1987-01-01

Study of 71 task-oriented groups revealed that perceived inequity was negatively related to amount of expressed satisfaction with the group and positively related to amount of perceived conflict within the group. Inequity was associated more strongly with conflict centered around people than with conflict centered around task; least associated…

Managing Conflict in School Teams: The Impact of Task and Goal Interdependence on Conflict Management and Team Effectiveness

ERIC Educational Resources Information Center

Somech, Anit

2008-01-01

Purpose: Although conflict has traditionally been considered destructive, recent studies have indicated that conflict management can contribute to effective teamwork. The present study explores conflict management as a team phenomenon in schools. The author examined how the contextual variables (task interdependence, goal interdependence) are…

Phasic valence and arousal do not influence post-conflict adjustments in the Simon task.

PubMed

Dignath, David; Janczyk, Markus; Eder, Andreas B

2017-03-01

According to theoretical accounts of cognitive control, conflict between competing responses is monitored and triggers post conflict behavioural adjustments. Some models proposed that conflict is detected as an affective signal. While the conflict monitoring theory assumed that conflict is registered as a negative valence signal, the adaptation by binding model hypothesized that conflict provides a high arousal signal. The present research induced phasic affect in a Simon task with presentations of pleasant and unpleasant pictures that were high or low in arousal. If conflict is registered as an affective signal, the presentation of a corresponding affective signal should potentiate post conflict adjustments. Results did not support the hypothesis, and Bayesian analyses corroborated the conclusion that phasic affects do not influence post conflict behavioural adjustments in the Simon task. Copyright © 2017 Elsevier B.V. All rights reserved.

Accommodation and Adjudication in Student-Administration Conflicts: The Difficult Legacy of the U.S. Supreme Court

ERIC Educational Resources Information Center

Meyer, Heinz-Dieter; Bratge, Katrina

2011-01-01

In this article, we consider a series of U.S. Supreme Court rulings that place public school students under an expansive shield of constitutional rights while often hampering the ability of administrators to engage in flexible and creative conflict resolution in the context of the school's mission. The court's readiness to adjudicate a large range…

State of the World's Mothers, 2003: Protecting Women and Children in War and Conflict.

ERIC Educational Resources Information Center

Geoghegan, Tracy

In commemoration of Mother's Day, Save the Children has published its fourth annual report focusing on the tens of millions of mothers and children whose lives have been disrupted by war and armed conflict and suggesting actions required to support women who are raising the children under horrific conditions and to shield children from the most…

Errors and conflict at the task level and the response level.

PubMed

Desmet, Charlotte; Fias, Wim; Hartstra, Egbert; Brass, Marcel

2011-01-26

In the last decade, research on error and conflict processing has become one of the most influential research areas in the domain of cognitive control. There is now converging evidence that a specific part of the posterior frontomedian cortex (pFMC), the rostral cingulate zone (RCZ), is crucially involved in the processing of errors and conflict. However, error-related research has focused primarily on a specific error type, namely, response errors. The aim of the present study was to investigate whether errors on the task level rely on the same neural and functional mechanisms. Here we report a dissociation of both error types in the pFMC: whereas response errors activate the RCZ, task errors activate the dorsal frontomedian cortex. Although this last region shows an overlap in activation for task and response errors on the group level, a closer inspection of the single-subject data is more in accordance with a functional anatomical dissociation. When investigating brain areas related to conflict on the task and response levels, a clear dissociation was perceived between areas associated with response conflict and with task conflict. Overall, our data support a dissociation between response and task levels of processing in the pFMC. In addition, we provide additional evidence for a dissociation between conflict and errors both at the response level and at the task level.

Why are background telephone conversations distracting?

PubMed

Marsh, John E; Ljung, Robert; Jahncke, Helena; MacCutcheon, Douglas; Pausch, Florian; Ball, Linden J; Vachon, François

2018-06-01

Telephone conversation is ubiquitous within the office setting. Overhearing a telephone conversation-whereby only one of the two speakers is heard-is subjectively more annoying and objectively more distracting than overhearing a full conversation. The present study sought to determine whether this "halfalogue" effect is attributable to unexpected offsets and onsets within the background speech (acoustic unexpectedness) or to the tendency to predict the unheard part of the conversation (semantic [un]predictability), and whether these effects can be shielded against through top-down cognitive control. In Experiment 1, participants performed an office-related task in quiet or in the presence of halfalogue and dialogue background speech. Irrelevant speech was either meaningful or meaningless speech. The halfalogue effect was only present for the meaningful speech condition. Experiment 2 addressed whether higher task-engagement could shield against the halfalogue effect by manipulating the font of the to-be-read material. Although the halfalogue effect was found with an easy-to-read font (fluent text), the use of a difficult-to-read font (disfluent text) eliminated the effect. The halfalogue effect is thus attributable to the semantic (un)predictability, not the acoustic unexpectedness, of background telephone conversation and can be prevented by simple means such as increasing the level of engagement required by the focal task. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

76 FR 28376 - Airworthiness Directives; Fokker Services B.V. Model F.28 Mark 1000, 2000, 3000, and 4000 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-17

... Configuration Control Limitations (CDCCL) task to make certain that the by-pass wire remains installed. On later... in-tank Fuel Quantity Indication (FQI) cable plug and the cable shield of the shielded FQI system... (FQI) cable plug and the cable shield of the shielded FQI system cables in the main and collector fuel...

Temporal and spectral profiles of stimulus-stimulus and stimulus-response conflict processing.

PubMed

Wang, Kai; Li, Qi; Zheng, Ya; Wang, Hongbin; Liu, Xun

2014-04-01

The ability to detect and resolve conflict is an essential function of cognitive control. Laboratory studies often use stimulus-response-compatibility (SRC) tasks to examine conflict processing in order to elucidate the mechanism and modular organization of cognitive control. Inspired by two influential theories regarding cognitive control, the conflict monitoring theory (Botvinick, Braver, Barch, Carter, & Cohen, 2001) and dimensional overlap taxonomy (Kornblum, Hasbroucq, & Osman, 1990), we explored the temporal and spectral similarities and differences between processing of stimulus-stimulus (S-S) and stimulus-response (S-R) conflicts with event related potential (ERP) and time-frequency measures. We predicted that processing of S-S conflict starts earlier than that of S-R conflict and that the two types of conflict may involve different frequency bands. Participants were asked to perform two parallel SRC tasks, both combining the Stroop task (involving S-S conflict) and Simon task (involving S-R conflict). ERP results showed pronounced SRC effects (incongruent vs. congruent) on N2 and P3 components for both S-S and S-R conflicts. In both tasks, SRC effects of S-S conflict took place earlier than those of S-R conflict. Time-frequency analysis revealed that both types of SRC effects modulated theta and alpha bands, while S-R conflict effects additionally modulated power in the beta band. These results indicated that although S-S and S-R conflict processing shared considerable ERP and time-frequency properties, they differed in temporal and spectral dynamics. We suggest that the modular organization of cognitive control should take both commonality and distinction of S-S and S-R conflict processing into consideration. Copyright © 2013 Elsevier Inc. All rights reserved.

Examining Classroom Interactions Related to Difference in Students' Science Achievement.

ERIC Educational Resources Information Center

Zady, Madelon F.; Portes, Pedro R.; Ochs, V. Dan

2003-01-01

Examines the cognitive supports that underlie achievement in science using a cultural historical framework and the activity setting (AS) construct with five features: personnel, motivation, scripts, task demands, and beliefs. Reports four emergent phenomena--science activities, the building of learning, meaning in lessons, and the conflict over…

Dissociable effects of motivation and expectancy on conflict processing: an fMRI study.

PubMed

Soutschek, Alexander; Stelzel, Christine; Paschke, Lena; Walter, Henrik; Schubert, Torsten

2015-02-01

Previous studies suggest that both motivation and task difficulty expectations activate brain regions associated with cognitive control. However, it remains an open question whether motivational and cognitive determinants of control have similar or dissociable impacts on conflict processing on a neural level. The current study tested the effects of motivation and conflict expectancy on activity in regions related to processing of the target and the distractor information. Participants performed a picture-word interference task in which we manipulated the size of performance-dependent monetary rewards (level of motivation) and the ratio of congruent to incongruent trials within a block (level of conflict expectancy). Our results suggest that motivation improves conflict processing by facilitating task-relevant stimulus processing and task difficulty expectations mainly modulate the processing of distractor information. We conclude that motivation and conflict expectancy engage dissociable control strategies during conflict resolution.

Conflict adaptation in emotional task underlies the amplification of target.

PubMed

Chechko, Natalia; Kellermann, Thilo; Schneider, Frank; Habel, Ute

2014-04-01

A primary function of cognitive control is to adjust the cognitive system according to situational demands. The so-called "conflict adaptation effect" elicited in laboratory experiments is supposed to reflect the above function. Neuroimaging studies suggest that adaptation of nonemotional conflict is mediated by the dorsolateral prefrontal cortex through a top-down enhancement of task-relevant (target), relative to task-irrelevant (distractor), stimulus representation in the sensory cortices. The adaptation of emotional conflict, on the other hand, is suggested to be related to the rostral anterior cingulate inhibiting the processing of emotional distractors through a top-down modulation of amygdala responsivity. In the present study, we manipulated, on a trial-by-trial basis, the levels of semantic interference conflict triggered by the incompatibility between emotional faces (targets) and emotional words (distractors) in a modified version of the emotional Stroop task. Similar to previous observations involving nonemotional interference effects, the behavioral adaptation of emotional conflict was found to be paralleled by a stronger recruitment of the fusiform face area. Additional areas related to the conflict adaptation effect were the bilateral insula, the bilateral frontal operculum (fO), the right amygdala, the left precentral and postcentral gyri, and the parietal cortex. These findings suggest that augmentation of cortical responses to task-relevant information in emotional conflict may be related to conflict adaptation processes in a way that has been observed in nonemotional conflict, challenging the view that brain circuitries underlying the conflict adaptation effect depend only on the nature of conflict.

Normal cognitive conflict resolution in psychosis patients with and without schizophrenia.

PubMed

Smid, Henderikus G O M; Bruggeman, Richard; Martens, Sander

2016-01-01

Schizophrenia is thought to be associated with impairments of executive functions, among which conflict control functions play an important role. The available evidence, however, suggests that conflict control is intact in schizophrenia, despite being based on methods that have successfully unveiled conflict control problems in other disorders. Differences between schizophrenia patients and healthy controls in stimulus perception, selective attention, alertness, processing speed and reaction time variability may have been previously overlooked. By controlling for these potential confounders, the present experiments were aimed to be more rigorous tests of the hypothesis that psychosis and schizophrenia are associated with impairments of conflict control. To that end, 27 healthy controls and 53 recent-onset psychosis patients with (n = 27) and without schizophrenia (n = 26) with comparable age, intelligence, and education level, performed three iconic conflict control tasks: the Simon task, the Eriksen flanker task, and the Stroop task, all equipped with neutral trials, and analyzed for various potential confounders. They further performed a battery of standard neuropsychological tests. Schizophrenia patients showed no increased conflict effects in any of the 3 tasks for any alternative measures used. Nonschizophrenia patients only showed abnormally increased response competition in the Simon task. All patients nevertheless demonstrated impaired control of attention and verbal memory. These findings indicate that the type of conflict control engaged by conflict tasks is intact in recent-onset schizophrenia, suggesting that a major component of executive function is spared in schizophrenia. We discuss these findings in terms of proactive and reactive control. (c) 2016 APA, all rights reserved.

The neural mechanisms of semantic and response conflicts: an fMRI study of practice-related effects in the Stroop task.

PubMed

Chen, Zhencai; Lei, Xu; Ding, Cody; Li, Hong; Chen, Antao

2013-02-01

Previous studies have demonstrated that there are separate neural mechanisms underlying semantic and response conflicts in the Stroop task. However, the practice effects of these conflicts need to be elucidated and the possible involvements of common neural mechanisms are yet to be established. We employed functional magnetic resonance imaging (fMRI) in a 4-2 mapping practice-related Stroop task to determine the neural substrates under these conflicts. Results showed that different patterns of brain activations are associated with practice in the attentional networks (e.g., dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and posterior parietal cortex (PPC)) for both conflicts, response control regions (e.g., inferior frontal junction (IFJ), inferior frontal gyrus (IFG)/insula, and pre-supplementary motor areas (pre-SMA)) for semantic conflict, and posterior cortex for response conflict. We also found areas of common activation in the left hemisphere within the attentional networks, for the early practice stage in semantic conflict and the late stage in "pure" response conflict using conjunction analysis. The different practice effects indicate that there are distinct mechanisms underlying these two conflict types: semantic conflict practice effects are attributable to the automation of stimulus processing, conflict and response control; response conflict practice effects are attributable to the proportional increase of conflict-related cognitive resources. In addition, the areas of common activation suggest that the semantic conflict effect may contain a partial response conflict effect, particularly at the beginning of the task. These findings indicate that there are two kinds of response conflicts contained in the key-pressing Stroop task: the vocal-level (mainly in the early stage) and key-pressing (mainly in the late stage) response conflicts; thus, the use of the subtraction method for the exploration of semantic and response conflicts may need to be further examined. Copyright © 2012 Elsevier Inc. All rights reserved.

A neural mechanism of cognitive control for resolving conflict between abstract task rules.

PubMed

Sheu, Yi-Shin; Courtney, Susan M

2016-12-01

Conflict between multiple sensory stimuli or potential motor responses is thought to be resolved via bias signals from prefrontal cortex (PFC). However, population codes in the PFC also represent abstract information, such as task rules. How is conflict between active abstract representations resolved? We used functional neuroimaging to investigate the mechanism responsible for resolving conflict between abstract representations of task rules. Participants performed two different tasks based on a cue. We manipulated the degree of conflict at the task-rule level by training participants to associate the color and shape dimensions of the cue with either the same task rule (congruent cues) or different ones (incongruent cues). Phonological and semantic tasks were used in which performance depended on learned, abstract representations of information, rather than sensory features of the target stimulus or on any habituated stimulus-response associations. In addition, these tasks activate distinct regions that allowed us to measure magnitude of conflict between tasks. We found that incongruent cues were associated with increased activity in several cognitive control areas, including the inferior frontal gyrus, inferior parietal lobule, insula, and subcortical regions. Conflict between abstract representations appears to be resolved by rule-specific activity in the inferior frontal gyrus that is correlated with enhanced activity related to the relevant information. Furthermore, multi-voxel pattern analysis of the activity in the inferior frontal gyrus was shown to carry information about both the currently relevant rule (semantic/phonological) and the currently relevant cue context (color/shape). Similar to models of attentional selection of conflicting sensory or motor representations, the current findings indicate part of the frontal cortex provides a bias signal, representing task rules, that enhances task-relevant information. However, the frontal cortex can also be the target of these bias signals in order to enhance abstract representations that are independent of particular stimuli or motor responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

A neural mechanism of cognitive control for resolving conflict between abstract task rules

PubMed Central

Sheu, Yi-Shin; Courtney, Susan M.

2016-01-01

Conflict between multiple sensory stimuli or potential motor responses is thought to be resolved via bias signals from prefrontal cortex. However, population codes in the prefrontal cortex also represent abstract information, such as task rules. How is conflict between active abstract representations resolved? We used functional neuroimaging to investigate the mechanism responsible for resolving conflict between abstract representations of task rules. Participants performed two different tasks based on a cue. We manipulated the degree of conflict at the task-rule level by training participants to associate the color and shape dimensions of the cue with either the same task rule (congruent cues) or different ones (incongruent cues). Phonological and semantic tasks were used in which performance depended on learned, abstract representations of information, rather than sensory features of the target stimulus or on any habituated stimulus-response associations. In addition, these tasks activate distinct regions that allowed us to measure magnitude of conflict between tasks. We found that incongruent cues were associated with increased activity in several cognitive control areas, including the inferior frontal gyrus, inferior parietal lobule, insula, and subcortical regions. Conflict between abstract representations appears to be resolved by rule-specific activity in the inferior frontal gyrus that is correlated with enhanced activity related to the relevant information. Furthermore, multivoxel pattern analysis of the activity in the inferior frontal gyrus was shown to carry information about both the currently relevant rule (semantic/phonological) and the currently relevant cue context (color/shape). Similar to models of attentional selection of conflicting sensory or motor representations, the current findings indicate part of the frontal cortex provides a bias signal, representing task rules, that enhances task-relevant information. However, the frontal cortex can also be the target of these bias signals in order to enhance abstract representations that are independent of particular stimuli or motor responses. PMID:27771559

Across-task priming revisited: response and task conflicts disentangled using ex-Gaussian distribution analysis.

PubMed

Moutsopoulou, Karolina; Waszak, Florian

2012-04-01

The differential effects of task and response conflict in priming paradigms where associations are strengthened between a stimulus, a task, and a response have been demonstrated in recent years with neuroimaging methods. However, such effects are not easily disentangled with only measurements of behavior, such as reaction times (RTs). Here, we report the application of ex-Gaussian distribution analysis on task-switching RT data and show that conflict related to stimulus-response associations retrieved after a switch of tasks is reflected in the Gaussian component. By contrast, conflict related to the retrieval of stimulus-task associations is reflected in the exponential component. Our data confirm that the retrieval of stimulus-task and -response associations affects behavior differently. Ex-Gaussian distribution analysis is a useful tool for pulling apart these different levels of associative priming that are not distinguishable in analyses of RT means.

Prioritizing Healthcare Delivery in a Conflict Zone Comment on "TB/HIV Co-Infection Care in Conflict-Affected Settings: A Mapping of Health Facilities in the Goma Area, Democratic Republic of Congo".

PubMed

Wood, Robin; Richardson, Eugene T

2013-09-01

Nowhere are the barriers to a functional health infrastructure more clearly on display than in the Goma region of Democratic Republic of Congo. Kaboru et al. report poorly integrated services for HIV and TB in this war-torn region. Priorities in conflict zones include provision of security, shelter, food, clean water and prevention of sexual violence. In Goma, immediate health priorities include emergency treatment of cholera, malaria, respiratory illnesses, provision of maternal care, millions of measles vaccinations, and management of an ongoing rabies epidemic. It is a daunting task to determine an essential package of medical services in a setting where there are so many competing priorities, where opportunity costs are limited and epidemiologic information is scarce. Non-governmental agencies sometimes add to the challenge via an insidious reduction of state sovereignty and the creation of new levels of income inequality. Kaboru et al. have successfully highlighted many of the complexities of rebuilding and prioritizing healthcare in a conflict zone.

Context Modulates Congruency Effects in Selective Attention to Social Cues.

PubMed

Ravagli, Andrea; Marini, Francesco; Marino, Barbara F M; Ricciardelli, Paola

2018-01-01

Head and gaze directions are used during social interactions as essential cues to infer where someone attends. When head and gaze are oriented toward opposite directions, we need to extract socially meaningful information despite stimulus conflict. Recently, a cognitive and neural mechanism for filtering-out conflicting stimuli has been identified while performing non-social attention tasks. This mechanism is engaged proactively when conflict is anticipated in a high proportion of trials and reactively when conflict occurs infrequently. Here, we investigated whether a similar mechanism is at play for limiting distraction from conflicting social cues during gaze or head direction discrimination tasks in contexts with different probabilities of conflict. Results showed that, for the gaze direction task only (Experiment 1), inverse efficiency (IE) scores for distractor-absent trials (i.e., faces with averted gaze and centrally oriented head) were larger (indicating worse performance) when these trials were intermixed with congruent/incongruent distractor-present trials (i.e., faces with averted gaze and tilted head in the same/opposite direction) relative to when the same distractor-absent trials were shown in isolation. Moreover, on distractor-present trials, IE scores for congruent (vs. incongruent) head-gaze pairs in blocks with rare conflict were larger than in blocks with frequent conflict, suggesting that adaptation to conflict was more efficient than adaptation to infrequent events. However, when the task required discrimination of head orientation while ignoring gaze direction, performance was not impacted by both block-level and current trial congruency (Experiment 2), unless the cognitive load of the task was increased by adding a concurrent task (Experiment 3). Overall, our study demonstrates that during attention to social cues proactive cognitive control mechanisms are modulated by the expectation of conflicting stimulus information at both the block- and trial-sequence level, and by the type of task and cognitive load. This helps to clarify the inherent differences in the distracting potential of head and gaze cues during speeded social attention tasks.

Domain-specific control mechanisms for emotional and nonemotional conflict processing.

PubMed

Soutschek, Alexander; Schubert, Torsten

2013-02-01

Recent neuroimaging studies suggest that the human brain activates dissociable cognitive control networks in response to conflicts arising within the cognitive and the affective domain. The present study tested the hypothesis that nonemotional and emotional conflict regulation can also be dissociated on a functional level. For that purpose, we examined the effects of a working memory and an emotional Go/Nogo task on cognitive control in an emotional and a nonemotional variant of the Stroop paradigm. The data confirmed the hypothesized dissociation: Working memory efforts selectively suppressed conflict regulation in the nonemotional Stroop task, while the demands of an emotional Go/Nogo task impaired only conflict regulation in the emotional Stroop task. We conclude that these findings support a modular architecture of cognitive control with domain-specific conflict regulation processes. Copyright © 2012 Elsevier B.V. All rights reserved.

Task conflict and proactive control: A computational theory of the Stroop task.

PubMed

Kalanthroff, Eyal; Davelaar, Eddy J; Henik, Avishai; Goldfarb, Liat; Usher, Marius

2018-01-01

The Stroop task is a central experimental paradigm used to probe cognitive control by measuring the ability of participants to selectively attend to task-relevant information and inhibit automatic task-irrelevant responses. Research has revealed variability in both experimental manipulations and individual differences. Here, we focus on a particular source of Stroop variability, the reverse-facilitation (RF; faster responses to nonword neutral stimuli than to congruent stimuli), which has recently been suggested as a signature of task conflict. We first review the literature that shows RF variability in the Stroop task, both with regard to experimental manipulations and to individual differences. We suggest that task conflict variability can be understood as resulting from the degree of proactive control that subjects recruit in advance of the Stroop stimulus. When the proactive control is high, task conflict does not arise (or is resolved very quickly), resulting in regular Stroop facilitation. When proactive control is low, task conflict emerges, leading to a slow-down in congruent and incongruent (but not in neutral) trials and thus to Stroop RF. To support this suggestion, we present a computational model of the Stroop task, which includes the resolution of task conflict and its modulation by proactive control. Results show that our model (a) accounts for the variability in Stroop-RF reported in the experimental literature, and (b) solves a challenge to previous Stroop models-their ability to account for reaction time distributional properties. Finally, we discuss theoretical implications to Stroop measures and control deficits observed in some psychopathologies. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The effects of age, sex, and hormones on emotional conflict-related brain response during adolescence

PubMed Central

Cservenka, Anita; Stroup, Madison L.; Etkin, Amit; Nagel, Bonnie J.

2015-01-01

While cognitive and emotional systems both undergo development during adolescence, few studies have explored top-down inhibitory control brain activity in the context of affective processing, critical to informing adolescent psychopathology. In this study, we used functional magnetic resonance imaging to examine brain response during an Emotional Conflict (EmC) Task across 10–15-year-old youth. During the EmC Task, participants indicated the emotion of facial expressions, while disregarding emotion-congruent and incongruent words printed across the faces. We examined the relationships of age, sex, and gonadal hormones with brain activity on Incongruent vs. Congruent trials. Age was negatively associated with middle frontal gyrus activity, controlling for performance and movement confounds. Sex differences were present in occipital and parietal cortices, and were driven by activation in females, and deactivation in males to Congruent trials. Testosterone was negatively related with frontal and striatal brain response in males, and cerebellar and precuneus response in females. Estradiol was negatively related with fronto-cerebellar, cingulate, and precuneus brain activity in males, and positively related with occipital response in females. To our knowledge, this is the first study reporting the effects of age, sex, and sex steroids during an emotion-cognition task in adolescents. Further research is needed to examine longitudinal development of emotion-cognition interactions and deviations in psychiatric disorders in adolescence. PMID:26175008

The effects of age, sex, and hormones on emotional conflict-related brain response during adolescence.

PubMed

Cservenka, Anita; Stroup, Madison L; Etkin, Amit; Nagel, Bonnie J

2015-10-01

While cognitive and emotional systems both undergo development during adolescence, few studies have explored top-down inhibitory control brain activity in the context of affective processing, critical to informing adolescent psychopathology. In this study, we used functional magnetic resonance imaging to examine brain response during an Emotional Conflict (EmC) Task across 10-15-year-old youth. During the EmC Task, participants indicated the emotion of facial expressions, while disregarding emotion-congruent and incongruent words printed across the faces. We examined the relationships of age, sex, and gonadal hormones with brain activity on Incongruent vs. Congruent trials. Age was negatively associated with middle frontal gyrus activity, controlling for performance and movement confounds. Sex differences were present in occipital and parietal cortices, and were driven by activation in females, and deactivation in males to Congruent trials. Testosterone was negatively related with frontal and striatal brain response in males, and cerebellar and precuneus response in females. Estradiol was negatively related with fronto-cerebellar, cingulate, and precuneus brain activity in males, and positively related with occipital response in females. To our knowledge, this is the first study reporting the effects of age, sex, and sex steroids during an emotion-cognition task in adolescents. Further research is needed to examine longitudinal development of emotion-cognition interactions and deviations in psychiatric disorders in adolescence. Copyright © 2015 Elsevier Inc. All rights reserved.

Measuring the Impact of the Micronegotiation Technique on Team Member Satisfaction and Team Performance

ERIC Educational Resources Information Center

Kaufman, Jeffery David

2013-01-01

Conflict is not an uncommon element of team interactions and processes; however, if unchecked it can cause issues in the ability of the team to achieve maximum performance. Research on task conflict and relationship conflict by de Wit, Greer, and Jehn (2012) found that while in many cases task conflict and relationship conflict within teams can…

Small, Task-Oriented Groups: Conflict, Conflict Management, Satisfaction, and Decision Quality.

ERIC Educational Resources Information Center

Wall, Victor D., Jr.; And Others

1987-01-01

Examined relationship among amount of conflict experienced, the style of its management, individual satisfaction, and decision quality of small, task-oriented groups using 129 college student subjects in 24 groups. Data suggest a curvilinear relationship between the number of conflict episodes experienced by group members and the subsequent…

The Role of Working Memory Gating in Task Switching: A Procedural Version of the Reference-Back Paradigm

PubMed Central

Kessler, Yoav

2017-01-01

Models of working memory (WM) suggest that the contents of WM are separated from perceptual input by a gate, that enables shielding information against interference when closed, and allows for rapid updating when open. Recent work in the declarative WM domain provided evidence for this notion, demonstrating the behavioral cost of opening and closing the gate. The goal of the present work was to examine gating in procedural WM, namely in a task-switching experiment. In each trial, participants were presented with a digit and a task cue, indicating whether the required task was a parity or a magnitude decision. Critically, a colored frame around the stimulus indicated whether the task cue was relevant (attend trials), or whether it had to be ignored, and the previous task set should be applied regardless of the present cue (ignore trials). Switching between tasks, and between ignore and attend trials, was manipulated. The results of two experiments demonstrated that the cost of gate opening was eliminated in task switching trials, implying that both processes operate in parallel. PMID:29312095

Causes and consequences of a tropical forest gold rush in the Guiana Shield, South America.

PubMed

Hammond, David S; Gond, Valéry; de Thoisy, Benoit; Forget, Pierre-Michel; DeDijn, Bart P E

2007-12-01

Statistical and spatial analyses of both historical time series and remotely sensed data show a link between the spatial distribution and growth of gold production across the Guiana Shield in northeast Amazonia. Results indicate that an exponential rise in production across an expanding area is primarily a delayed response to the 1971-1978 market flotation of international gold prices. The subsequent 10-fold (2-fold) average nominal (real) price increase has provided a compelling economic incentive to mass exploitation of lower-grade gold deposits. The ground-based and remotely sensed distributions of mining activity are strongly attached to these deposits that dominate the region's gold geology. The presence of these gold-bearing formations in conservation and sustainable timber zones has sparked social conflict and environmental degradation across the region. Left unmanaged, more than a quarter-million square-kilometer area of tropical forest zoned for protection and sustainable management could ultimately be compromised by the price-driven boom in gold mining through poorly integrated resource use planning, lack of reclamation effort, and control of illegal operations. Serious public health issues propagated through the unregulated mining environment further erode the financial benefits achieved through gold extraction. This study demonstrates in part how international economic policies successfully stabilizing more conspicuous centers of the global economy can have unintended but profound environmental and social impacts on remote commodity frontiers.

High voltage design structure for high temperature superconducting device

DOEpatents

Tekletsadik, Kasegn D [Rexford, NY

2008-05-20

In accordance with the present invention, modular corona shields are employed in a HTS device to reduce the electric field surrounding the HTS device. In a exemplary embodiment a fault current limiter module in the insulation region of a cryogenic cooling system has at least one fault current limiter set which employs a first corona shield disposed along the top portion of the fault current limiter set and is electrically coupled to the fault current limiter set. A second corona shield is disposed along the bottom portion of the fault current limiter set and is electrically coupled to the fault current limiter set. An insulation barrier is disposed within the insulation region along at least one side of the fault current limiter set. The first corona shield and the second corona shield act together to reduce the electric field surrounding the fault limiter set when voltage is applied to the fault limiter set.

Context-specific adjustment of cognitive control: Transfer of adaptive control sets.

PubMed

Surrey, Caroline; Dreisbach, Gesine; Fischer, Rico

2017-11-01

Cognitive control protects processing of relevant information from interference by irrelevant information. The level of this processing selectivity can be flexibly adjusted to different control demands (e.g., frequency of conflict) associated with a certain context, leading to the formation of specific context-control associations. In the present study we investigated the robustness and transferability of the acquired context-control demands to new situations. In three experiments, we used a version of the context-specific proportion congruence (CSPC) paradigm, in which each context (e.g., location) is associated with a specific conflict frequency, determining high and low control demands. In a learning phase, associations between context and control demands were established. In a subsequent transfer block, stimulus-response mappings, whole task sets, or context-control demands changed. Results showed an impressive robustness of context-control associations, as context-specific adjustments of control from the learning phase were virtually unaffected by new stimuli and tasks in the transfer block. Only a change of the context-control demand eliminated the context-specific adjustment of control. These findings suggest that context-control associations that have proven to be adaptive in the past are continuously applied despite major changes in the task structure as long as the context-control associations remain the same.

Multi-attribute subjective evaluations of manual tracking tasks vs. objective performance of the human operator

NASA Technical Reports Server (NTRS)

Siapkaras, A.

1977-01-01

A computational method to deal with the multidimensional nature of tracking and/or monitoring tasks is developed. Operator centered variables, including the operator's perception of the task, are considered. Matrix ratings are defined based on multidimensional scaling techniques and multivariate analysis. The method consists of two distinct steps: (1) to determine the mathematical space of subjective judgements of a certain individual (or group of evaluators) for a given set of tasks and experimental conditionings; and (2) to relate this space with respect to both the task variables and the objective performance criteria used. Results for a variety of second-order trackings with smoothed noise-driven inputs indicate that: (1) many of the internally perceived task variables form a nonorthogonal set; and (2) the structure of the subjective space varies among groups of individuals according to the degree of familiarity they have with such tasks.

Cognitive Control Acts Locally

ERIC Educational Resources Information Center

Notebaert, Wim; Verguts, Tom

2008-01-01

Cognitive control adjusts information processing to momentary needs and task requirements. We investigated conflict adaptation when participants are performing two tasks, a Simon task and a SNARC task. The results indicated that one congruency effect (e.g., Simon) was reduced after conflict in the other task (e.g., SNARC), but only when both tasks…

Neural cascade of conflict processing: Not just time-on-task.

PubMed

McKay, Cameron C; van den Berg, Berry; Woldorff, Marty G

2017-02-01

In visual conflict tasks (e.g., Stroop or flanker), response times (RTs) are generally longer on incongruent trials relative to congruent ones. Two event-related-potential (ERP) components classically associated with the processing of stimulus conflict are the fronto-central, incongruency-related negativity (N inc ) and the posterior late-positive complex (LPC), which are derived from the ERP difference waves for incongruent minus congruent trials. It has been questioned, however, whether these effects, or other neural measures of incongruency (e.g., fMRI responses in the anterior cingulate), reflect true conflict processing, or whether such effects derive mainly from differential time-on-task. To address this question, we leveraged high-temporal-resolution ERP measures of brain activity during two behavioral tasks. The first task, a modified Erikson flanker paradigm (with congruent and incongruent trials), was used to evoke the classic RT and ERP effects associated with conflict. The second was a non-conflict control task in which, participants visually discriminated a single stimulus (with easy and hard discrimination conditions). Behaviorally, the parameters were titrated to yield similar RT effects of conflict and difficulty (27ms). Neurally, both within-task contrasts showed an initial fronto-central negative-polarity wave (N2-latency effect), but they then diverged. In the difficulty difference wave, the initial negativity led directly into the posterior LPC, whereas in the incongruency contrast the initial negativity was followed a by a second fronto-central negative peak (N inc ), which was then followed by a considerably longer-latency LPC. These results provide clear evidence that the longer processing for incongruent stimulus inputs do not just reflect time-on-task or difficulty, but include a true conflict-processing component. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cognitive control during a spatial Stroop task: Comparing conflict monitoring and prediction of response-outcome theories.

PubMed

Pires, Luís; Leitão, José; Guerrini, Chiara; Simões, Mário R

2017-07-03

Cognitive control allows information processing and behaviour to vary adaptively from moment to moment depending on current goals. Two of the most prominent theories that have been proposed to account for the processing of cognitive control are the Conflict Monitoring Theory (CMT) and the Prediction of Response-Outcome Theory (PRO). According to both theories, the implementation of cognitive control during a trial in a conflict task reflects processing events that occurred in the preceding trial. Both CMT and PRO advocate that the detection of conflict situations leads to the recruitment of cognitive control, but they differ regarding the processing underpinnings of cognitive control during conflict resolution. CMT proposes that conflict between alternative responses is resolved by enhancing the task's relevant dimension, reducing interference from the task's irrelevant dimension(s). This control setup promotes conflict adaptation in the subsequent trial. PRO proposes that conflict is resolved by means of a cost-effectiveness analysis that identifies and suppresses action plans linked to the less appropriate responses, facilitating conflict resolution in the subsequent trial. To adjudicate between these alternatives, we manipulated contingencies pertaining to two-trial sequences (n-1; n), namely, the congruency between task relevant/irrelevant dimensions in trial n-1 and response repetition in trial n. A spatial Stroop task was used, in which task-relevant and irrelevant information were integrated within the same stimulus. In this task, participants were required to attend to the direction of an arrow while ignoring its position. The arrow's direction and position could be congruent (C) or incongruent (IC). In one experiment, trials in which the participant was required to respond according to the position of a circle (PO; position only trials), occupying the sequential position n, were the focus of the analyses. Three experiments were conducted manipulating the trials' sequence structure. In Experiment 1, we studied a low control/low conflict condition (cC trials), and two high control/low conflict conditions (icC with and without response repetition). In Experiment 2, we studied two low control/no conflict conditions (cPO with and without response repetition) and two high control/no conflict conditions (icPO with and without response repetition). In Experiment 3, we studied a high control/high conflict condition (icIC) and two low control/high conflict conditions (cIC with and without response repetition). Overall, our findings are in agreement with previous studies in which both bottom-up processing, linked to response and stimulus position repetition, and top-down processing, linked to cognitive control, were shown to contribute to sequence effects in conflict tasks. Specifically, our observations mainly support PRO's account of conflict resolution, in which the intervention of top-down processing is substantially more complex than in CMT's account. Copyright © 2017 Elsevier B.V. All rights reserved.

Acute Effects of MPH on the Parent-Teen Interactions of Adolescents With ADHD.

PubMed

Pelham, William E; Meichenbaum, David L; Smith, Bradley H; Sibley, Margaret H; Gnagy, Elizabeth M; Bukstein, Oscar

2017-01-01

This study explored the nature of interactions between adolescent males with ADHD and their mothers, and the effects of methylphenidate (MPH) on an analogue parent-teen interaction task. Twenty-five adolescent males with ADHD ( M = 13.6 years) and their mothers and 14 non-ADHD adolescent males ( M = 13.4 years) and their mothers completed ratings of perceived dyadic conflict. Behavioral observations of dyads during 10-min conflict-resolution tasks were also collected. The ADHD dyads completed these tasks twice, with adolescents receiving either 0.3 mg/kg MPH or placebo. Videotaped sessions were coded using the Parent-Adolescent Interaction Rating Scale. Following the conflict-resolution task, participants rated their perceived conflict and affect during the interaction. Findings indicated higher conflict in the ADHD dyads, and minimal MPH effects on parent-teen interactions during the analogue task. Results suggest that stimulant medication does not produce meaningful acute effects on parent-teen interactions.

The effects of culture and cohesiveness on intragroup conflict and effectiveness.

PubMed

Nibler, Roger; Harris, Karen L

2003-10-01

To investigate the influence of culture and cohesiveness on intragroup conflict and effectiveness, the authors made comparisons among groups of U.S. friends and strangers and among groups of Chinese friends and strangers. Groups consisting of 5 members of the same culture engaged in a decision-making task. Among U.S. participants, task conflict and performance results tended to vary together. U.S. strangers reported little task conflict (disagreements about fact or opinion) and performed relatively poorly, whereas U.S. friends' performances benefited from an uninhibited exchange of individual ideas and opinions. In contrast, Chinese participants reported uniformly high levels of intragroup conflict and experienced relatively low performance. The results suggest that a task conflict advantage, with which group members feel comfortable enough to freely express and exchange opinions and disagree with each other to achieve optimal outcomes, might be culture specific.

Conflict Adaptation and Congruency Sequence Effects to Social-Emotional Stimuli in Individuals with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Worsham, Whitney; Gray, Whitney E.; Larson, Michael J.; South, Mikle

2015-01-01

Background: The modification of performance following conflict can be measured using conflict adaptation tasks thought to measure the change in the allocation of cognitive resources in order to reduce conflict interference and improve performance. While previous studies have suggested atypical processing during nonsocial cognitive control tasks,…

Conflict Background Triggered Congruency Sequence Effects in Graphic Judgment Task

PubMed Central

Zhao, Liang; Wang, Yonghui

2013-01-01

Congruency sequence effects refer to the reduction of congruency effects when following an incongruent trial than following a congruent trial. The conflict monitoring account, one of the most influential contributions to this effect, assumes that the sequential modulations are evoked by response conflict. The present study aimed at exploring the congruency sequence effects in the absence of response conflict. We found congruency sequence effects occurred in graphic judgment task, in which the conflict stimuli acted as irrelevant information. The findings reveal that processing task-irrelevant conflict stimulus features could also induce sequential modulations of interference. The results do not support the interpretation of conflict monitoring and favor a feature integration account that the congruency sequence effects are attributed to the repetitions of stimulus and response features. PMID:23372766

Automated radiotherapy treatment plan integrity verification

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

Yang Deshan; Moore, Kevin L.

2012-03-15

Purpose: In our clinic, physicists spend from 15 to 60 min to verify the physical and dosimetric integrity of radiotherapy plans before presentation to radiation oncology physicians for approval. The purpose of this study was to design and implement a framework to automate as many elements of this quality control (QC) step as possible. Methods: A comprehensive computer application was developed to carry out a majority of these verification tasks in the Philips PINNACLE treatment planning system (TPS). This QC tool functions based on both PINNACLE scripting elements and PERL sub-routines. The core of this technique is the method ofmore » dynamic scripting, which involves a PERL programming module that is flexible and powerful for treatment plan data handling. Run-time plan data are collected, saved into temporary files, and analyzed against standard values and predefined logical rules. The results were summarized in a hypertext markup language (HTML) report that is displayed to the user. Results: This tool has been in clinical use for over a year. The occurrence frequency of technical problems, which would cause delays and suboptimal plans, has been reduced since clinical implementation. Conclusions: In addition to drastically reducing the set of human-driven logical comparisons, this QC tool also accomplished some tasks that are otherwise either quite laborious or impractical for humans to verify, e.g., identifying conflicts amongst IMRT optimization objectives.« less

Electrophysiological measures of conflict detection and resolution in the Stroop task.

PubMed

Coderre, Emily; Conklin, Kathy; van Heuven, Walter J B

2011-09-21

Conflict detection and resolution is crucial in a cognitive task like the Stroop task. Previous studies have identified an early negativity component (N(inc)) as a prominent marker of Stroop conflict in event-related potentials (ERPs). However, to what extent this ERP component reflects conflict detection and/or resolution is still unclear. Here, we report a Stroop task in which the stimulus onset asynchrony (SOA) of color and word stimuli presentation was manipulated in order to disentangle the roles of conflict detection and conflict resolution in generating Stroop-related ERP components. Separating the word from the color information gives us precise control over the timing of conflict. If the N(inc) is related with conflict resolution it should be absent when the word appears during response preparation, as in a long-latency positive SOA. Our data shows that the N(inc) occurs in all SOAs, even after a response has been made, supporting its role in the detection of stimulus conflict rather than conflict resolution. The use of SOA manipulation therefore allows for the examination of a wider temporal spectrum of interference in order to specify the functions of this conflict-related component. These results provide insight into the neural signatures of conflict processes, and have implications for models of cognitive control mechanisms in the brain. Copyright © 2011 Elsevier B.V. All rights reserved.

One Task, Divergent Solutions: High- versus Low-Status Sources and Social Comparison Guide Adaptation in a Computer-Supported Socio-Cognitive Conflict Task

ERIC Educational Resources Information Center

Baumeister, Antonia E.; Engelmann, Tanja; Hesse, Friedrich W.

2017-01-01

This experimental study extends conflict elaboration theory (1) by revealing social influence dynamics for a knowledge-rich computer-supported socio-cognitive conflict task not investigated in the context of this theory before and (2) by showing the impact of individual differences in social comparison orientation. Students in two conditions…

School District Cabinet Member Task and Relationship Conflict Behavior during Budget Development in a State Fiscal Crisis

ERIC Educational Resources Information Center

Nickerson, John

2009-01-01

Purpose. The first purpose of this study was to determine to what extent task and relationship conflict occurred in school district cabinets during budget development in a state budget crisis. The second purpose was to determine which cabinet member task and relationship conflict behaviors were demonstrated during budget development in a state…

When passion makes the heart grow colder: the role of passion in alternative goal suppression.

PubMed

Bélanger, Jocelyn J; Lafrenière, Marc-André K; Vallerand, Robert J; Kruglanski, Arie W

2013-01-01

Quality of goal engagement and alternative goal suppression were investigated in this research. Integrating the dualistic model of passion (Vallerand et al., 2003) with goal-systems theory (Kruglanski et al., 2002), we hypothesized that obsessive passion--associated with recurrent goal-conflicts--would predict greater alternative goal suppression (i.e., goal-shielding) than would harmonious passion--characterized by effective synthesis of the passionate activity with other life domains. Results from 5 laboratory studies supported these hypotheses. In Study 1, participants' dispositional measures of harmonious and obsessive passion were correlated with an implicit measure of goal-shielding. Obsessive (but not harmonious) passion predicted the suppression of alternative goals and the progressive inhibition of unfamiliar goals. In Study 2, we extended these findings by demonstrating the interrelation between quality of goal engagement and goal-commitment such that goal-shielding effects were enhanced, but only for goals in conflict with other life domains (vs. well-integrated goals). In Study 3, the causal influence of passion on goal-shielding was supported via an experimental manipulation of passion. In Study 4, we replicated and extended Studies 1 and 3 by experimentally demonstrating that obsessive (but not harmonious) passion is a mindset conducive to the development of inhibitory links with alternative goals. Study 5 explored the psychological costs associated with repeated unconscious goal suppression by examining its effects on the depletion of self-regulatory resources. Collectively, the present results suggest that the qualitative distinction between obsessive and harmonious passion has implications for the goal-shielding effect and for subsequent self-regulatory behavior.

Switching between univalent task-sets in schizophrenia: ERP evidence of an anticipatory task-set reconfiguration deficit.

PubMed

Karayanidis, Frini; Nicholson, Rebecca; Schall, Ulrich; Meem, Lydia; Fulham, Ross; Michie, Patricia T

2006-10-01

The present study used behavioral and event-related potential (ERP) indices of task-switching to examine whether schizophrenia patients have a specific deficit in anticipatory task-set reconfiguration. Participants switched between univalent tasks in an alternating runs paradigms with blocked response-stimulus interval (RSI) manipulation (150, 300, 600, and 1200ms). Nineteen high functioning people with schizophrenia were compared to controls that were matched for age, gender, education and premorbid IQ estimate. Schizophrenia patients had overall increased RT, but no increase in corrected RT switch cost. In the schizophrenia group, ERPs showed reduced activation of the differential positivity in anticipation of switch trial at the optimal 600ms RSI and reduced activation of the frontal post-stimulus switch negativity at both 600 and 1200ms RSI compared to the control group. Despite no behavioral differences in task switching performance, anticipatory and stimulus-triggered ERP indices of task-switching suggest group differences in processing of switch and repeat trials, especially at longer RSI conditions that for control participants provide opportunity for anticipatory activation of task-set reconfiguration processes. These results are compatible with impaired implementation of endogenously driven processes in schizophrenia and greater reliance on external task cues, especially at long preparation intervals.

Examining the Role of the Human Hippocampus in Approach-Avoidance Decision Making Using a Novel Conflict Paradigm and Multivariate Functional Magnetic Resonance Imaging.

PubMed

O'Neil, Edward B; Newsome, Rachel N; Li, Iris H N; Thavabalasingam, Sathesan; Ito, Rutsuko; Lee, Andy C H

2015-11-11

Rodent models of anxiety have implicated the ventral hippocampus in approach-avoidance conflict processing. Few studies have, however, examined whether the human hippocampus plays a similar role. We developed a novel decision-making paradigm to examine neural activity when participants made approach/avoidance decisions under conditions of high or absent approach-avoidance conflict. Critically, our task required participants to learn the associated reward/punishment values of previously neutral stimuli and controlled for mnemonic and spatial processing demands, both important issues given approach-avoidance behavior in humans is less tied to predation and foraging compared to rodents. Participants played a points-based game where they first attempted to maximize their score by determining which of a series of previously neutral image pairs should be approached or avoided. During functional magnetic resonance imaging, participants were then presented with novel pairings of these images. These pairings consisted of images of congruent or opposing learned valences, the latter creating conditions of high approach-avoidance conflict. A data-driven partial least squares multivariate analysis revealed two reliable patterns of activity, each revealing differential activity in the anterior hippocampus, the homolog of the rodent ventral hippocampus. The first was associated with greater hippocampal involvement during trials with high as opposed to no approach-avoidance conflict, regardless of approach or avoidance behavior. The second pattern encompassed greater hippocampal activity in a more anterior aspect during approach compared to avoid responses, for conflict and no-conflict conditions. Multivoxel pattern classification analyses yielded converging findings, underlining a role of the anterior hippocampus in approach-avoidance conflict decision making. Approach-avoidance conflict has been linked to anxiety and occurs when a stimulus or situation is associated with reward and punishment. Although rodent work has implicated the hippocampus in approach-avoidance conflict processing, there is limited data on whether this role applies to learned, as opposed to innate, incentive values, and whether the human hippocampus plays a similar role. Using functional neuroimaging with a novel decision-making task that controlled for perceptual and mnemonic processing, we found that the human hippocampus was significantly active when approach-avoidance conflict was present for stimuli with learned incentive values. These findings demonstrate a role for the human hippocampus in approach-avoidance decision making that cannot be explained easily by hippocampal-dependent long-term memory or spatial cognition. Copyright © 2015 the authors 0270-6474/15/3515040-11$15.00/0.

Sexual conflict arising from extrapair matings in birds.

PubMed

Chaine, Alexis S; Montgomerie, Robert; Lyon, Bruce E

2015-01-20

The discovery that extrapair copulation (EPC) and extrapair paternity (EPP) are common in birds led to a paradigm shift in our understanding of the evolution of mating systems. The prevalence of extrapair matings in pair-bonded species sets the stage for sexual conflict, and a recent focus has been to consider how this conflict can shape variation in extrapair mating rates. Here, we invert the causal arrow and consider the consequences of extrapair matings for sexual conflict. Extrapair matings shift sexual conflict from a simple two-player (male vs. female) game to a game with three or more players, the nature of which we illustrate with simple diagrams that highlight the net costs and benefits of extrapair matings to each player. This approach helps identify the sorts of traits that might be under selection because of sexual conflict. Whether EPP is driven primarily by the extrapair male or the within-pair female profoundly influences which players are in conflict, but the overall pattern of conflict varies little among different mating systems. Different aspects of conflict are manifest at different stages of the breeding cycle and can be profitably considered as distinct episodes of selection caused by conflict. This perspective is illuminating both because conflict between specific players can change across episodes and because the traits that evolve to mediate conflict likely differ between episodes. Although EPP clearly leads to sexual conflict, we suggest that the link between sexual conflict and multiple paternity might be usefully understood by examining how deviations from lifetime sexual monogamy influence sexual conflict. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

Sexual Conflict Arising from Extrapair Matings in Birds

PubMed Central

Chaine, Alexis S.; Montgomerie, Robert; Lyon, Bruce E.

2015-01-01

The discovery that extrapair copulation (EPC) and extrapair paternity (EPP) are common in birds led to a paradigm shift in our understanding of the evolution of mating systems. The prevalence of extrapair matings in pair-bonded species sets the stage for sexual conflict, and a recent focus has been to consider how this conflict can shape variation in extrapair mating rates. Here, we invert the causal arrow and consider the consequences of extrapair matings for sexual conflict. Extrapair matings shift sexual conflict from a simple two-player (male vs. female) game to a game with three or more players, the nature of which we illustrate with simple diagrams that highlight the net costs and benefits of extrapair matings to each player. This approach helps identify the sorts of traits that might be under selection because of sexual conflict. Whether EPP is driven primarily by the extrapair male or the within-pair female profoundly influences which players are in conflict, but the overall pattern of conflict varies little among different mating systems. Different aspects of conflict are manifest at different stages of the breeding cycle and can be profitably considered as distinct episodes of selection caused by conflict. This perspective is illuminating both because conflict between specific players can change across episodes and because the traits that evolve to mediate conflict likely differ between episodes. Although EPP clearly leads to sexual conflict, we suggest that the link between sexual conflict and multiple paternity might be usefully understood by examining how deviations from lifetime sexual monogamy influence sexual conflict. PMID:25605708

Cognitive Conflict in a Syllable Identification Task Causes Transient Activation of Speech Perception Area

ERIC Educational Resources Information Center

Saetrevik, Bjorn; Specht, Karsten

2012-01-01

It has previously been shown that task performance and frontal cortical activation increase after cognitive conflict. This has been argued to support a model of attention where the level of conflict automatically adjusts the amount of cognitive control applied. Conceivably, conflict could also modulate lower-level processing pathways, which would…

Conflict Inhibitory Control Facilitates Pretense Quality in Young Preschoolers

PubMed Central

Van Reet, Jennifer

2013-01-01

The present research explores the role of inhibitory control in young preschoolers’ pretense ability using an ego depletion paradigm. In Experiment 1 (N = 56), children’s pretense ability was assessed either before or after participating in conflict inhibitory control or control tasks, and in Experiment 2 (N = 36), pretense ability was measured after children engaged in either conflict or delay inhibitory control tasks. In both experiments, pretense scores were significantly higher only after engaging in conflict inhibitory control tasks. Further, pretense scores were positively correlated with inhibitory control scores when conflict inhibitory control was not experienced first. This pattern of results suggests that inhibitory control may underlie pretense, and conflict inhibitory control can boost the quality of children’s subsequent pretending. PMID:26074736

“Off with the Old”: Mindfulness Practice Improves Backward Inhibition

PubMed Central

Greenberg, Jonathan; Reiner, Keren; Meiran, Nachshon

2013-01-01

Mindfulness practice has been linked to reduced depressive rumination and described as involving inhibition of information that has been relevant in the past and is no longer relevant in the present moment. Backward inhibition (BI) is considered to be one of the purest measures of task set inhibition, and impaired BI has been linked to depressive rumination. BI was contrasted with Competitor Rule Suppression (CRS), which is another phenomenon observed in task switching, yet one which involves episodic memory tagging of information that is currently conflicting rather than active inhibition. Although similar at baseline level, a randomly assigned group (n = 38) who underwent an eight session mindfulness training program exhibited improved BI but not CRS compared to a waiting list group (n = 38). Findings indicate that mindfulness improves the specific component of task set inhibition, which has previously been linked to reduced rumination. Implications regarding the potential role of task set inhibition in mediating between mindfulness and reduced rumination, as well as the role of mindfulness in “being in the present moment” are discussed. PMID:23335909

The role of personality in task and relationship conflict.

PubMed

Bono, Joyce E; Boles, Terry L; Judge, Timothy A; Lauver, Kristy J

2002-06-01

Two studies explored the extent to which dispositions influence the attributions individuals make about the type of conflict they experience. Traits from the Five-Factor Model of personality (FFM) were linked to the tendency to experience task-and relationship-oriented conflict. Results provide some support for the idea that individuals have stable tendencies in the attributions they make about their conflict experiences across time, partners, and situations. Agreeableness and openness were related to reports of relationship conflict at the individual level. However, the strongest effects of personality on conflict attributions were found in the analysis of dyads. This analysis revealed that partner levels of extraversion and conscientiousness were associated with individuals' tendencies to report relationship conflict. Moreover, mean levels of extraversion and conscientiousness in a pair were associated with reports of relationship conflict. Differences between partners in extraversion were associated with more frequent conflict and a greater likelihood of reporting task-related conflict. Implications of these findings with respect to the role of personality in interpersonal relationships are discussed. Finally, these studies provide confirmatory evidence that conflict attributions have a meaningful impact on relationship satisfaction.

Neural cascade of conflict processing: not just time-on-task

PubMed Central

McKay, Cameron C.; van den Berg, Berry; Woldorff, Marty G.

2017-01-01

In visual conflict tasks (e.g., Stroop or flanker), response times (RTs) are generally longer on incongruent trials relative to congruent ones. Two event-related-potential (ERP) components classically associated with the processing of stimulus conflict are the fronto-central, incongruency-related negativity (Ninc) and the posterior late-positive complex (LPC), which are derived from the ERP difference waves for incongruent minus congruent trials. It has been questioned, however, whether these effects, or other neural measures of incongruency (e.g., fMRI responses in the anterior cingulate), reflect true conflict processing, or whether such effects derive mainly from differential time-on-task. To address this question, we leveraged high-temporal-resolution ERP measures of brain activity during two behavioral tasks. The first task, a modified Erikson flanker paradigm (with congruent and incongruent trials), was used to evoke the classic RT and ERP effects associated with conflict. In the second, a non-conflict comparison condition, participants visually discriminated a single stimulus (with easy and hard discrimination conditions). Behaviorally, the parameters were titrated to yield similar RT effects of conflict and difficulty (27 ms). Neurally, both within-task contrasts showed an initial fronto-central negative-polarity wave (N2-latency effect), but they then diverged. In the difficulty difference wave, the initial negativity led directly into the posterior LPC, whereas in the incongruency contrast the initial negativity was followed a by a second fronto-central negative peak (Ninc), which was then followed by a considerably longer-latency LPC. These results provide clear evidence that the longer processing for incongruent stimulus inputs do not just reflect time-on-task or difficulty, but include a true conflict-processing component. PMID:28017818

Intraoperative radiation therapy using mobile electron linear accelerators: report of AAPM Radiation Therapy Committee Task Group No. 72.

PubMed

Beddar, A Sam; Biggs, Peter J; Chang, Sha; Ezzell, Gary A; Faddegon, Bruce A; Hensley, Frank W; Mills, Michael D

2006-05-01

Intraoperative radiation therapy (IORT) has been customarily performed either in a shielded operating suite located in the operating room (OR) or in a shielded treatment room located within the Department of Radiation Oncology. In both cases, this cancer treatment modality uses stationary linear accelerators. With the development of new technology, mobile linear accelerators have recently become available for IORT. Mobility offers flexibility in treatment location and is leading to a renewed interest in IORT. These mobile accelerator units, which can be transported any day of use to almost any location within a hospital setting, are assembled in a nondedicated environment and used to deliver IORT. Numerous aspects of the design of these new units differ from that of conventional linear accelerators. The scope of this Task Group (TG-72) will focus on items that particularly apply to mobile IORT electron systems. More specifically, the charges to this Task Group are to (i) identify the key differences between stationary and mobile electron linear accelerators used for IORT, (ii) describe and recommend the implementation of an IORT program within the OR environment, (iii) present and discuss radiation protection issues and consequences of working within a nondedicated radiotherapy environment, (iv) describe and recommend the acceptance and machine commissioning of items that are specific to mobile electron linear accelerators, and (v) design and recommend an efficient quality assurance program for mobile systems.

Stimulus and response conflict processing during perceptual decision making.

PubMed

Wendelken, Carter; Ditterich, Jochen; Bunge, Silvia A; Carter, Cameron S

2009-12-01

Encoding and dealing with conflicting information is essential for successful decision making in a complex environment. In the present fMRI study, stimulus conflict and response conflict are contrasted in the context of a perceptual decision-making dot-motion discrimination task. Stimulus conflict was manipulated by varying dot-motion coherence along task-relevant and task-irrelevant dimensions. Response conflict was manipulated by varying whether or not competing stimulus dimensions provided evidence for the same or different responses. The right inferior frontal gyrus was involved specifically in the resolution of stimulus conflict, whereas the dorsal anterior cingulate cortex was shown to be sensitive to response conflict. Additionally, two regions that have been linked to perceptual decision making with dot-motion stimuli in monkey physiology studies were differentially engaged by stimulus conflict and response conflict. The middle temporal area, previously linked to processing of motion, was strongly affected by the presence of stimulus conflict. On the other hand, the superior parietal lobe, previously associated with accumulation of evidence for a response, was affected by the presence of response conflict. These results shed light on the neural mechanisms that support decision making in the presence of conflict, a cognitive operation fundamental to both basic survival and high-level cognition.

Electrophysiological evidence for cognitive control during conflict processing in visual spatial attention.

PubMed

Kehrer, Stefanie; Kraft, Antje; Irlbacher, Kerstin; Koch, Stefan P; Hagendorf, Herbert; Kathmann, Norbert; Brandt, Stephan A

2009-11-01

Event-related potentials were measured to investigate the role of visual spatial attention mechanisms in conflict processing. We suggested that a more difficult target selection leads to stronger attentional top-down control, thereby reducing the effects of arising conflicts. This hypothesis was tested by varying the selection difficulty in a location negative priming (NP) paradigm. The difficult task resulted in prolonged responses as compared to the easy task. A behavioral NP effect was only evident in the easy task. Psychophysiologically the easy task was associated with reduced parietal N1, enhanced frontocentral N2 and N2pc components and a prolonged P3 latency for the conflict as compared to the control condition. The N2pc effect was also obvious in the difficult task. Additionally frontocentral N2 amplitudes increased and latencies of N2pc and P3 were delayed compared to the easy task. The differences at frontocentral and parietal electrodes are consistent with previous studies ascribing activity in the prefrontal and parietal cortex as the source of top-down attentional control. Thus, we propose that stronger cognitive control is involved in the difficult task, resulting in a reduced behavioral NP conflict.

WE-G-BRA-02: SafetyNet: Automating Radiotherapy QA with An Event Driven Framework

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

Hadley, S; Kessler, M; Litzenberg, D

2015-06-15

Purpose: Quality assurance is an essential task in radiotherapy that often requires many manual tasks. We investigate the use of an event driven framework in conjunction with software agents to automate QA and eliminate wait times. Methods: An in house developed subscription-publication service, EventNet, was added to the Aria OIS to be a message broker for critical events occurring in the OIS and software agents. Software agents operate without user intervention and perform critical QA steps. The results of the QA are documented and the resulting event is generated and passed back to EventNet. Users can subscribe to those eventsmore » and receive messages based on custom filters designed to send passing or failing results to physicists or dosimetrists. Agents were developed to expedite the following QA tasks: Plan Revision, Plan 2nd Check, SRS Winston-Lutz isocenter, Treatment History Audit, Treatment Machine Configuration. Results: Plan approval in the Aria OIS was used as the event trigger for plan revision QA and Plan 2nd check agents. The agents pulled the plan data, executed the prescribed QA, stored the results and updated EventNet for publication. The Winston Lutz agent reduced QA time from 20 minutes to 4 minutes and provided a more accurate quantitative estimate of radiation isocenter. The Treatment Machine Configuration agent automatically reports any changes to the Treatment machine or HDR unit configuration. The agents are reliable, act immediately, and execute each task identically every time. Conclusion: An event driven framework has inverted the data chase in our radiotherapy QA process. Rather than have dosimetrists and physicists push data to QA software and pull results back into the OIS, the software agents perform these steps immediately upon receiving the sentinel events from EventNet. Mr Keranen is an employee of Varian Medical Systems. Dr. Moran’s institution receives research support for her effort for a linear accelerator QA project from Varian Medical Systems. Other quality projects involving her effort are funded by Blue Cross Blue Shield of Michigan, Breast Cancer Research Foundation, and the NIH.« less

Neural activity in the hippocampus during conflict resolution.

PubMed

Sakimoto, Yuya; Okada, Kana; Hattori, Minoru; Takeda, Kozue; Sakata, Shogo

2013-01-15

This study examined configural association theory and conflict resolution models in relation to hippocampal neural activity during positive patterning tasks. According to configural association theory, the hippocampus is important for responses to compound stimuli in positive patterning tasks. In contrast, according to the conflict resolution model, the hippocampus is important for responses to single stimuli in positive patterning tasks. We hypothesized that if configural association theory is applicable, and not the conflict resolution model, the hippocampal theta power should be increased when compound stimuli are presented. If, on the other hand, the conflict resolution model is applicable, but not configural association theory, then the hippocampal theta power should be increased when single stimuli are presented. If both models are valid and applicable in the positive patterning task, we predict that the hippocampal theta power should be increased by presentation of both compound and single stimuli during the positive patterning task. To examine our hypotheses, we measured hippocampal theta power in rats during a positive patterning task. The results showed that hippocampal theta power increased during the presentation of a single stimulus, but did not increase during the presentation of a compound stimulus. This finding suggests that the conflict resolution model is more applicable than the configural association theory for describing neural activity during positive patterning tasks. Copyright © 2012 Elsevier B.V. All rights reserved.

Memory and language improvements following cognitive control training.

PubMed

Hussey, Erika K; Harbison, J Isaiah; Teubner-Rhodes, Susan E; Mishler, Alan; Velnoskey, Kayla; Novick, Jared M

2017-01-01

Cognitive control refers to adjusting thoughts and actions when confronted with conflict during information processing. We tested whether this ability is causally linked to performance on certain language and memory tasks by using cognitive control training to systematically modulate people's ability to resolve information-conflict across domains. Different groups of subjects trained on 1 of 3 minimally different versions of an n-back task: n-back-with-lures (High-Conflict), n-back-without-lures (Low-Conflict), or 3-back-without-lures (3-Back). Subjects completed a battery of recognition memory and language processing tasks that comprised both high- and low-conflict conditions before and after training. We compared the transfer profiles of (a) the High- versus Low-Conflict groups to test how conflict resolution training contributes to transfer effects, and (b) the 3-Back versus Low-Conflict groups to test for differences not involving cognitive control. High-Conflict training-but not Low-Conflict training-produced discernable benefits on several untrained transfer tasks, but only under selective conditions requiring cognitive control. This suggests that the conflict-focused intervention influenced functioning on ostensibly different outcome measures across memory and language domains. 3-Back training resulted in occasional improvements on the outcome measures, but these were not selective for conditions involving conflict resolution. We conclude that domain-general cognitive control mechanisms are plastic, at least temporarily, and may play a causal role in linguistic and nonlinguistic performance. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The effects of bilingualism on conflict monitoring, cognitive control, and garden-path recovery.

PubMed

Teubner-Rhodes, Susan E; Mishler, Alan; Corbett, Ryan; Andreu, Llorenç; Sanz-Torrent, Monica; Trueswell, John C; Novick, Jared M

2016-05-01

Bilinguals demonstrate benefits on non-linguistic tasks requiring cognitive control-the regulation of mental activity to resolve information-conflict during processing. This "bilingual advantage" has been attributed to the consistent management of two languages, yet it remains unknown if these benefits extend to sentence processing. In monolinguals, cognitive control helps detect and revise misinterpretations of sentence meaning. Here, we test if the bilingual advantage extends to parsing and interpretation by comparing bilinguals' and monolinguals' syntactic ambiguity resolution before and after practicing N-back, a non-syntactic cognitive-control task. Bilinguals outperformed monolinguals on a high-conflict but not a no-conflict version of N-back and on sentence comprehension, indicating that the advantage extends to language interpretation. Gains on N-back conflict trials also predicted comprehension improvements for ambiguous sentences, suggesting that the bilingual advantage emerges across tasks tapping shared cognitive-control procedures. Because the overall task benefits were observed for conflict and non-conflict trials, bilinguals' advantage may reflect increased cognitive flexibility. Copyright © 2016 Elsevier B.V. All rights reserved.

Age-related changes in cognitive conflict processing: an event-related potential study.

PubMed

Mager, Ralph; Bullinger, Alex H; Brand, Serge; Schmidlin, Maria; Schärli, Heinz; Müller-Spahn, Franz; Störmer, Robert; Falkenstein, Michael

2007-12-01

Cognitive tasks involving conflicting stimuli and responses are associated with an early age-related decline in performance. Conflict and conflict-induced interference can be stimulus- or response-related. In classical stimulus-response compatibility tasks, such as the Stroop task, the event-related potential (ERP) usually reveals a greater negativity on incongruent versus congruent trials which has often been linked with conflict processing. However, it is unclear whether this negativity is related to stimulus- or response-related conflict, thus rendering the meaning of age-related changes inconclusive. In the present study, a modified Stroop task was used to focus on stimulus-related interference processes while excluding response-related interference. Since we intended to study work-relevant effects ERPs and performance were determined in young (about 30 years old) and middle-aged (about 50 years old) healthy subjects (total n=80). In the ERP, a broad negativity developed after incongruent versus congruent stimuli between 350 and 650 ms. An age-related increase of the latency and amplitude of this negativity was observed. These results indicate age-related alterations in the processing of conflicting stimuli already in middle age.

The Gratton effect remains after controlling for contingencies and stimulus repetitions

PubMed Central

Blais, Chris; Stefanidi, Aikaterini; Brewer, Gene A.

2014-01-01

Highlights: The conflict monitoring hypothesis signals the need for cognitive controlThe Gratton effect is a key result attributed to the conflict monitoring hypothesisSome argue that controlling binding confounds eliminates the Gratton effect A Gratton effect remains in a vocal Stroop task after eliminating confounds The Gratton effect, the observation that the size of the Stroop effect is larger following a congruent trial compared to an incongruent trial, is one pivotal observation in support of the conflict-monitoring hypothesis. Previous reports have demonstrated that non-conflict components, such as feature binding, also contribute to this effect. Critically, Schmidt and De Houwer (2011) report a flanker task and a button-press Stroop task suggesting that there is no conflict adaptation in the Gratton effect; it is entirely caused by feature binding. The current investigation attempts to replicate and extend this important finding across two experiments using a canonical four-choice Stroop task with vocal responses. In contrast to Schmidt and De Houwer, we observe reliable conflict adaptation after controlling for feature binding. We argue that the overall strength of conflict is critical for determining whether a conflict adaptation component will remain in the Gratton effect after explaining binding components. PMID:25386151

The heart of parenting: Parent HR dynamics and negative parenting while resolving conflict with child.

PubMed

Zhang, Xutong; Cui, Lixian; Han, Zhuo Rachel; Yan, Jia

2017-03-01

The current study examined parent heart rate (HR) dynamic changing patterns and their links to observed negative parenting (i.e., emotional unavailability and psychological control) during a parent-child conflict resolution task among 150 parent-child dyads (child age ranged from 6 to 12 years, Mage = 8.54 ± 1.67). Parent HR was obtained from electrocardiogram (ECG) data collected during the parent-child conflict resolution task. Negative parenting was coded offline based on the video recording of the same task. Results revealed that emotionally sensitive parents during the task showed greater HR increases while discussing a conflict and greater HR decreases while resolving the conflict, whereas emotionally unavailable parents showed no changes in HR. However, parent psychological control was not associated with HR dynamics during the task. These findings indicated the physiological underpinnings of parent emotional sensitivity and responsiveness during parent-child interactions. The potential association between HR baseline levels and parenting behaviors was also discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Composite Structures Materials Testing for the Orion Crew Vehicle Heat Shield

NASA Technical Reports Server (NTRS)

Khemani, Farah N.

2011-01-01

As research is being performed for the new heat shield for the Orion capsule, National Aeronautics and Space Administration (NASA) is developing the first composite heat shield. As an intern of the Structures Branch in the Engineering Directorate (ES 2), my main task was to set up a test plan to determine the material properties of the honeycomb that will be used on the Orion Crew Module heat shield to verify that the composite is suitable for the capsule. Before conducting composite shell tests, which are performed to simulate the crush performance of the heat shield on the capsule, it is necessary to determine the compression and shear properties of the composite used on the shell. During this internship, I was responsible for developing a test plan, designing parts for the test fixtures as well as getting them fabricated for the honeycomb shear and compression testing. This involved work in Pro/Engineer as well as coordinating with Fab Express, the Building 9 Composite Shop and the Structures Test Laboratory (STL). The research and work executed for this project will be used for composite sandwich panel testing in the future as well. As a part of the Structures Branch, my main focus was to research composite structures. This involves system engineering and integration (SE&I) integration, manufacturing, and preliminary testing. The procedures for these projects that were executed during this internship included design work, conducting tests and performing analysis.

Dissociable early attentional control mechanisms underlying cognitive and affective conflicts

PubMed Central

Chen, Taolin; Kendrick, Keith M.; Feng, Chunliang; Sun, Shiyue; Yang, Xun; Wang, Xiaogang; Luo, Wenbo; Yang, Suyong; Huang, Xiaoqi; Valdés-Sosa, Pedro A.; Gong, Qiyong; Fan, Jin; Luo, Yue-Jia

2016-01-01

It has been well documented that cognitive conflict is sensitive to the relative proportion of congruent and incongruent trials. However, few studies have examined whether affective conflict processing is modulated as a function of proportion congruency (PC). To address this question we recorded event-related potentials (ERP) while subjects performed both cognitive and affective face-word Stroop tasks. By varying the proportion of congruent and incongruent trials in each block, we examined the extent to which PC impacts both cognitive and affective conflict control at different temporal stages. Results showed that in the cognitive task an anteriorly localized early N2 component occurred predominantly in the low proportion congruency context, whereas in the affective task it was found to occur in the high proportion congruency one. The N2 effects across the two tasks were localized to the dorsolateral prefrontal cortex, where responses were increased in the cognitive task but decreased in the affective one. Furthermore, high proportions of congruent items produced both larger amplitude of a posteriorly localized sustained potential component and a larger behavioral Stroop effect in cognitive and affective tasks. Our findings suggest that cognitive and affective conflicts engage early dissociable attentional control mechanisms and a later common conflict response system. PMID:27892513

Amygdala alterations during an emotional conflict task in women recovered from anorexia nervosa.

PubMed

Bang, Lasse; Rø, Øyvind; Endestad, Tor

2016-02-28

The pathophysiology of anorexia nervosa (AN) is not completely understood, but research suggests that alterations in brain circuits related to cognitive control and emotion are central. The aim of this study was to explore neural responses to an emotional conflict task in women recovered from AN. Functional magnetic resonance imaging was used to measure neural responses to an emotional conflict task in 22 women recovered from AN and 21 age-matched healthy controls. The task involved categorizing affective faces while ignoring affective words. Face and word stimuli were either congruent (non-conflict) or incongruent (conflict). Brain responses to emotional conflict did not differ between groups. However, in response to emotional non-conflict, women recovered from AN relative to healthy controls showed significantly less activation in the bilateral amygdala. Specifically, while emotional non-conflict evoked significant activations of the amygdala in healthy controls, recovered AN women did not show such activations. Similar significant group differences were also observed in the hippocampus and basal ganglia. These results suggest that women recovered from AN are characterized by alterations within emotion-related brain circuits. Recovered women's absence of amygdala and hippocampus activation during non-conflict trials possibly reflects an impaired ability to process emotional significant stimuli. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Context-Sensitive Adjustment of Cognitive Control in Dual-Task Performance

ERIC Educational Resources Information Center

Fischer, Rico; Gottschalk, Caroline; Dreisbach, Gesine

2014-01-01

Performing 2 highly similar tasks at the same time requires an adaptive regulation of cognitive control to shield prioritized primary task processing from between-task (cross-talk) interference caused by secondary task processing. In the present study, the authors investigated how implicitly and explicitly delivered information promotes the…

Adaptation to conflict via context-driven anticipatory signals in the dorsomedial prefrontal cortex.

PubMed

Horga, Guillermo; Maia, Tiago V; Wang, Pengwei; Wang, Zhishun; Marsh, Rachel; Peterson, Bradley S

2011-11-09

Behavioral interference elicited by competing response tendencies adapts to contextual changes. Recent nonhuman primate research suggests a key mnemonic role of distinct prefrontal cells in supporting such context-driven behavioral adjustments by maintaining conflict information across trials, but corresponding prefrontal functions have yet to be probed in humans. Using event-related functional magnetic resonance imaging, we investigated the human neural substrates of contextual adaptations to conflict. We found that a neural system comprising the rostral dorsomedial prefrontal cortex and portions of the dorsolateral prefrontal cortex specifically encodes the history of previously experienced conflict and influences subsequent adaptation to conflict on a trial-by-trial basis. This neural system became active in anticipation of stimulus onsets during preparatory periods and interacted with a second neural system engaged during the processing of conflict. Our findings suggest that a dynamic interaction between a system that represents conflict history and a system that resolves conflict underlies the contextual adaptation to conflict.

Adaptation to Conflict via Context-Driven Anticipatory Signals in the Dorsomedial Prefrontal Cortex

PubMed Central

Horga, Guillermo; Maia, Tiago V.; Wang, Pengwei; Wang, Zhishun; Marsh, Rachel; Peterson, Bradley S.

2011-01-01

Behavioral interference elicited by competing response tendencies adapts to contextual changes. Recent nonhuman primate research suggests a key mnemonic role of distinct prefrontal cells in supporting such context-driven behavioral adjustments by maintaining conflict information across trials, but corresponding prefrontal functions have yet to be probed in humans. Using event-related functional magnetic resonance imaging (fMRI), we investigated the human neural substrates of contextual adaptations to conflict. We found that a neural system comprising the rostral dorsomedial prefrontal cortex and portions of the dorsolateral prefrontal cortex specifically encodes the history of previously experienced conflict and influences subsequent adaptation to conflict on a trial-by-trial basis. This neural system became active in anticipation of stimulus onsets during preparatory periods and interacted with a second neural system engaged during the processing of conflict. Our findings suggest that a dynamic interaction between a system that represents conflict history and a system that resolves conflict underlies the contextual adaptation to conflict. PMID:22072672

The role of RT carry-over for congruence sequence effects in masked priming.

PubMed

Huber-Huber, Christoph; Ansorge, Ulrich

2017-05-01

The present study disentangles 2 sources of the congruence sequence effect with masked primes: congruence and response time of the previous trial (reaction time [RT] carry-over). Using arrows as primes and targets and a metacontrast masking procedure we found congruence as well as congruence sequence effects. In addition, congruence sequence effects decreased when RT carry-over was accounted for in a mixed model analysis, suggesting that RT carry-over contributes to congruence sequence effects in masked priming. Crucially, effects of previous trial congruence were not cancelled out completely indicating that RT carry-over and previous trial congruence are 2 sources feeding into the congruence sequence effect. A secondary task requiring response speed judgments demonstrated general awareness of response speed (Experiments 1), but removing this secondary task (Experiment 2) showed that RT carry-over effects were also present in single-task conditions. During (dual-task) prime-awareness test parts of both experiments, however, RT carry-over failed to modulate congruence effects, suggesting that some task sets of the participants can prevent the effect. The basic RT carry-over effects are consistent with the conflict adaptation account, with the adaptation to the statistics of the environment (ASE) model, and possibly with the temporal learning explanation. Additionally considering the task-dependence of RT carry-over, the results are most compatible with the conflict adaptation account. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Task Prioritization in Dual-Tasking: Instructions versus Preferences

PubMed Central

Jansen, Reinier J.; van Egmond, René; de Ridder, Huib

2016-01-01

The role of task prioritization in performance tradeoffs during multi-tasking has received widespread attention. However, little is known on whether people have preferences regarding tasks, and if so, whether these preferences conflict with priority instructions. Three experiments were conducted with a high-speed driving game and an auditory memory task. In Experiment 1, participants did not receive priority instructions. Participants performed different sequences of single-task and dual-task conditions. Task performance was evaluated according to participants’ retrospective accounts on preferences. These preferences were reformulated as priority instructions in Experiments 2 and 3. The results showed that people differ in their preferences regarding task prioritization in an experimental setting, which can be overruled by priority instructions, but only after increased dual-task exposure. Additional measures of mental effort showed that performance tradeoffs had an impact on mental effort. The interpretation of these findings was used to explore an extension of Threaded Cognition Theory with Hockey’s Compensatory Control Model. PMID:27391779

Task factor usability ratings for different age groups writing Chinese.

PubMed

Chan, A H S; So, J C Y

2009-11-01

This study evaluated how different task factors affect performance and user subjective preferences for three different age groups of Chinese subjects (6-11, 20-23, 65-70 years) when hand writing Chinese characters. The subjects copied Chinese character sentences with different settings for the task factors of writing plane angle (horizontal 0 degrees , slanted 15 degrees ), writing direction (horizontal, vertical), and line spacing (5 mm, 7 mm and no lines). Writing speed was measured and subjective preferences (effectiveness and satisfaction) were assessed for each of the task factor settings. The result showed that there was a conflict between writing speed and personal preference for the line spacing factor; 5 mm line spacing increased writing speed but it was the least preferred. It was also found that: vertical and horizontal writing directions and a slanted work surface suited school-aged children; a horizontal work surface and horizontal writing direction suited university students; and a horizontal writing direction with either a horizontal or slanted work surface suited the older adults.

Discrepancies in mother and child perceptions of spina bifida medical responsibilities during the transition to adolescence: associations with family conflict and medical adherence.

PubMed

Psihogios, Alexandra M; Holmbeck, Grayson N

2013-09-01

This study investigated mother-child discrepancies over perceptions of who is responsible for spina bifida (SB) medical tasks in relation to family conflict and medical adherence. 140 youth with SB and their mothers completed questionnaires regarding who is responsible for specific SB medical tasks, family conflict, and medical adherence. An observational measure was also used to assess family conflict. Although children viewed themselves as more responsible for medical management than mothers did, mother-child discrepancies were not associated with family conflict or medical adherence. Interaction effects revealed that adherence was better when family conflict was low and when parents were responsible for medical tasks. Parental involvement in SB medical care is essential for optimal medical adherence during adolescence. The presence of family conflict also plays an influential role on SB medical adherence. Future research should evaluate the relations between discrepancies, family conflict, and medical adherence across time.

Discrepancies in Mother and Child Perceptions of Spina Bifida Medical Responsibilities During the Transition to Adolescence: Associations With Family Conflict and Medical Adherence

PubMed Central

Psihogios, Alexandra M.

2013-01-01

Objective This study investigated mother–child discrepancies over perceptions of who is responsible for spina bifida (SB) medical tasks in relation to family conflict and medical adherence. Method 140 youth with SB and their mothers completed questionnaires regarding who is responsible for specific SB medical tasks, family conflict, and medical adherence. An observational measure was also used to assess family conflict. Results Although children viewed themselves as more responsible for medical management than mothers did, mother–child discrepancies were not associated with family conflict or medical adherence. Interaction effects revealed that adherence was better when family conflict was low and when parents were responsible for medical tasks. Conclusions Parental involvement in SB medical care is essential for optimal medical adherence during adolescence. The presence of family conflict also plays an influential role on SB medical adherence. Future research should evaluate the relations between discrepancies, family conflict, and medical adherence across time. PMID:23843631

Adolescent Perceptions of Conflict in Interdependent and Disengaged Friendships

PubMed Central

Shulman, Shmuel; Laursen, Brett

2009-01-01

Interdependent and disengaged friendships in a middle-class sample of suburban Israeli adolescents were examined for differences in reports of conflict behavior. A total of 194 (100 females, and 94 males) close, reciprocal friends participated in a joint problem-solving task used to categorize friendships. Interdependent friends balanced closeness and individuality by cooperating on the task, whereas disengaged friends emphasized individuality by working independently on the task. In separate interviews, these friends recounted their most important conflict from the previous week. Older adolescents (M = 17.4 years) reported more conflicts over private disrespect than did younger adolescents (M = 12.7 years), whereas younger adolescents reported more conflicts over public disrespect and undependability than did older adolescents. Differences between friendship types in conflict initiation, negative affect, and relationship impact were found among older adolescents but not younger adolescents; differences in conflict resolutions were found in both age groups. In contrast to disengaged friends, interdependent friends were better able to manage conflicts in a manner that emphasized relationship harmony over individual gain. PMID:20090925

Two Simon tasks with different sources of conflict: an ERP study of motion- and location-based compatibility effects.

PubMed

Galashan, Daniela; Wittfoth, Matthias; Fehr, Thorsten; Herrmann, Manfred

2008-07-01

Behavioral and electrophysiological correlates of two Simon tasks were examined using comparable stimuli but different task-irrelevant and conflict-inducing stimulus features. Whereas target shape was always the task-relevant stimulus attribute, either target location (location-based task) or motion direction within the target stimuli (motion-based task) was used as a source of conflict. Data from ten healthy participants who performed both tasks are presented. In the motion-based task the incompatible condition showed smaller P300 amplitudes at Pz than the compatible condition and the location-based task yielded a trend towards a reduced P300 amplitude in the incompatible condition. For both tasks, no P300 latency differences between the conditions were found at Pz. The results suggest that the motion-based task elicits behavioral and electrophysiological effects comparable with regular Simon tasks. As all stimuli in the motion-based Simon task were presented centrally the present data strongly argue against the attention-shifting account as an explanatory approach.

Carving Executive Control At Its Joints: Working Memory Capacity Predicts Stimulus-Stimulus, But Not Stimulus-Response, Conflict

PubMed Central

Meier, Matt E.; Kane, Michael J.

2015-01-01

Three experiments examined the relation between working memory capacity (WMC) and two different forms of cognitive conflict: stimulus-stimulus (S-S) and stimulus-response (SR) interference. Our goal was to test whether WMC’s relation to conflict-task performance is mediated by stimulus-identification processes (captured by S-S conflict), response-selection processes (captured by S-R conflict), or both. In Experiment 1, subjects completed a single task presenting both S-S and S-R conflict trials, plus trials that combined the two conflict types. We limited ostensible goal-maintenance contributions to performance by requiring the same goal for all trial types and by presenting frequent conflict trials that reinforced the goal. WMC predicted resolution of S-S conflict as expected: Higher-WMC subjects showed reduced response time interference. Although WMC also predicted S-R interference, here, higher-WMC subjects showed increased error interference. Experiment 2A replicated these results in a version of the conflict task without combined S-S/S-R trials. Experiment 2B increased the proportion of congruent (non-conflict) trials to promote reliance on goal-maintenance processes. Here, higher-WMC subjects resolved both S-S and S-R conflict more successfully than did lower-WMC subjects. The results were consistent with Kane and Engle’s (2003) two-factor theory of cognitive control, according to which WMC predicts executive-task performance through goal-maintenance and conflict-resolution processes. However, the present results add specificity to the account by suggesting that higher-WMC subjects better resolve cognitive conflict because they more efficiently select relevant stimulus features against irrelevant, distracting ones. PMID:26120774

The Critical Roles of Task Conflict and Job Autonomy in the Relationship Between Proactive Personalities and Innovative Employee Behavior.

PubMed

Giebels, Ellen; de Reuver, Renee S M; Rispens, Sonja; Ufkes, Elze G

2016-09-01

We examine why and when proactive personality is beneficial for innovative behavior at work. Based on a survey among 166 employees working in 35 departments of a large municipality in the Netherlands we show that an increase in task conflicts explains the positive relation between a proactive personality and innovative employee behavior. This process is moderated by job autonomy in such a way that the relationship between proactive personality and task conflict is particularly strong under low compared with high autonomy. The present research contributes to the discussion on the potential benefits of task conflict for change processes and highlights the importance of examining the interplay between personality and work context for understanding innovation practices.

Conflict and Bias in Heuristic Judgment

ERIC Educational Resources Information Center

Bhatia, Sudeep

2017-01-01

Conflict has been hypothesized to play a key role in recruiting deliberative processing in reasoning and judgment tasks. This claim suggests that changing the task so as to add incorrect heuristic responses that conflict with existing heuristic responses can make individuals less likely to respond heuristically and can increase response accuracy.…

Multiple Systems for Cognitive Control: Evidence from a Hybrid Prime-Simon Task

ERIC Educational Resources Information Center

Schlaghecken, Friederike; Refaat, Malik; Maylor, Elizabeth A.

2011-01-01

Cognitive control resolves conflicts between appropriate and inappropriate response tendencies. Is this achieved by a unitary all-purpose conflict control system, or do independent subsystems deal with different aspects of conflicting information? In a fully factorial hybrid prime-Simon task, participants responded to the identity of targets…

The self in conflict: actors and agency in the mediated sequential Simon task.

PubMed

Spapé, Michiel M; Ahmed, Imtiaj; Jacucci, Giulio; Ravaja, Niklas

2015-01-01

Executive control refers to the ability to withstand interference in order to achieve task goals. The effect of conflict adaptation describes that after experiencing interference, subsequent conflict effects are weaker. However, changes in the source of conflict have been found to disrupt conflict adaptation. Previous studies indicated that this specificity is determined by the degree to which one source causes episodic retrieval of a previous source. A virtual reality version of the Simon task was employed to investigate whether changes in a visual representation of the self would similarly affect conflict adaptation. Participants engaged in a mediated Simon task via 3D "avatar" models that either mirrored the participants' movements, or were presented statically. A retrieval cue was implemented as the identity of the avatar: switching it from a male to a female avatar was expected to disrupt the conflict adaptation effect (CAE). The results show that only in static conditions did the CAE depend on the avatar identity, while in dynamic conditions, changes did not cause disruption. We also explored the effect of conflict and adaptation on the degree of movement made with the task-irrelevant hand and replicated the reaction time pattern. The findings add to earlier studies of source-specific conflict adaptation by showing that a visual representation of the self in action can provide a cue that determines episodic retrieval. Furthermore, the novel paradigm is made openly available to the scientific community and is described in its significance for studies of social cognition, cognitive psychology, and human-computer interaction.

Decomposing interference during Stroop performance into different conflict factors: an event-related fMRI study.

PubMed

Melcher, Tobias; Gruber, Oliver

2009-02-01

In the current event-related functional magnetic resonance imaging (fMRI) study, we sought to trace back Stroop-interference to circumscribed properties of task-irrelevant word information - response-incompatibility, semantic incongruency and task-reference - that we conceive as conflict factors. Thereby, we particularly wanted to disentangle intermingled contributions of semantic conflict and response conflict to the overall Stroop-interference effect. To delineate neural substrates of single factors, we referred to the logics of cognitive subtraction and cognitive conjunction. Moreover, in a second step, we conducted correlation analyses to determine the relationship between neural activations and behavioral interference costs (i.e., conflict-related reaction time (RT) slowing) so as to further elucidate the functional role of the respective brain regions in conflict processing. Response-incompatibility was associated with activation in the left premotor cortex which can be interpreted as indicating motor competition or conflict, i.e., the presence of competing response tendencies. Accordingly, this activation was positively correlated with behavioral conflict costs. Semantic incongruency exhibited specific activation in the anterior cingulate cortex (ACC), the bilateral insula, and thalamus as well as in left somatosensory cortex. As supported by the consistent negative correlation with behavioral conflict costs, these activations most probably reflect strengthened control efforts to overcome interference and to ensure adequate task performance. Finally, task-reference elicited activation in the left temporo-polar cortex (TPC) and the right medial superior as well as in left rostroventral prefrontal cortex (rvPFC, sub-threshold activation). As strongly supported by prior studies' findings, this neural activation pattern may underlie residual semantic processing of the task-irrelevant word information.

A musculoskeletal model of human locomotion driven by a low dimensional set of impulsive excitation primitives

PubMed Central

Sartori, Massimo; Gizzi, Leonardo; Lloyd, David G.; Farina, Dario

2013-01-01

Human locomotion has been described as being generated by an impulsive (burst-like) excitation of groups of musculotendon units, with timing dependent on the biomechanical goal of the task. Despite this view being supported by many experimental observations on specific locomotion tasks, it is still unknown if the same impulsive controller (i.e., a low-dimensional set of time-delayed excitastion primitives) can be used as input drive for large musculoskeletal models across different human locomotion tasks. For this purpose, we extracted, with non-negative matrix factorization, five non-negative factors from a large sample of muscle electromyograms in two healthy subjects during four motor tasks. These included walking, running, sidestepping, and crossover cutting maneuvers. The extracted non-negative factors were then averaged and parameterized to obtain task-generic Gaussian-shaped impulsive excitation curves or primitives. These were used to drive a subject-specific musculoskeletal model of the human lower extremity. Results showed that the same set of five impulsive excitation primitives could be used to predict the dynamics of 34 musculotendon units and the resulting hip, knee and ankle joint moments (i.e., NRMSE = 0.18 ± 0.08, and R2 = 0.73 ± 0.22 across all tasks and subjects) without substantial loss of accuracy with respect to using experimental electromyograms (i.e., NRMSE = 0.16 ± 0.07, and R2 = 0.78 ± 0.18 across all tasks and subjects). Results support the hypothesis that biomechanically different motor tasks might share similar neuromuscular control strategies. This might have implications in neurorehabilitation technologies such as human-machine interfaces for the torque-driven, proportional control of powered prostheses and orthoses. In this, device control commands (i.e., predicted joint torque) could be derived without direct experimental data but relying on simple parameterized Gaussian-shaped curves, thus decreasing the input drive complexity and the number of needed sensors. PMID:23805099

A musculoskeletal model of human locomotion driven by a low dimensional set of impulsive excitation primitives.

PubMed

Sartori, Massimo; Gizzi, Leonardo; Lloyd, David G; Farina, Dario

2013-01-01

Human locomotion has been described as being generated by an impulsive (burst-like) excitation of groups of musculotendon units, with timing dependent on the biomechanical goal of the task. Despite this view being supported by many experimental observations on specific locomotion tasks, it is still unknown if the same impulsive controller (i.e., a low-dimensional set of time-delayed excitastion primitives) can be used as input drive for large musculoskeletal models across different human locomotion tasks. For this purpose, we extracted, with non-negative matrix factorization, five non-negative factors from a large sample of muscle electromyograms in two healthy subjects during four motor tasks. These included walking, running, sidestepping, and crossover cutting maneuvers. The extracted non-negative factors were then averaged and parameterized to obtain task-generic Gaussian-shaped impulsive excitation curves or primitives. These were used to drive a subject-specific musculoskeletal model of the human lower extremity. Results showed that the same set of five impulsive excitation primitives could be used to predict the dynamics of 34 musculotendon units and the resulting hip, knee and ankle joint moments (i.e., NRMSE = 0.18 ± 0.08, and R (2) = 0.73 ± 0.22 across all tasks and subjects) without substantial loss of accuracy with respect to using experimental electromyograms (i.e., NRMSE = 0.16 ± 0.07, and R (2) = 0.78 ± 0.18 across all tasks and subjects). Results support the hypothesis that biomechanically different motor tasks might share similar neuromuscular control strategies. This might have implications in neurorehabilitation technologies such as human-machine interfaces for the torque-driven, proportional control of powered prostheses and orthoses. In this, device control commands (i.e., predicted joint torque) could be derived without direct experimental data but relying on simple parameterized Gaussian-shaped curves, thus decreasing the input drive complexity and the number of needed sensors.

Dynamics of task sets: evidence from dense-array event-related potentials.

PubMed

Poulsen, Catherine; Luu, Phan; Davey, Colin; Tucker, Don M

2005-06-01

Prior research suggests that task sets facilitate coherent, goal-directed behavior by providing an internal, contextual frame that biases selection toward context-relevant stimulus attributes and responses. Questions about how task sets are engaged, maintained, and shifted have recently become a major focus of research on executive control processes. We employed dense-array (128-channel) event-related potential (ERP) methodology to examine the dynamics of brain systems engaged during the preparation and implementation of task switching. The EEG was recorded while participants performed letter and digit judgments to pseudorandomly-ordered, univalent (#3, A%) and bivalent (G5) stimulus trials, with the appropriate task cued by a colored rectangle presented 450 ms before target onset. Results revealed spatial and temporal variations in brain activity that could be related to preparatory processes common to both switch and repeat trials, switch-specific control processes engaged to reconfigure and maintain task set under conflict, and visual priming benefits of task repetition. Despite extensive practice and improvement, both behavioral and ERP results indicated that subjects maintained high levels of executive control processing with extended task engagement. The patterns of ERP activity obtained in the present study fit well with functional neuroanatomical models of self-regulation of action. The frontopolar and right-lateralized frontal switch effects obtained in the present study are consistent with the role of these regions in adapting to changing contextual contingencies. In contrast, the centroparietal P3b and N384 effects related to the contextual ambiguity of bivalent trials are consistent with the context monitoring and updating functions associated with the posterior cingulate learning circuit.

Work-Family Conflict, Perceived Organizational Support and Professional Commitment: A Mediation Mechanism for Chinese Project Professionals

PubMed Central

2018-01-01

Projects are characterized by long working hours, complex tasks and being a kind of temporary organization. As such, work-family conflict is particularly prominent for project employees. This research examined whether and how work-family conflict affects professional commitment among Chinese project professionals. Research hypotheses were developed to explore the relationship between work-family conflict, professional commitment to the project and the mediating effects of perceived organizational support. Data were collected from 327 project managers or professionals working in construction enterprises in China; data were analyzed using structural equation modeling, applying the bootstrapping method. Results showed that there were three dimensions of work-family conflict: time-based conflict, strain-based conflict and behavior-based conflict. There were two dimensions of perceived organizational support: emotional support and instrumental support. The study also tested the negative effect of work-family conflict on professional commitment and the positive effect of perceived organizational support on professional commitment. Specifically, time-based conflict and emotional support had positive effects on professional commitment. Perceived organizational support had a total mediating effect between work-family conflict and professional commitment. The strain-based conflict dimension of work-family conflict had negative impacts on professional commitment through perceived emotional support and instrumental support. Overall, our findings extend a better understanding of work-family conflict and professional commitment in the project setting and verify the importance of social support in balancing work and family and improving employee mobility. PMID:29462860

Work-Family Conflict, Perceived Organizational Support and Professional Commitment: A Mediation Mechanism for Chinese Project Professionals.

PubMed

Zheng, Junwei; Wu, Guangdong

2018-02-15

Projects are characterized by long working hours, complex tasks and being a kind of temporary organization. As such, work-family conflict is particularly prominent for project employees. This research examined whether and how work-family conflict affects professional commitment among Chinese project professionals. Research hypotheses were developed to explore the relationship between work-family conflict, professional commitment to the project and the mediating effects of perceived organizational support. Data were collected from 327 project managers or professionals working in construction enterprises in China; data were analyzed using structural equation modeling, applying the bootstrapping method. Results showed that there were three dimensions of work-family conflict: time-based conflict, strain-based conflict and behavior-based conflict. There were two dimensions of perceived organizational support: emotional support and instrumental support. The study also tested the negative effect of work-family conflict on professional commitment and the positive effect of perceived organizational support on professional commitment. Specifically, time-based conflict and emotional support had positive effects on professional commitment. Perceived organizational support had a total mediating effect between work-family conflict and professional commitment. The strain-based conflict dimension of work-family conflict had negative impacts on professional commitment through perceived emotional support and instrumental support. Overall, our findings extend a better understanding of work-family conflict and professional commitment in the project setting and verify the importance of social support in balancing work and family and improving employee mobility.

Task-dependent response conflict monitoring and cognitive control in anterior cingulate and dorsolateral prefrontal cortices.

PubMed

Kim, Chobok; Chung, Chongwook; Kim, Jeounghoon

2013-11-06

Previous experience affects our behavior in terms of adjustments. It has been suggested that the conflict monitor-controller system implemented in the prefrontal cortex plays a critical role in such adjustments. Previous studies suggested that there exists multiple conflict monitor-controller systems associated with the level of information (i.e., stimulus and response levels). In this study, we sought to test whether different types of conflicts occur at the same information processing level (i.e., response level) are independently processed. For this purpose, we designed a task paradigm to measure two different types of response conflicts using color-based and location-based conflict stimuli and measured the conflict adaptation effects associated with the two types of conflicts either independently (i.e., single conflict conditions) or simultaneously (i.e., a double-conflict condition). The behavioral results demonstrated that performance on current incongruent trials was faster only when the preceding trial was the same type of response conflict regardless of whether they included a single- or double-conflict. Imaging data also showed that anterior cingulate and dorsolateral prefrontal cortices operate in a task-specific manner. These findings suggest that there may be multiple monitor-controller loops for color-based and location-based conflicts even at the same response level. Importantly, our results suggest that double-conflict processing is qualitatively different from single-conflict processing although double-conflict shares the same sources of conflict with two single-conflict conditions. © 2013 Published by Elsevier B.V.

Evolution of policies on human resources for health: opportunities and constraints in four post-conflict and post-crisis settings.

PubMed

Witter, Sophie; Bertone, Maria Paola; Chirwa, Yotamu; Namakula, Justine; So, Sovannarith; Wurie, Haja R

2016-01-01

Few studies look at policy making in the health sector in the aftermath of a conflict or crisis and even fewer specifically focus on Human Resources for Health, which is a critical domain for health sector performance. The main objective of the article is to shed light on the patterns and drivers of post-conflict policy-making. In particular, we explore whether the post -conflict period offers increased chances for the opening of 'windows for opportunity' for change and reform and the potential to reset health systems. This article uses a comparative policy analysis framework. It is based on qualitative data, collected using three main tools - stakeholder mapping, key informant interviews and document reviews - in Uganda, Sierra Leone, Cambodia and Zimbabwe. We found that HRH challenges were widely shared across the four cases in the post-conflict period but that the policy trajectories were different - driven by the nature of the conflicts but also the wider context. Our findings suggest that there is no formula for whether or when a 'window of opportunity' will arise which allows health systems to be reset. Problems are well understood in all four cases but core issues - such as adequate pay, effective distribution and HRH management - are to a greater or lesser degree unresolved. These problems are not confined to post-conflict settings, but underlying challenges to addressing them - including fiscal space, political consensus, willingness to pursue public objectives over private, and personal and institutional capacity to manage technical solutions - are liable to be even more acute in these settings. The role of the MoH emerged as weaker than expected, while the shift from donor dependence was clearly not linear and can take a considerable time. Windows of opportunity for change and reform can occur but are by no means guaranteed by a crisis - rather they depend on a constellation of leadership, financing, and capacity. Recognition of urgency is certainly a facilitator but not sufficient alone. Post-conflict environments face particularly severe challenges to evidence-based policy making and policy implementation, which also constrain their ability to effectively use the windows which are presented.

Inhibitory Processes in Young Children and Individual Variation in Short-Term Memory

PubMed Central

Espy, Kimberly Andrews; Bull, Rebecca

2009-01-01

A precise definition of executive control remains elusive, related in part to the variations among executive tasks in the nature of the task demands, which complicate the identification of test-specific versus construct-specific performance. In this study, tasks were chosen that varied in the nature of the stimulus (verbal, nonverbal), response (naming, somatic motor), conflict type (proactive interference, distraction), and inhibitory process (attention control, response suppression) required. Then performance differences were examined in 184 young children (age range = 3 years 6 months to 6 years 1 month), comparing those with high (5 or more digits) and low (3 or fewer digits) spans to determine the dependence on short-term memory. Results indicated that there was communality in inhibitory task demands across instruments, although the specific pattern of task intercorrelations varied in children with high and low spans. Furthermore, only performance on attention control tasks—that is, that require cognitive engagement/disengagement among an internally represented rule or response set that was previously active versus those currently active—differed between children of high and low spans. In contrast, there were differences neither between children with high and low spans on response suppression tasks nor on tasks when considered by type of stimulus, response, or conflict. Individual differences in well-regulated thought may rest in variations in the ability to maintain information in an active, quickly retrievable state that subserve controlling attention in a goal-relevant fashion. PMID:16144432

Deficits in inhibitory control and conflict resolution on cognitive and motor tasks in Parkinson's disease.

PubMed

Obeso, Ignacio; Wilkinson, Leonora; Casabona, Enrique; Bringas, Maria Luisa; Álvarez, Mario; Álvarez, Lázaro; Pavón, Nancy; Rodríguez-Oroz, Maria-Cruz; Macías, Raúl; Obeso, Jose A; Jahanshahi, Marjan

2011-07-01

Recent imaging studies in healthy controls with a conditional stop signal reaction time (RT) task have implicated the subthalamic nucleus (STN) in response inhibition and the pre-supplementary motor area (pre-SMA) in conflict resolution. Parkinson's disease (PD) is characterized by striatal dopamine deficiency and overactivity of the STN and underactivation of the pre-SMA during movement. We used the conditional stop signal RT task to investigate whether PD produced similar or dissociable effects on response initiation, response inhibition and response initiation under conflict. In addition, we also examined inhibition of prepotent responses on three cognitive tasks: the Stroop, random number generation and Hayling sentence completion. PD patients were impaired on the conditional stop signal reaction time task, with response initiation both in situations with or without conflict and response inhibition all being significantly delayed, and had significantly greater difficulty in suppressing prepotent or habitual responses on the Stroop, Hayling and random number generation tasks relative to controls. These results demonstrate the existence of a generalized inhibitory deficit in PD, which suggest that PD is a disorder of inhibition as well as activation and that in situations of conflict, executive control over responses is compromised.

Developmental Increase in Top-Down and Bottom-Up Processing in a Phonological Task: An Effective Connectivity, fMRI Study

ERIC Educational Resources Information Center

Bitan, Tali; Cheon, Jimmy; Lu, Dong; Burman, Douglas D.; Booth, James R.

2009-01-01

We examined age-related changes in the interactions among brain regions in children performing rhyming judgments on visually presented words. The difficulty of the task was manipulated by including a conflict between task-relevant (phonological) information and task-irrelevant (orthographic) information. The conflicting conditions included pairs…

Across-Task Priming Revisited: Response and Task Conflicts Disentangled Using Ex-Gaussian Distribution Analysis

ERIC Educational Resources Information Center

Moutsopoulou, Karolina; Waszak, Florian

2012-01-01

The differential effects of task and response conflict in priming paradigms where associations are strengthened between a stimulus, a task, and a response have been demonstrated in recent years with neuroimaging methods. However, such effects are not easily disentangled with only measurements of behavior, such as reaction times (RTs). Here, we…

Neural Conflict–Control Mechanisms Improve Memory for Target Stimuli

PubMed Central

Krebs, Ruth M.; Boehler, Carsten N.; De Belder, Maya; Egner, Tobias

2015-01-01

According to conflict-monitoring models, conflict serves as an internal signal for reinforcing top-down attention to task-relevant information. While evidence based on measures of ongoing task performance supports this idea, implications for long-term consequences, that is, memory, have not been tested yet. Here, we evaluated the prediction that conflict-triggered attentional enhancement of target-stimulus processing should be associated with superior subsequent memory for those stimuli. By combining functional magnetic resonance imaging (fMRI) with a novel variant of a face-word Stroop task that employed trial-unique face stimuli as targets, we were able to assess subsequent (incidental) memory for target faces as a function of whether a given face had previously been accompanied by congruent, neutral, or incongruent (conflicting) distracters. In line with our predictions, incongruent distracters not only induced behavioral conflict, but also gave rise to enhanced memory for target faces. Moreover, conflict-triggered neural activity in prefrontal and parietal regions was predictive of subsequent retrieval success, and displayed conflict-enhanced functional coupling with medial-temporal lobe regions. These data provide support for the proposal that conflict evokes enhanced top-down attention to task-relevant stimuli, thereby promoting their encoding into long-term memory. Our findings thus delineate the neural mechanisms of a novel link between cognitive control and memory. PMID:24108799

A New Structural Model for the Red Sea from Seismic Data

NASA Astrophysics Data System (ADS)

Mooney, W. D.; Yao, Z.; Zahran, H. M.; El-Hadidy, S. Y.

2017-12-01

We present a new structureal model for the Red Sea that shows opening on an east-dipping low-angle detachment fault. We measured phase velocities using Rayleigh-wave data recorded at recently-installed, dense broadband seismic stations in the Arabian shield and determined the shear-wave velocity structure. Our results clearly reveal a 300-km wide upper mantle seismic low-velocity zone (LVZ) beneath the western Arabian shield at a depth of 60 km and with a thickness of 130 km. The LVZ has a north-south trend and follows the late-Cenozoic volcanic areas. The lithosphere beneath the western Arabian shield is remarkably thin (60-90 km). The 130-km thick mantle LVZ does not appear beneath the western Red Sea and the spreading axis. Thus, the Red Sea at 20°- 26° N is an asymmetric rift, with thin lithosphere located east of the Red Sea axis, as predicted by the low-angle detachment model for rift development. Passive rifting at the Red Sea and extensional stresses in the shield are probably driven by slab pull from the Zagros subduction zone. The low shear-wave velocity (4.0-4.2 km/s) and the geometry of LVZ beneath the western shield indicate northward flow of hot asthenosphere from the Afar hot spot. The upwelling of basaltic melt in fractures or zones of localized lithospheric thinning has produced extensive late Cenozoic volcanism on the western edge of the shield, and the buoyant LVZ has caused pronounced topography uplift there. Thus, the evolution of the Red Sea and the Arabian shield is driven by subduction of the Arabian plate along its northeastern boundary, and the Red Sea opened on a east-dipping low-angle detachment fault.

Carving executive control at its joints: Working memory capacity predicts stimulus-stimulus, but not stimulus-response, conflict.

PubMed

Meier, Matt E; Kane, Michael J

2015-11-01

Three experiments examined the relation between working memory capacity (WMC) and 2 different forms of cognitive conflict: stimulus-stimulus (S-S) and stimulus-response (S-R) interference. Our goal was to test whether WMC's relation to conflict-task performance is mediated by stimulus-identification processes (captured by S-S conflict), response-selection processes (captured by S-R conflict), or both. In Experiment 1, subjects completed a single task presenting both S-S and S-R conflict trials, plus trials that combined the 2 conflict types. We limited ostensible goal-maintenance contributions to performance by requiring the same goal for all trial types and by presenting frequent conflict trials that reinforced the goal. WMC predicted resolution of S-S conflict as expected: Higher WMC subjects showed reduced response time interference. Although WMC also predicted S-R interference, here, higher WMC subjects showed increased error interference. Experiment 2A replicated these results in a version of the conflict task without combined S-S/S-R trials. Experiment 2B increased the proportion of congruent (nonconflict) trials to promote reliance on goal-maintenance processes. Here, higher WMC subjects resolved both S-S and S-R conflict more successfully than did lower WMC subjects. The results were consistent with Kane and Engle's (2003) 2-factor theory of cognitive control, according to which WMC predicts executive-task performance through goal-maintenance and conflict-resolution processes. However, the present results add specificity to the account by suggesting that higher WMC subjects better resolve cognitive conflict because they more efficiently select relevant stimulus features against irrelevant, distracting ones. (c) 2015 APA, all rights reserved).

Neural conflict-control mechanisms improve memory for target stimuli.

PubMed

Krebs, Ruth M; Boehler, Carsten N; De Belder, Maya; Egner, Tobias

2015-03-01

According to conflict-monitoring models, conflict serves as an internal signal for reinforcing top-down attention to task-relevant information. While evidence based on measures of ongoing task performance supports this idea, implications for long-term consequences, that is, memory, have not been tested yet. Here, we evaluated the prediction that conflict-triggered attentional enhancement of target-stimulus processing should be associated with superior subsequent memory for those stimuli. By combining functional magnetic resonance imaging (fMRI) with a novel variant of a face-word Stroop task that employed trial-unique face stimuli as targets, we were able to assess subsequent (incidental) memory for target faces as a function of whether a given face had previously been accompanied by congruent, neutral, or incongruent (conflicting) distracters. In line with our predictions, incongruent distracters not only induced behavioral conflict, but also gave rise to enhanced memory for target faces. Moreover, conflict-triggered neural activity in prefrontal and parietal regions was predictive of subsequent retrieval success, and displayed conflict-enhanced functional coupling with medial-temporal lobe regions. These data provide support for the proposal that conflict evokes enhanced top-down attention to task-relevant stimuli, thereby promoting their encoding into long-term memory. Our findings thus delineate the neural mechanisms of a novel link between cognitive control and memory. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

False belief understanding and "cool" inhibitory control in 3-and 4-years-old Italian children.

PubMed

Bellagamba, Francesca; Addessi, Elsa; Focaroli, Valentina; Pecora, Giulia; Maggiorelli, Valentina; Pace, Beatrice; Paglieri, Fabio

2015-01-01

During preschool years, major developments occur in both executive function and theory of mind (ToM), and several studies have demonstrated a correlation between these processes. Research on the development of inhibitory control (IC) has distinguished between more cognitive, "cool" aspects of self-control, measured by conflict tasks, that require inhibiting an habitual response to generate an arbitrary one, and "hot," affective aspects, such as affective decision making, measured by delay tasks, that require inhibition of a prepotent response. The aim of this study was to investigate the relations between 3- and 4-year-olds' performance on a task measuring false belief understanding, the most widely used index of ToM in preschoolers, and three tasks measuring cognitive versus affective aspects of IC. To this end, we tested 101 Italian preschool children in four tasks: (a) the Unexpected Content False Belief task, (b) the Conflict task (a simplified version of the Day-Night Stroop task), (c) the Delay task, and (d) the Delay Choice task. Children's receptive vocabulary was assessed by the Peabody Picture Vocabulary test. Children's performance in the False Belief task was significantly related only to performance in the Conflict task, controlling for vocabulary and age. Importantly, children's performance in the Conflict task did not significantly correlate with their performance in the Delay task or in the Delay Choice task, suggesting that these tasks measure different components of IC. The dissociation between the Conflict and the Delay tasks may indicate that monitoring and regulating a cool process (as flexible categorization) may involve different abilities than monitoring and regulating a hot process (not touching an available and highly attractive stimulus or choosing between a smaller immediate option and a larger delayed one). Moreover, our findings support the view that "cool" aspects of IC and ToM are interrelated, extending to an Italian sample of children previous findings on an association between self-control and ToM.

False belief understanding and “cool” inhibitory control in 3-and 4-years-old Italian children

PubMed Central

Bellagamba, Francesca; Addessi, Elsa; Focaroli, Valentina; Pecora, Giulia; Maggiorelli, Valentina; Pace, Beatrice; Paglieri, Fabio

2015-01-01

During preschool years, major developments occur in both executive function and theory of mind (ToM), and several studies have demonstrated a correlation between these processes. Research on the development of inhibitory control (IC) has distinguished between more cognitive, “cool” aspects of self-control, measured by conflict tasks, that require inhibiting an habitual response to generate an arbitrary one, and “hot,” affective aspects, such as affective decision making, measured by delay tasks, that require inhibition of a prepotent response. The aim of this study was to investigate the relations between 3- and 4-year-olds’ performance on a task measuring false belief understanding, the most widely used index of ToM in preschoolers, and three tasks measuring cognitive versus affective aspects of IC. To this end, we tested 101 Italian preschool children in four tasks: (a) the Unexpected Content False Belief task, (b) the Conflict task (a simplified version of the Day–Night Stroop task), (c) the Delay task, and (d) the Delay Choice task. Children’s receptive vocabulary was assessed by the Peabody Picture Vocabulary test. Children’s performance in the False Belief task was significantly related only to performance in the Conflict task, controlling for vocabulary and age. Importantly, children’s performance in the Conflict task did not significantly correlate with their performance in the Delay task or in the Delay Choice task, suggesting that these tasks measure different components of IC. The dissociation between the Conflict and the Delay tasks may indicate that monitoring and regulating a cool process (as flexible categorization) may involve different abilities than monitoring and regulating a hot process (not touching an available and highly attractive stimulus or choosing between a smaller immediate option and a larger delayed one). Moreover, our findings support the view that “cool” aspects of IC and ToM are interrelated, extending to an Italian sample of children previous findings on an association between self-control and ToM. PMID:26175700

Event-related near-infrared spectroscopy detects conflict in the motor cortex in a Stroop task.

PubMed

Szűcs, Dénes; Killikelly, Clare; Cutini, Simone

2012-10-05

The Stroop effect is one of the most popular models of conflict processing in neuroscience and psychology. The response conflict theory of the Stroop effect explains decreased performance in the incongruent condition of Stroop tasks by assuming that the task-relevant and the task-irrelevant stimulus features elicit conflicting response tendencies. However, to date, there is not much explicit neural evidence supporting this theory. Here we used functional near-infrared imaging (fNIRS) to examine whether conflict at the level of the motor cortex can be detected in the incongruent relative to the congruent condition of a Stroop task. Response conflict was determined by comparing the activity of the hemisphere ipsilateral to the response hand in the congruent and incongruent conditions. First, results provided explicit hemodynamic evidence supporting the response conflict theory of the Stroop effect: there was greater motor cortex activation in the hemisphere ipsilateral to the response hand in the incongruent than in the congruent condition during the initial stage of the hemodynamic response. Second, as fNIRS is still a relatively novel technology, it is methodologically significant that our data shows that fNIRS is able to detect a brief and transient increase in hemodynamic activity localized to the motor cortex, which in this study is related to subthreshold motor response activation. Copyright © 2012 Elsevier B.V. All rights reserved.

Gulf War Illness Inflammation Reduction Trial

DTIC Science & Technology

2016-10-01

the Kuwaiti Theater of Operations during Operation Desert Shield and Operation Desert Storm (Gulf War). Many veterans of this conflict now suffer...complete blood count with differential, plasma proteomics, platelet function studies, and the measurement of multiple coagulation parameters. The

Comparison of two Simon tasks: neuronal correlates of conflict resolution based on coherent motion perception.

PubMed

Wittfoth, Matthias; Buck, Daniela; Fahle, Manfred; Herrmann, Manfred

2006-08-15

The present study aimed at characterizing the neural correlates of conflict resolution in two variations of the Simon effect. We introduced two different Simon tasks where subjects had to identify shapes on the basis of form-from-motion perception (FFMo) within a randomly moving dot field, while (1) motion direction (motion-based Simon task) or (2) stimulus location (location-based Simon task) had to be ignored. Behavioral data revealed that both types of Simon tasks induced highly significant interference effects. Using event-related fMRI, we could demonstrate that both tasks share a common cluster of activated brain regions during conflict resolution (pre-supplementary motor area (pre-SMA), superior parietal lobule (SPL), and cuneus) but also show task-specific activation patterns (left superior temporal cortex in the motion-based, and the left fusiform gyrus in the location-based Simon task). Although motion-based and location-based Simon tasks are conceptually very similar (Type 3 stimulus-response ensembles according to the taxonomy of [Kornblum, S., Stevens, G. (2002). Sequential effects of dimensional overlap: findings and issues. In: Prinz, W., Hommel., B. (Eds.), Common mechanism in perception and action. Oxford University Press, Oxford, pp. 9-54]) conflict resolution in both tasks results in the activation of different task-specific regions probably related to the different sources of task-irrelevant information. Furthermore, the present data give evidence those task-specific regions are most likely to detect the relationship between task-relevant and task-irrelevant information.

A Reinforcement Model of the Relationships of Supervisors' General Communication Styles and Conflict Management Styles to Task Attraction.

ERIC Educational Resources Information Center

Wheeless, Lawrence R.; Reichel, Lisa S.

1990-01-01

Investigates the relationship between general styles of communicating and more situation-specific conflict management styles. Finds substantial relationships between general communication styles and conflict management styles, as well as very substantial relationships between the style constructs and task attraction of supervisors. (SR)

It Is Not What You Expect: Dissociating Conflict Adaptation from Expectancies in a Stroop Task

ERIC Educational Resources Information Center

Jimenez, Luis; Mendez, Amavia

2013-01-01

In conflict tasks, congruency effects are modulated by the sequence of preceding trials. This modulation effect has been interpreted as an influence of a proactive mechanism of adaptation to conflict (Botvinick, Nystrom, Fissell, Carter, & Cohen, 1999), but the possible contribution of explicit expectancies to this adaptation effect remains…

The Critical Roles of Task Conflict and Job Autonomy in the Relationship Between Proactive Personalities and Innovative Employee Behavior

PubMed Central

Giebels, Ellen; de Reuver, Renee S.M.; Rispens, Sonja; Ufkes, Elze G.

2016-01-01

We examine why and when proactive personality is beneficial for innovative behavior at work. Based on a survey among 166 employees working in 35 departments of a large municipality in the Netherlands we show that an increase in task conflicts explains the positive relation between a proactive personality and innovative employee behavior. This process is moderated by job autonomy in such a way that the relationship between proactive personality and task conflict is particularly strong under low compared with high autonomy. The present research contributes to the discussion on the potential benefits of task conflict for change processes and highlights the importance of examining the interplay between personality and work context for understanding innovation practices. PMID:27536008

[The role of self-guided training in the relationship between task conflict and innovation in virtual teams].

PubMed

Martínez Moreno, Edurne; Orengo Castellá, Virginia; Zornoza Abad, Ana

2012-02-01

This study was conducted to evaluate the moderating role of self-guided training in the relationship between task conflict and team innovation in synchronic computer-mediated communication (SCMC) teams. For this purpose, a laboratory study was carried out in which 26 teams were assigned to the training condition and 24 to the control condition. Results confirmed that SCMC teams develop a negative relationship between task conflict and innovation, but also revealed that self-guided training may slow these counterproductive effects down. Our study provides new evidence of the linear relationship between task conflict and team innovation in SCMC teams, extending previous research findings obtained in face-to-face teams to virtual context and suggest that self-guided training can be useful for virtual team innovation.

Climate uniformity: its influence on team communication quality, task conflict, and team performance.

PubMed

González-Romá, Vicente; Hernández, Ana

2014-11-01

We investigated whether climate uniformity (the pattern of climate perceptions of organizational support within the team) is related to task conflict, team communication quality, and team performance. We used a sample composed of 141 bank branches and collected data at 3 time points. The results obtained showed that, after controlling for aggregate team climate, climate strength, and their interaction, a type of nonuniform climate pattern (weak dissimilarity) was directly related to task conflict and team communication quality. Teams with weak dissimilarity nonuniform patterns tended to show higher levels of task conflict and lower levels of team communication quality than teams with uniform climate patterns. The relationship between weak dissimilarity patterns and team performance was fully mediated by team communication quality. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Stroop proactive control and task conflict are modulated by concurrent working memory load.

PubMed

Kalanthroff, Eyal; Avnit, Amir; Henik, Avishai; Davelaar, Eddy J; Usher, Marius

2015-06-01

Performance on the Stroop task reflects two types of conflict-informational (between the incongruent word and font color) and task (between the contextually relevant color-naming task and the irrelevant, but automatic, word-reading task). According to the dual mechanisms of control theory (DMC; Braver, 2012), variability in Stroop performance can result from variability in the deployment of a proactive task-demand control mechanism. Previous research has shown that when proactive control (PC) is diminished, both increased Stroop interference and a reversed Stroop facilitation (RF) are observed. Although the current DMC model accounts for the former effect, it does not predict the observed RF, which is considered to be behavioral evidence for task conflict in the Stroop task. Here we expanded the DMC model to account for Stroop RF. Assuming that a concurrent working memory (WM) task reduces PC, we predicted both increased interference and an RF. Nineteen participants performed a standard Stroop task combined with a concurrent n-back task, which was aimed at reducing available WM resources, and thus overloading PC. Although the results indicated common Stroop interference and facilitation in the low-load condition (zero-back), in the high-load condition (two-back), both increased Stroop interference and RF were observed, consistent with the model's prediction. These findings indicate that PC is modulated by concurrent WM load and serves as a common control mechanism for both informational and task Stroop conflicts.

‘I'm So Stressed!’: A Longitudinal Model of Stress, Burnout and Engagement among Social Workers in Child Welfare Settings

PubMed Central

Travis, Dnika J.; Lizano, Erica Leeanne; Mor Barak, Michàlle E.

2016-01-01

The well-documented day-to-day and long-term experiences of job stress and burnout among employees in child welfare organisations increasingly raise concerns among leaders, policy makers and scholars. Testing a theory-driven longitudinal model, this study seeks to advance understanding of the differential impact of job stressors (work–family conflict, role conflict and role ambiguity) and burnout (emotional exhaustion and depersonalisation) on employee disengagement (work withdrawal and exit-seeking behaviours). Data were collected at three six-month intervals from an availability sample of 362 front line social workers or social work supervisors who work in a large urban public child welfare organisation in the USA. The study's results yielded a good model fit (RMSEA = 0.06, CFI = 0.96, NFI = 0.94). Work–family conflict, role ambiguity and role conflict were found to impact work withdrawal and exit-seeking behaviours indirectly through burnout. The outcome variable, exit-seeking behaviours, was positively impacted by depersonalisation and work withdrawal at a statistically significant level. Overall, findings, at least in the US context, highlight the importance of further examining the development of job burnout among social workers and social work supervisors working in child welfare settings, as well as the utility of long-term administrative strategies to mitigate risks of burnout development and support engagement. PMID:27559215

'I'm So Stressed!': A Longitudinal Model of Stress, Burnout and Engagement among Social Workers in Child Welfare Settings.

PubMed

Travis, Dnika J; Lizano, Erica Leeanne; Mor Barak, Michàlle E

2016-06-01

The well-documented day-to-day and long-term experiences of job stress and burnout among employees in child welfare organisations increasingly raise concerns among leaders, policy makers and scholars. Testing a theory-driven longitudinal model, this study seeks to advance understanding of the differential impact of job stressors (work-family conflict, role conflict and role ambiguity) and burnout (emotional exhaustion and depersonalisation) on employee disengagement (work withdrawal and exit-seeking behaviours). Data were collected at three six-month intervals from an availability sample of 362 front line social workers or social work supervisors who work in a large urban public child welfare organisation in the USA. The study's results yielded a good model fit (RMSEA = 0.06, CFI = 0.96, NFI = 0.94). Work-family conflict, role ambiguity and role conflict were found to impact work withdrawal and exit-seeking behaviours indirectly through burnout. The outcome variable, exit-seeking behaviours, was positively impacted by depersonalisation and work withdrawal at a statistically significant level. Overall, findings, at least in the US context, highlight the importance of further examining the development of job burnout among social workers and social work supervisors working in child welfare settings, as well as the utility of long-term administrative strategies to mitigate risks of burnout development and support engagement.

A common neural hub resolves syntactic and non-syntactic conflict through cooperation with task-specific networks

PubMed Central

Hsu, Nina S.; Jaeggi, Susanne M.; Novick, Jared M.

2017-01-01

Regions within the left inferior frontal gyrus (LIFG) have simultaneously been implicated in syntactic processing and cognitive control. Accounts attempting to unify LIFG’s function hypothesize that, during comprehension, cognitive control resolves conflict between incompatible representations of sentence meaning. Some studies demonstrate co-localized activity within LIFG for syntactic and non-syntactic conflict resolution, suggesting domain-generality, but others show non-overlapping activity, suggesting domain-specific cognitive control and/or regions that respond uniquely to syntax. We propose however that examining exclusive activation sites for certain contrasts creates a false dichotomy: both domain-general and domain-specific neural machinery must coordinate to facilitate conflict resolution across domains. Here, subjects completed four diverse tasks involving conflict —one syntactic, three non-syntactic— while undergoing fMRI. Though LIFG consistently activated within individuals during conflict processing, functional connectivity analyses revealed task-specific coordination with distinct brain networks. Thus, LIFG may function as a conflict-resolution “hub” that cooperates with specialized neural systems according to information content. PMID:28110105

The effects of stimulus-driven competition and task set on involuntary attention

PubMed Central

Han, Suk Won; Marois, René

2014-01-01

It is well established that involuntary attention—the exogenous capture of attention by salient but task-irrelevant stimuli—can strongly modulate target detection and discrimination performance. There is an ongoing debate, however, about how involuntary attention affects target performance. Some studies suggest that it results from enhanced perception of the target, whereas others indicate instead that it affects decisional stages of information processing. From a review of these studies, we hypothesized that the presence of distractors and task sets are key factors in determining the effect of involuntary attention on target perception. Consistent with this hypothesis, here we found that noninformative cues summoning involuntary attention affected perceptual identification of a target when distractors were present. This cuing effect could not be attributed to reduced target location uncertainty or decision bias. The only condition under which involuntary attention improved target perception in the absence of distractors occurred when observers did not adopt a task set to focus attention on the target location. We conclude that the perceptual effects of involuntary attention depend on distractor interference and the adoption of a task set to resolve such stimulus competition. PMID:24970921

High body mass index is associated with impaired cognitive control.

PubMed

Sellaro, Roberta; Colzato, Lorenza S

2017-06-01

The prevalence of weight problems is increasing worldwide. There is growing evidence that high body mass index (BMI) is associated with frontal lobe dysfunction and cognitive deficits concerning mental flexibility and inhibitory control efficiency. The present study aims at replicating and extending these observations. We compared cognitive control performance of normal weight (BMI < 25) and overweight (BMI ≥ 25) university students on a task tapping either inhibitory control (Experiment 1) or interference control (Experiment 2). Experiment 1 replicated previous findings that found less efficient inhibitory control in overweight individuals. Experiment 2 complemented these findings by showing that cognitive control impairments associated with high BMI also extend to the ability to resolve stimulus-induced response conflict and to engage in conflict-driven control adaptation. The present results are consistent with and extend previous literature showing that high BMI in young, otherwise healthy individuals is associated with less efficient cognitive control functioning. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development Context Driven Change Awareness and Analysis Framework

NASA Technical Reports Server (NTRS)

Sarma, Anita; Branchaud, Josh; Dwyer, Matthew B.; Person, Suzette; Rungta, Neha

2014-01-01

Recent work on workspace monitoring allows conflict prediction early in the development process, however, these approaches mostly use syntactic differencing techniques to compare different program versions. In contrast, traditional change-impact analysis techniques analyze related versions of the program only after the code has been checked into the master repository. We propose a novel approach, De- CAF (Development Context Analysis Framework), that leverages the development context to scope a change impact analysis technique. The goal is to characterize the impact of each developer on other developers in the team. There are various client applications such as task prioritization, early conflict detection, and providing advice on testing that can benefit from such a characterization. The DeCAF framework leverages information from the development context to bound the iDiSE change impact analysis technique to analyze only the parts of the code base that are of interest. Bounding the analysis can enable DeCAF to efficiently compute the impact of changes using a combination of program dependence and symbolic execution based approaches.

Development Context Driven Change Awareness and Analysis Framework

NASA Technical Reports Server (NTRS)

Sarma, Anita; Branchaud, Josh; Dwyer, Matthew B.; Person, Suzette; Rungta, Neha; Wang, Yurong; Elbaum, Sebastian

2014-01-01

Recent work on workspace monitoring allows conflict prediction early in the development process, however, these approaches mostly use syntactic differencing techniques to compare different program versions. In contrast, traditional change-impact analysis techniques analyze related versions of the program only after the code has been checked into the master repository. We propose a novel approach, DeCAF (Development Context Analysis Framework), that leverages the development context to scope a change impact analysis technique. The goal is to characterize the impact of each developer on other developers in the team. There are various client applications such as task prioritization, early conflict detection, and providing advice on testing that can benefit from such a characterization. The DeCAF framework leverages information from the development context to bound the iDiSE change impact analysis technique to analyze only the parts of the code base that are of interest. Bounding the analysis can enable DeCAF to efficiently compute the impact of changes using a combination of program dependence and symbolic execution based approaches.

Diffusion of e-health innovations in 'post-conflict' settings: a qualitative study on the personal experiences of health workers.

PubMed

Woodward, Aniek; Fyfe, Molly; Handuleh, Jibril; Patel, Preeti; Godman, Brian; Leather, Andrew; Finlayson, Alexander

2014-04-23

Technological innovations have the potential to strengthen human resources for health and improve access and quality of care in challenging 'post-conflict' contexts. However, analyses on the adoption of technology for health (that is, 'e-health') and whether and how e-health can strengthen a health workforce in these settings have been limited so far. This study explores the personal experiences of health workers using e-health innovations in selected post-conflict situations. This study had a cross-sectional qualitative design. Telephone interviews were conducted with 12 health workers, from a variety of cadres and stages in their careers, from four post-conflict settings (Liberia, West Bank and Gaza, Sierra Leone and Somaliland) in 2012. Everett Roger's diffusion of innovation-decision model (that is, knowledge, persuasion, decision, implementation, contemplation) guided the thematic analysis. All health workers interviewed held positive perceptions of e-health, related to their beliefs that e-health can help them to access information and communicate with other health workers. However, understanding of the scope of e-health was generally limited, and often based on innovations that health workers have been introduced through by their international partners. Health workers reported a range of engagement with e-health innovations, mostly for communication (for example, email) and educational purposes (for example, online learning platforms). Poor, unreliable and unaffordable Internet was a commonly mentioned barrier to e-health use. Scaling-up existing e-health partnerships and innovations were suggested starting points to increase e-health innovation dissemination. Results from this study showed ICT based e-health innovations can relieve information and communication needs of health workers in post-conflict settings. However, more efforts and investments, preferably driven by healthcare workers within the post-conflict context, are needed to make e-health more widespread and sustainable. Increased awareness is necessary among health professionals, even among current e-health users, and physical and financial access barriers need to be addressed. Future e-health initiatives are likely to increase their impact if based on perceived health information needs of intended users.

An analysis of relational complexity in an air traffic control conflict detection task.

PubMed

Boag, Christine; Neal, Andrew; Loft, Shayne; Halford, Graeme S

2006-11-15

Theoretical analyses of air traffic complexity were carried out using the Method for the Analysis of Relational Complexity. Twenty-two air traffic controllers examined static air traffic displays and were required to detect and resolve conflicts. Objective measures of performance included conflict detection time and accuracy. Subjective perceptions of mental workload were assessed by a complexity-sorting task and subjective ratings of the difficulty of different aspects of the task. A metric quantifying the complexity of pair-wise relations among aircraft was able to account for a substantial portion of the variance in the perceived complexity and difficulty of conflict detection problems, as well as reaction time. Other variables that influenced performance included the mean minimum separation between aircraft pairs and the amount of time that aircraft spent in conflict.

The paradox of intragroup conflict: a meta-analysis.

PubMed

de Wit, Frank R C; Greer, Lindred L; Jehn, Karen A

2012-03-01

Since the meta-analysis by De Dreu and Weingart (2003b) on the effects of intragroup conflict on group outcomes, more than 80 new empirical studies of conflict have been conducted, often investigating more complex, moderated relationships between conflict and group outcomes, as well as new types of intragroup conflict, such as process conflict. To explore the trends in this new body of literature, we conducted a meta-analysis of 116 empirical studies of intragroup conflict (n = 8,880 groups) and its relationship with group outcomes. To address the heterogeneity across the studies included in the meta-analysis, we also investigated a number of moderating variables. Stable negative relationships were found between relationship and process conflict and group outcomes. In contrast to the results of De Dreu and Weingart, we did not find a strong and negative association between task conflict and group performance. Analyses of main effects as well as moderator analyses revealed a more complex picture. Task conflict and group performance were more positively related among studies where the association between task and relationship conflict was relatively weak, in studies conducted among top management teams rather than non-top management teams, and in studies where performance was measured in terms of financial performance or decision quality rather than overall performance.

Neural correlates of conflict between gestures and words: A domain-specific role for a temporal-parietal complex.

PubMed

Noah, J Adam; Dravida, Swethasri; Zhang, Xian; Yahil, Shaul; Hirsch, Joy

2017-01-01

The interpretation of social cues is a fundamental function of human social behavior, and resolution of inconsistencies between spoken and gestural cues plays an important role in successful interactions. To gain insight into these underlying neural processes, we compared neural responses in a traditional color/word conflict task and to a gesture/word conflict task to test hypotheses of domain-general and domain-specific conflict resolution. In the gesture task, recorded spoken words ("yes" and "no") were presented simultaneously with video recordings of actors performing one of the following affirmative or negative gestures: thumbs up, thumbs down, head nodding (up and down), or head shaking (side-to-side), thereby generating congruent and incongruent communication stimuli between gesture and words. Participants identified the communicative intent of the gestures as either positive or negative. In the color task, participants were presented the words "red" and "green" in either red or green font and were asked to identify the color of the letters. We observed a classic "Stroop" behavioral interference effect, with participants showing increased response time for incongruent trials relative to congruent ones for both the gesture and color tasks. Hemodynamic signals acquired using functional near-infrared spectroscopy (fNIRS) were increased in the right dorsolateral prefrontal cortex (DLPFC) for incongruent trials relative to congruent trials for both tasks consistent with a common, domain-general mechanism for detecting conflict. However, activity in the left DLPFC and frontal eye fields and the right temporal-parietal junction (TPJ), superior temporal gyrus (STG), supramarginal gyrus (SMG), and primary and auditory association cortices was greater for the gesture task than the color task. Thus, in addition to domain-general conflict processing mechanisms, as suggested by common engagement of right DLPFC, socially specialized neural modules localized to the left DLPFC and right TPJ including adjacent homologous receptive language areas were engaged when processing conflicting communications. These findings contribute to an emerging view of specialization within the TPJ and adjacent areas for interpretation of social cues and indicate a role for the region in processing social conflict.

Novel Hybrid Scheduling Technique for Sensor Nodes with Mixed Criticality Tasks.

PubMed

Micea, Mihai-Victor; Stangaciu, Cristina-Sorina; Stangaciu, Valentin; Curiac, Daniel-Ioan

2017-06-26

Sensor networks become increasingly a key technology for complex control applications. Their potential use in safety- and time-critical domains has raised the need for task scheduling mechanisms specially adapted to sensor node specific requirements, often materialized in predictable jitter-less execution of tasks characterized by different criticality levels. This paper offers an efficient scheduling solution, named Hybrid Hard Real-Time Scheduling (H²RTS), which combines a static, clock driven method with a dynamic, event driven scheduling technique, in order to provide high execution predictability, while keeping a high node Central Processing Unit (CPU) utilization factor. From the detailed, integrated schedulability analysis of the H²RTS, a set of sufficiency tests are introduced and demonstrated based on the processor demand and linear upper bound metrics. The performance and correct behavior of the proposed hybrid scheduling technique have been extensively evaluated and validated both on a simulator and on a sensor mote equipped with ARM7 microcontroller.

Brain circuitries involved in emotional interference task in major depression disorder.

PubMed

Chechko, Natalia; Augustin, Marc; Zvyagintsev, Michael; Schneider, Frank; Habel, Ute; Kellermann, Thilo

2013-07-01

Emotional and non-emotional Stroop are frequently applied to study major depressive disorder (MDD). The versions of emotional Stroop used in previous studies were not, unlike the ones employed in the present study, based on semantic incongruence, making it difficult to compare the tasks. We used functional magnetic resonance imaging (fMRI) to study the neural and behavioral responses of 18 healthy subjects and 18 subjects with MDD to emotional and non-emotional word-face Stroop tasks based on semantic incompatibility between targets and distractors. In both groups, the distractors triggered significant amounts of interference conflict. A between-groups comparison revealed hypoactivation in MDD during emotional task in areas supporting conflict resolution (lateral prefrontal cortex, parietal and extrastriate cortices) paralleled by increased response in the right amygdala. Response in the amygdala, however, did not vary between conflicting and non-conflicting trials. While in the emotional (compared to non-emotional) task healthy controls showed considerably stronger involvement of networks related to conflict resolution, in patients, the processing differences between the two conflict types were negligible. The patients group was inhomogeneous in terms of medication and clinical characteristics. The number of female participants was higher, due to which gender effects could not be studied or excluded. Whilst healthy controls seemed able to adjust the involvement of the network supporting conflict resolution based on conflict demand, patients appeared to lack this capability. The reduced cortical involvement coupled with increased response of limbic structures might underlie the maladjustment vis-à-vis new demands in depressed mood. Copyright © 2013 Elsevier B.V. All rights reserved.

The congruency sequence effect 3.0: a critical test of conflict adaptation.

PubMed

Duthoo, Wout; Abrahamse, Elger L; Braem, Senne; Boehler, C Nico; Notebaert, Wim

2014-01-01

Over the last two decades, the congruency sequence effect (CSE) -the finding of a reduced congruency effect following incongruent trials in conflict tasks- has played a central role in advancing research on cognitive control. According to the influential conflict-monitoring account, the CSE reflects adjustments in selective attention that enhance task focus when needed, often termed conflict adaptation. However, this dominant interpretation of the CSE has been called into question by several alternative accounts that stress the role of episodic memory processes: feature binding and (stimulus-response) contingency learning. To evaluate the notion of conflict adaptation in accounting for the CSE, we construed versions of three widely used experimental paradigms (the colour-word Stroop, picture-word Stroop and flanker task) that effectively control for feature binding and contingency learning. Results revealed that a CSE can emerge in all three tasks. This strongly suggests a contribution of attentional control to the CSE and highlights the potential of these unprecedentedly clean paradigms for further examining cognitive control.

The heterogeneous world of congruency sequence effects: an update.

PubMed

Duthoo, Wout; Abrahamse, Elger L; Braem, Senne; Boehler, Carsten N; Notebaert, Wim

2014-01-01

Congruency sequence effects (CSEs) refer to the observation that congruency effects in conflict tasks are typically smaller following incongruent compared to following congruent trials. This measure has long been thought to provide a unique window into top-down attentional adjustments and their underlying brain mechanisms. According to the renowned conflict monitoring theory, CSEs reflect enhanced selective attention following conflict detection. Still, alternative accounts suggested that bottom-up associative learning suffices to explain the pattern of reaction times and error rates. A couple of years ago, a review by Egner (2007) pitted these two rivalry accounts against each other, concluding that both conflict adaptation and feature integration contribute to the CSE. Since then, a wealth of studies has further debated this issue, and two additional accounts have been proposed, offering intriguing alternative explanations. Contingency learning accounts put forward that predictive relationships between stimuli and responses drive the CSE, whereas the repetition expectancy hypothesis suggests that top-down, expectancy-driven control adjustments affect the CSE. In the present paper, we build further on the previous review (Egner, 2007) by summarizing and integrating recent behavioral and neurophysiological studies on the CSE. In doing so, we evaluate the relative contribution and theoretical value of the different attentional and memory-based accounts. Moreover, we review how all of these influences can be experimentally isolated, and discuss designs and procedures that can critically judge between them.

The heterogeneous world of congruency sequence effects: an update

PubMed Central

Duthoo, Wout; Abrahamse, Elger L.; Braem, Senne; Boehler, Carsten N.; Notebaert, Wim

2014-01-01

Congruency sequence effects (CSEs) refer to the observation that congruency effects in conflict tasks are typically smaller following incongruent compared to following congruent trials. This measure has long been thought to provide a unique window into top-down attentional adjustments and their underlying brain mechanisms. According to the renowned conflict monitoring theory, CSEs reflect enhanced selective attention following conflict detection. Still, alternative accounts suggested that bottom-up associative learning suffices to explain the pattern of reaction times and error rates. A couple of years ago, a review by Egner (2007) pitted these two rivalry accounts against each other, concluding that both conflict adaptation and feature integration contribute to the CSE. Since then, a wealth of studies has further debated this issue, and two additional accounts have been proposed, offering intriguing alternative explanations. Contingency learning accounts put forward that predictive relationships between stimuli and responses drive the CSE, whereas the repetition expectancy hypothesis suggests that top-down, expectancy-driven control adjustments affect the CSE. In the present paper, we build further on the previous review (Egner, 2007) by summarizing and integrating recent behavioral and neurophysiological studies on the CSE. In doing so, we evaluate the relative contribution and theoretical value of the different attentional and memory-based accounts. Moreover, we review how all of these influences can be experimentally isolated, and discuss designs and procedures that can critically judge between them. PMID:25250005

Electrokinetically driven active micro-mixers utilizing zeta potential variation induced by field effect

NASA Astrophysics Data System (ADS)

Lee, Chia-Yen; Lee, Gwo-Bin; Fu, Lung-Ming; Lee, Kuo-Hoong; Yang, Ruey-Jen

2004-10-01

This paper presents a new electrokinetically driven active micro-mixer which uses localized capacitance effects to induce zeta potential variations along the surface of silica-based microchannels. The mixer is fabricated by etching bulk flow and shielding electrode channels into glass substrates and then depositing Au/Cr thin films within the latter to form capacitor electrodes, which establish localized zeta potential variations near the electrical double layer (EDL) region of the electroosmotic flow (EOF) within the microchannels. The potential variations induce flow velocity changes within a homogeneous fluid and a rapid mixing effect if an alternating electric field is provided. The current experimental data confirm that the fluid velocity can be actively controlled by using the capacitance effect of the buried shielding electrodes to vary the zeta potential along the channel walls. While compared with commonly used planar electrodes across the microchannels, the buried shielding electrodes prevent current leakage caused by bad bonding and allow direct optical observation during operation. It also shows that the buried shielding electrodes can significantly induce the field effect, resulting in higher variations of zeta potential. Computational fluid dynamic simulations are also used to study the fluid characteristics of the developed active mixers. The numerical and experimental results demonstrate that the developed microfluidic device permits a high degree of control over the fluid flow and an efficient mixing effect. Moreover, the developed device could be used as a pumping device as well. The development of the active electrokinetically driven micro-mixer could be crucial for micro-total-analysis-systems.

Priming can affect naming colours using the study-test procedure. Revealing the role of task conflict.

PubMed

Sharma, Dinkar

2016-11-14

The Stroop paradigm has been widely used to study attention whilst its use to explore implicit memory have been mixed. Using the non-colour word Stroop task we tested contrasting predictions from the proactive-control/task-conflict model (Kalanthroff, Avnit, Henik, Davelaar & Usher, 2015) that implicate response conflict and task conflict for the priming effects. Using the study-test procedure 60 native English speakers were tested to determine whether priming effects from words that had previously been studied would cause interference when presented in a colour naming task. The results replicate a finding by MacLeod (1996) who showed no differences between the response latencies to studied and unstudied words. However, this pattern was predominately in the first half of the study where it was also found that both studied and unstudied words in a mixed block were slower to respond to than a block of pure unstudied words. The second half of the study showed stronger priming interference effects as well as a sequential modulation effect in which studied words slowed down the responses of studied words on the next trial. We discuss the role of proactive and reactive control processes and conclude that task conflict best explains the pattern of priming effects reported. Copyright © 2016. Published by Elsevier B.V.

Adaptation to recent conflict in the classical color-word Stroop-task mainly involves facilitation of processing of task-relevant information.

PubMed

Purmann, Sascha; Pollmann, Stefan

2015-01-01

To process information selectively and to continuously fine-tune selectivity of information processing are important abilities for successful goal-directed behavior. One phenomenon thought to represent this fine-tuning are conflict adaptation effects in interference tasks, i.e., reduction of interference after an incompatible trial and when incompatible trials are frequent. The neurocognitive mechanisms of these effects are currently only partly understood and results from brainimaging studies so far are mixed. In our study we validate and extend recent findings by examining adaption to recent conflict in the classical Stroop task using functional magnetic resonance imaging. Consistent with previous research we found increased activity in a fronto-parietal network comprising the medial prefrontal cortex, ventro-lateral prefrontal cortex, and posterior parietal cortex when contrasting incompatible with compatible trials. These areas have been associated with attentional processes and might reflect increased cognitive conflict and resolution thereof during incompatible trials. While carefully controlling for non-attentional sequential effects we found smaller Stroop interference after an incompatible trial (conflict adaptation effect). These behavioral conflict adaptation effects were accompanied by changes in activity in visual color-selective areas (V4, V4α), while there was no modulation by previous trial compatibility in a visual word-selective area (VWFA). Our results provide further evidence for the notion, that adaptation to recent conflict seems to be based mainly on enhancement of processing of the task-relevant information.

Attentional capture under high perceptual load.

PubMed

Cosman, Joshua D; Vecera, Shaun P

2010-12-01

Attentional capture by abrupt onsets can be modulated by several factors, including the complexity, or perceptual load, of a scene. We have recently demonstrated that observers are less likely to be captured by abruptly appearing, task-irrelevant stimuli when they perform a search that is high, as opposed to low, in perceptual load (Cosman & Vecera, 2009), consistent with perceptual load theory. However, recent results indicate that onset frequency can influence stimulus-driven capture, with infrequent onsets capturing attention more often than did frequent onsets. Importantly, in our previous task, an abrupt onset was present on every trial, and consequently, attentional capture might have been affected by both onset frequency and perceptual load. In the present experiment, we examined whether onset frequency influences attentional capture under conditions of high perceptual load. When onsets were presented frequently, we replicated our earlier results; attentional capture by onsets was modulated under conditions of high perceptual load. Importantly, however, when onsets were presented infrequently, we observed robust capture effects. These results conflict with a strong form of load theory and, instead, suggest that exposure to the elements of a task (e.g., abrupt onsets) combines with high perceptual load to modulate attentional capture by task-irrelevant information.

Faculty Perceptions of Conflict with Administrators: An Analysis of the Associations between the Nature of Conflict and Positive and Negative Outcomes

ERIC Educational Resources Information Center

Hancks, Meredith L.

2013-01-01

This study examines the perceptions of faculty members regarding conflict experiences with administrators. It is driven by the question, "To what extent are faculty perceptions of positive and negative outcomes of faculty-administrator conflict associated with domain, nature and disciplinary context of the conflict," where domain refers…

Neural correlates of distraction and conflict resolution for nonverbal auditory events.

PubMed

Stewart, Hannah J; Amitay, Sygal; Alain, Claude

2017-05-09

In everyday situations auditory selective attention requires listeners to suppress task-irrelevant stimuli and to resolve conflicting information in order to make appropriate goal-directed decisions. Traditionally, these two processes (i.e. distractor suppression and conflict resolution) have been studied separately. In the present study we measured neuroelectric activity while participants performed a new paradigm in which both processes are quantified. In separate block of trials, participants indicate whether two sequential tones share the same pitch or location depending on the block's instruction. For the distraction measure, a positive component peaking at ~250 ms was found - a distraction positivity. Brain electrical source analysis of this component suggests different generators when listeners attended to frequency and location, with the distraction by location more posterior than the distraction by frequency, providing support for the dual-pathway theory. For the conflict resolution measure, a negative frontocentral component (270-450 ms) was found, which showed similarities with that of prior studies on auditory and visual conflict resolution tasks. The timing and distribution are consistent with two distinct neural processes with suppression of task-irrelevant information occurring before conflict resolution. This new paradigm may prove useful in clinical populations to assess impairments in filtering out task-irrelevant information and/or resolving conflicting information.

Performance monitoring and response conflict resolution associated with choice stepping reaction tasks.

PubMed

Watanabe, Tatsunori; Tsutou, Kotaro; Saito, Kotaro; Ishida, Kazuto; Tanabe, Shigeo; Nojima, Ippei

2016-11-01

Choice reaction requires response conflict resolution, and the resolution processes that occur during a choice stepping reaction task undertaken in a standing position, which requires maintenance of balance, may be different to those processes occurring during a choice reaction task performed in a seated position. The study purpose was to investigate the resolution processes during a choice stepping reaction task at the cortical level using electroencephalography and compare the results with a control task involving ankle dorsiflexion responses. Twelve young adults either stepped forward or dorsiflexed the ankle in response to a visual imperative stimulus presented on a computer screen. We used the Simon task and examined the error-related negativity (ERN) that follows an incorrect response and the correct-response negativity (CRN) that follows a correct response. Error was defined as an incorrect initial weight transfer for the stepping task and as an incorrect initial tibialis anterior activation for the control task. Results revealed that ERN and CRN amplitudes were similar in size for the stepping task, whereas the amplitude of ERN was larger than that of CRN for the control task. The ERN amplitude was also larger in the stepping task than the control task. These observations suggest that a choice stepping reaction task involves a strategy emphasizing post-response conflict and general performance monitoring of actual and required responses and also requires greater cognitive load than a choice dorsiflexion reaction. The response conflict resolution processes appear to be different for stepping tasks and reaction tasks performed in a seated position.

Modulation of the conflict monitoring intensity: the role of aversive reinforcement, cognitive demand, and trait-BIS.

PubMed

Leue, Anja; Lange, Sebastian; Beauducel, André

2012-06-01

According to Botvinick's (2007) integrative account, conflict monitoring is aversive because individuals anticipate cognitive demand, whereas the revised reinforcement sensitivity theory (rRST) predicts that conflict processing is aversive because individuals anticipate aversive reinforcement of erroneous responses. Because these accounts give different reasons for the aversive aspects of conflict, we manipulated cognitive demand and the aversive reinforcement as a consequence of wrong choices in a go/no-go task. Thereby, we also aimed to investigate whether individual differences in conflict sensitivity (i.e., in trait anxiety, linked to high sensitivity of the behavioral inhibition system [trait-BIS]) represent the effects of aversive reinforcement and cognitive demand in conflict tasks. We expected that these manipulations would have effects on the frontal N2 component representing activity of the anterior cingulate cortex. Moreover, higher-trait-BIS individuals should be more sensitive than lower-trait-BIS individuals to aversive effects in conflict situations, resulting in a more negative frontal N2 for higher-trait-BIS individuals. In Study 1, with N = 104 students, and Study 2, with N = 47 students, aversive reinforcement was manipulated in three levels (within-subjects factor) and cognitive demand in two levels (between-subjects factor). The behavioral findings from the go/no-go task with noncounterbalanced reinforcement levels (Study 1) could be widely replicated in a task with counterbalanced reinforcement levels (Study 2). The frontal mean no-go N2 amplitude and the frontal no-go N2 dipole captured predicted reinforcement-related variations of conflict monitoring, indicating that the anticipation of aversive reinforcement induces variations in conflict monitoring intensity in frontal brain areas. The aversive nature of conflict was underlined by the more pronounced conflict monitoring in higher- than in lower-trait-BIS individuals.

Livelihoods, conflict and aid programming: is the evidence base good enough?

PubMed

Mallett, Richard; Slater, Rachel

2016-04-01

In conflict-affected situations, aid-funded livelihood interventions are often tasked with a dual imperative: to generate material welfare benefits and to contribute to peacebuilding outcomes. There may be some logic to such a transformative agenda, but does the reality square with the rhetoric? Through a review of the effectiveness of a range of livelihood promotion interventions--from job creation to microfinance--this paper finds that high quality empirical evidence is hard to come by in conflict-affected situations. Many evaluations appear to conflate outputs with impacts and numerous studies fail to include adequate information on their methodologies and datasets, making it difficult to appraise the reliability of their conclusions. Given the primary purpose of this literature--to provide policy guidance on effective ways to promote livelihoods--this silence is particularly concerning. As such, there is a strong case to be made for a restrained and nuanced handling of such interventions in conflict-affected settings. © 2016 The Author(s). Disasters © Overseas Development Institute, 2016.

Working with bacteria and putting bacteria to work: The biopolitics of synthetic biology for energy in the United Kingdom.

PubMed

McLeod, Carmen; Nerlich, Brigitte; Mohr, Alison

2017-08-01

The UK government has made significant investment into so called 'fourth-generation' biofuel technologies. These biofuels are based on engineering the metabolic pathways of bacteria in order to create products compatible with existing infrastructure. Bacteria play an important role in what is promoted as a potentially new biological industrial revolution, which could address some of the negative environmental legacies of the last. This article presents results from ethnographic research with synthetic biologists who are challenged with balancing the curiosity-driven and intrinsically fulfilling scientific task of working with bacteria, alongside the policy-driven task of putting bacteria to work for extrinsic economic gains. In addition, the scientists also have to balance these demands with a new research governance framework, Responsible Research and Innovation, which envisions technoscientific innovation will be responsive to societal concerns and work in collaboration with stakeholders and members of the public. Major themes emerging from the ethnographic research revolve around stewardship, care, responsibility and agency. An overall conflict surfaces between individual agents assuming responsibility for 'stewarding' bacteria, against funding systems and structures imposing responsibility for economic growth. We discuss these findings against the theoretical backdrop of a new concept of 'energopolitics' and an anthropology of ethics and responsibility.

Conflict adaptation and congruency sequence effects to social-emotional stimuli in individuals with autism spectrum disorders.

PubMed

Worsham, Whitney; Gray, Whitney E; Larson, Michael J; South, Mikle

2015-11-01

The modification of performance following conflict can be measured using conflict adaptation tasks thought to measure the change in the allocation of cognitive resources in order to reduce conflict interference and improve performance. While previous studies have suggested atypical processing during nonsocial cognitive control tasks, conflict adaptation (i.e. congruency sequence effects) for social-emotional stimuli have not been previously studied in autism spectrum disorder. A total of 32 participants diagnosed with autism spectrum disorder and 27 typically developing matched controls completed an emotional Stroop conflict task that required the classification of facial affect while simultaneously ignoring an overlaid affective word. Both groups showed behavioral evidence for emotional conflict adaptation based on response times and accuracy rates. However, the autism spectrum disorder group demonstrated a speed-accuracy trade-off manifested through significantly faster response times and decreased accuracy rates on trials containing conflict between the emotional face and the overlaid emotional word. Reduced selective attention toward socially relevant information may bias individuals with autism spectrum disorder toward more rapid processing and decision making even when conflict is present. Nonetheless, the loss of important information from the social stimuli reduces decision-making accuracy, negatively affecting the ability to adapt both cognitively and emotionally when conflict arises. © The Author(s) 2014.

Conflict in object affordance revealed by grip force

PubMed Central

McBride, Jennifer; Sumner, Petroc; Husain, Masud

2011-01-01

Viewing objects can result in automatic, partial activation of motor plans associated with them—“object affordance”. Here, we recorded grip force simultaneously from both hands in an object affordance task to investigate the effects of conflict between coactivated responses. Participants classified pictures of objects by squeezing force transducers with their left or right hand. Responses were faster on trials where the object afforded an action with the same hand that was required to make the response (congruent trials) compared to the opposite hand (incongruent trials). In addition, conflict between coactivated responses was reduced if it was experienced on the preceding trial, just like Gratton adaptation effects reported in “conflict” tasks (e.g., Eriksen flanker). This finding suggests that object affordance demonstrates conflict effects similar to those shown in other stimulus–response mapping tasks and thus could be integrated into the wider conceptual framework on overlearnt stimulus–response associations. Corrected erroneous responses occurred more frequently when there was conflict between the afforded response and the response required by the task, providing direct evidence that viewing an object activates motor plans appropriate for interacting with that object. Recording continuous grip force, as here, provides a sensitive way to measure coactivated responses in affordance tasks. PMID:21824035

Unconsciously triggered conflict adaptation.

PubMed

van Gaal, Simon; Lamme, Victor A F; Ridderinkhof, K Richard

2010-07-09

In conflict tasks such as the Stroop, the Eriksen flanker or the Simon task, it is generally observed that the detection of conflict in the current trial reduces the impact of conflicting information in the subsequent trial; a phenomenon termed conflict adaptation. This higher-order cognitive control function has been assumed to be restricted to cases where conflict is experienced consciously. In the present experiment we manipulated the awareness of conflict-inducing stimuli in a metacontrast masking paradigm to directly test this assumption. Conflicting response tendencies were elicited either consciously (through primes that were weakly masked) or unconsciously (strongly masked primes). We demonstrate trial-by-trial conflict adaptation effects after conscious as well as unconscious conflict, which could not be explained by direct stimulus/response repetitions. These findings show that unconscious information can have a longer-lasting influence on our behavior than previously thought and further stretch the functional boundaries of unconscious cognition.

Unconsciously Triggered Conflict Adaptation

PubMed Central

van Gaal, Simon; Lamme, Victor A. F.; Ridderinkhof, K. Richard

2010-01-01

In conflict tasks such as the Stroop, the Eriksen flanker or the Simon task, it is generally observed that the detection of conflict in the current trial reduces the impact of conflicting information in the subsequent trial; a phenomenon termed conflict adaptation. This higher-order cognitive control function has been assumed to be restricted to cases where conflict is experienced consciously. In the present experiment we manipulated the awareness of conflict-inducing stimuli in a metacontrast masking paradigm to directly test this assumption. Conflicting response tendencies were elicited either consciously (through primes that were weakly masked) or unconsciously (strongly masked primes). We demonstrate trial-by-trial conflict adaptation effects after conscious as well as unconscious conflict, which could not be explained by direct stimulus/response repetitions. These findings show that unconscious information can have a longer-lasting influence on our behavior than previously thought and further stretch the functional boundaries of unconscious cognition. PMID:20634898

"We've Got Creative Differences": The Effects of Task Conflict and Participative Safety on Team Creative Performance

ERIC Educational Resources Information Center

Fairchild, Joshua; Hunter, Samuel T.

2014-01-01

Although both participative safety and team task conflict are widely thought to be related to team creative performance, the nature of this relationship is still not well understood, and prior studies have frequently yielded conflicting results. This study examines the ambiguity in the extant literature and proposes that "both"…

Conflict Tasks of Different Types Divergently Affect the Attentional Processing of Gaze and Arrow.

PubMed

Fan, Lingxia; Yu, Huan; Zhang, Xuemin; Feng, Qing; Sun, Mengdan; Xu, Mengsi

2018-01-01

The present study explored the attentional processing mechanisms of gaze and arrow cues in two different types of conflict tasks. In Experiment 1, participants performed a flanker task in which gaze and arrow cues were presented as central targets or bilateral distractors. The congruency between the direction of the target and the distractors was manipulated. Results showed that arrow distractors greatly interfered with the attentional processing of gaze, while the processing of arrow direction was immune to conflict from gaze distractors. Using a spatial compatibility task, Experiment 2 explored the conflict effects exerted on gaze and arrow processing by their relative spatial locations. When the direction of the arrow was in conflict with its spatial layout on screen, response times were slowed; however, the encoding of gaze was unaffected by spatial location. In general, processing to an arrow cue is less influenced by bilateral gaze cues but is affected by irrelevant spatial information, while processing to a gaze cue is greatly disturbed by bilateral arrows but is unaffected by irrelevant spatial information. Different effects on gaze and arrow cues by different types of conflicts may reflect two relatively distinct specific modes of the attentional process.

Stroboscopic Goggles as a Countermeasure for Dynamic Visual Acuity and Landing Sickness After Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Rosenberg, M. J. F.; Kreutzberg, G. A.; Peters, B. T.; Reschke, M. F.

2017-01-01

Gravity transitions cause changes in the vestibulo-occular reflex (VOR), which manifests as poor gaze control, a decrement in dynamic visual acuity (the ability to maintain gaze while in motion), both of which are caused by retinal slip. Retinal slip, the inability to keep an image focused on the retina, can drive or worsen sensory conflict, resulting in motion sickness (MS). Currently 100% of returning crewmembers report MS symptoms, which might affect their ability to perform mission critical tasks immediately after landing. Reschke et al. (2007) demonstrate that stroboscopic vision goggles improve motion sickness onset and symptom severity in motion sickness driven by retinal slip.

Threat prompts defensive brain responses independently of attentional control.

PubMed

Pichon, Swann; de Gelder, Beatrice; Grèzes, Julie

2012-02-01

Negative emotional signals are known to influence task performance, but so far, investigations have focused on how emotion interacts with perceptual processes by mobilizing attentional resources. The attention-independent effects of negative emotional signals are less well understood. Here, we show that threat signals trigger defensive responses independently of what observers pay attention to. Participants were scanned using functional magnetic resonance imaging while watching short video clips of threatening actions and performed either color or emotion judgments. Seeing threatening actions interfered with performance in both tasks. Amygdala activation reflected both stimulus and task conditions. In contrast, threat stimuli prompted a constant activity in a network underlying reflexive defensive behavior (periaqueductal gray, hypothalamus, and premotor cortex). Threat stimuli also disrupted ongoing behavior and provoked motor conflict in prefrontal regions during both tasks. The present results are consistent with the view that emotions trigger adaptive action tendencies independently of task settings.

Different neural systems contribute to semantic bias and conflict detection in the inclusion fallacy task.

PubMed

Liang, Peipeng; Goel, Vinod; Jia, Xiuqin; Li, Kuncheng

2014-01-01

The inclusion fallacy is a phenomenon in which generalization from a specific premise category to a more general conclusion category is considered stronger than a generalization to a specific conclusion category nested within the more general set. Such inferences violate rational norms and are part of the reasoning fallacy literature that provides interesting tasks to explore cognitive and neural basis of reasoning. To explore the functional neuroanatomy of the inclusion fallacy, we used a 2 × 2 factorial design, with factors for quantification (explicit and implicit) and response (fallacious and non-fallacious). It was found that a left fronto-temporal system, along with a superior medial frontal system, was specifically activated in response to fallacious responses consistent with a semantic biasing of judgment explanation. A right fronto-parietal system was specifically recruited in response to detecting conflict associated with the heightened fallacy condition. These results are largely consistent with previous studies of reasoning fallacy and support a multiple systems model of reasoning.

On the differentiation of N2 components in an appetitive choice task: evidence for the revised Reinforcement Sensitivity Theory.

PubMed

Leue, Anja; Chavanon, Mira-Lynn; Wacker, Jan; Stemmler, Gerhard

2009-11-01

Task- and personality-related modulations of the N2 were probed within the framework of the revised Reinforcement Sensitivity Theory (RST). Using an appetitive choice task, we investigated 58 students with extreme scores on the behavioral inhibition system and behavioral approach system (BIS/BAS) scales. The baseline-to-peak N2 amplitude was sensitive to the strength of decision conflict and demonstrated RST-related personality differences. In addition to the baseline N2 amplitude, temporal PCA results suggested two N2 components accounting for a laterality effect and capturing different N2 patterns for BIS/BAS groups with increasing conflict level. Evidence for RST-related personality differences was obtained for baseline-to-peak N2 and tPCA components in the present task. The results support the RST prediction that BAS sensitivity modulates conflict processing and confirm the cognitive-motivational conflict concept of RST.

A common neural hub resolves syntactic and non-syntactic conflict through cooperation with task-specific networks.

PubMed

Hsu, Nina S; Jaeggi, Susanne M; Novick, Jared M

2017-03-01

Regions within the left inferior frontal gyrus (LIFG) have simultaneously been implicated in syntactic processing and cognitive control. Accounts attempting to unify LIFG's function hypothesize that, during comprehension, cognitive control resolves conflict between incompatible representations of sentence meaning. Some studies demonstrate co-localized activity within LIFG for syntactic and non-syntactic conflict resolution, suggesting domain-generality, but others show non-overlapping activity, suggesting domain-specific cognitive control and/or regions that respond uniquely to syntax. We propose however that examining exclusive activation sites for certain contrasts creates a false dichotomy: both domain-general and domain-specific neural machinery must coordinate to facilitate conflict resolution across domains. Here, subjects completed four diverse tasks involving conflict -one syntactic, three non-syntactic- while undergoing fMRI. Though LIFG consistently activated within individuals during conflict processing, functional connectivity analyses revealed task-specific coordination with distinct brain networks. Thus, LIFG may function as a conflict-resolution "hub" that cooperates with specialized neural systems according to information content. Copyright © 2016 Elsevier Inc. All rights reserved.

Regional gray matter density associated with emotional conflict resolution: evidence from voxel-based morphometry.

PubMed

Deng, Z; Wei, D; Xue, S; Du, X; Hitchman, G; Qiu, J

2014-09-05

Successful emotion regulation is a fundamental prerequisite for well-being and dysregulation may lead to psychopathology. The ability to inhibit spontaneous emotions while behaving in accordance with desired goals is an important dimension of emotion regulation and can be measured using emotional conflict resolution tasks. Few studies have investigated the gray matter correlates underlying successful emotional conflict resolution at the whole-brain level. We had 190 adults complete an emotional conflict resolution task (face-word task) and examined the brain regions significantly correlated with successful emotional conflict resolution using voxel-based morphometry. We found successful emotional conflict resolution was associated with increased regional gray matter density in widely distributed brain regions. These regions included the dorsal anterior cingulate/dorsal medial prefrontal cortex, ventral medial prefrontal cortex, supplementary motor area, amygdala, ventral striatum, precuneus, posterior cingulate cortex, inferior parietal lobule, superior temporal gyrus and fusiform face area. Together, our results indicate that individual differences in emotional conflict resolution ability may be attributed to regional structural differences across widely distributed brain regions. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Personal Conflict Impairs Performance on an Unrelated Self-Control Task: Lingering Costs of Uncertainty and Conflict.

PubMed

Alquist, Jessica L; Baumeister, Roy F; McGregor, Ian; Core, Tammy J; Benjamin, Ilil; Tice, Dianne M

2018-01-01

People have the ability to make important choices in their lives, but deliberating about these choices can have costs. The present study was designed to test the hypothesis that writing about conflicted personal goals and values (conflict condition) would impair self-control on an unrelated subsequent task as compared to writing about clear personal goals and values (clarity condition). Personal conflict activates the behavioral inhibition system (BIS; Hirsh, Mar, & Peterson, 2012), which may make it harder for participants to successfully execute self-control. In this large ( N =337), pre-registered study participants in the conflict condition performed worse on anagrams than participants in the clarity condition, and the effect of condition on anagram performance was mediated by a subjective uncertainty measure of BIS activation. This suggests that BIS activation leads to poor self-control. Moreover, given that conflict is inherent in the exercise of self-control, results point to BIS activation as a mechanism for why initial acts of self-control impair self-control on subsequent, unrelated tasks.

INVESTIGATING UNCERTAINTY AND SENSITIVITY IN INTEGRATED MULTIMEDIA ENVIRONMENTAL MODELS: TOOLS FOR 3MRA

EPA Science Inventory

Sufficiently elucidating uncertainty and sensitivity structures in environmental models can be a difficult task, even for low-order, single-media constructs driven by a unique set of site-specific data. The ensuing challenge of examining ever more complex, integrated, higher-ord...

INVESTIGATING UNCERTAINTY AND SENSITIVITY IN INTEGRATED, MULTIMEDIA ENVIRONMENTAL MODELS: TOOLS FOR FRAMES-3MRA

EPA Science Inventory

Elucidating uncertainty and sensitivity structures in environmental models can be a difficult task, even for low-order, single-medium constructs driven by a unique set of site-specific data. Quantitative assessment of integrated, multimedia models that simulate hundreds of sites...

Reducing absorbed dose to eye lenses in head CT examinations: the effect of bismuth shielding.

PubMed

Ciarmatori, Alberto; Nocetti, L; Mistretta, G; Zambelli, G; Costi, T

2016-06-01

The eye lens is considered to be among the most radiosensitive human tissues. Brain CT scans may unnecessarily expose it to radiation even if the area of clinical interest is far from the eyes. The aim of this study is to implement a bismuth eye lens shielding system for Head-CT acquisitions in these cases. The study is focused on the assessment of the dosimetric characteristics of the shielding system as well as on its effect on image quality. The shielding system was tested in two set-ups which differ for distance ("contact" and "4 cm" Set up respectively). Scans were performed on a CTDI phantom and an anthropomorphic phantom. A reference set up without shielding system was acquired to establish a baseline. Image quality was assessed by signal (not HU converted), noise and contrast-to-noise ratio (CNR) evaluation. The overall dose reduction was evaluated by measuring the CTDIvol while the eye lens dose reduction was assessed by placing thermoluminescent dosimeters (TLDs) on an anthropomorphic phantom. The image quality analysis exhibits the presence of an artefact that mildly increases the CT number up to 3 cm below the shielding system. Below the artefact, the difference of the Signal and the CNR are negligible between the three different set-ups. Regarding the CTDI, the analysis demonstrates a decrease by almost 12 % (in the "contact" set-up) and 9 % (in the "4 cm" set-up). TLD measurements exhibit an eye lens dose reduction by 28.5 ± 5 and 21.1 ± 5 % respectively at the "contact" and the "4 cm" distance. No relevant artefact was found and image quality was not affected by the shielding system. Significant dose reductions were measured. These features make the shielding set-up useful for clinical implementation in both studied positions.

Neural Correlates of Task-Irrelevant First and Second Language Emotion Words – Evidence from the Emotional Face–Word Stroop Task

PubMed Central

Fan, Lin; Xu, Qiang; Wang, Xiaoxi; Zhang, Feng; Yang, Yaping; Liu, Xiaoping

2016-01-01

Emotionally valenced words have thus far not been empirically examined in a bilingual population with the emotional face–word Stroop paradigm. Chinese-English bilinguals were asked to identify the facial expressions of emotion with their first (L1) or second (L2) language task-irrelevant emotion words superimposed on the face pictures. We attempted to examine how the emotional content of words modulated behavioral performance and cerebral functioning in the bilinguals’ two languages. The results indicated that there were significant congruency effects for both L1 and L2 emotion words, and that identifiable differences in the magnitude of the Stroop effect between the two languages were also observed, suggesting L1 is more capable of activating the emotional response to word stimuli. For event-related potentials data, an N350–550 effect was observed only in the L1 task with greater negativity for incongruent than congruent trials. The size of the N350–550 effect differed across languages, whereas no identifiable language distinction was observed in the effect of conflict slow potential (conflict SP). Finally, more pronounced negative amplitude at 230–330 ms was observed in L1 than in L2, but only for incongruent trials. This negativity, likened to an orthographic decoding N250, may reflect the extent of attention to emotion word processing at word-form level, while the N350–550 reflects a complicated set of processes in the conflict processing. Overall, the face–word congruency effect has reflected identifiable language distinction at 230–330 and 350-550 ms, which provides supporting evidence for the theoretical proposals assuming attenuated emotionality of L2 processing. PMID:27847485

A Brief History of Meteoroid and Orbital Debris Shielding Technology for US Manned Spacecraft

NASA Technical Reports Server (NTRS)

Bjorkman, Michael D.; Hyde, James L.

2008-01-01

Meteoroid and orbital debris shielding has played an important role from the beginning of manned spaceflight. During the early 60 s, meteoroid protection drove requirements for new meteor and micrometeoroid impact science. Meteoroid protection also stimulated advances in the technology of hypervelocity impact launchers and impact damage assessment methodologies. The first phase of meteoroid shielding assessments closed in the early 70 s with the end of the Apollo program. The second phase of meteoroid protection technology began in the early 80 s when it was determined that there is a manmade Earth orbital debris belt that poses a significant risk to LEO manned spacecraft. The severity of the Earth orbital debris environment has dictated changes in Space Shuttle and ISS operations as well as driven advances in shielding technology and assessment methodologies. A timeline of shielding technology and assessment methodology advances is presented along with a summary of risk assessment results.

Age affects the adjustment of cognitive control after a conflict: evidence from the bivalency effect.

PubMed

Rey-Mermet, Alodie; Meier, Beat

2015-01-01

Age affects cognitive control. When facing a conflict, older adults are less able to activate goal-relevant information and inhibit irrelevant information. However, cognitive control also affects the events after a conflict. The purpose of this study was to determine whether age affects the adjustment of cognitive control following a conflict. To this end, we investigated the bivalency effect, that is, the performance slowing occurring after the conflict induced by bivalent stimuli (i.e., stimuli with features for two tasks). In two experiments, we tested young adults (aged 20-30) and older adults (aged 65-85) in a paradigm requiring alternations between three tasks, with bivalent stimuli occasionally occurring on one task. The young adults showed a slowing for all trials following bivalent stimuli. This indicates a widespread and long-lasting bivalency effect, replicating previous findings. In contrast, the older adults showed a more specific and shorter-lived slowing. Thus, age affects the adjustment of cognitive control following a conflict.

Emotions in cognitive conflicts are not aversive but are task specific.

PubMed

Schacht, Annekathrin; Dimigen, Olaf; Sommer, Werner

2010-09-01

It has been suggested that cognitive conflicts require effortful processing and, therefore, are aversive (Botvinick, 2007). In the present study, we compared conflicts emerging from the inhibition of a predominant response tendency in a go/no-go task with those between incompatible response activations in a Simon task in a within-subjects design, using the same type of stimuli. Whereas no-go trials elicited reduced skin conductance and pupillometric responses, but prolonged corrugator muscle activity, as compared with go trials, incompatible and compatible Simon trials were indistinguishable with respect to these parameters. Furthermore, the conflict-sensitive N2 components of the event-related brain potential were similar in amplitude, but showed significantly different scalp distributions, indicating dissociable neural generator systems. The present findings suggest the involvement of different emotional and cognitive processes in both types of cognitive conflicts-none being aversive, however. In addition, the N2 findings call into question claims of common monitoring systems for all kinds of cognitive conflicts.

Moving beyond relationship and task conflict: toward a process-state perspective.

PubMed

DeChurch, Leslie A; Mesmer-Magnus, Jessica R; Doty, Dan

2013-07-01

Teams are formed to benefit from an expanded pool of expertise and experience, yet 2 aspects of the conflict stemming from those core differences will ultimately play a large role in determining team viability and productivity: conflict states and conflict processes. The current study theoretically reorganizes the literature on team conflict--distinguishing conflict states from conflict processes--and details the effects of each on team effectiveness. Findings from a meta-analytic cumulation of 45 independent studies (total number of teams = 3,218) suggest states and processes are distinct and important predictors of team performance and affective outcomes. Controlling for conflict states (i.e., task and relationship conflict), conflict processes explain an additional 13% of the variance in both team performance and team affective outcomes. Furthermore, findings reveal particular conflict processes that are beneficial and others detrimental to teams. The truth about team conflict: conflict processes, that is, how teams interact regarding their differences, are at least as important as conflict states, that is, the source and intensity of their perceived incompatibilities. PsycINFO Database Record (c) 2013 APA, all rights reserved.

The emergence of the Activity Reduces Conflict Associated Strain (ARCAS) model: a test of a conditional mediation model of workplace conflict and employee strain.

PubMed

Dijkstra, Maria T M; Beersma, Bianca; Cornelissen, Roosmarijn A W M

2012-07-01

To test and extend the emerging Activity Reduces Conflict-Associated Strain (ARCAS) model, we predicted that the relationship between task conflict and employee strain would be weakened to the extent that people experience high organization-based self-esteem (OBSE). A survey among Dutch employees demonstrated that, consistent with the model, the conflict-employee strain relationship was weaker the higher employees' OBSE and the more they engaged in active problem-solving conflict management. Our data also revealed that higher levels of OBSE were related to more problem-solving conflict management. Moreover, consistent with the ARCAS model, we could confirm a conditional mediation model in which organization-based self-esteem through its relationship with problem-solving conflict management weakened the relationship between task conflict and employee strain. Potential applications of the results are discussed.

Dissociating response conflict and error likelihood in anterior cingulate cortex.

PubMed

Yeung, Nick; Nieuwenhuis, Sander

2009-11-18

Neuroimaging studies consistently report activity in anterior cingulate cortex (ACC) in conditions of high cognitive demand, leading to the view that ACC plays a crucial role in the control of cognitive processes. According to one prominent theory, the sensitivity of ACC to task difficulty reflects its role in monitoring for the occurrence of competition, or "conflict," between responses to signal the need for increased cognitive control. However, a contrasting theory proposes that ACC is the recipient rather than source of monitoring signals, and that ACC activity observed in relation to task demand reflects the role of this region in learning about the likelihood of errors. Response conflict and error likelihood are typically confounded, making the theories difficult to distinguish empirically. The present research therefore used detailed computational simulations to derive contrasting predictions regarding ACC activity and error rate as a function of response speed. The simulations demonstrated a clear dissociation between conflict and error likelihood: fast response trials are associated with low conflict but high error likelihood, whereas slow response trials show the opposite pattern. Using the N2 component as an index of ACC activity, an EEG study demonstrated that when conflict and error likelihood are dissociated in this way, ACC activity tracks conflict and is negatively correlated with error likelihood. These findings support the conflict-monitoring theory and suggest that, in speeded decision tasks, ACC activity reflects current task demands rather than the retrospective coding of past performance.

Age of second language acquisition affects nonverbal conflict processing in children: an fMRI study.

PubMed

Mohades, Seyede Ghazal; Struys, Esli; Van Schuerbeek, Peter; Baeken, Chris; Van De Craen, Piet; Luypaert, Robert

2014-09-01

In their daily communication, bilinguals switch between two languages, a process that involves the selection of a target language and minimization of interference from a nontarget language. Previous studies have uncovered the neural structure in bilinguals and the activation patterns associated with performing verbal conflict tasks. One question that remains, however is whether this extra verbal switching affects brain function during nonverbal conflict tasks. In this study, we have used fMRI to investigate the impact of bilingualism in children performing two nonverbal tasks involving stimulus-stimulus and stimulus-response conflicts. Three groups of 8-11-year-old children--bilinguals from birth (2L1), second language learners (L2L), and a control group of monolinguals (1L1)--were scanned while performing a color Simon and a numerical Stroop task. Reaction times and accuracy were logged. Compared to monolingual controls, bilingual children showed higher behavioral congruency effect of these tasks, which is matched by the recruitment of brain regions that are generally used in general cognitive control, language processing or to solve language conflict situations in bilinguals (caudate nucleus, posterior cingulate gyrus, STG, precuneus). Further, the activation of these areas was found to be higher in 2L1 compared to L2L. The coupling of longer reaction times to the recruitment of extra language-related brain areas supports the hypothesis that when dealing with language conflicts the specialization of bilinguals hampers the way they can process with nonverbal conflicts, at least at early stages in life.

The time course of attentional modulation on emotional conflict processing.

PubMed

Zhou, Pingyan; Yang, Guochun; Nan, Weizhi; Liu, Xun

2016-01-01

Cognitive conflict resolution is critical to human survival in a rapidly changing environment. However, emotional conflict processing seems to be particularly important for human interactions. This study examined whether the time course of attentional modulation on emotional conflict processing was different from cognitive conflict processing during a flanker task. Results showed that emotional N200 and P300 effects, similar to colour conflict processing, appeared only during the relevant task. However, the emotional N200 effect preceded the colour N200 effect, indicating that emotional conflict can be identified earlier than cognitive conflict. Additionally, a significant emotional N100 effect revealed that emotional valence differences could be perceived during early processing based on rough aspects of input. The present data suggest that emotional conflict processing is modulated by top-down attention, similar to cognitive conflict processing (reflected by N200 and P300 effects). However, emotional conflict processing seems to have more time advantages during two different processing stages.

Conflict monitoring and adaptation in individuals at familial risk for developing bipolar disorder.

PubMed

Patino, Luis R; Adler, Caleb M; Mills, Neil P; Strakowski, Stephen M; Fleck, David E; Welge, Jeffrey A; DelBello, Melissa P

2013-05-01

To examine conflict monitoring and conflict-driven adaptation in individuals at familial risk for developing bipolar disorder. We recruited 24 adolescents who had a parent with bipolar disorder and 23 adolescents with healthy parents. Participants completed an arrow version of the Eriksen Flanker Task that included trials with three levels of conflict: neutral, congruent, and incongruent flanks. Differences in performance were explored based upon the level of conflict in the current and previous trials. Individuals at risk for developing bipolar disorder performed more slowly than youth with healthy parents in all trials. Analyses evaluating sequential effects revealed that at-risk subjects responded more slowly than youth of healthy parents for all trial types when preceded by an incongruent trial, for incongruent trials preceded by congruent trials, and for neutral and congruent trials when preceded by neutral trials. In contrast to the comparison group, at-risk adolescents failed to display a response time advantage for incongruent trials preceded by an incongruent trial. When removing subjects with attention-deficit hyperactivity disorder (ADHD), differences between groups in response time fell below significant level, but a difference in sequence modulation remained significant. Subjects at risk for bipolar disorder also displayed greater intra-subject response time variability for incongruent and congruent trials compared with the comparison adolescents. No differences in response accuracy were observed between groups. Adolescents at risk for developing bipolar disorder displayed specific deficits in cognitive flexibility, which might be useful as a potential marker related to the development of bipolar disorder. © 2013 John Wiley and Sons A/S. Published by Blackwell Publishing Ltd.

Working memory contents revive the neglected, but suppress the inhibited.

PubMed

Han, Suk Won

2015-12-01

It is well known that attention is biased toward a stimulus matching working memory contents. However, it remains unknown whether the maintenance of information in working memory by itself is sufficient to create memory-driven attentional capture. Notably, in many previous studies showing the memory-driven attentional capture, the task settings might have explicitly or implicitly incentivized participants to strategically attend to a memory-matching stimulus. By innovating an experimental paradigm, the present study overcame this challenge and directly tested whether working memory contents capture attention in the absence of task-level attentional bias toward a memory-matching stimulus. I found that a stimulus that is usually outside the focus of attention, powerfully captured attention when it matched working memory contents, whereas a match between working memory and an inhibited stimulus suppressed attentional allocation toward the memory-matching stimulus. These findings suggest that in the absence of any task-level attentional bias toward memory-matching stimuli, attention is biased toward a memory-matching stimulus, but this memory-driven attentional capture is diminished when top-down inhibition is imposed on the stimulus. Copyright © 2015 Elsevier B.V. All rights reserved.

Physical activity and trial-by-trial adjustments of response conflict.

PubMed

Kamijo, Keita; Takeda, Yuji

2013-08-01

The relationship of physical activity to trial-by-trial adjustments of response conflict was assessed using behavioral task performance, the N2 event-related brain potential component, and phase-locking values (PLVs) in a lower gamma band during a perceptual conflict task. Nineteen physically active and 19 inactive young adults (mean age = 21.3 years) performed a Navon task, using a global letter made up of local letters of either the same kind (congruent trials) or a different kind (incongruent trials). Findings revealed that active individuals exhibited smaller N2 amplitudes and greater PLVs on incongruent trials that were preceded by incongruent trials compared with those preceded by congruent trials. Such phenomena were not observed for inactive individuals. These results suggest that greater physical activity is associated with larger trial-by-trial adjustments of response conflict, which we attribute to upregulation of top-down cognitive control and reductions in response conflict.

Hohlraum modeling for opacity experiments on the National Ignition Facility

NASA Astrophysics Data System (ADS)

Dodd, E. S.; DeVolder, B. G.; Martin, M. E.; Krasheninnikova, N. S.; Tregillis, I. L.; Perry, T. S.; Heeter, R. F.; Opachich, Y. P.; Moore, A. S.; Kline, J. L.; Johns, H. M.; Liedahl, D. A.; Cardenas, T.; Olson, R. E.; Wilde, B. H.; Urbatsch, T. J.

2018-06-01

This paper discusses the modeling of experiments that measure iron opacity in local thermodynamic equilibrium (LTE) using laser-driven hohlraums at the National Ignition Facility (NIF). A previous set of experiments fielded at Sandia's Z facility [Bailey et al., Nature 517, 56 (2015)] have shown up to factors of two discrepancies between the theory and experiment, casting doubt on the validity of the opacity models. The purpose of the new experiments is to make corroborating measurements at the same densities and temperatures, with the initial measurements made at a temperature of 160 eV and an electron density of 0.7 × 1022 cm-3. The X-ray hot spots of a laser-driven hohlraum are not in LTE, and the iron must be shielded from a direct line-of-sight to obtain the data [Perry et al., Phys. Rev. B 54, 5617 (1996)]. This shielding is provided either with the internal structure (e.g., baffles) or external wall shapes that divide the hohlraum into a laser-heated portion and an LTE portion. In contrast, most inertial confinement fusion hohlraums are simple cylinders lacking complex gold walls, and the design codes are not typically applied to targets like those for the opacity experiments. We will discuss the initial basis for the modeling using LASNEX, and the subsequent modeling of five different hohlraum geometries that have been fielded on the NIF to date. This includes a comparison of calculated and measured radiation temperatures.

Simulator-induced spatial disorientation: effects of age, sleep deprivation, and type of conflict.

PubMed

Previc, Fred H; Ercoline, William R; Evans, Richard H; Dillon, Nathan; Lopez, Nadia; Daluz, Christina M; Workman, Andrew

2007-05-01

Spatial disorientation mishaps are greater at night and with greater time on task, and sleep deprivation is known to decrease cognitive and overall flight performance. However, the ability to perceive and to be influenced by physiologically appropriate simulated SD conflicts has not previously been studied in an automated simulator flight profile. A set of 10 flight profiles were flown by 10 U.S. Air Force (USAF) pilots over a period of 28 h in a specially designed flight simulator for spatial disorientation research and training. Of the 10 flights, 4 had a total of 7 spatial disorientation (SD) conflicts inserted into each of them, 5 simulating motion illusions and 2 involving visual illusions. The percentage of conflict reports was measured along with the effects of four conflicts on flight performance. The results showed that, with one exception, all motion conflicts were reported over 60% of the time, whereas the two visual illusions were reported on average only 25% of the time, although they both significantly affected flight performance. Pilots older than 35 yr of age were more likely to report conflicts than were those under 30 yr of age (63% vs. 38%), whereas fatigue had little effect overall on either recognized or unrecognized SD. The overall effects of these conflicts on perception and performance were generally not altered by sleep deprivation, despite clear indications of fatigue in our pilots.

Smooth criminal: convicted rule-breakers show reduced cognitive conflict during deliberate rule violations.

PubMed

Jusyte, Aiste; Pfister, Roland; Mayer, Sarah V; Schwarz, Katharina A; Wirth, Robert; Kunde, Wilfried; Schönenberg, Michael

2017-09-01

Classic findings on conformity and obedience document a strong and automatic drive of human agents to follow any type of rule or social norm. At the same time, most individuals tend to violate rules on occasion, and such deliberate rule violations have recently been shown to yield cognitive conflict for the rule-breaker. These findings indicate persistent difficulty to suppress the rule representation, even though rule violations were studied in a controlled experimental setting with neither gains nor possible sanctions for violators. In the current study, we validate these findings by showing that convicted criminals, i.e., individuals with a history of habitual and severe forms of rule violations, can free themselves from such cognitive conflict in a similarly controlled laboratory task. These findings support an emerging view that aims at understanding rule violations from the perspective of the violating agent rather than from the perspective of outside observer.

Basic EMC Technology Advancement for C(3) Systems - SHIELD. Volume IV B. A Digital Computer Program for Computing Crosstalk between Shielded Cables

DTIC Science & Technology

1982-11-01

your organization , please notify RADC OBCT) Griffiss AFB NY 13441. This will assist us in maintaining a current mailing list. Do not return copies of...RMING ORGANIZATION NAME r AND ADDRESS 10. PROGRAM ELEMENT. PROJECT. TASK Southeastern Center for Electrical AREA6WORKUNITNUMBERS Engineering Education...The program requires that the input data groups be organized as shown in Table 1 where the number of unshielded wires is U and the number of shielded

Malaria Control and Elimination in Sri Lanka: Documenting Progress and Success Factors in a Conflict Setting

PubMed Central

Abeyasinghe, Rabindra R.; Galappaththy, Gawrie N. L.; Smith Gueye, Cara; Kahn, James G.; Feachem, Richard G. A.

2012-01-01

Background Sri Lanka has a long history of malaria control, and over the past decade has had dramatic declines in cases amid a national conflict. A case study of Sri Lanka's malaria programme was conducted to characterize the programme and explain recent progress. Methods The case study employed qualitative and quantitative methods. Data were collected from published and grey literature, district-level and national records, and thirty-three key informant interviews. Expenditures in two districts for two years – 2004 and 2009 – were compiled. Findings Malaria incidence in Sri Lanka has declined by 99.9% since 1999. During this time, there were increases in the proportion of malaria infections due to Plasmodium vivax, and the proportion of infections occurring in adult males. Indoor residual spraying and distribution of long-lasting insecticide-treated nets have likely contributed to the low transmission. Entomological surveillance was maintained. A strong passive case detection system captures infections and active case detection was introduced. When comparing conflict and non-conflict districts, vector control and surveillance measures were maintained in conflict areas, often with higher coverage reported in conflict districts. One of two districts in the study reported a 48% decline in malaria programme expenditure per person at risk from 2004 to 2009. The other district had stable malaria spending. Conclusions/Significance Malaria is now at low levels in Sri Lanka – 124 indigenous cases were found in 2011. The majority of infections occur in adult males and are due to P. vivax. Evidence-driven policy and an ability to adapt to new circumstances contributed to this decline. Malaria interventions were maintained in the conflict districts despite an ongoing war. Sri Lanka has set a goal of eliminating malaria by the end of 2014. Early identification and treatment of infections, especially imported ones, together with effective surveillance and response, will be critical to achieving this goal. PMID:22952642

Orthogonally interdigitated shielded serpentine travelling wave cathode ray tube deflection structure

DOEpatents

Hagen, E.C.; Hudson, C.L.

1995-07-25

A new deflection structure which deflects a beam of charged particles, such as an electron beam, includes a serpentine set for transmitting a deflection field, and a shielding frame for housing the serpentine set. The serpentine set includes a vertical serpentine deflection element and a horizontal serpentine deflection element. These deflection elements are identical, and are interdigitatedly and orthogonally disposed relative to each other, for forming a central transmission passage, through which the electron beam passes, and is deflected by the deflection field, so as to minimize drift space signal distortion. The shielding frame includes a plurality of ground blocks, and forms an internal serpentine trough within these ground blocks, for housing the serpentine set. The deflection structure further includes a plurality of feedthrough connectors which are inserted through the shielding frame, and which are electrically connected to the serpentine set. 10 figs.

Motivational climate, staff and members' behaviors, and members' psychological well-being at a national fitness franchise.

PubMed

Brown, Theresa C; Fry, Mary D

2014-06-01

The purpose of this study was to examine the association between members' perceptions of staffs behaviors, motivational climate, their own behaviors, commitment to future exercise, and life satisfaction in a group-fitness setting. The theory-driven hypothesized mediating role of perceptions of the climate was also tested. Members (N = 5,541) of a national group-fitness studio franchise completed a survey regarding their class experiences. The survey included questions that measured participants' perceptions of the motivational climate (caring, task-involving, ego-involving), perceptions of staff's behaviors, their own behaviors, commitment to exercise, and life satisfaction. Structural equation modeling was used to assess both the association between variables and the theoretically driven predictive relationships. The participants perceived the environment as highly caring and task-involving and low ego-involving. They reported high exercise commitment and moderately high life satisfaction and perceived that the staffs and their own behaviors reflected caring, task-involving characteristics. Structural equation modeling demonstrated that those who perceived a higher caring, task-involving climate and lower ego-involving climate were more likely to report more task-involving, caring behaviors among the staff and themselves as well as greater commitment to exercise. In addition, a theory-driven mediational model suggested that staff behaviors may be an antecedent to members' exercise experiences by impacting their perceptions of the climate. The results of this study give direction to specific behaviors in which staff of group-fitness programs might engage to positively influence members' exercise experiences.

Depending on My Mood: Mood-Driven Influences on Text Comprehension

ERIC Educational Resources Information Center

Bohn-Gettler, Catherine M.; Rapp, David N.

2011-01-01

Reading comprehension is a critical component of success in educational settings. To date, research on text processing in educational and cognitive psychological domains has focused predominantly on cognitive influences on comprehension and, in particular, those influences that might be derived from particular tasks or strategies. However, there…

Changes in entrance surface dose in relation to the location of shielding material in chest computed tomography

NASA Astrophysics Data System (ADS)

Kang, Y. M.; Cho, J. H.; Kim, S. C.

2015-07-01

This study examined the effects of entrance surface dose (ESD) on the abdomen and pelvis of the patient when undergoing chest computed tomography (CT) procedure, and evaluated the effects of ESD reduction depending on the location of radiation shield. For CT scanner, the 64-slice multi-detector computed tomography was used. The alderson radiation therapy phantom and optically stimulated luminescence dosimeter (OSLD), which enabled measurement from low to high dose, were also used. For measurement of radiation dose, the slice number from 9 to 21 of the phantom was set as the test range, which included apex up to both costophrenic angles. A total of 10 OSLD nanoDots were attached for measurement of the front and rear ESD. Cyclic tests were performed using the low-dose chest CT and high-resolution CT (HRCT) protocol on the following set-ups: without shielding; shielding only on the front side; shielding only on the rear side; and shielding for both front and rear sides. According to the test results, ESD for both front and rear sides was higher in HRCT than low-dose CT when radiation shielding was not used. It was also determined that, compared to the set-up that did not use the radiation shield, locating the radiation shield on the front side was effective in reducing front ESD, while locating the radiation shield on the rear side reduced rear ESD level. Shielding both the front and rear sides resulted in ESD reduction. In conclusion, it was confirmed that shielding the front and rear sides was the most effective method to reduce the ESD effect caused by scatter ray during radiography.

Division of Labor in Two-Earner Homes: Task Accomplishment versus Household Management as Critical Variables in Perceptions about Family Work.

ERIC Educational Resources Information Center

Mederer, Helen J.

1993-01-01

Data from 359 married, full-time employed women tested extent to which allocation of tasks and allocation of household management predict perceptions of fairness and conflict. Task and management allocation contributed independently and differently to perceptions of fairness and conflict about housework allocation. Unfairness was predicted by both…

The influence of emotional interference on cognitive control: A meta-analysis of neuroimaging studies using the emotional Stroop task.

PubMed

Song, Sensen; Zilverstand, Anna; Song, Hongwen; d'Oleire Uquillas, Federico; Wang, Yongming; Xie, Chao; Cheng, Li; Zou, Zhiling

2017-05-18

The neural correlates underlying the influence of emotional interference on cognitive control remain a topic of discussion. Here, we assessed 16 neuroimaging studies that used an emotional Stroop task and that reported a significant interaction effect between emotion (stimulus type) and cognitive conflict. There were a total of 330 participants, equaling 132 foci for an activation likelihood estimation (ALE) analysis. Results revealed consistent brain activation patterns related to emotionally-salient stimuli (as compared to emotionally-neutral trials) during cognitive conflict trials [incongruent trials (with task-irrelevant information interfering), versus congruent/baseline trials (less disturbance from task-irrelevant information)], that span the lateral prefrontal cortex (dorsolateral prefrontal cortex and inferior frontal gyrus), the medial prefrontal cortex, and the dorsal anterior cingulate cortex. Comparing mild emotional interference trials (without semantic conflict) versus intense emotional interference trials (with semantic conflict), revealed that while concurrent activation in similar brain regions as mentioned above was found for intense emotional interference trials, activation for mild emotional interference trials was only found in the precentral/postcentral gyrus. These data provide evidence for the potential neural mechanisms underlying emotional interference on cognitive control, and further elucidate an important distinction in brain activation patterns for different levels of emotional conflict across emotional Stroop tasks.

Reduction of influence of task difficulty on perceptual decision making by STN deep brain stimulation.

PubMed

Green, Nikos; Bogacz, Rafal; Huebl, Julius; Beyer, Ann-Kristin; Kühn, Andrea A; Heekeren, Hauke R

2013-09-09

Neurocomputational models of optimal decision making ascribe a crucial role-the computation of conflict between choice alternatives-to the subthalamic nucleus (STN). Specifically, these models predict that deep brain stimulation (DBS) of the STN will diminish the influence of decision conflict on decision making. In this work, patients with Parkinson's disease judged the direction of motion in random dot stimuli while ON and OFF DBS. To induce decision conflict, we varied the task difficulty (motion coherence), leading to increased reaction time (RT) in trials with greater task difficulty in healthy subjects. Results indicate that DBS significantly influences performance for perceptual decisions under high decision conflict. RT increased substantially OFF DBS as the task became more difficult, and a diffusion model best accounted for behavioral data. In contrast, ON DBS, the influence of task difficulty on RT was significantly reduced and a race model best accounted for the observed data. Individual data fits of evidence accumulation models demonstrate different information processing under distinct DBS states. Furthermore, ON DBS, speed-accuracy tradeoffs affected the magnitude of decision criterion adjustment significantly less compared to OFF DBS. Together, these findings suggest a crucial role for the STN in adjusting decision making during high-conflict trials in perceptual decision making. Copyright © 2013 Elsevier Ltd. All rights reserved.

Gaze Behavior in a Natural Environment with a Task-Relevant Distractor: How the Presence of a Goalkeeper Distracts the Penalty Taker

PubMed Central

Kurz, Johannes; Hegele, Mathias; Munzert, Jörn

2018-01-01

Gaze behavior in natural scenes has been shown to be influenced not only by top–down factors such as task demands and action goals but also by bottom–up factors such as stimulus salience and scene context. Whereas gaze behavior in the context of static pictures emphasizes spatial accuracy, gazing in natural scenes seems to rely more on where to direct the gaze involving both anticipative components and an evaluation of ongoing actions. Not much is known about gaze behavior in far-aiming tasks in which multiple task-relevant targets and distractors compete for the allocation of visual attention via gaze. In the present study, we examined gaze behavior in the far-aiming task of taking a soccer penalty. This task contains a proximal target, the ball; a distal target, an empty location within the goal; and a salient distractor, the goalkeeper. Our aim was to investigate where participants direct their gaze in a natural environment with multiple potential fixation targets that differ in task relevance and salience. Results showed that the early phase of the run-up seems to be driven by both the salience of the stimulus setting and the need to perform a spatial calibration of the environment. The late run-up, in contrast, seems to be controlled by attentional demands of the task with penalty takers having habitualized a visual routine that is not disrupted by external influences (e.g., the goalkeeper). In addition, when trying to shoot a ball as accurately as possible, penalty takers directed their gaze toward the ball in order to achieve optimal foot-ball contact. These results indicate that whether gaze is driven by salience of the stimulus setting or by attentional demands depends on the phase of the actual task. PMID:29434560

Conflict-Specific Aging Effects Mainly Manifest in Early Information Processing Stages-An ERP Study with Different Conflict Types.

PubMed

Korsch, Margarethe; Frühholz, Sascha; Herrmann, Manfred

2016-01-01

Aging is usually accompanied by alterations of cognitive control functions such as conflict processing. Recent research suggests that aging effects on cognitive control seem to vary with degree and source of conflict, and conflict specific aging effects on performance measures as well as neural activation patterns have been shown. However, there is sparse information whether and how aging affects different stages of conflict processing as indicated by event related potentials (ERPs) such as the P2, N2 and P3 components. In the present study, 19 young and 23 elderly adults performed a combined Flanker conflict and stimulus-response-conflict (SRC) task. Analysis of the reaction times (RTs) revealed an increased SRC related conflict effect in elderly. ERP analysis furthermore demonstrated an age-related increase of the P2 amplitude in response to the SRC task. In addition, elderly adults exhibited an increased P3 amplitude modulation induced by incongruent SRC and Flanker conflict trials.

Emotion triggers executive attention: anterior cingulate cortex and amygdala responses to emotional words in a conflict task.

PubMed

Kanske, Philipp; Kotz, Sonja A

2011-02-01

Coherent behavior depends on attentional control that detects and resolves conflict between opposing actions. The current functional magnetic resonance imaging study tested the hypothesis that emotion triggers attentional control to speed up conflict processing in particularly salient situations. Therefore, we presented emotionally negative and neutral words in a version of the flanker task. In response to conflict, we found activation of the dorsal anterior cingulate cortex (ACC) and of the amygdala for emotional stimuli. When emotion and conflict coincided, a region in the ventral ACC was activated, which resulted in faster conflict processing in reaction times. Emotion also increased functional connectivity between the ventral ACC and activation of the dorsal ACC and the amygdala in conflict trials. These data suggest that the ventral ACC integrates emotion and conflict and prioritizes the processing of conflict in emotional trials. This adaptive mechanism ensures rapid detection and resolution of conflict in potentially threatening situations signaled by emotional stimuli. Copyright © 2010 Wiley-Liss, Inc.

Conflict processing is modulated by positive emotion: ERP data from a flanker task.

PubMed

Kanske, Philipp; Kotz, Sonja A

2011-06-01

Recent evidence shows that negative emotional stimuli speed up the resolution of conflict between opposing response tendencies. This mechanism ensures rapid reactions in potentially threatening situations. However, it is unclear whether positive emotion has a similar effect on conflict processing. We therefore presented positive emotional words in a version of the flanker conflict task, in which conflict is elicited by incongruent target and flanker stimuli. Response times to incongruent stimuli were shortened in positive words, indicating a speeding up of conflict resolution. We also observed an enlargement of the first conflict-sensitive event-related potential (ERP) of the electroencephalogram, the N200, in positive emotional trials. The data suggest that positive emotion already modulates first stages of conflict processing. The results demonstrate that positive, reward-predicting stimuli influence conflict processing in a similar manner to threat signals. Positive emotion thus reduces the time that an organism is unable to respond due to simultaneously present conflicting action tendencies. Copyright © 2011 Elsevier B.V. All rights reserved.

Portable convertible blast effects shield

DOEpatents

Pastrnak, John W.; Hollaway, Rocky; Henning, Carl D.; Deteresa, Steve; Grundler, Walter; Hagler,; Lisle B.; Kokko, Edwin; Switzer, Vernon A

2010-10-26

A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

Portable convertible blast effects shield

DOEpatents

Pastrnak, John W [Livermore, CA; Hollaway, Rocky [Modesto, CA; Henning, Carl D [Livermore, CA; Deteresa, Steve [Livermore, CA; Grundler, Walter [Hayward, CA; Hagler, Lisle B [Berkeley, CA; Kokko, Edwin [Dublin, CA; Switzer, Vernon A [Livermore, CA

2007-05-22

A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

Simbol-X Background Minimization: Mirror Spacecraft Passive Shielding Trade-off Study

NASA Astrophysics Data System (ADS)

Fioretti, V.; Malaguti, G.; Bulgarelli, A.; Palumbo, G. G. C.; Ferri, A.; Attinà, P.

2009-05-01

The present work shows a quantitative trade-off analysis of the Simbol-X Mirror Spacecraft (MSC) passive shielding, in the phase space of the various parameters: mass budget, dimension, geometry and composition. A simplified physical (and geometrical) model of the sky screen, implemented by means of a GEANT4 simulation, has been developed to perform a performance-driven mass optimization and evaluate the residual background level on Simbol-X focal plane.

Shielding of longitudinal magnetic fields with thin, closely, spaced concentric cylindrical shells with applications to atomic clocks

NASA Technical Reports Server (NTRS)

Wolf, S. A.; Gubser, D. U.; Cox, J. E.

1978-01-01

A general formula is given for the longitudinal shielding effectiveness of N closed concentric cylinders. The use of these equations is demonstrated by application to the design of magnetic shields for hydrogen maser atomic clocks. Examples of design tradeoffs such as size, weight, and material thickness are discussed. Experimental results on three sets of shields fabricated by three manufacturers are presented. Two of the sets were designed employing the techniques described. Agreement between the experimental results and the design calculations is then demonstrated.

EEG neural oscillatory dynamics reveal semantic and response conflict at difference levels of conflict awareness

PubMed Central

Jiang, Jun; Zhang, Qinglin; Van Gaal, Simon

2015-01-01

Although previous work has shown that conflict can be detected in the absence of awareness, it is unknown how different sources of conflict (i.e., semantic, response) are processed in the human brain and whether these processes are differently modulated by conflict awareness. To explore this issue, we extracted oscillatory power dynamics from electroencephalographic (EEG) data recorded while human participants performed a modified version of the Stroop task. Crucially, in this task conflict awareness was manipulated by masking a conflict-inducing color word preceding a color patch target. We isolated semantic from response conflict by introducing four color words/patches, of which two were matched to the same response. We observed that both semantic as well as response conflict were associated with mid-frontal theta-band and parietal alpha-band power modulations, irrespective of the level of conflict awareness (high vs. low), although awareness of conflict increased these conflict-related power dynamics. These results show that both semantic and response conflict can be processed in the human brain and suggest that the neural oscillatory mechanisms in EEG reflect mainly “domain general” conflict processing mechanisms, instead of conflict source specific effects. PMID:26169473

EEG neural oscillatory dynamics reveal semantic and response conflict at difference levels of conflict awareness.

PubMed

Jiang, Jun; Zhang, Qinglin; Van Gaal, Simon

2015-07-14

Although previous work has shown that conflict can be detected in the absence of awareness, it is unknown how different sources of conflict (i.e., semantic, response) are processed in the human brain and whether these processes are differently modulated by conflict awareness. To explore this issue, we extracted oscillatory power dynamics from electroencephalographic (EEG) data recorded while human participants performed a modified version of the Stroop task. Crucially, in this task conflict awareness was manipulated by masking a conflict-inducing color word preceding a color patch target. We isolated semantic from response conflict by introducing four color words/patches, of which two were matched to the same response. We observed that both semantic as well as response conflict were associated with mid-frontal theta-band and parietal alpha-band power modulations, irrespective of the level of conflict awareness (high vs. low), although awareness of conflict increased these conflict-related power dynamics. These results show that both semantic and response conflict can be processed in the human brain and suggest that the neural oscillatory mechanisms in EEG reflect mainly "domain general" conflict processing mechanisms, instead of conflict source specific effects.

Relations between spouses' depressive symptoms and marital conflict: a longitudinal investigation of the role of conflict resolution styles.

PubMed

Du Rocher Schudlich, Tina D; Papp, Lauren M; Cummings, E Mark

2011-08-01

This study investigated longitudinal relations between spouses' depressive symptoms and styles of conflict resolution displayed by husbands and wives in marital conflict, including angry, depressive, and constructive patterns of expression. Behavioral observations were made from a community sample of 276 couples during marital conflict resolution tasks once a year for 3 years. Couples were observed engaging in a major and minor conflict resolution task. Constructive, angry, and depressive conflict resolution styles were derived from the behavioral observation coding. Couples self-reported on depressive symptoms and marital dissatisfaction. Path analyses provided support for an extension of the marital discord model of depression (Beach, Sandeen, & O'Leary, 1990). Specifically, angry, depressive, and constructive styles of conflict each mediated the link between marital dissatisfaction and depressive symptoms. Significant cross-spouse effects were found. Implications for the treatment of depressed and/or relationally discordant couples are discussed.

Relations between Spouses’ Depressive Symptoms and Marital Conflict: A Longitudinal Investigation of the Role of Conflict Resolution Styles

PubMed Central

Du Rocher Schudlich, Tina D.; Papp, Lauren M.; Cummings, E. Mark

2011-01-01

This study investigated longitudinal relations between spouses’ depressive symptoms and styles of conflict resolution displayed by husbands and wives in marital conflict, including angry, depressive, and constructive patterns of expression. Behavioral observations were made from a community sample of 276 couples during marital conflict resolution tasks once a year for three years. Couples were observed engaging in a major and minor conflict resolution task. Constructive, angry, and depressive conflict resolution styles were derived from the behavioral observation coding. Couples self-reported on depressive symptoms and marital dissatisfaction. Path analyses provided support for an extension of the marital discord model of depression (Beach and colleagues, 1990). Specifically, angry, depressive, and constructive styles of conflict each mediated the link between marital dissatisfaction and depressive symptoms. Significant cross-spouse effects were found. Implications for the treatment of depressed and/or relationally-discordant couples are discussed. PMID:21668119

Modulation of the error-related negativity by response conflict.

PubMed

Danielmeier, Claudia; Wessel, Jan R; Steinhauser, Marco; Ullsperger, Markus

2009-11-01

An arrow version of the Eriksen flanker task was employed to investigate the influence of conflict on the error-related negativity (ERN). The degree of conflict was modulated by varying the distance between flankers and the target arrow (CLOSE and FAR conditions). Error rates and reaction time data from a behavioral experiment were used to adapt a connectionist model of this task. This model was based on the conflict monitoring theory and simulated behavioral and event-related potential data. The computational model predicted an increased ERN amplitude in FAR incompatible (the low-conflict condition) compared to CLOSE incompatible errors (the high-conflict condition). A subsequent ERP experiment confirmed the model predictions. The computational model explains this finding with larger post-response conflict in far trials. In addition, data and model predictions of the N2 and the LRP support the conflict interpretation of the ERN.

A functional dissociation of conflict processing within anterior cingulate cortex.

PubMed

Kim, Chobok; Kroger, James K; Kim, Jeounghoon

2011-02-01

Goal-directed behavior requires cognitive control to regulate the occurrence of conflict. The dorsal anterior cingulate cortex (dACC) has been suggested in detecting response conflict during various conflict tasks. Recent findings, however, have indicated not only that two distinct subregions of dACC are involved in conflict processing but also that the conflict occurs at both perceptual and response levels. In this study, we sought to examine whether perceptual and response conflicts are functionally dissociated in dACC. Thirteen healthy subjects performed a version of the Stroop task during functional magnetic resonance imaging (fMRI) scanning. We identified a functional dissociation of the caudal dACC (cdACC) and the rostral dACC (rdACC) in their responses to different sources of conflict. The cdACC was selectively engaged in perceptual conflict whereas the rdACC was more active in response conflict. Further, the dorsolateral prefrontal cortex (DLPFC) was coactivated not with cdACC but with rdACC. We suggest that cdACC plays an important role in regulative processing of perceptual conflict whereas rdACC is involved in detecting response conflict. Copyright © 2010 Wiley-Liss, Inc.

Practice-driven evaluation of a multi-layered psychosocial care package for children in areas of armed conflict.

PubMed

Jordans, M J D; Komproe, I H; Tol, W A; Susanty, D; Vallipuram, A; Ntamatumba, P; Lasuba, A C; De Jong, J T V M

2011-06-01

Psychosocial and mental health service delivery frameworks for children in low-income countries are scarce. This paper presents a practice-driven evaluation of a multi-layered community-based care package in Burundi, Indonesia, Sri Lanka and Sudan, through a set of indicators; (a) perceived treatment gains; (b) treatment satisfaction; (c) therapist burden; (d) access to care; (e) care package costs. Across four settings (n = 29,292 children), beneficiaries reported high levels of client satisfaction and moderate post-treatment problem reductions. Service providers reported significant levels of distress related to service delivery. Cost analyses demonstrated mean cost per service user to vary from 3.46 to 17.32 depending on country and specification of costs. The results suggest a multi-layered psychosocial care package appears feasible and satisfactory in reaching out to substantial populations of distressed children through different levels of care. Future replication should address therapist burden, cost reductions to increase sustainability and increase evidence for treatment efficacy.

Multi-Constraint Multi-Variable Optimization of Source-Driven Nuclear Systems

NASA Astrophysics Data System (ADS)

Watkins, Edward Francis

1995-01-01

A novel approach to the search for optimal designs of source-driven nuclear systems is investigated. Such systems include radiation shields, fusion reactor blankets and various neutron spectrum-shaping assemblies. The novel approach involves the replacement of the steepest-descents optimization algorithm incorporated in the code SWAN by a significantly more general and efficient sequential quadratic programming optimization algorithm provided by the code NPSOL. The resulting SWAN/NPSOL code system can be applied to more general, multi-variable, multi-constraint shield optimization problems. The constraints it accounts for may include simple bounds on variables, linear constraints, and smooth nonlinear constraints. It may also be applied to unconstrained, bound-constrained and linearly constrained optimization. The shield optimization capabilities of the SWAN/NPSOL code system is tested and verified in a variety of optimization problems: dose minimization at constant cost, cost minimization at constant dose, and multiple-nonlinear constraint optimization. The replacement of the optimization part of SWAN with NPSOL is found feasible and leads to a very substantial improvement in the complexity of optimization problems which can be efficiently handled.

Focused cognitive control in dishonesty: Evidence for predominantly transient conflict adaptation.

PubMed

Foerster, Anna; Pfister, Roland; Schmidts, Constantin; Dignath, David; Wirth, Robert; Kunde, Wilfried

2018-04-01

Giving a dishonest response to a question entails cognitive conflict due to an initial activation of the truthful response. Following conflict monitoring theory, dishonest responding could therefore elicit transient and sustained control adaptation processes to mitigate such conflict, and the current experiments take on the scope and specificity of such conflict adaptation in dishonesty. Transient adaptation reduces differences between honest and dishonest responding following a recent dishonest response. Sustained adaptation has a similar behavioral signature but is driven by the overall frequency of dishonest responding. Both types of adaptation to recent and frequent dishonest responses have been separately documented, leaving open whether control processes in dishonest responding can flexibly adapt to transient and sustained conflict signals of dishonest and other actions. This was the goal of the present experiments which studied (dis)honest responding to autobiographical yes/no questions. Experiment 1 showed robust transient adaptation to recent dishonest responses whereas sustained control adaptation failed to exert an influence on behavior. It further revealed that transient effects may create a spurious impression of sustained adaptation in typical experimental settings. Experiments 2 and 3 examined whether dishonest responding can profit from transient and sustained adaption processes triggered by other behavioral conflicts. This was clearly not the case: Dishonest responding adapted markedly to recent (dis)honest responses but not to any context of other conflicts. These findings indicate that control adaptation in dishonest responding is strong but surprisingly focused and they point to a potential trade-off between transient and sustained adaptation. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Response competition and response inhibition during different choice-discrimination tasks: evidence from ERP measured inside MRI scanner.

PubMed

Gonzalez-Rosa, Javier J; Inuggi, Alberto; Blasi, Valeria; Cursi, Marco; Annovazzi, Pietro; Comi, Giancarlo; Falini, Andrea; Leocani, Letizia

2013-07-01

We investigated the neural correlates underlying response inhibition and conflict detection processes using ERPs and source localization analyses simultaneously acquired during fMRI scanning. ERPs were elicited by a simple reaction time task (SRT), a Go/NoGo task, and a Stroop-like task (CST). The cognitive conflict was thus manipulated in order to probe the degree to which information processing is shared across cognitive systems. We proposed to dissociate inhibition and interference conflict effects on brain activity by using identical Stroop-like congruent/incongruent stimuli in all three task contexts and while varying the response required. NoGo-incongruent trials showed a larger N2 and enhanced activations of rostral anterior cingulate cortex (ACC) and pre-supplementary motor area, whereas Go-congruent trials showed a larger P3 and increased parietal activations. Congruent and incongruent conditions of the CST task also elicited similar N2, P3 and late negativity (LN) ERPs, though CST-incongruent trials revealed a larger LN and enhanced prefrontal and ACC activations. Considering the stimulus probability and experimental manipulation of our study, current findings suggest that NoGo N2 and frontal NoGo P3 appear to be more associated to response inhibition rather than a specific conflict monitoring, whereas occipito-parietal P3 of Go and CST conditions may be more linked to a planned response competition between the prepared and required response. LN, however, appears to be related to higher level conflict monitoring associated with response choice-discrimination but not when the presence of cognitive conflict is associated with response inhibition. Copyright © 2013. Published by Elsevier B.V.

Task-Driven Optimization of Fluence Field and Regularization for Model-Based Iterative Reconstruction in Computed Tomography.

PubMed

Gang, Grace J; Siewerdsen, Jeffrey H; Stayman, J Webster

2017-12-01

This paper presents a joint optimization of dynamic fluence field modulation (FFM) and regularization in quadratic penalized-likelihood reconstruction that maximizes a task-based imaging performance metric. We adopted a task-driven imaging framework for prospective designs of the imaging parameters. A maxi-min objective function was adopted to maximize the minimum detectability index ( ) throughout the image. The optimization algorithm alternates between FFM (represented by low-dimensional basis functions) and local regularization (including the regularization strength and directional penalty weights). The task-driven approach was compared with three FFM strategies commonly proposed for FBP reconstruction (as well as a task-driven TCM strategy) for a discrimination task in an abdomen phantom. The task-driven FFM assigned more fluence to less attenuating anteroposterior views and yielded approximately constant fluence behind the object. The optimal regularization was almost uniform throughout image. Furthermore, the task-driven FFM strategy redistribute fluence across detector elements in order to prescribe more fluence to the more attenuating central region of the phantom. Compared with all strategies, the task-driven FFM strategy not only improved minimum by at least 17.8%, but yielded higher over a large area inside the object. The optimal FFM was highly dependent on the amount of regularization, indicating the importance of a joint optimization. Sample reconstructions of simulated data generally support the performance estimates based on computed . The improvements in detectability show the potential of the task-driven imaging framework to improve imaging performance at a fixed dose, or, equivalently, to provide a similar level of performance at reduced dose.

The effect of a preceding cue on the conflict solving mechanism.

PubMed

Goldfarb, Liat; Henik, Avishai

2013-01-01

In everyday life cues and signs are used in order to improve our performance and to modify and control our behavior. This study examines whether cues can improve the performance of the mental mechanism in charge of solving conflicts when the nature of the irrelevant task remains constant. In two experiments participants performed the Stroop task in which they were asked to name the color of a stimulus while ignoring its meaning. Half the trials were preceded by a conflict-cue containing information about an upcoming conflict. In addition, conflict trial proportions were manipulated. We found that only when the probability of conflict is low can cues alter the conflict solving mechanism. These findings are discussed in the context of the nature of the control mechanism and its tendency to minimize the cost of mental resources.

Age-related reorganization of functional networks for successful conflict resolution: a combined functional and structural MRI study.

PubMed

Schulte, Tilman; Müller-Oehring, Eva M; Chanraud, Sandra; Rosenbloom, Margaret J; Pfefferbaum, Adolf; Sullivan, Edith V

2011-11-01

Aging has readily observable effects on the ability to resolve conflict between competing stimulus attributes that are likely related to selective structural and functional brain changes. To identify age-related differences in neural circuits subserving conflict processing, we combined structural and functional MRI and a Stroop Match-to-Sample task involving perceptual cueing and repetition to modulate resources in healthy young and older adults. In our Stroop Match-to-Sample task, older adults handled conflict by activating a frontoparietal attention system more than young adults and engaged a visuomotor network more than young adults when processing repetitive conflict and when processing conflict following valid perceptual cueing. By contrast, young adults activated frontal regions more than older adults when processing conflict with perceptual cueing. These differential activation patterns were not correlated with regional gray matter volume despite smaller volumes in older than young adults. Given comparable performance in speed and accuracy of responding between both groups, these data suggest that successful aging is associated with functional reorganization of neural systems to accommodate functionally increasing task demands on perceptual and attentional operations. Copyright © 2009 Elsevier Inc. All rights reserved.

OGUPSA sensor scheduling architecture and algorithm

NASA Astrophysics Data System (ADS)

Zhang, Zhixiong; Hintz, Kenneth J.

1996-06-01

This paper introduces a new architecture for a sensor measurement scheduler as well as a dynamic sensor scheduling algorithm called the on-line, greedy, urgency-driven, preemptive scheduling algorithm (OGUPSA). OGUPSA incorporates a preemptive mechanism which uses three policies, (1) most-urgent-first (MUF), (2) earliest- completed-first (ECF), and (3) least-versatile-first (LVF). The three policies are used successively to dynamically allocate and schedule and distribute a set of arriving tasks among a set of sensors. OGUPSA also can detect the failure of a task to meet a deadline as well as generate an optimal schedule in the sense of minimum makespan for a group of tasks with the same priorities. A side benefit is OGUPSA's ability to improve dynamic load balance among all sensors while being a polynomial time algorithm. Results of a simulation are presented for a simple sensor system.

Domain-specific conflict adaptation without feature repetitions.

PubMed

Akçay, Çağlar; Hazeltine, Eliot

2011-06-01

An influential account of how cognitive control deals with conflicting sources of information holds that conflict is monitored by a module that automatically recruits attention to resolve the conflict. This leads to reduced effects of conflict on the subsequent trial, a phenomenon termed conflict adaptation. A prominent question is whether control processes are domain specific--that is, recruited only by the particular type of conflict they resolve. Previous studies that have examined this question used two-choice tasks in which feature repetition effects could be responsible for domain-specific adaptation effects. We report two experiments using four-choice (Experiment 1) and five-choice (Experiment 2) tasks that contain two types of irrelevant sources of potentially conflicting information: stimulus location (Simon conflict) and distractors (flanker conflict). In both experiments, we found within-type conflict adaptation for both types of conflict after eliminating trials on which stimulus features were repeated from one trial to the next. Across-type conflict adaptation, however, was not significant. Thus, conflict adaptation was due to domain-specific recruitment of cognitive control. Our results add converging evidence to the idea that multiple independent control processes are involved in reactive cognitive control, although whether control is always local remains to be determined.

Alcohol Hits You When It Is Hard: Intoxication, Task Difficulty, and Theta Brain Oscillations.

PubMed

Rosen, Burke Q; Padovan, Nevena; Marinkovic, Ksenija

2016-04-01

Alcohol intoxication is known to impair decision making in a variety of situations. Previous neuroimaging evidence suggests that the neurofunctional system subserving controlled processing is especially vulnerable to alcohol in conflict-evoking tasks. The present study investigated the effects of moderate alcohol intoxication on the spatiotemporal neural dynamics of event-related total theta (4 to 7 Hz) power as a function of task difficulty. Two variants of the Simon task manipulated incongruity via simple spatial stimulus-response mismatch and, in a more difficult version, by combining spatial and semantic interference. Healthy social drinkers participated in both alcohol (0.6 g/kg ethanol for men, 0.55 g/kg for women) and placebo conditions in a counterbalanced design. Whole-head magnetoencephalography (MEG) signals were acquired and event-related total theta power was calculated on each trial with Morlet wavelets. MEG sources were estimated using anatomically constrained, noise-normalized, spectral dynamic statistical parametric mapping. Longer reaction times and lower accuracy confirmed the difficulty manipulation. Response conflict (incongruity) increased and alcohol intoxication decreased event-related theta power overall during both tasks bilaterally in the medial and ventrolateral prefrontal cortices. However, alcohol-induced theta suppression was selective for conflict only in the more difficult task which engaged the dorsal anterior cingulate (dAC) and anterior inferolateral prefrontal cortices. Theta power correlated negatively with drinking levels and disinhibition, suggesting that cognitive control is susceptible in more impulsive individuals with higher alcohol intake. The spatiotemporal theta profile across the 2 tasks supports the concept of a rostrocaudal activity gradient in the medial prefrontal cortex that is modulated by task difficulty, with the dAC as the key node in the network subserving cognitive control. Conflict-related theta power was selectively reduced by alcohol only under the more difficult task which is indicative of the alcohol-induced impairment of conflict monitoring and top-down regulation. Compromised executive control under alcohol may underlie a range of adverse effects including reduced competency in conflict-inducing or complex situations. © 2016 The Authors. Alcoholism: Clinical and Experimental Research published by Wiley Periodicals, Inc. on behalf of Research Society on Alcoholism.

Novel Hybrid Scheduling Technique for Sensor Nodes with Mixed Criticality Tasks

PubMed Central

Micea, Mihai-Victor; Stangaciu, Cristina-Sorina; Stangaciu, Valentin; Curiac, Daniel-Ioan

2017-01-01

Sensor networks become increasingly a key technology for complex control applications. Their potential use in safety- and time-critical domains has raised the need for task scheduling mechanisms specially adapted to sensor node specific requirements, often materialized in predictable jitter-less execution of tasks characterized by different criticality levels. This paper offers an efficient scheduling solution, named Hybrid Hard Real-Time Scheduling (H2RTS), which combines a static, clock driven method with a dynamic, event driven scheduling technique, in order to provide high execution predictability, while keeping a high node Central Processing Unit (CPU) utilization factor. From the detailed, integrated schedulability analysis of the H2RTS, a set of sufficiency tests are introduced and demonstrated based on the processor demand and linear upper bound metrics. The performance and correct behavior of the proposed hybrid scheduling technique have been extensively evaluated and validated both on a simulator and on a sensor mote equipped with ARM7 microcontroller. PMID:28672856

Evaluating Cognitive Action Control Using Eye-Movement Analysis: An Oculomotor Adaptation of the Simon Task.

PubMed

Duprez, Joan; Houvenaghel, Jean-François; Naudet, Florian; Dondaine, Thibaut; Auffret, Manon; Robert, Gabriel; Drapier, Dominique; Argaud, Soizic; Vérin, Marc; Sauleau, Paul

2016-01-01

Cognitive action control has been extensively studied using conflict tasks such as the Simon task. In most recent studies, this process has been investigated in the light of the dual route hypothesis and more specifically of the activation-suppression model using distributional analyses. Some authors have suggested that cognitive action control assessment is not specific to response modes. In this study we adapted the Simon task, using oculomotor responses instead of manual responses, in order to evaluate whether the resolution of conflict induced by a two-dimensional stimulus yielded similar results to what is usually reported in tasks with manual responses. Results obtained from 43 young healthy participants revealed the typical congruence effect, with longer reaction times (RT) and lesser accuracy in the incongruent condition. Conditional accuracy functions (CAF) also revealed a higher proportion of fast errors in the incongruent condition and delta plots confirmed that conflict resolution was easier, as the time taken to respond increased. These results are very similar to what has been reported in the literature. Furthermore, our observations are in line with the assumptions of the activation-suppression model, in which automatic activation in conflict situations is captured in the fastest responses and selective inhibition of cognitive action control needs time to build up. Altogether, our results suggest that conflict resolution has core mechanisms whatever the response mode, manual or oculomotor. Using oculomotor responses in such tasks could be of interest when investigating cognitive action control in patients with severe motor disorders.

Inter-subject phase synchronization for exploratory analysis of task-fMRI.

PubMed

Bolt, Taylor; Nomi, Jason S; Vij, Shruti G; Chang, Catie; Uddin, Lucina Q

2018-08-01

Analysis of task-based fMRI data is conventionally carried out using a hypothesis-driven approach, where blood-oxygen-level dependent (BOLD) time courses are correlated with a hypothesized temporal structure. In some experimental designs, this temporal structure can be difficult to define. In other cases, experimenters may wish to take a more exploratory, data-driven approach to detecting task-driven BOLD activity. In this study, we demonstrate the efficiency and power of an inter-subject synchronization approach for exploratory analysis of task-based fMRI data. Combining the tools of instantaneous phase synchronization and independent component analysis, we characterize whole-brain task-driven responses in terms of group-wise similarity in temporal signal dynamics of brain networks. We applied this framework to fMRI data collected during performance of a simple motor task and a social cognitive task. Analyses using an inter-subject phase synchronization approach revealed a large number of brain networks that dynamically synchronized to various features of the task, often not predicted by the hypothesized temporal structure of the task. We suggest that this methodological framework, along with readily available tools in the fMRI community, provides a powerful exploratory, data-driven approach for analysis of task-driven BOLD activity. Copyright © 2018 Elsevier Inc. All rights reserved.

Benchmarking shielding simulations for an accelerator-driven spallation neutron source

DOE PAGES

Cherkashyna, Nataliia; Di Julio, Douglas D.; Panzner, Tobias; ...

2015-08-09

The shielding at an accelerator-driven spallation neutron facility plays a critical role in the performance of the neutron scattering instruments, the overall safety, and the total cost of the facility. Accurate simulation of shielding components is thus key for the design of upcoming facilities, such as the European Spallation Source (ESS), currently in construction in Lund, Sweden. In this paper, we present a comparative study between the measured and the simulated neutron background at the Swiss Spallation Neutron Source (SINQ), at the Paul Scherrer Institute (PSI), Villigen, Switzerland. The measurements were carried out at several positions along the SINQ monolithmore » wall with the neutron dosimeter WENDI-2, which has a well-characterized response up to 5 GeV. The simulations were performed using the Monte-Carlo radiation transport code Geant4, and include a complete transport from the proton beam to the measurement locations in a single calculation. An agreement between measurements and simulations is about a factor of 2 for the points where the measured radiation dose is above the background level, which is a satisfactory result for such simulations spanning many energy regimes, different physics processes and transport through several meters of shielding materials. The neutrons contributing to the radiation field emanating from the monolith were confirmed to originate from neutrons with energies above 1 MeV in the target region. The current work validates Geant4 as being well suited for deep-shielding calculations at accelerator-based spallation sources. We also extrapolate what the simulated flux levels might imply for short (several tens of meters) instruments at ESS.« less

An evidence accumulation model for conflict detection performance in a simulated air traffic control task.

PubMed

Neal, Andrew; Kwantes, Peter J

2009-04-01

The aim of this article is to develop a formal model of conflict detection performance. Our model assumes that participants iteratively sample evidence regarding the state of the world and accumulate it over time. A decision is made when the evidence reaches a threshold that changes over time in response to the increasing urgency of the task. Two experiments were conducted to examine the effects of conflict geometry and timing on response proportions and response time. The model is able to predict the observed pattern of response times, including a nonmonotonic relationship between distance at point of closest approach and response time, as well as effects of angle of approach and relative velocity. The results demonstrate that evidence accumulation models provide a good account of performance on a conflict detection task. Evidence accumulation models are a form of dynamic signal detection theory, allowing for the analysis of response times as well as response proportions, and can be used for simulating human performance on dynamic decision tasks.

Attendance dynamics at work: the antecedents and correlates of presenteeism, absenteeism, and productivity loss.

PubMed

Johns, Gary

2011-10-01

Presenteeism is attending work when ill. This study examined the antecedents and correlates of presenteeism, absenteeism, and productivity loss attributed to presenteeism. Predictors included work context, personal characteristics, and work experiences. Business school graduates employed in a variety of work positions (N = 444) completed a Web-based survey. Presenteeism was positively associated with task significance, task interdependence, ease of replacement, and work to family conflict and negatively associated with neuroticism, equity, job security, internal health locus of control, and the perceived legitimacy of absence. Absenteeism was positively related to task significance, perceived absence legitimacy, and family to work conflict and negatively related to task interdependence and work to family conflict. Those high on neuroticism, the unconscientious, the job-insecure, those who viewed absence as more legitimate, and those experiencing work-family conflict reported more productivity loss. Overall, the results reveal the value of a behavioral approach to presenteeism over and above a strict medical model. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

A gas-puff-driven theta pinch for plasma-surface interaction studies

NASA Astrophysics Data System (ADS)

Jung, Soonwook; Kesler, Leigh; Yun, Hyun-Ho; Curreli, Davide; Andruczyk, Daniel; Ruzic, David

2012-10-01

DEVeX is a theta pinch device used to investigate fusion-related material interaction such as vapor shielding and ICRF antenna interactions with plasma-pulses in a laboratory setting. The simulator is required to produce high heat-flux plasma enough to induce temperature gradient high enough to study extreme conditions happened in a plasma fusion reactor. In order to achieve it, DEVeX is reconfigured to be combined with gas puff system as gas puffing may reduce heat flux loss resulting from collisions with neutral. A gas puff system as well as a conical gas nozzle is manufactured and several diagnostics including hot wire anemometer and fast ionization gauge are carried out to quantitatively estimate the supersonic flow of gas. Energy deposited on the target for gas puffing and static-filled conditions is measured with thermocouples and its application to TELS, an innovative concept utilizing a thermoelectric-driven liquid metal flow for plasma facing component, is discussed.

Managing Conflict with Effective Communication Skills.

ERIC Educational Resources Information Center

Clough, Dick B.

Conflict is a basic social process; there is no conceivable way of removing all conflict from an organization. Interpersonal conflict, often created by interdependency of people and tasks within an organization, lowers staff morale and employee productivity and drives people away. Difficult employees who foster conflicts fall into five distinct…

An Investigation of the Reliability and Self-Regulatory Correlates of Conflict Adaptation.

PubMed

Feldman, Julia L; Freitas, Antonio L

2016-07-01

The study of the conflict-adaptation effect, in which encountering information-processing conflict attenuates the disruptive influence of information-processing conflicts encountered subsequently, is a burgeoning area of research. The present study investigated associations among performance measures on a Stroop-trajectory task (measuring Stroop interference and conflict adaptation), on a Wisconsin Card Sorting Task (WCST; measuring cognitive flexibility), and on self-reported measures of self-regulation (including impulsivity and tenacity). We found significant reliability of the conflict-adaptation effects across a two-week period, for response-time and accuracy. Variability in conflict adaptation was not associated significantly with any indicators of performance on the WCST or with most of the self-reported self-regulation measures. There was substantial covariance between Stroop interference for accuracy and conflict adaptation for accuracy. The lack of evidence of covariance across distinct aspects of cognitive control (conflict adaptation, WCST performance, self-reported self-control) may reflect the operation of relatively independent component processes.

Electrophysiological explorations of the bilingual advantage: evidence from a Stroop task.

PubMed

Coderre, Emily L; van Heuven, Walter J B

2014-01-01

Bilinguals have been shown to exhibit a performance advantage on executive control tasks, outperforming their monolingual counterparts. Although a wealth of research has investigated this 'bilingual advantage' behaviourally, electrophysiological correlates are lacking. Using EEG with a Stroop task that manipulated the stimulus onset asynchrony (SOA) of word and colour presentation, the current study addressed two facets of the bilingual advantage. The possibility that bilinguals experience superior conflict processing relative to monolinguals (a 'conflict-specific advantage') was investigated by comparing behavioural interference effects as well as the amplitude of the Ninc, a conflict-related ERP component occurring from approximately 300-500 ms after the onset of conflict. In contrast, the hypothesis that bilinguals experience domain-general, conflict-independent enhancements in executive processing (a 'non-conflict-specific advantage') was evaluated by comparing the control condition (symbol strings) between groups. There was some significant, but inconsistent, evidence for a conflict-specific bilingual advantage. In contrast, strong evidence emerged for a non-conflict-specific advantage, with bilinguals demonstrating faster RTs and reduced ERP amplitudes on control trials compared to monolinguals. Importantly, when the control stimulus was presented before the colour, ERPs to control trials revealed group differences before the onset of conflict, suggesting differences in the ability to ignore or suppress distracting irrelevant information. This indicates that bilinguals experience superior executive processing even in the absence of conflict and semantic salience, and suggests that the advantage extends to more efficient proactive management of the environment.

Electrophysiological Explorations of the Bilingual Advantage: Evidence from a Stroop Task

PubMed Central

Coderre, Emily L.; van Heuven, Walter J. B.

2014-01-01

Bilinguals have been shown to exhibit a performance advantage on executive control tasks, outperforming their monolingual counterparts. Although a wealth of research has investigated this ‘bilingual advantage’ behaviourally, electrophysiological correlates are lacking. Using EEG with a Stroop task that manipulated the stimulus onset asynchrony (SOA) of word and colour presentation, the current study addressed two facets of the bilingual advantage. The possibility that bilinguals experience superior conflict processing relative to monolinguals (a ‘conflict-specific advantage’) was investigated by comparing behavioural interference effects as well as the amplitude of the Ninc, a conflict-related ERP component occurring from approximately 300–500 ms after the onset of conflict. In contrast, the hypothesis that bilinguals experience domain-general, conflict-independent enhancements in executive processing (a ‘non-conflict-specific advantage’) was evaluated by comparing the control condition (symbol strings) between groups. There was some significant, but inconsistent, evidence for a conflict-specific bilingual advantage. In contrast, strong evidence emerged for a non-conflict-specific advantage, with bilinguals demonstrating faster RTs and reduced ERP amplitudes on control trials compared to monolinguals. Importantly, when the control stimulus was presented before the colour, ERPs to control trials revealed group differences before the onset of conflict, suggesting differences in the ability to ignore or suppress distracting irrelevant information. This indicates that bilinguals experience superior executive processing even in the absence of conflict and semantic salience, and suggests that the advantage extends to more efficient proactive management of the environment. PMID:25068723

Cultural transformation toward patient safety: one conversation at a time.

PubMed

Moore, Martie L; Putman, Patrice A

2008-01-01

Patient safety has become a critical objective for nursing leaders within the healthcare setting. Changing the culture to ensure the highest level of communication and safety is a daunting task. Many of the contributing factors that lead to patient harm are rooted in conflict and ineffective conversations. This article shares the story of how 1 organization agreed to make a cultural transformation and the success it realized one conversation at a time.

Threaded cognition: an integrated theory of concurrent multitasking.

PubMed

Salvucci, Dario D; Taatgen, Niels A

2008-01-01

The authors propose the idea of threaded cognition, an integrated theory of concurrent multitasking--that is, performing 2 or more tasks at once. Threaded cognition posits that streams of thought can be represented as threads of processing coordinated by a serial procedural resource and executed across other available resources (e.g., perceptual and motor resources). The theory specifies a parsimonious mechanism that allows for concurrent execution, resource acquisition, and resolution of resource conflicts, without the need for specialized executive processes. By instantiating this mechanism as a computational model, threaded cognition provides explicit predictions of how multitasking behavior can result in interference, or lack thereof, for a given set of tasks. The authors illustrate the theory in model simulations of several representative domains ranging from simple laboratory tasks such as dual-choice tasks to complex real-world domains such as driving and driver distraction. (c) 2008 APA, all rights reserved

Simulation of the hohlraum for a laser facility of Megajoule scale

NASA Astrophysics Data System (ADS)

Chizhkov, M. N.; Kozmanov, M. Y. U.; Lebedev, S. N.; Lykov, V. A.; Rykovanova, V. V.; Seleznev, V. N.; Selezneva, K. I.; Stryakhnina, O. V.; Shestakov, A. A.; Vronskiy, A. V.

2010-08-01

2D calculations of the promising laser hohlraums were performed with using of the Sinara computer code. These hohlraums are intended for achievement of indirectly-driven thermonuclear ignition at laser energy above 1 MJ. Two calculation variants of the laser assembly with the form close to a rugby ball were carried out: with laser entrance hole shields and without shields. Time dependent hohlraum radiation temperature and x-ray flux asymmetry on a target were obtained.

Dataset-Driven Research to Support Learning and Knowledge Analytics

ERIC Educational Resources Information Center

Verbert, Katrien; Manouselis, Nikos; Drachsler, Hendrik; Duval, Erik

2012-01-01

In various research areas, the availability of open datasets is considered as key for research and application purposes. These datasets are used as benchmarks to develop new algorithms and to compare them to other algorithms in given settings. Finding such available datasets for experimentation can be a challenging task in technology enhanced…

Cortisol and Anti-social Behavior in Early Adolescence: The Role of Gender in an Economically Disadvantaged Sample

PubMed Central

Kobak, Roger; Zajac, Kristyn; Levine, Seymour

2014-01-01

This study examines the relation between adolescents’ anti-social behaviors and adrenocortical activity during a laboratory visit in a sample of economically disadvantaged families (N = 116, ages 12 – 14, 51% female). Pre-task cortisol levels indexed adolescents’ pre-challenge response to the lab visit, while adolescents’ response to a conflict discussion with their caregivers was indexed with residualized change in pre- to post- conflict cortisol levels. A trait measure of anti-social behavior (derived from parent, teacher, and self-reports) was associated with lower pre-task cortisol levels but greater cortisol response to the conflict discussion. Gender moderated anti-social adolescents’ cortisol response to the conflict discussion with girls who reported more covert risky problem behaviors showing an increased cortisol response. The findings suggest that, while anti-social adolescents had lower pre-task cortisol levels, conflict discussions with caregivers present a unique challenge to anti-social girls compared with anti-social boys. PMID:19338699

The Congruency Sequence Effect 3.0: A Critical Test of Conflict Adaptation

PubMed Central

Duthoo, Wout; Abrahamse, Elger L.; Braem, Senne; Boehler, C. Nico; Notebaert, Wim

2014-01-01

Over the last two decades, the congruency sequence effect (CSE) –the finding of a reduced congruency effect following incongruent trials in conflict tasks– has played a central role in advancing research on cognitive control. According to the influential conflict-monitoring account, the CSE reflects adjustments in selective attention that enhance task focus when needed, often termed conflict adaptation. However, this dominant interpretation of the CSE has been called into question by several alternative accounts that stress the role of episodic memory processes: feature binding and (stimulus-response) contingency learning. To evaluate the notion of conflict adaptation in accounting for the CSE, we construed versions of three widely used experimental paradigms (the colour-word Stroop, picture-word Stroop and flanker task) that effectively control for feature binding and contingency learning. Results revealed that a CSE can emerge in all three tasks. This strongly suggests a contribution of attentional control to the CSE and highlights the potential of these unprecedentedly clean paradigms for further examining cognitive control. PMID:25340396

The dorsal medial frontal cortex is sensitive to time on task, not response conflict or error likelihood.

PubMed

Grinband, Jack; Savitskaya, Judith; Wager, Tor D; Teichert, Tobias; Ferrera, Vincent P; Hirsch, Joy

2011-07-15

The dorsal medial frontal cortex (dMFC) is highly active during choice behavior. Though many models have been proposed to explain dMFC function, the conflict monitoring model is the most influential. It posits that dMFC is primarily involved in detecting interference between competing responses thus signaling the need for control. It accurately predicts increased neural activity and response time (RT) for incompatible (high-interference) vs. compatible (low-interference) decisions. However, it has been shown that neural activity can increase with time on task, even when no decisions are made. Thus, the greater dMFC activity on incompatible trials may stem from longer RTs rather than response conflict. This study shows that (1) the conflict monitoring model fails to predict the relationship between error likelihood and RT, and (2) the dMFC activity is not sensitive to congruency, error likelihood, or response conflict, but is monotonically related to time on task. Copyright © 2010 Elsevier Inc. All rights reserved.

Neuronal activity in primate dorsal anterior cingulate cortex signals task conflict and predicts adjustments in pupil-linked arousal

PubMed Central

Ebitz, R. Becket; Platt, Michael L.

2014-01-01

Summary Whether driving a car, shopping for food, or paying attention in a classroom of boisterous teenagers, it’s often hard to maintain focus on goals in the face of distraction. Brain imaging studies in humans implicate the dorsal anterior cingulate cortex (dACC) in regulating the conflict between goals and distractors. Here we show for the first time that single dACC neurons signal conflict between task goals and distractors in the rhesus macaque, particularly for biologically-relevant social stimuli. For some neurons, task conflict signals predicted subsequent changes in pupil size—a peripheral index of arousal linked to noradrenergic tone—associated with reduced distractor interference. dACC neurons also responded to errors and these signals predicted adjustments in pupil size. These findings provide the first neurophysiological endorsement of the hypothesis that dACC regulates conflict, in part, via modulation of pupil-linked processes such as arousal. PMID:25654259

Size matters: large objects capture attention in visual search.

PubMed

Proulx, Michael J

2010-12-23

Can objects or events ever capture one's attention in a purely stimulus-driven manner? A recent review of the literature set out the criteria required to find stimulus-driven attentional capture independent of goal-directed influences, and concluded that no published study has satisfied that criteria. Here visual search experiments assessed whether an irrelevantly large object can capture attention. Capture of attention by this static visual feature was found. The results suggest that a large object can indeed capture attention in a stimulus-driven manner and independent of displaywide features of the task that might encourage a goal-directed bias for large items. It is concluded that these results are either consistent with the stimulus-driven criteria published previously or alternatively consistent with a flexible, goal-directed mechanism of saliency detection.

Orthogonally interdigitated shielded serpentine travelling wave cathode ray tube deflection structure

DOEpatents

Hagen, Edward C.; Hudson, Charles L.

1995-01-01

A new deflection structure (12) which deflects a beam of charged particles, uch as an electron beam (15), includes a serpentine set (20) for transmitting a deflection field, and a shielding frame (25) for housing the serpentine set (20). The serpentine set (20) includes a vertical serpentine deflection element (22) and a horizontal serpentine deflection element (24). These deflection elements (22, 24) are identical, and are interdigitatedly and orthogonally disposed relative to each other, for forming a central transmission passage (75), through which the electron beam (15) passes, and is deflected by the deflection field, so as to minimize drift space signal distortion. The shielding frame (25) includes a plurality of ground blocks (26, 28, 30, 32), and forms an internal serpentine trough (77) within these ground blocks, for housing the serpentine set (20). The deflection structure (12) further includes a plurality of feedthrough connectors (35, 37, 35I, 37I), which are inserted through the shielding frame (25), and which are electrically connected to the serpentine set (20).

Conflict, social support, and relationship quality: an observational study of heterosexual, gay male, and lesbian couples' communication.

PubMed

Julien, Danielle; Chartrand, Elise; Simard, Marie-Claude; Bouthillier, Donald; Bégin, Jean

2003-09-01

Data from 42 heterosexual, 46 gay male, and 33 lesbian couples were used to assess the contribution of conflict and support discussions to relationship quality. Couples completed questionnaires, and videotaped discussions were coded for levels of negative and positive behaviors. Correlations showed that behaviors were associated with relationship quality in the expected directions. Hierarchical linear modeling analyses assessed the unique contributions of individual and dyadic behaviors to the variability of relationship quality. The findings indicated that, beyond the contribution of individual negative behaviors in the conflict task, the variables of dyadic positive behaviors in the conflict task, individual positive behaviors in the support task, and perceived help accounted for unexplained variance in relationship quality. There were no differences between types of couples on levels of behaviors or on their contributions to relationship quality.

Midfrontal Theta and Posterior Parietal Alpha Band Oscillations Support Conflict Resolution in a Masked Affective Priming Task.

PubMed

Jiang, Jun; Bailey, Kira; Xiao, Xiao

2018-01-01

Past attempts to characterize the neural mechanisms of affective priming have conceptualized it in terms of classic cognitive conflict, but have not examined the neural oscillatory mechanisms of subliminal affective priming. Using behavioral and electroencephalogram (EEG) time frequency (TF) analysis, the current study examines the oscillatory dynamics of unconsciously triggered conflict in an emotional facial expressions version of the masked affective priming task. The results demonstrate that the power dynamics of conflict are characterized by increased midfrontal theta activity and suppressed parieto-occipital alpha activity. Across-subject and within-trial correlation analyses further confirmed this pattern. Phase synchrony and Granger causality analyses (GCAs) revealed that the fronto-parietal network was involved in unconscious conflict detection and resolution. Our findings support a response conflict account of affective priming, and reveal the role of the fronto-parietal network in unconscious conflict control.

Context-specific control and context selection in conflict tasks.

PubMed

Schouppe, Nathalie; Ridderinkhof, K Richard; Verguts, Tom; Notebaert, Wim

2014-02-01

This study investigated whether participants prefer contexts with relatively little cognitive conflict and whether this preference is related to context-specific control. A conflict selection task was administered in which participants had to choose between two categories that contained different levels of conflict. One category was associated with 80% congruent Stroop trials and 20% incongruent Stroop trials, while the other category was associated with only 20% congruent Stroop trials and 80% incongruent Stroop trials. As predicted, participants selected the low-conflict category more frequently, indicating that participants avoid contexts with high-conflict likelihood. Furthermore, we predicted a correlation between this preference for the low-conflict category and the control implementation associated with the categories (i.e., context-specific proportion congruency effect, CSPC effect). Results however did not show such a correlation, thereby failing to support a relationship between context control and context selection. Copyright © 2013 Elsevier B.V. All rights reserved.

Task frequency influences stimulus-driven effects on task selection during voluntary task switching.

PubMed

Arrington, Catherine M; Reiman, Kaitlin M

2015-08-01

Task selection during voluntary task switching involves both top-down (goal-directed) and bottom-up (stimulus-driven) mechanisms. The factors that shift the balance between these two mechanisms are not well characterized. In the present research, we studied the role that task frequency plays in determining the extent of stimulus-driven task selection. In two experiments, we used the basic paradigm adapted from Arrington (Memory & Cognition, 38, 991-997, 2008), in which the effect of stimulus availability serves as a marker of stimulus-driven task selection. A number and letter appeared on each trial with varying stimulus onset asynchronies, and participants performed either a consonant/vowel or an even/odd judgment. In Experiment 1, participants were instructed as to the relative frequency with which each task was to be performed (i.e., 50/50, 60/40, or 75/25) and were further instructed to make their transitions between tasks unpredictable. In Experiment 2, participants were given no instructions about how to select tasks, resulting in naturally occurring variation in task frequency. With both instructed (Exp. 1) and naturally occurring (Exp. 2) relative task frequencies, the less frequently performed task showed a greater effect of stimulus availability on task selection, suggestive of a larger influence of stimulus-driven mechanisms during task performance for the less frequent task. When goal-directed mechanisms of task choice are engaged less frequently, the relative influence of the stimulus environment increases.

Parenting Style, Parent-Youth Conflict, and Medication Adherence in Youth with Type 2 Diabetes Participating in an Intensive Lifestyle Change Intervention

PubMed Central

Saletsky, Ronald D.; Trief, Paula M.; Anderson, Barbara J.; Rosenbaum, Paula; Weinstock, Ruth S.

2014-01-01

INTRODUCTION Parenting behaviors and family conflict relate to type 1 diabetes outcomes in youth. The purpose of this study was to understand these relationships in parents and youth with type 2 diabetes (T2DM). METHODS The TODAY (Treatment Options for type 2 Diabetes in Adolescents and Youth) trial enrolled youth (10-17 years) with recent-onset T2DM and parent/guardian. For this ancillary study, we enrolled a sample of youth-parent pairs (N =137) in one TODAY study arm (metformin plus lifestyle intervention). Parents and youths completed questionnaires to assess parenting style related to normative (e.g., completing homework) and diabetes self-care (e.g., testing blood glucose) tasks, and parent-youth verbal conflict (baseline, 6 and 12 months). RESULTS Parenting style was consistent across normative and diabetes tasks, with gradual increases in autonomy perceived by youth. Conversations were generally calm, with greater conflict regarding normative tasks than diabetes tasks at baseline (youth: p<0.001, parent: p=0.01), 6 months (youth: p=0.02, parent: p >0.05) and 12 months (youth: p> 0.05., parent: p=0.05). A permissive parenting style towards normative tasks and a less authoritarian style towards diabetes tasks, at baseline, predicted better medication adherence (8-12 months) (normative: adjusted R2=0.48, p<0.001; diabetes: adjusted R2 = 0.47, p<0.001). Parent-youth conflict did not predict medication adherence. DISCUSSION Youth with T2DM who perceive more autonomy (less parental control) in day-to-day and diabetes tasks are more likely to adhere to medication regimens. It may be valuable to assess youth perceptions of parenting style at onset of medication treatment and help parents understand youths’ needs for autonomy. PMID:24548045

Effects of Resource Availability on Children's Behavior and Conflict Management.

ERIC Educational Resources Information Center

Brown, Enora R.

1996-01-01

Examined the effect of resource availability on dyadic interaction of African American three- to five-year olds in a painting activity conducted under two resource conditions. Limited resources promoted more resource and task conflict, while plentiful resources promoted more nonconflictive social and task interactions. Results underscored the role…

Conflict monitoring and adjustment in the task-switching paradigm under different memory load conditions: an ERP/sLORETA analysis.

PubMed

Deng, Yuqin; Wang, Yan; Ding, Xiaoqian; Tang, Yi-Yuan

2015-02-11

The aim of the present study was to examine electrophysiological and behavioral changes caused by different memory loads in a task-switching paradigm. A total of 31 healthy individuals were subjected to a task, in which the stimulus-response reversal paradigm was combined with the task-switching paradigm. The event-related potentials were recorded and the N2 component, an index of conflict processing, was measured. In addition, the neural sources of N2 were further analyzed by standardized low-resolution brain electromagnetic tomography. The event-related potential results showed that high memory load triggered a higher N2 mean amplitude. Moreover, the standardized low-resolution brain electromagnetic tomography data showed that high memory load caused an increase in current densities at the anterior cingulate cortex and the prefrontal cortex in the task-switching paradigm. In summary, our findings provide electrophysiological evidence to interpret possible influences of memory loads on conflict monitoring and modulation during the task switching. These results imply that the working memory load overrules the influence of task-switching performance on the intensification of cognitive control.

Brain Activations Related to Saccadic Response Conflict are not Sensitive to Time on Task.

PubMed

Beldzik, Ewa; Domagalik, Aleksandra; Oginska, Halszka; Marek, Tadeusz; Fafrowicz, Magdalena

2015-01-01

Establishing a role of the dorsal medial frontal cortex in the performance monitoring and cognitive control has been a challenge to neuroscientists for the past decade. In light of recent findings, the conflict monitoring hypothesis has been elaborated to an action-outcome predictor theory. One of the findings that led to this re-evaluation was the fMRI study in which conflict-related brain activity was investigated in terms of the so-called time on task effect, i.e., a linear increase of the BOLD signal with longer response times. The aim of this study was to investigate brain regions involved in the processing of saccadic response conflict and to account for the time on task effect. A modified spatial cueing task was implemented in the event-related fMRI study with oculomotor responses. The results revealed several brain regions which show higher activity for incongruent trials in comparison to the congruent ones, including pre-supplementary motor area together with the frontal and parietal regions. Further analysis accounting for the effect of response time provided evidence that these brain activations were not sensitive to time on task but reflected purely the congruency effect.

Time utilization and perceived psychosocial work environment among staff in Swedish primary care settings.

PubMed

Anskär, Eva; Lindberg, Malou; Falk, Magnus; Andersson, Agneta

2018-03-07

Over the past decades, reorganizations and structural changes in Swedish primary care have affected time utilization among health care professionals. Consequently, increases in administrative tasks have substantially reduced the time available for face-to-face consultations. This study examined how work-time was utilized and the association between work time utilization and the perceived psychosocial work environment in Swedish primary care settings. This descriptive, multicentre, cross-sectional study was performed in 2014-2015. Data collection began with questionnaire. In the first section, respondents were asked to estimate how their workload was distributed between patients (direct and indirect patient work) and other work tasks. The questionnaire also comprised the Copenhagen Psychosocial Questionnaire, which assessed the psychosocial work environment. Next a time study was conducted where the participants reported their work-time based on three main categories: direct patient-related work, indirect patient-related work, and other work tasks. Each main category had a number of subcategories. The participants recorded the time spent (minutes) on each work task per hour, every day, for two separate weeks. Eleven primary care centres located in southeast Sweden participated. All professionals were asked to participate (n = 441), including registered nurses, primary care physicians, care administrators, nurse assistants, and allied professionals. Response rates were 75% and 79% for the questionnaires and the time study, respectively. All health professionals allocated between 30.9% - 37.2% of their work-time to each main category: direct patient work, indirect patient work, and other work. All professionals estimated a higher proportion of time spent in direct patient work than they reported in the time study. Physicians scored highest on the psychosocial scales of quantitative demands, stress, and role conflicts. Among allied professionals, the proportion of work-time spent on administrative tasks was associated with more role conflicts. Younger staff perceived more adverse working conditions than older staff. This study indicated that Swedish primary care staff spent a limited proportion of their work time directly with patients. PCPs seemed to perceive their work environment in negative terms to a greater extent than other staff members. This study showed that work task allocations influenced the perceived psychosocial work environment.

Portable convertible blast effects shield

DOEpatents

Pastrnak, John W [Livermore, CA; Hollaway, Rocky [Modesto, CA; Henning, Carl D [Livermore, CA; Deteresa, Steve [Livermore, CA; Grundler, Walter [Hayward, CA; Hagler, Lisle B [Berkeley, CA; Kokko, Edwin [Dublin, CA; Switzer, Vernon A [Livermore, CA

2011-03-15

A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more frusto-conically-tapered telescoping rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration by the friction fit of adjacent pairs of frusto-conically-tapered rings to each other.

Study of low-cost fabrication of ablative heat shields

NASA Technical Reports Server (NTRS)

Norwood, L. B.

1972-01-01

The major objectives were accomplished in three tasks: (1) modification of the ablative material composition for ease of fabrication as well as thermal and mechanical performance; (2) scaled-up, simplified, manufacturing techniques which resulted in cost reductions; and (3) the identification of a significant design problem caused by the differential pressure buildup imposed on mechanically attached ablative heat shield panels during launch.

Human shields mediate sexual conflict in a top predator.

PubMed

Steyaert, S M J G; Leclerc, M; Pelletier, F; Kindberg, J; Brunberg, S; Swenson, J E; Zedrosser, A

2016-06-29

Selecting the right habitat in a risky landscape is crucial for an individual's survival and reproduction. In predator-prey systems, prey often can anticipate the habitat use of their main predator and may use protective associates (i.e. typically an apex predator) as shields against predation. Although never tested, such mechanisms should also evolve in systems in which sexual conflict affects offspring survival. Here, we assessed the relationship between offspring survival and habitat selection, as well as the use of protective associates, in a system in which sexually selected infanticide (SSI), rather than interspecific predation, affects offspring survival. We used the Scandinavian brown bear (Ursus arctos) population with SSI in a human-dominated landscape as our model system. Bears, especially adult males, generally avoid humans in our study system. We used resource selection functions to contrast habitat selection of GPS-collared mothers that were successful (i.e. surviving litters, n = 19) and unsuccessful (i.e. complete litter loss, n = 11) in keeping their young during the mating season (2005-2012). Habitat selection was indeed a predictor of litter survival. Successful mothers were more likely to use humans as protective associates, whereas unsuccessful mothers avoided humans. Our results suggest that principles of predator-prey and fear ecology theory (e.g. non-consumptive and cascading effects) can also be applied to the context of sexual conflict. © 2016 The Authors.

Frontal theta accounts for individual differences in the cost of conflict on decision making.

PubMed

Pinner, John F L; Cavanagh, James F

2017-10-01

Cognitive conflict is often experienced as a difficult, frustrating, and aversive state. Recent studies have indicated that conflict acts as an implicit cost during learning, valuation, and the instantiation of cognitive control. Here we investigated if an implicit manipulation of conflict also influences explicit decision making to risk. Participants were required to perform a Balloon Analogue Risk Task wherein the virtual balloon was inflated by performing a flankers task. By varying the percent of incongruent flanker trials between balloons, we hypothesized that participants would pump the balloon fewer times in conditions of higher conflict and that frontal midline theta would account for significant variance in this relationship. Across two studies, we demonstrate that conflict did not elicit reliable behavioral changes in this task across participants. However, individual differences in frontal theta power accounted for significant variance by predicting diminished balloon pumps. Thus, while conflict costs may act as investments to some individuals (invigorating behavior), it is aversive to others (diminishing behavior), and frontal midline theta power accounts for these varying behavioral tendencies between individuals. These findings demonstrate how frontal midline theta is not only a candidate mechanism for implementing cognitive control, but it is sensitive to the inherent costs therein. Copyright © 2017 Elsevier B.V. All rights reserved.

The importance of source and cue type in time-based everyday prospective memory.

PubMed

Oates, Joyce M; Peynircioğlu, Zehra F

2014-01-01

We examined the effects of the source of a prospective memory task (provided or generated) and the type of cue (specific or general) triggering that task in everyday settings. Participants were asked to complete both generated and experimenter-provided tasks and to send a text message when each task was completed. The cue/context for the to-be-completed tasks was either a specific time or a general deadline (time-based cue), and the cue/context for the texting task was the completion of the task itself (activity-based cue). Although generated tasks were completed more often, generated cues/contexts were no more effective than provided ones in triggering the intention. Furthermore, generated tasks were completed more often when the cue/context comprised a specific time, whereas provided tasks were completed more often when the cue/context comprised a general deadline. However, texting was unaffected by the source of the cue/context. Finally, emotion modulated the effects. Results are discussed within a process-driven framework.

The neural correlates of belief-bias inhibition: the impact of logic training.

PubMed

Luo, Junlong; Tang, Xiaochen; Zhang, Entao; Stupple, Edward J N

2014-12-01

Functional Magnetic Resonance Imaging (fMRI) was used to investigate the brain activity associated with response change in a belief bias paradigm before and after logic training. Participants completed two sets of belief biased reasoning tasks. In the first set they were instructed to respond based on their empirical beliefs, and in the second - following logic training - they were instructed to respond logically. The comparison between conflict problems in the second scan versus in the first scan revealed differing activation for the left inferior frontal gyrus, left middle frontal gyrus, cerebellum, and precuneus. The scan was time locked to the presentation of the minor premise, and thus demonstrated effects of belief-logic conflict on neural activation earlier in the time course than has previously been shown in fMRI. These data, moreover, indicated that logical training results in changes in brain activity associated with cognitive control processing. Copyright © 2014 Elsevier B.V. All rights reserved.

Spin-orbit ZORA and four-component Dirac-Coulomb estimation of relativistic corrections to isotropic nuclear shieldings and chemical shifts of noble gas dimers.

PubMed

Jankowska, Marzena; Kupka, Teobald; Stobiński, Leszek; Faber, Rasmus; Lacerda, Evanildo G; Sauer, Stephan P A

2016-02-05

Hartree-Fock and density functional theory with the hybrid B3LYP and general gradient KT2 exchange-correlation functionals were used for nonrelativistic and relativistic nuclear magnetic shielding calculations of helium, neon, argon, krypton, and xenon dimers and free atoms. Relativistic corrections were calculated with the scalar and spin-orbit zeroth-order regular approximation Hamiltonian in combination with the large Slater-type basis set QZ4P as well as with the four-component Dirac-Coulomb Hamiltonian using Dyall's acv4z basis sets. The relativistic corrections to the nuclear magnetic shieldings and chemical shifts are combined with nonrelativistic coupled cluster singles and doubles with noniterative triple excitations [CCSD(T)] calculations using the very large polarization-consistent basis sets aug-pcSseg-4 for He, Ne and Ar, aug-pcSseg-3 for Kr, and the AQZP basis set for Xe. For the dimers also, zero-point vibrational (ZPV) corrections are obtained at the CCSD(T) level with the same basis sets were added. Best estimates of the dimer chemical shifts are generated from these nuclear magnetic shieldings and the relative importance of electron correlation, ZPV, and relativistic corrections for the shieldings and chemical shifts is analyzed. © 2015 Wiley Periodicals, Inc.

The Wake Shield Facility: A space experiment platform

NASA Technical Reports Server (NTRS)

Allen, Joseph P.

1991-01-01

Information is given in viewgraph form on Wakeshield, a space experiment platform. The Wake Shield Facility (WSF) flight program objectives, product applications, commercial development approach, and cooperative experiments are listed. The program objectives are to produce new industry-driven electronic, magnetic, and superconducting thin-film materials and devices both in terrestrial laboratories and in space; utilize the ultra-vacuum of space for thin film epitaxial growth and materials processing; and develop commercial space hardware for research and development and enhanced access to space.

Reducing radiation dose to the female breast during CT coronary angiography: A simulation study comparing breast shielding, angular tube current modulation, reduced kV, and partial angle protocols using an unknown-location signal-detectability metric

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

Rupcich, Franco; Gilat Schmidt, Taly; Badal, Andreu

2013-08-15

Purpose: The authors compared the performance of five protocols intended to reduce dose to the breast during computed tomography (CT) coronary angiography scans using a model observer unknown-location signal-detectability metric.Methods: The authors simulated CT images of an anthropomorphic female thorax phantom for a 120 kV reference protocol and five “dose reduction” protocols intended to reduce dose to the breast: 120 kV partial angle (posteriorly centered), 120 kV tube-current modulated (TCM), 120 kV with shielded breasts, 80 kV, and 80 kV partial angle (posteriorly centered). Two image quality tasks were investigated: the detection and localization of 4-mm, 3.25 mg/ml and 1-mm,more » 6.0 mg/ml iodine contrast signals randomly located in the heart region. For each protocol, the authors plotted the signal detectability, as quantified by the area under the exponentially transformed free response characteristic curve estimator (A-caret{sub FE}), as well as noise and contrast-to-noise ratio (CNR) versus breast and lung dose. In addition, the authors quantified each protocol's dose performance as the percent difference in dose relative to the reference protocol achieved while maintaining equivalent A-caret{sub FE}.Results: For the 4-mm signal-size task, the 80 kV full scan and 80 kV partial angle protocols decreased dose to the breast (80.5% and 85.3%, respectively) and lung (80.5% and 76.7%, respectively) with A-caret{sub FE} = 0.96, but also resulted in an approximate three-fold increase in image noise. The 120 kV partial protocol reduced dose to the breast (17.6%) at the expense of increased lung dose (25.3%). The TCM algorithm decreased dose to the breast (6.0%) and lung (10.4%). Breast shielding increased breast dose (67.8%) and lung dose (103.4%). The 80 kV and 80 kV partial protocols demonstrated greater dose reductions for the 4-mm task than for the 1-mm task, and the shielded protocol showed a larger increase in dose for the 4-mm task than for the 1-mm task. In general, the CNR curves indicate a similar relative ranking of protocol performance as the corresponding A-caret{sub FE} curves, however, the CNR metric overestimated the performance of the shielded protocol for both tasks, leading to corresponding underestimates in the relative dose increases compared to those obtained when using the A-caret{sub FE} metric.Conclusions: The 80 kV and 80 kV partial angle protocols demonstrated the greatest reduction to breast and lung dose, however, the subsequent increase in image noise may be deemed clinically unacceptable. Tube output for these protocols can be adjusted to achieve a more desirable noise level with lesser breast dose savings. Breast shielding increased breast and lung dose when maintaining equivalent A-caret{sub FE}. The results demonstrated that comparisons of dose performance depend on both the image quality metric and the specific task, and that CNR may not be a reliable metric of signal detectability.« less

Division of Household and Childcare Labor and Relationship Conflict Among Low-Income New Parents

PubMed Central

Newkirk, Katie; Perry-Jenkins, Maureen; Sayer, Aline G.

2016-01-01

We examine the relationships among the division of housework and childcare labor, perceptions of its fairness for two types of family labor (housework and childcare), and parents’ relationship conflict across the transition to parenthood. Perceived fairness is examined as a mediator of the relationships between change in the division of housework and childcare and relationship conflict. Working-class, dual-earner couples (n = 108) in the U.S Northeast were interviewed at five time points from the third trimester of pregnancy and across the first year of parenthood. Research questions addressed whether change in the division of housework and childcare across the transition to parenthood predicted mothers’ and fathers’ relationship conflict, with attention to the mediating role of perceived fairness of these chores. Findings for housework indicated that perceived fairness was related to relationship conflict for mothers and fathers, such that when spouses perceived the change in the division of household tasks to be unfair to either partner, they reported more conflict, However, fairness did not significantly mediate relations between changes in division of household tasks and later relationship conflict. For childcare, fairness mediated relations between mothers’ violated expectations concerning the division of childcare and later conflict such that mothers reported less conflict when they perceived the division of childcare as less unfair to themselves; there was no relationship for fathers. Findings highlight the importance of considering both childcare and household tasks independently in our models and suggest that the division of housework and childcare holds different implications for mothers’ and fathers’ assessments of relationship conflict. PMID:28348454

Top-down dimensional weight set determines the capture of visual attention: evidence from the PCN component.

PubMed

Töllner, Thomas; Müller, Hermann J; Zehetleitner, Michael

2012-07-01

Visual search for feature singletons is slowed when a task-irrelevant, but more salient distracter singleton is concurrently presented. While there is a consensus that this distracter interference effect can be influenced by internal system settings, it remains controversial at what stage of processing this influence starts to affect visual coding. Advocates of the "stimulus-driven" view maintain that the initial sweep of visual processing is entirely driven by physical stimulus attributes and that top-down settings can bias visual processing only after selection of the most salient item. By contrast, opponents argue that top-down expectancies can alter the initial selection priority, so that focal attention is "not automatically" shifted to the location exhibiting the highest feature contrast. To precisely trace the allocation of focal attention, we analyzed the Posterior-Contralateral-Negativity (PCN) in a task in which the likelihood (expectancy) with which a distracter occurred was systematically varied. Our results show that both high (vs. low) distracter expectancy and experiencing a distracter on the previous trial speed up the timing of the target-elicited PCN. Importantly, there was no distracter-elicited PCN, indicating that participants did not shift attention to the distracter before selecting the target. This pattern unambiguously demonstrates that preattentive vision is top-down modifiable.

View of Kotov working with Debris Panels during EVA18

NASA Image and Video Library

2007-05-30

ISS015-E-10043 (30 May 2007) --- Cosmonaut Oleg V. Kotov, Expedition 15 flight engineer representing Russia's Federal Space Agency, wearing a Russian Orlan spacesuit, participates in a session of extravehicular activity (EVA). Among other tasks, Kotov and cosmonaut Fyodor N. Yurchikhin (out of frame), commander representing Russia's Federal Space Agency, retrieved the "Christmas tree" bundle of three packages of 17 protective debris panels for installation around the forward cone of the Zvezda Service Module of the International Space Station and to install the first set of those panels. The aluminum debris protection panels are designed to shield the module from micro-meteoroids.

Prospective memory in an air traffic control simulation: External aids that signal when to act

PubMed Central

Loft, Shayne; Smith, Rebekah E.; Bhaskara, Adella

2011-01-01

At work and in our personal life we often need to remember to perform intended actions at some point in the future, referred to as Prospective Memory. Individuals sometimes forget to perform intentions in safety-critical work contexts. Holding intentions can also interfere with ongoing tasks. We applied theories and methods from the experimental literature to test the effectiveness of external aids in reducing prospective memory error and costs to ongoing tasks in an air traffic control simulation. Participants were trained to accept and hand-off aircraft, and to detect aircraft conflicts. For the prospective memory task participants were required to substitute alternative actions for routine actions when accepting target aircraft. Across two experiments, external display aids were provided that presented the details of target aircraft and associated intended actions. We predicted that aids would only be effective if they provided information that was diagnostic of target occurrence and in this study we examined the utility of aids that directly cued participants when to allocate attention to the prospective memory task. When aids were set to flash when the prospective memory target aircraft needed to be accepted, prospective memory error and costs to ongoing tasks of aircraft acceptance and conflict detection were reduced. In contrast, aids that did not alert participants specifically when the target aircraft were present provided no advantage compared to when no aids we used. These findings have practical implications for the potential relative utility of automated external aids for occupations where individuals monitor multi-item dynamic displays. PMID:21443381

Prospective memory in an air traffic control simulation: external aids that signal when to act.

PubMed

Loft, Shayne; Smith, Rebekah E; Bhaskara, Adella

2011-03-01

At work and in our personal life we often need to remember to perform intended actions at some point in the future, referred to as Prospective Memory. Individuals sometimes forget to perform intentions in safety-critical work contexts. Holding intentions can also interfere with ongoing tasks. We applied theories and methods from the experimental literature to test the effectiveness of external aids in reducing prospective memory error and costs to ongoing tasks in an air traffic control simulation. Participants were trained to accept and hand-off aircraft and to detect aircraft conflicts. For the prospective memory task, participants were required to substitute alternative actions for routine actions when accepting target aircraft. Across two experiments, external display aids were provided that presented the details of target aircraft and associated intended actions. We predicted that aids would only be effective if they provided information that was diagnostic of target occurrence, and in this study, we examined the utility of aids that directly cued participants when to allocate attention to the prospective memory task. When aids were set to flash when the prospective memory target aircraft needed to be accepted, prospective memory error and costs to ongoing tasks of aircraft acceptance and conflict detection were reduced. In contrast, aids that did not alert participants specifically when the target aircraft were present provided no advantage compared to when no aids were used. These findings have practical implications for the potential relative utility of automated external aids for occupations where individuals monitor multi-item dynamic displays.

Is lorazepam-induced amnesia specific to the type of memory or to the task used to assess it?

PubMed

File, S E; Sharma, R; Shaffer, J

1992-01-01

Retrieval tasks can be classified along a continuum from conceptually driven (relying on the encoded meaning of the material) to data driven (relying on the perceptual record and surface features of the material). Since most explicit memory tests are conceptually driven and most implicit memory tests are data driven there has been considerable confounding of the memory system being assessed and the processing required by the retrieval task. The purpose of the present experiment was to investigate the effects of lorazepam on explicit memory, using both types of retrieval task. Lorazepam (2.5 mg) or matched placebo was administered to healthy volunteers and changes in subjective mood ratings and in performance in tests of memory were measured. Lorazepam made subjects significantly more drowsy, feeble, clumsy, muzzy, lethargic and mentally slow. Lorazepam significantly impaired recognition memory for slides, impaired the number of words remembered when the retrieval was cued by the first two letters and reduced the number of pictures remembered when retention was cued with picture fragments. Thus episodic memory was impaired whether the task used was conceptually driven (as in slide recognition) or data driven, as in the other two tasks. Analyses of covariance indicated that the memory impairments were independent of increased sedation, as assessed by self-ratings. In contrast to the deficits in episodic memory, there were no lorazepam-induced impairments in tests of semantic memory, whether this was measured in the conceptually driven task of category generation or in the data-driven task of wordstem completion.

Acoustic Shielding for a Model Scale Counter-rotation Open Rotor

NASA Technical Reports Server (NTRS)

Stephens, David B.; Edmane, Envia

2012-01-01

The noise shielding benefit of installing an open rotor above a simplified wing or tail is explored experimentally. The test results provide both a benchmark data set for validating shielding prediction tools and an opportunity for a system level evaluation of the noise reduction potential of propulsion noise shielding by an airframe component. A short barrier near the open rotor was found to provide up to 8.5 dB of attenuation at some directivity angles, with tonal sound particularly well shielded. Predictions from two simple shielding theories were found to overestimate the shielding benefit.

Task probability and report of feature information: what you know about what you 'see' depends on what you expect to need.

PubMed

Pilling, Michael; Gellatly, Angus

2013-07-01

We investigated the influence of dimensional set on report of object feature information using an immediate memory probe task. Participants viewed displays containing up to 36 coloured geometric shapes which were presented for several hundred milliseconds before one item was abruptly occluded by a probe. A cue presented simultaneously with the probe instructed participants to report either about the colour or shape of the probe item. A dimensional set towards the colour or shape of the presented items was induced by manipulating task probability - the relative probability with which the two feature dimensions required report. This was done across two participant groups: One group was given trials where there was a higher report probability of colour, the other a higher report probability of shape. Two experiments showed that features were reported most accurately when they were of high task probability, though in both cases the effect was largely driven by the colour dimension. Importantly the task probability effect did not interact with display set size. This is interpreted as tentative evidence that this manipulation influences feature processing in a global manner and at a stage prior to visual short term memory. Copyright © 2013 Elsevier B.V. All rights reserved.

Human resource management in post-conflict health systems: review of research and knowledge gaps.

PubMed

Roome, Edward; Raven, Joanna; Martineau, Tim

2014-01-01

In post-conflict settings, severe disruption to health systems invariably leaves populations at high risk of disease and in greater need of health provision than more stable resource-poor countries. The health workforce is often a direct victim of conflict. Effective human resource management (HRM) strategies and policies are critical to addressing the systemic effects of conflict on the health workforce such as flight of human capital, mismatches between skills and service needs, breakdown of pre-service training, and lack of human resource data. This paper reviews published literatures across three functional areas of HRM in post-conflict settings: workforce supply, workforce distribution, and workforce performance. We searched published literatures for articles published in English between 2003 and 2013. The search used context-specific keywords (e.g. post-conflict, reconstruction) in combination with topic-related keywords based on an analytical framework containing the three functional areas of HRM (supply, distribution, and performance) and several corresponding HRM topic areas under these. In addition, the framework includes a number of cross-cutting topics such as leadership and governance, finance, and gender. The literature is growing but still limited. Many publications have focused on health workforce supply issues, including pre-service education and training, pay, and recruitment. Less is known about workforce distribution, especially governance and administrative systems for deployment and incentive policies to redress geographical workforce imbalances. Apart from in-service training, workforce performance is particularly under-researched in the areas of performance-based incentives, management and supervision, work organisation and job design, and performance appraisal. Research is largely on HRM in the early post-conflict period and has relied on secondary data. More primary research is needed across the areas of workforce supply, workforce distribution, and workforce performance. However, this should apply a longer-term focus throughout the different post-conflict phases, while paying attention to key cross-cutting themes such as leadership and governance, gender equity, and task shifting. The research gaps identified should enable future studies to examine how HRM could be used to meet both short and long term objectives for rebuilding health workforces and thereby contribute to achieving more equitable and sustainable health systems outcomes after conflict.

Shielding and activation calculations around the reactor core for the MYRRHA ADS design

NASA Astrophysics Data System (ADS)

Ferrari, Anna; Mueller, Stefan; Konheiser, J.; Castelliti, D.; Sarotto, M.; Stankovskiy, A.

2017-09-01

In the frame of the FP7 European project MAXSIMA, an extensive simulation study has been done to assess the main shielding problems in view of the construction of the MYRRHA accelerator-driven system at SCK·CEN in Mol (Belgium). An innovative method based on the combined use of the two state-of-the-art Monte Carlo codes MCNPX and FLUKA has been used, with the goal to characterize complex, realistic neutron fields around the core barrel, to be used as source terms in detailed analyses of the radiation fields due to the system in operation, and of the coupled residual radiation. The main results of the shielding analysis are presented, as well as the construction of an activation database of all the key structural materials. The results evidenced a powerful way to analyse the shielding and activation problems, with direct and clear implications on the design solutions.

Using Conflict Mapping to Foster Peace-Related Learning and Change in Schools

ERIC Educational Resources Information Center

John, Vaughn M.

2016-01-01

South African societies, including learners in primary and secondary schools, experience high levels of violent conflict. The lack of interventions in terms of peace education and peace building is cause for concern. Driven by an interest to build educators' capacity and agency to become agents of change in the face of growing conflict and…

Cohort-Sequential Study of Conflict Inhibition during Middle Childhood

ERIC Educational Resources Information Center

Rollins, Leslie; Riggins, Tracy

2017-01-01

This longitudinal study examined developmental changes in conflict inhibition and error correction in three cohorts of children (5, 7, and 9 years of age). At each point of assessment, children completed three levels of Luria's tapping task (1980), which requires the inhibition of a dominant response and maintenance of task rules in working…

Stress Regulation in Adolescents: Physiological Reactivity during the Adult Attachment Interview and Conflict Interaction

ERIC Educational Resources Information Center

Beijersbergen, Marielle D.; Bakermans-Kranenburg, Marian J.; van IJzendoorn, Marinus H.; Juffer, Femmie

2008-01-01

The current study examined whether adolescents' attachment representations were associated with differences in emotion regulation during the Adult Attachment Interview (AAI; C. George, N. Kaplan, & M. Main, 1996) and during a mother-adolescent conflict interaction task (Family Interaction Task [FIT]; J. P. Allen et al., 2003). Participants…

Second language proficiency modulates conflict-monitoring in an oculomotor Stroop task: evidence from Hindi-English bilinguals

PubMed Central

Singh, Niharika; Mishra, Ramesh K.

2013-01-01

Many studies have confirmed the presence of a bilingual advantage which is manifested as enhanced cognitive and attention control. However, very few studies have investigated the role of second language proficiency on the modulation of conflict-monitoring in bilinguals. We investigated this by comparing high and low proficient Hindi-English bilinguals on a modified saccadic arrow Stroop task under different monitoring conditions, and tested the predictions of the bilingual executive control advantage proposal. The task of the participants was to make an eye movement toward the color patch in the same color as the central arrow, ignoring the patch to which the arrow was pointing. High-proficient bilinguals had overall faster saccade latency on all types of trials as compared to the low proficient bilinguals. The overall saccadic latency for high proficiency bilinguals was similarly affected by the different types of monitoring conditions, whereas conflict resolution advantage was found only for high monitoring demanding condition. The results support a conflict-monitoring account in a novel oculomotor task and also suggest that language proficiency could modulate executive control in bilinguals. PMID:23781210

Striatopallidal neurons control avoidance behavior in exploratory tasks.

PubMed

LeBlanc, Kimberly H; London, Tanisha D; Szczot, Ilona; Bocarsly, Miriam E; Friend, Danielle M; Nguyen, Katrina P; Mengesha, Marda M; Rubinstein, Marcelo; Alvarez, Veronica A; Kravitz, Alexxai V

2018-04-25

The dorsal striatum has been linked to decision-making under conflict, but the mechanism by which striatal neurons contribute to approach-avoidance conflicts remains unclear. We hypothesized that striatopallidal dopamine D2 receptor (D2R)-expressing neurons promote avoidance, and tested this hypothesis in two exploratory approach-avoidance conflict paradigms in mice: the elevated zero maze and open field. Genetic elimination of D2Rs on striatopallidal neurons (iMSNs), but not other neural populations, increased avoidance of the open areas in both tasks, in a manner that was dissociable from global changes in movement. Population calcium activity of dorsomedial iMSNs was disrupted in mice lacking D2Rs on iMSNs, suggesting that disrupted output of iMSNs contributes to heightened avoidance behavior. Consistently, artificial disruption of iMSN output with optogenetic stimulation heightened avoidance of open areas of these tasks, while inhibition of iMSN output reduced avoidance. We conclude that dorsomedial striatal iMSNs control approach-avoidance conflicts in exploratory tasks, and highlight this neural population as a potential target for reducing avoidance in anxiety disorders.

Is conflict monitoring supramodal? Spatiotemporal dynamics of cognitive control processes in an auditory Stroop task

PubMed Central

Donohue, Sarah E.; Liotti, Mario; Perez, Rick; Woldorff, Marty G.

2011-01-01

The electrophysiological correlates of conflict processing and cognitive control have been well characterized for the visual modality in paradigms such as the Stroop task. Much less is known about corresponding processes in the auditory modality. Here, electroencephalographic recordings of brain activity were measured during an auditory Stroop task, using three different forms of behavioral response (Overt verbal, Covert verbal, and Manual), that closely paralleled our previous visual-Stroop study. As expected, behavioral responses were slower and less accurate for incongruent compared to congruent trials. Neurally, incongruent trials showed an enhanced fronto-central negative-polarity wave (Ninc), similar to the N450 in visual-Stroop tasks, with similar variations as a function of behavioral response mode, but peaking ~150 ms earlier, followed by an enhanced positive posterior wave. In addition, sequential behavioral and neural effects were observed that supported the conflict-monitoring and cognitive-adjustment hypothesis. Thus, while some aspects of the conflict detection processes, such as timing, may be modality-dependent, the general mechanisms would appear to be supramodal. PMID:21964643

Competency--and Process-Driven e-Learning--A Model-Based Approach

ERIC Educational Resources Information Center

Leyking, Katrina; Chikova, Pavlina; Loos, Peter

2007-01-01

As a matter of fact e-Learning still has not really caught on for corporate training purposes. Investigations on the reasons reveal that e-Learning modules like WBTs often miss any relevance for the tasks to be accomplished in the day-to-day workplace settings. The very learning needs both from an organizational and individual perspective are…

THE RELATIVE IMPORTANCE OF THE VADOSE ZONE IN MULTIMEDIA RISK ASSESSMENT MODELING APPLIED AT A NATIONAL SCALE: AN ANALYSIS OF BENZENE USING 3MRA

EPA Science Inventory

Evaluating uncertainty and parameter sensitivity in environmental models can be a difficult task, even for low-order, single-media constructs driven by a unique set of site-specific data. The challenge of examining ever more complex, integrated, higher-order models is a formidab...

An fMRI Study of Risky Decision Making: The Role of Mental Preparation and Conflict.

PubMed

Sohrabi, Ahmad; Smith, Andra M; West, Robert L; Cameron, Ian

2015-10-01

The current study aimed to elucidate the role of preparatory cognitive control in decision making and its neural correlates using functional Magnetic Resonance Imaging (fMRI). To this effect, by employing a series of new cognitive tasks, we assessed the role of preparatory cognitive control in monetary (risky) decision making. The participants had to decide between a risky and a safe gamble based on their chance of winning (high or low). In the 2-phase gambling task (similar to Cambridge gambling task), the chance and the gamble were presented at the same time (i.e. in a single phase), but in a new 3-phase gambling task, the chance is presented before the gamble. The tasks ended with a feedback phase. In the 3-phase task, holding the chance in memory to guide their decision enabled the participants to have more control on their risk taking behaviors as shown by activation in a network of brain areas involved in the control and conflict, including dorsal Anterior Cingulate Cortex (dACC), indexed by faster reaction times and better performance in the gambling task, and the temporal lobe, which has a role in holding contextual information. Holding information in memory to guide decision presumably enables the participants to have more control on their risk taking behaviors. The conflict and uncertainty resulting from this risky decision was indexed by the activation of dACC, known to be activated in conflict and cognitive control.

Conflicting Demands of Abstract and Specific Visual Object Processing Resolved by Fronto-Parietal Networks

PubMed Central

McMenamin, Brenton W.; Marsolek, Chad J.; Morseth, Brianna K.; Speer, MacKenzie F.; Burton, Philip C.; Burgund, E. Darcy

2016-01-01

Object categorization and exemplar identification place conflicting demands on the visual system, yet humans easily perform these fundamentally contradictory tasks. Previous studies suggest the existence of dissociable visual processing subsystems to accomplish the two abilities – an abstract category (AC) subsystem that operates effectively in the left hemisphere, and a specific exemplar (SE) subsystem that operates effectively in the right hemisphere. This multiple subsystems theory explains a range of visual abilities, but previous studies have not explored what mechanisms exist for coordinating the function of multiple subsystems and/or resolving the conflicts that would arise between them. We collected functional MRI data while participants performed two variants of a cue-probe working memory task that required AC or SE processing. During the maintenance phase of the task, the bilateral intraparietal sulcus (IPS) exhibited hemispheric asymmetries in functional connectivity consistent with exerting proactive control over the two visual subsystems: greater connectivity to the left hemisphere during the AC task, and greater connectivity to the right hemisphere during the SE task. Moreover, probe-evoked activation revealed activity in a broad fronto-parietal network (containing IPS) associated with reactive control when the two visual subsystems were in conflict, and variations in this conflict signal across trials was related to the visual similarity of the cue/probe stimulus pairs. Although many studies have confirmed the existence of multiple visual processing subsystems, this study is the first to identify the mechanisms responsible for coordinating their operations. PMID:26883940

Conflicting demands of abstract and specific visual object processing resolved by frontoparietal networks.

PubMed

McMenamin, Brenton W; Marsolek, Chad J; Morseth, Brianna K; Speer, MacKenzie F; Burton, Philip C; Burgund, E Darcy

2016-06-01

Object categorization and exemplar identification place conflicting demands on the visual system, yet humans easily perform these fundamentally contradictory tasks. Previous studies suggest the existence of dissociable visual processing subsystems to accomplish the two abilities-an abstract category (AC) subsystem that operates effectively in the left hemisphere and a specific exemplar (SE) subsystem that operates effectively in the right hemisphere. This multiple subsystems theory explains a range of visual abilities, but previous studies have not explored what mechanisms exist for coordinating the function of multiple subsystems and/or resolving the conflicts that would arise between them. We collected functional MRI data while participants performed two variants of a cue-probe working memory task that required AC or SE processing. During the maintenance phase of the task, the bilateral intraparietal sulcus (IPS) exhibited hemispheric asymmetries in functional connectivity consistent with exerting proactive control over the two visual subsystems: greater connectivity to the left hemisphere during the AC task, and greater connectivity to the right hemisphere during the SE task. Moreover, probe-evoked activation revealed activity in a broad frontoparietal network (containing IPS) associated with reactive control when the two visual subsystems were in conflict, and variations in this conflict signal across trials was related to the visual similarity of the cue-probe stimulus pairs. Although many studies have confirmed the existence of multiple visual processing subsystems, this study is the first to identify the mechanisms responsible for coordinating their operations.

Context, Not Conflict, Drives Cognitive Control

ERIC Educational Resources Information Center

Schlaghecken, Friederike; Martini, Paolo

2012-01-01

Theories of cognitive control generally assume that perceived conflict acts as a signal to engage inhibitory mechanisms that suppress subsequent conflicting information. Crucially, an absence of conflict is not regarded as being a relevant signal for cognitive control. Using a cueing, a priming, and a Simon task, we provide evidence that conflict…

Plasma Oscillation Characterization of NASA's HERMeS Hall Thruster via High Speed Imaging

NASA Technical Reports Server (NTRS)

Huang, Wensheng; Kamhawi, Hani; Haag, Thomas W.

2016-01-01

The performance and facility effect characterization tests of NASA's 12.5-kW Hall Effect Rocket with Magnetic Shielding had been completed. As a part of these tests, three plasma oscillation characterization studies were performed to help determine operation settings and quantify margins. The studies included the magnetic field strength variation study, background pressure effect study, and cathode flow fraction study. Separate high-speed videos of the thruster including the cathode and of only the cathode were recorded. Breathing mode at 10-15 kHz and cathode gradient-driven mode at 60-75 kHz were observed. An additional high frequency (40-70 kHz) global oscillation mode with sinusoidal probability distribution function was identified.

A case for conflict across multiple domains: Memory and language impairments following damage to ventrolateral prefrontal cortex

PubMed Central

Novick, Jared M.; Kan, Irene P.; Trueswell, John C.; Thompson-Schill, Sharon L.

2013-01-01

Patients with focal lesions to the left inferior frontal gyrus (LIFG; BA 44/45) exhibit difficulty with language production and comprehension tasks, although the nature of their impairments has been somewhat difficult to characterize. No reported cases suggest that these patients are Broca's aphasics in the classic agrammatic sense. Recent case studies, however, do reveal a consistent pattern of deficit regarding their general cognitive processes: They are reliably impaired on tasks in which conflicting representations must be resolved by implementing top-down cognitive control (e.g., Stroop; memory tasks involving proactive interference). In the present study, we ask whether the language production and comprehension impairments displayed by a patient with circumscribed LIFG damage can best be understood within a general conflict resolution deficit account. We focus on one patient in particular—patient I.G.—and discuss the implications for language processing abilities as a consequence of a general cognitive control disorder. We compared I.G. and other frontal patients to age-matched control participants across four experiments. Experiment 1 tested participants’ general conflict resolution abilities within a modified working memory paradigm in an attempt to replicate prior case study findings. We then tested language production abilities on tasks of picture naming (Experiment 2) and verbal fluency (Experiment 3), tasks that generated conflict at the semantic and/or conceptual levels. Experiment 4 tested participants’ sentence processing and comprehension abilities using both online (eye movement) and offline measures. In this task, participants carried out spoken instructions containing a syntactic ambiguity, in which early interpretation commitments had to be overridden in order to recover an alternative, intended analysis of sentence meaning. Comparisons of I.G.'s performance with frontal and healthy control participants supported the following claim: I.G. suffers from a general conflict resolution impairment, which affects his ability to produce and comprehend language under specific conditions—namely, when semantic, conceptual, and/or syntactic representations compete and must be resolved. PMID:20183014

New paradigm for task switching strategies while performing multiple tasks: entropy and symbolic dynamics analysis of voluntary patterns.

PubMed

Guastello, Stephen J; Gorin, Hillary; Huschen, Samuel; Peters, Natalie E; Fabisch, Megan; Poston, Kirsten

2012-10-01

It has become well established in laboratory experiments that switching tasks, perhaps due to interruptions at work, incur costs in response time to complete the next task. Conditions are also known that exaggerate or lessen the switching costs. Although switching costs can contribute to fatigue, task switching can also be an adaptive response to fatigue. The present study introduces a new research paradigm for studying the emergence of voluntary task switching regimes, self-organizing processes therein, and the possibly conflicting roles of switching costs and minimum entropy. Fifty-four undergraduates performed 7 different computer-based cognitive tasks producing sets of 49 responses under instructional conditions requiring task quotas or no quotas. The sequences of task choices were analyzed using orbital decomposition to extract pattern types and lengths, which were then classified and compared with regard to Shannon entropy, topological entropy, number of task switches involved, and overall performance. Results indicated that similar but different patterns were generated under the two instructional conditions, and better performance was associated with lower topological entropy. Both entropy metrics were associated with the amount of voluntary task switching. Future research should explore conditions affecting the trade-off between switching costs and entropy, levels of automaticity between task elements, and the role of voluntary switching regimes on fatigue.

A systematic review of resilience and mental health outcomes of conflict-driven adult forced migrants

PubMed Central

2014-01-01

Background The rising global burden of forced migration due to armed conflict is increasingly recognised as an important issue in global health. Forced migrants are at a greater risk of developing mental disorders. However, resilience, defined as the ability of a person to successfully adapt to or recover from stressful and traumatic experiences, has been highlighted as a key potential protective factor. This study aimed to review systematically the global literature on the impact of resilience on the mental health of adult conflict-driven forced migrants. Methodology Both quantitative and qualitative studies that reported resilience and mental health outcomes among forcibly displaced persons (aged 18+) by way of exploring associations, links, pathways and causative mechanisms were included. Fourteen bibliographic databases and seven humanitarian study databases/websites were searched and a four stage screening process was followed. Results Twenty three studies were included in the final review. Ten qualitative studies identified highlighted family and community cohesion, family and community support, individual personal qualities, collective identity, supportive primary relationships and religion. Thirteen quantitative studies were identified, but only two attempted to link resilience with mental disorders, and three used a specific resilience measure. Over-reliance on cross-sectional designs was noted. Resilience was generally shown to be associated with better mental health in displaced populations, but the evidence on this and underlying mechanisms was limited. Discussion The review highlights the need for more epidemiological and qualitative evidence on resilience in forcibly displaced persons as a potential avenue for intervention development, particularly in resource-poor settings. PMID:25177360

A problem with problem solving: motivational traits, but not cognition, predict success on novel operant foraging tasks.

PubMed

van Horik, Jayden O; Madden, Joah R

2016-04-01

Rates of innovative foraging behaviours and success on problem-solving tasks are often used to assay differences in cognition, both within and across species. Yet the cognitive features of some problem-solving tasks can be unclear. As such, explanations that attribute cognitive mechanisms to individual variation in problem-solving performance have revealed conflicting results. We investigated individual consistency in problem-solving performances in captive-reared pheasant chicks, Phasianus colchicus , and addressed whether success depends on cognitive processes, such as trial-and-error associative learning, or whether performances may be driven solely via noncognitive motivational mechanisms, revealed through subjects' willingness to approach, engage with and persist in their interactions with an apparatus, or via physiological traits such as body condition. While subjects' participation and success were consistent within the same problems and across similar tasks, their performances were inconsistent across different types of task. Moreover, subjects' latencies to approach each test apparatus and their attempts to access the reward were not repeatable across trials. Successful individuals did not improve their performances with experience, nor were they consistent in their techniques in repeated presentations of a task. However, individuals that were highly motivated to enter the experimental chamber were more likely to participate. Successful individuals were also faster to approach each test apparatus and more persistent in their attempts to solve the tasks than unsuccessful individuals. Our findings therefore suggest that individual differences in problem-solving success can arise from inherent motivational differences alone and hence be achieved without inferring more complex cognitive processes.

A problem with problem solving: motivational traits, but not cognition, predict success on novel operant foraging tasks

PubMed Central

van Horik, Jayden O.; Madden, Joah R.

2016-01-01

Rates of innovative foraging behaviours and success on problem-solving tasks are often used to assay differences in cognition, both within and across species. Yet the cognitive features of some problem-solving tasks can be unclear. As such, explanations that attribute cognitive mechanisms to individual variation in problem-solving performance have revealed conflicting results. We investigated individual consistency in problem-solving performances in captive-reared pheasant chicks, Phasianus colchicus, and addressed whether success depends on cognitive processes, such as trial-and-error associative learning, or whether performances may be driven solely via noncognitive motivational mechanisms, revealed through subjects' willingness to approach, engage with and persist in their interactions with an apparatus, or via physiological traits such as body condition. While subjects' participation and success were consistent within the same problems and across similar tasks, their performances were inconsistent across different types of task. Moreover, subjects' latencies to approach each test apparatus and their attempts to access the reward were not repeatable across trials. Successful individuals did not improve their performances with experience, nor were they consistent in their techniques in repeated presentations of a task. However, individuals that were highly motivated to enter the experimental chamber were more likely to participate. Successful individuals were also faster to approach each test apparatus and more persistent in their attempts to solve the tasks than unsuccessful individuals. Our findings therefore suggest that individual differences in problem-solving success can arise from inherent motivational differences alone and hence be achieved without inferring more complex cognitive processes. PMID:27122637

Experimental Studies of Intent Information on Cockpit Traffic Displays

NASA Technical Reports Server (NTRS)

Barhydt, Richard; Hansman, R. John, Jr.

1997-01-01

Intent information provides knowledge of another aircraft's current and future trajectory states. Prototype traffic displays were designed for four different levels of intent: No Intent, Rate, Commanded State, and Flight Management System (FMS)-Path. The TCAS Display was used as a baseline and represents the No Intent Level. The Rate, Commanded State, and FMS-Path Displays show increasing levels of intent information using TCAS-like symbology in addition to incorporating a conflict probe and profile view display. An experiment was run on the MIT Part Task Flight Simulator in which eight airline pilots flew five traffic scenarios with each of the four displays. Results show that pilots had fewer separation violations and maneuvered earlier with the three intent displays. Separation violations were reduced when pilots maneuvered earlier. A second experiment was run to compare performance between displaying intent information directly and incorporating it into a conflict probe. A different set of eight airline pilots flew four traffic scenarios with the TCAS and Commanded State Displays with and without the conflict probe. Conflict probes with two minute and long range look-ahead times were tested. Displaying conflict bands or showing intent information directly both led to fewer separation violations and earlier avoidance maneuvers than the base TCAS Display. Performance was similar between the two minute and long range look-ahead conflict probes. Pilots preferred all intent displays over the TCAS Display.

Arc Deflection Length Affected by Transverse Rotating Magnetic Field with Lateral Gas

NASA Astrophysics Data System (ADS)

Shiino, Toru; Ishii, Yoko; Yamamoto, Shinji; Iwao, Toru; High Current Energy Laboratory (HiCEL) Team

2016-10-01

Gas metal arc welding using shielding gas is often used in the welding industry. However, the arc deflection affected by lateral gas is problem because of inappropriate heat transfer. Shielding gas is used in order to prevent the instability affected by the arc deflection. However, the shielding gas causes turbulence, then blowhole of weld defect occurs because the arc affected by the instability is contaminated by the air. Thus, the magnetic field is applied to the arc in order to stabilize the arc using low amount of shielding gas. The method of applying the transverse rotating magnetic field (RMF) to the arc is one of the methods to prevent the arc instability. The RMF drives the arc because of electromagnetic force. The driven arc is considered to be prevented to arc deflection of lateral gas because the arc is restrained by the magnetic field because of the driven arc. In addition, it is assume the RMF prevented to the arc deflection of lateral gas from the multiple directions. In this paper, the arc deflection length affected by the RMF with lateral gas was elucidated in order to know the effect of the RMF for arc stabilization. Specifically, the arc deflection length affected by the magnetic frequency and the magnetic flux density is measured by high speed video camera. As a result, the arc deflection length decreases with increasing magnetic frequency, and the arc deflection length increases with increasing the magnetic flux density.

In conflict with ourselves? An investigation of heuristic and analytic processes in decision making.

PubMed

Bonner, Carissa; Newell, Ben R

2010-03-01

Many theorists propose two types of processing: heuristic and analytic. In conflict tasks, in which these processing types lead to opposing responses, giving the analytic response may require both detection and resolution of the conflict. The ratio bias task, in which people tend to treat larger numbered ratios (e.g., 20/100) as indicating a higher likelihood of winning than do equivalent smaller numbered ratios (e.g., 2/10), is considered to induce such a conflict. Experiment 1 showed response time differences associated with conflict detection, resolution, and the amount of conflict induced. The conflict detection and resolution effects were replicated in Experiment 2 and were not affected by decreasing the influence of the heuristic response or decreasing the capacity to make the analytic response. The results are consistent with dual-process accounts, but a single-process account in which quantitative, rather than qualitative, differences in processing are assumed fares equally well in explaining the data.

Parenting style, parent-youth conflict, and medication adherence in youth with type 2 diabetes participating in an intensive lifestyle change intervention.

PubMed

Saletsky, Ronald D; Trief, Paula M; Anderson, Barbara J; Rosenbaum, Paula; Weinstock, Ruth S

2014-06-01

Parenting behaviors and family conflict relate to type 1 diabetes outcomes in youth. Our purpose was to understand these relationships in parents and youth with type 2 diabetes (T2DM). The TODAY (Treatment Options for Type 2 Diabetes in Adolescents and Youth) trial enrolled youth (10-17 years) with T2DM and parent/guardian. For this ancillary study, we enrolled a sample of youth-parent pairs (N = 137) in 1 study arm (metformin plus lifestyle intervention). They completed questionnaires measuring parenting style related to normative (e.g., completing homework) and diabetes self-care (e.g., testing blood glucose) tasks, and parent-youth verbal conflict (baseline, 6, and 12 months). Parenting style was consistent across normative and diabetes tasks, with gradual increases in autonomy perceived by youth. Conversations were generally calm, with greater conflict regarding normative than diabetes tasks at baseline (youth: p < .001, parent: p = .01), 6 months (youth: p = .02, parent: p > .05), and 12 months (youth: p > .05., parent: p = .05). A permissive parenting style toward normative tasks and a less authoritarian style toward diabetes tasks, at baseline, predicted better medication adherence (8-12 months) (normative: adjusted R2 = 0.48, p < .001; diabetes: adjusted R2 = 0.47, p < .001). Parent-youth conflict did not predict medication adherence. Youth with T2DM who perceive more autonomy (less parental control) in day-to-day and diabetes tasks are more likely to adhere to medication regimens. It may be valuable to assess youth perceptions of parenting style and help parents understand youths' needs for autonomy.

Incorporating Target Priorities in the Sensor Tasking Reward Function

NASA Astrophysics Data System (ADS)

Gehly, S.; Bennett, J.

2016-09-01

Orbital debris tracking poses many challenges, most fundamentally the need to track a large number of objects from a limited number of sensors. The use of information theoretic sensor allocation provides a means to efficiently collect data on the multitarget system. An additional need of the community is the ability to specify target priorities, driven both by user needs and environmental factors such as collision warnings. This research develops a method to incorporate target priorities in the sensor tasking reward function, allowing for several applications in different tasking modes such as catalog maintenance, calibration, and collision monitoring. A set of numerical studies is included to demonstrate the functionality of the method.

Bilateral stimulation of the subthalamic nucleus has differential effects on reactive and proactive inhibition and conflict-induced slowing in Parkinson's disease.

PubMed

Obeso, Ignacio; Wilkinson, Leonora; Rodríguez-Oroz, Maria-Cruz; Obeso, Jose A; Jahanshahi, Marjan

2013-05-01

It has been proposed that the subthalamic nucleus (STN) mediates response inhibition and conflict resolution through the fronto-basal ganglia pathways. Our aim was to compare the effects of deep brain stimulation (DBS) of the STN on reactive and proactive inhibition and conflict resolution in Parkinson's disease using a single task. We used the conditional Stop signal reaction time task that provides the Stop signal reaction time (SSRT) as a measure of reactive inhibition, the response delay effect (RDE) as a measure of proactive inhibition and conflict-induced slowing (CIS) as a measure of conflict resolution. DBS of the STN significantly prolonged SSRT relative to stimulation off. However, while the RDE measure of proactive inhibition was not significantly altered by DBS of the STN, relative to healthy controls, RDE was significantly lower with DBS off but not DBS on. DBS of the STN did not alter the mean CIS but produced a significant differential effect on the slowest and fastest RTs on conflict trials, further prolonging the slowest RTs on the conflict trials relative to DBS off and to controls. These results are the first demonstration, using a single task in the same patient sample, that DBS of the STN produces differential effects on reactive and proactive inhibition and on conflict resolution, suggesting that these effects are likely to be mediated through the impact of STN stimulation on different fronto-basal ganglia pathways: hyperdirect, direct and indirect.

Does incongruence of lexicosemantic and prosodic information cause discernible cognitive conflict?

PubMed

Mitchell, Rachel L C

2006-12-01

We are often required to interpret discordant emotional signals. Whereas equivalent cognitive paradigms cause noticeable conflict via their behavioral and psychophysiological effects, the same may not necessarily be true for discordant emotions. Skin conductance responses (SCRs) and heart rates (HRs) were measured during a classic Stroop task and one in which the emotions conveyed by lexicosemantic content and prosody were congruent or incongruent. The participants' task was to identify the emotion conveyed by lexicosemantic content or prosody. No relationship was observed between HR and congruence. SCR was higher during incongruent than during congruent conditions of the experimental task (as well as in the classic Stroop task), but no difference in SCR was observed in a comparison between congruence effects during lexicosemantic emotion identification and those during prosodic emotion identification. It is concluded that incongruence between lexicosemantic and prosodic emotion does cause notable cognitive conflict. Functional neuroanatomic implications are discussed.

Cognitive rigidity in unipolar depression and obsessive compulsive disorder: examination of task switching, Stroop, working memory updating and post-conflict adaptation.

PubMed

Meiran, Nachshon; Diamond, Gary M; Toder, Doron; Nemets, Boris

2011-01-30

Obsessive compulsive disorder (OCD) and depressive rumination are both characterized by cognitive rigidity. We examined the performance of 17 patients (9 suffering from unipolar depression [UD] without OCD, and 8 suffering from OCD without UD), and 17 control participants matched on age, gender, language and education, on a battery covering the four main executive functions. Results indicated that, across both disorders, patients required more trials to adjust to single-task conditions after experiencing task switching, reflecting slow disengagement from switching mode, and showed abnormal post-conflict adaptation of processing mode following high conflict Stroop trials in comparison to controls. Rumination, which was elevated in UD and not in OCD, was associated with poor working memory updating and less task preparation. The results show that OCD and UD are associated with similar cognitive rigidity in the presently tested paradigms. Copyright © 2010 Elsevier Ltd. All rights reserved.

Compositions of micas in peraluminous granitoids of the eastern Arabian shield - Implications for petrogenesis and tectonic setting of highly evolved, rare-metal enriched granites

USGS Publications Warehouse

du Bray, E.A.

1994-01-01

Compositions and pleochroism of micas in fourteen peraluminous alkali-feldspar granites in the eastern part of the Late Proterozoic Arabian Shield are unlike those of micas (principally biotite) in most calc-alkaline granitoid rocks. Compositions of these micas are distinguished by elevated abundances of Li2O, F, and numerous cations and by low MgO abundances. These micas, constituents of highly evolved rare-metal enriched granitoids, represent an iron-lithium substitution series that ranges from lithium-poor siderophyllite to lithium-rich ferroan lepidolite. The eastern Arabian Shield also hosts six epizonal granitoids that contain colorless micas. Compositions of these micas, mostly muscovite, and their host granitoids are distinct from those of the iron-lithium micas and their host granitoids. Compositions of the analyzed micas have a number of petrogenetic implications. The twenty granitoids containing these micas form three compositional groups that reflect genesis in particular tectonic regimes; mica compositions define the same three groups. The presence of magmatic muscovite in six of these shallowly crystallized granitoids conflicts with experimental data indicating muscovite stability at pressures greater than 3 kbar. Muscovite in the Arabian granitoids probably results from its non-ideal composition; the presence of muscovite cannot be used as a pressure indicator. Finally, mineral/matrix partition coefficients are significantly greater than 1.0 for a number of cations, the rare-earth elements in particular, in many of the analyzed iron-lithium micas. Involvement of these types of micas in partial melting or fractionation processes can have a major influence on silicate liquid compositions. ?? 1994 Springer-Verlag.

Between- and within-Ear Congruency and Laterality Effects in an Auditory Semantic/Emotional Prosody Conflict Task

ERIC Educational Resources Information Center

Techentin, Cheryl; Voyer, Daniel; Klein, Raymond M.

2009-01-01

The present study investigated the influence of within- and between-ear congruency on interference and laterality effects in an auditory semantic/prosodic conflict task. Participants were presented dichotically with words (e.g., mad, sad, glad) pronounced in either congruent or incongruent emotional tones (e.g., angry, happy, or sad) and…

Patterns of Conflict Interaction in Mother-Toddler Dyads: Differences between Depressed and Non-Depressed Mothers

ERIC Educational Resources Information Center

Caughy, Margaret O'Brien; Huang, Keng-Yen; Lima, Julie

2009-01-01

We examined the differences in conflict interaction between depressed mothers and their toddler and non-depressed dyads and whether these differences mediated the association of maternal depression with compromised child socioemotional development. Mother/child interaction was videotaped during a teaching task and during a free play task as part…

The adolescent parent: A dual developmental crisis.

PubMed

Sadler, L S; Catrone, C

1983-06-01

This paper examines salient developmental characteristics of adolescents and beginning parents. In the case of many teenage parents, specific developmental tasks of adolescence affect and may potentially conflict with the tasks of early parenthood. A conceptual framework is presented which describes this conflict and serves as the basis for examining and explaining certain unique behaviors observed in young adolescent parents.

Anterior cingulate cortex activity can be independent of response conflict in Stroop-like tasks.

PubMed

Roelofs, Ardi; van Turennout, Miranda; Coles, Michael G H

2006-09-12

Cognitive control includes the ability to formulate goals and plans of action and to follow these while facing distraction. Previous neuroimaging studies have shown that the presence of conflicting response alternatives in Stroop-like tasks increases activity in dorsal anterior cingulate cortex (ACC), suggesting that the ACC is involved in cognitive control. However, the exact nature of ACC function is still under debate. The prevailing conflict detection hypothesis maintains that the ACC is involved in performance monitoring. According to this view, ACC activity reflects the detection of response conflict and acts as a signal that engages regulative processes subserved by lateral prefrontal brain regions. Here, we provide evidence from functional MRI that challenges this view and favors an alternative view, according to which the ACC has a role in regulation itself. Using an arrow-word Stroop task, subjects responded to incongruent, congruent, and neutral stimuli. A critical prediction made by the conflict detection hypothesis is that ACC activity should be increased only when conflicting response alternatives are present. Our data show that ACC responses are larger for neutral than for congruent stimuli, in the absence of response conflict. This result demonstrates the engagement of the ACC in regulation itself. A computational model of Stroop-like performance instantiating a version of the regulative hypothesis is shown to account for our findings.

Adaptation in conflict: are conflict-triggered control adjustments protected in the presence of motivational distractors?

PubMed

Becker, Daniela; Jostmann, Nils B; Holland, Rob W

2018-06-06

Solving a conflict between two response options in an interference task has been found to increase control in a subsequent conflict situation. The present research examined whether such conflict adaptation persists in the presence of distractors that have motivational relevance and are therefore competing for attentional resources (i.e. they signal opportunities for monetary gains or losses contingent on overall task performance). In an adjusted flanker task, motivational (versus neutral versus no) distractors were presented together with the current trial while the previous trial never included any distractor. Accumulated evidence across three studies showed that motivational distractors reduced the conflict adaptation effect. This was found irrespective of the location at which the distractor occurred (Study 1), and independent of its valence (i.e. reward or loss, Study 2). Study 3 and a merged data analysis ruled out low-level alternative explanations. In line with a dual competition account (Pessoa, L. (2009). How do emotion and motivation direct executive control? Trends in Cognitive Sciences, 13(4), 160-166. doi: 10.1016/j.tics.2009.01.006 ), our results show that conflict adaptation is not fully protected in the presence of motivational distractors. We discuss whether this should be interpreted as a limitation, or as reflecting the flexibility of the control system in dealing with motivationally relevant information.

Source credibility and idea improvement have independent effects on unconscious plagiarism errors in recall and generate-new tasks.

PubMed

Perfect, Timothy J; Field, Ian; Jones, Robert

2009-01-01

Unconscious plagiarism occurs when people try to generate new ideas or when they try to recall their own ideas from among a set generated by a group. In this study, the factors that independently influence these two forms of plagiarism error were examined. Participants initially generated solutions to real-world problems in 2 domains of knowledge in collaboration with a confederate presented as an expert in 1 domain. Subsequently, the participant generated improvements to half of the ideas from each person. Participants returned 1 day later to recall either their own ideas or their partner's ideas and to complete a generate-new task. A double dissociation was observed. Generate-new plagiarism was driven by partner expertise but not by idea improvement, whereas recall plagiarism was driven by improvement but not expertise. This improvement effect on recall plagiarism was seen for the recall-own but not the recall-partner task, suggesting that the increase in recall-own plagiarism is due to mistaken idea ownership, not source confusion.

Parametric effects of syntactic-semantic conflict in Broca's area during sentence processing.

PubMed

Thothathiri, Malathi; Kim, Albert; Trueswell, John C; Thompson-Schill, Sharon L

2012-03-01

The hypothesized role of Broca's area in sentence processing ranges from domain-general executive function to domain-specific computation that is specific to certain syntactic structures. We examined this issue by manipulating syntactic structure and conflict between syntactic and semantic cues in a sentence processing task. Functional neuroimaging revealed that activation within several Broca's area regions of interest reflected the parametric variation in syntactic-semantic conflict. These results suggest that Broca's area supports sentence processing by mediating between multiple incompatible constraints on sentence interpretation, consistent with this area's well-known role in conflict resolution in other linguistic and non-linguistic tasks. Copyright © 2011 Elsevier Inc. All rights reserved.

Conflict Management Strategies in the ICU Differ Between Palliative Care Specialists and Intensivists.

PubMed

Chiarchiaro, Jared; White, Douglas B; Ernecoff, Natalie C; Buddadhumaruk, Praewpannarai; Schuster, Rachel A; Arnold, Robert M

2016-05-01

Conflict is common between physicians and surrogate decision makers around end-of-life care in ICU. Involving experts in conflict management improve outcomes, but little is known about what differences in conflict management styles may explain the benefit. We used simulation to examine potential differences in how palliative care specialists manage conflict with surrogates about end-of-life treatment decisions in ICUs compared with intensivists. Subjects participated in a high-fidelity simulation of conflict with a surrogate in an ICU. In this simulation, a medical actor portrayed a surrogate decision maker during an ICU family meeting who refuses to follow an advance directive that clearly declines advanced life-sustaining therapies. We audiorecorded the simulation encounters and applied a coding framework to quantify conflict management behaviors, which was organized into two categories: task-focused communication and relationship building. We used negative binomial modeling to determine whether there were differences between palliative care specialists' and intensivists' use of task-focused communication and relationship building. Single academic medical center ICU. Palliative care specialists and intensivists. None. We enrolled 11 palliative care specialists and 25 intensivists. The palliative care specialists were all attending physicians. The intensivist group consisted of 11 attending physicians, 9 pulmonary and critical care fellows, and 5 internal medicine residents rotating in the ICU. We excluded five residents from the primary analysis in order to reduce confounding due to training level. Physicians' mean age was 37 years with a mean of 8 years in practice. Palliative care specialists used 55% fewer task-focused communication statements (incidence rate ratio, 0.55; 95% CI, 0.36-0.83; p = 0.005) and 48% more relationship-building statements (incidence rate ratio, 1.48; 95% CI, 0.89-2.46; p = 0.13) compared with intensivists. We found that palliative care specialists engage in less task-focused communication when managing conflict with surrogates compared with intensivists. These differences may help explain the benefit of palliative care involvement in conflict and could be the focus of interventions to improve clinicians' conflict resolution skills.

Managing Conflict with Peers. An Ideas Into Action Guidebook.

ERIC Educational Resources Information Center

Cartwright, Talula

This short publication provides a process for managing conflict among managerial peers. It focuses more on conflicts among managers that involve personal values, office politics, power struggles, and emotional reactions than on conflicts that arise from incompatible goals or from different views on how to accomplish a task. The process described…

EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing.

PubMed

Cohen, Michael X; Ridderinkhof, K Richard

2013-01-01

Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus) conflict modulation in stimulus-contralateral parietal gamma (30-50 Hz), followed by a later alpha-band (8-12 Hz) conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4-8 Hz), alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials) had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions.

Involvement of Spearman's g in conceptualisation versus execution of complex tasks.

PubMed

Carroll, Ellen L; Bright, Peter

2016-10-01

Strong correlations between measures of fluid intelligence (or Spearman's g) and working memory are widely reported in the literature, but there is considerable controversy concerning the nature of underlying mechanisms driving this relationship. In the four experiments presented here we consider the role of response conflict and task complexity in the context of real-time task execution demands (Experiments 1-3) and also address recent evidence that g confers an advantage at the level of task conceptualisation rather than (or in addition to) task execution (Experiment 4). We observed increased sensitivity of measured fluid intelligence to task performance in the presence (vs. the absence) of response conflict, and this relationship remained when task complexity was reduced. Performance-g correlations were also observed in the absence of response conflict, but only in the context of high task complexity. Further, we present evidence that differences in conceptualisation or 'modelling' of task instructions prior to execution had an important mediating effect on observed correlations, but only when the task encompassed a strong element of response inhibition. Our results suggest that individual differences in ability reflect, in large part, variability in the efficiency with which the relational complexity of task constraints are held in mind. It follows that fluid intelligence may support successful task execution through the construction of effective action plans via optimal allocation of limited resources. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Real-time value-driven diagnosis

NASA Technical Reports Server (NTRS)

Dambrosio, Bruce

1995-01-01

Diagnosis is often thought of as an isolated task in theoretical reasoning (reasoning with the goal of updating our beliefs about the world). We present a decision-theoretic interpretation of diagnosis as a task in practical reasoning (reasoning with the goal of acting in the world), and sketch components of our approach to this task. These components include an abstract problem description, a decision-theoretic model of the basic task, a set of inference methods suitable for evaluating the decision representation in real-time, and a control architecture to provide the needed continuing coordination between the agent and its environment. A principal contribution of this work is the representation and inference methods we have developed, which extend previously available probabilistic inference methods and narrow, somewhat, the gap between probabilistic and logical models of diagnosis.

Northeast Artificial Intelligence Consortium Annual Report for 1987. Volume 5. Building an Intelligent Assistant: The Acquisition, Integration, and Maintenance of Complex Distributed Tasks

DTIC Science & Technology

1989-03-01

resolved through global or local (associated with specific nodes) conflict resolution strategies.$ One solution is to order the arcs in the set... according to their specificity and to execute the first triggered arc. In this way, the most specific subsuming situation will be preferred over other...priority; another says that random questions should be discouraged. In such a case a non-conventional resolution mechanism must be used to resolve the

Asymetrically driven implosion experiment on the Laser MégaJoule

NASA Astrophysics Data System (ADS)

Philippe, Franck; Seytor, Patricia; Tassin, Veronique; Rosch, Rudolf; Villette, Bruno

2017-10-01

We report on the results of the first implosion experiments performed on the Laser MégaJoule (LMJ) facility. Their main purpose was to study implosion with large polar asymmetries of incident radiative flux on a capsule, while preserving azimuthal symmetry, in the context of ICF. In these experiments, one quad of LMJ is focused axially on a gold shield inside a hohlraum. The shield effectively divides the hohlraum in two compartments, and a capsule placed in the second compartment is indirectly driven by the x-ray flux generated in the first one. The subsequent asymmetric implosion is backlit by an x-ray source generated by another quad of LMJ and imaged with an x-ray microscope coupled to a framing camera. Time-gated x-ray radiographs of the imploding capsule and diode array measurements of the hohlraum x-ray emission are found to be in good agreement with FCI2 radiative hydrodynamics simulations.

Emotion speeds up conflict resolution: a new role for the ventral anterior cingulate cortex?

PubMed

Kanske, Philipp; Kotz, Sonja A

2011-04-01

It has been hypothesized that processing of conflict is facilitated by emotion. Emotional stimuli signal significance in a situation. Thus, when an emotional stimulus is task relevant, more resources may be devoted to conflict processing to reduce the time that an organism is unable to act. In the present electroencephalography and functional magnetic resonance imaging (fMRI) studies, we employed a conflict task and manipulated the emotional content and prosody of auditory target stimuli. In line with our hypothesis, reaction times revealed faster conflict resolution for emotional stimuli. Early stages of event-related potential conflict processing were modulated by emotion as indexed in an enhanced frontocentral negativity at 420 ms. FMRI yielded conflict activation in the dorsal anterior cingulate cortex (dACC), a crucial part of the executive control network. The right ventral ACC (vACC) was activated for conflict processing in emotional stimuli, suggesting that it is additionally activated for conflict processing in emotional stimuli. The amygdala was also activated by emotion. Furthermore, emotion increased functional connectivity between the vACC and activity in the amygdala and the dACC. The results support the hypothesis that emotion speeds up conflict processing and suggest a new role for the vACC in processing conflict in particularly significant situations signaled by emotion.

Air traffic surveillance and control using hybrid estimation and protocol-based conflict resolution

NASA Astrophysics Data System (ADS)

Hwang, Inseok

The continued growth of air travel and recent advances in new technologies for navigation, surveillance, and communication have led to proposals by the Federal Aviation Administration (FAA) to provide reliable and efficient tools to aid Air Traffic Control (ATC) in performing their tasks. In this dissertation, we address four problems frequently encountered in air traffic surveillance and control; multiple target tracking and identity management, conflict detection, conflict resolution, and safety verification. We develop a set of algorithms and tools to aid ATC; These algorithms have the provable properties of safety, computational efficiency, and convergence. Firstly, we develop a multiple-maneuvering-target tracking and identity management algorithm which can keep track of maneuvering aircraft in noisy environments and of their identities. Secondly, we propose a hybrid probabilistic conflict detection algorithm between multiple aircraft which uses flight mode estimates as well as aircraft current state estimates. Our algorithm is based on hybrid models of aircraft, which incorporate both continuous dynamics and discrete mode switching. Thirdly, we develop an algorithm for multiple (greater than two) aircraft conflict avoidance that is based on a closed-form analytic solution and thus provides guarantees of safety. Finally, we consider the problem of safety verification of control laws for safety critical systems, with application to air traffic control systems. We approach safety verification through reachability analysis, which is a computationally expensive problem. We develop an over-approximate method for reachable set computation using polytopic approximation methods and dynamic optimization. These algorithms may be used either in a fully autonomous way, or as supporting tools to increase controllers' situational awareness and to reduce their work load.

An Efficient Soft Set-Based Approach for Conflict Analysis

PubMed Central

Sutoyo, Edi; Mungad, Mungad; Hamid, Suraya; Herawan, Tutut

2016-01-01

Conflict analysis has been used as an important tool in economic, business, governmental and political dispute, games, management negotiations, military operations and etc. There are many mathematical formal models have been proposed to handle conflict situations and one of the most popular is rough set theory. With the ability to handle vagueness from the conflict data set, rough set theory has been successfully used. However, computational time is still an issue when determining the certainty, coverage, and strength of conflict situations. In this paper, we present an alternative approach to handle conflict situations, based on some ideas using soft set theory. The novelty of the proposed approach is that, unlike in rough set theory that uses decision rules, it is based on the concept of co-occurrence of parameters in soft set theory. We illustrate the proposed approach by means of a tutorial example of voting analysis in conflict situations. Furthermore, we elaborate the proposed approach on real world dataset of political conflict in Indonesian Parliament. We show that, the proposed approach achieves lower computational time as compared to rough set theory of up to 3.9%. PMID:26928627

An Efficient Soft Set-Based Approach for Conflict Analysis.

PubMed

Sutoyo, Edi; Mungad, Mungad; Hamid, Suraya; Herawan, Tutut

2016-01-01

Conflict analysis has been used as an important tool in economic, business, governmental and political dispute, games, management negotiations, military operations and etc. There are many mathematical formal models have been proposed to handle conflict situations and one of the most popular is rough set theory. With the ability to handle vagueness from the conflict data set, rough set theory has been successfully used. However, computational time is still an issue when determining the certainty, coverage, and strength of conflict situations. In this paper, we present an alternative approach to handle conflict situations, based on some ideas using soft set theory. The novelty of the proposed approach is that, unlike in rough set theory that uses decision rules, it is based on the concept of co-occurrence of parameters in soft set theory. We illustrate the proposed approach by means of a tutorial example of voting analysis in conflict situations. Furthermore, we elaborate the proposed approach on real world dataset of political conflict in Indonesian Parliament. We show that, the proposed approach achieves lower computational time as compared to rough set theory of up to 3.9%.

The effects of methylphenidate on cerebral responses to conflict anticipation and unsigned prediction error in a stop-signal task.

PubMed

Manza, Peter; Hu, Sien; Ide, Jaime S; Farr, Olivia M; Zhang, Sheng; Leung, Hoi-Chung; Li, Chiang-shan R

2016-03-01

To adapt flexibly to a rapidly changing environment, humans must anticipate conflict and respond to surprising, unexpected events. To this end, the brain estimates upcoming conflict on the basis of prior experience and computes unsigned prediction error (UPE). Although much work implicates catecholamines in cognitive control, little is known about how pharmacological manipulation of catecholamines affects the neural processes underlying conflict anticipation and UPE computation. We addressed this issue by imaging 24 healthy young adults who received a 45 mg oral dose of methylphenidate (MPH) and 62 matched controls who did not receive MPH prior to performing the stop-signal task. We used a Bayesian Dynamic Belief Model to make trial-by-trial estimates of conflict and UPE during task performance. Replicating previous research, the control group showed anticipation-related activation in the presupplementary motor area and deactivation in the ventromedial prefrontal cortex and parahippocampal gyrus, as well as UPE-related activations in the dorsal anterior cingulate, insula, and inferior parietal lobule. In group comparison, MPH increased anticipation activity in the bilateral caudate head and decreased UPE activity in each of the aforementioned regions. These findings highlight distinct effects of catecholamines on the neural mechanisms underlying conflict anticipation and UPE, signals critical to learning and adaptive behavior. © The Author(s) 2016.

The effects of methylphenidate on cerebral responses to conflict anticipation and unsigned prediction error in a stop-signal task

PubMed Central

Manza, Peter; Hu, Sien; Ide, Jaime S; Farr, Olivia M; Zhang, Sheng; Leung, Hoi-Chung; Li, Chiang-shan R

2016-01-01

To adapt flexibly to a rapidly changing environment, humans must anticipate conflict and respond to surprising, unexpected events. To this end, the brain estimates upcoming conflict on the basis of prior experience and computes unsigned prediction error (UPE). Although much work implicates catecholamines in cognitive control, little is known about how pharmacological manipulation of catecholamines affects the neural processes underlying conflict anticipation and UPE computation. We addressed this issue by imaging 24 healthy young adults who received a 45 mg oral dose of methylphenidate (MPH) and 62 matched controls who did not receive MPH prior to performing the stop-signal task. We used a Bayesian Dynamic Belief Model to make trial-by-trial estimates of conflict and UPE during task performance. Replicating previous research, the control group showed anticipation-related activation in the presupplementary motor area and deactivation in the ventromedial prefrontal cortex and parahippocampal gyrus, as well as UPE-related activations in the dorsal anterior cingulate, insula, and inferior parietal lobule. In group comparison, MPH increased anticipation activity in the bilateral caudate head and decreased UPE activity in each of the aforementioned regions. These findings highlight distinct effects of catecholamines on the neural mechanisms underlying conflict anticipation and UPE, signals critical to learning and adaptive behavior. PMID:26755547

The role of the anterior cingulate cortex in the affective evaluation of conflict

PubMed Central

Braem, Senne; King, Joseph A.; Korb, Franziska M.; Krebs, Ruth M.; Notebaert, Wim; Egner, Tobias

2017-01-01

An influential theory of anterior cingulate cortex (ACC) function argues that this brain region plays a crucial role in the affective evaluation of performance monitoring and control demands. Specifically, control-demanding processes such as response conflict, are thought to be registered as aversive signals by the ACC, which in turn triggers processing adjustments to support avoidance-learning. In support of conflict being treated as an aversive event, recent behavioural studies demonstrated that incongruent (i.e., conflict-inducing) relative to congruent stimuli can speed up subsequent negative relative to positive affective picture processing. Here, we used functional magnetic resonance imaging (fMRI) to investigate directly whether ACC activity in response to negative versus positive pictures is modulated by preceding control demands, consisting of conflict and task-switching conditions. The results show that negative relative to positive pictures elicited higher ACC activation following congruent relative to incongruent trials, suggesting that the ACC’s response to negative (positive) pictures was indeed affectively primed by incongruent (congruent) trials. Interestingly, this pattern of results was observed on task repetitions, but disappeared on task alternations. Our findings support the proposal that conflict induces negative affect, and are the first to show that this affective signal is reflected in ACC activation. PMID:27575278

Task-driven imaging in cone-beam computed tomography.

PubMed

Gang, G J; Stayman, J W; Ouadah, S; Ehtiati, T; Siewerdsen, J H

Conventional workflow in interventional imaging often ignores a wealth of prior information of the patient anatomy and the imaging task. This work introduces a task-driven imaging framework that utilizes such information to prospectively design acquisition and reconstruction techniques for cone-beam CT (CBCT) in a manner that maximizes task-based performance in subsequent imaging procedures. The framework is employed in jointly optimizing tube current modulation, orbital tilt, and reconstruction parameters in filtered backprojection reconstruction for interventional imaging. Theoretical predictors of noise and resolution relates acquisition and reconstruction parameters to task-based detectability. Given a patient-specific prior image and specification of the imaging task, an optimization algorithm prospectively identifies the combination of imaging parameters that maximizes task-based detectability. Initial investigations were performed for a variety of imaging tasks in an elliptical phantom and an anthropomorphic head phantom. Optimization of tube current modulation and view-dependent reconstruction kernel was shown to have greatest benefits for a directional task (e.g., identification of device or tissue orientation). The task-driven approach yielded techniques in which the dose and sharp kernels were concentrated in views contributing the most to the signal power associated with the imaging task. For example, detectability of a line pair detection task was improved by at least three fold compared to conventional approaches. For radially symmetric tasks, the task-driven strategy yielded results similar to a minimum variance strategy in the absence of kernel modulation. Optimization of the orbital tilt successfully avoided highly attenuating structures that can confound the imaging task by introducing noise correlations masquerading at spatial frequencies of interest. This work demonstrated the potential of a task-driven imaging framework to improve image quality and reduce dose beyond that achievable with conventional imaging approaches.

Jet Noise Shielding Provided by a Hybrid Wing Body Aircraft

NASA Technical Reports Server (NTRS)

Doty, Michael J.; Brooks, Thomas F.; Burley, Casey L.; Bahr, Christopher J.; Pope, Dennis S.

2014-01-01

One approach toward achieving NASA's aggressive N+2 noise goal of 42 EPNdB cumulative margin below Stage 4 is through the use of novel vehicle configurations like the Hybrid Wing Body (HWB). Jet noise measurements from an HWB acoustic test in NASA Langley's 14- by 22-Foot Subsonic Tunnel are described. Two dual-stream, heated Compact Jet Engine Simulator (CJES) units are mounted underneath the inverted HWB model on a traversable support to permit measurement of varying levels of shielding provided by the fuselage. Both an axisymmetric and low noise chevron nozzle set are investigated in the context of shielding. The unshielded chevron nozzle set shows 1 to 2 dB of source noise reduction (relative to the unshielded axisymmetric nozzle set) with some penalties at higher frequencies. Shielding of the axisymmetric nozzles shows up to 6.5 dB of reduction at high frequency. The combination of shielding and low noise chevrons shows benefits beyond the expected additive benefits of the two, up to 10 dB, due to the effective migration of the jet source peak noise location upstream for increased shielding effectiveness. Jet noise source maps from phased array results processed with the Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) algorithm reinforce these observations.

Attenuation of acute d-amphetamine-induced disruption of conflict resolution by clozapine, but not α-flupenthixol in rats.

PubMed

Reichelt, Amy C; Good, Mark A; Killcross, Simon

2013-11-01

Previous research demonstrates that disruption of forebrain dopamine systems impairs the use of high-order information to guide goal-directed performance, and that this deficit may be related to impaired use of task-setting cues in patients with schizophrenia. Such deficits can be interrogated through conflict resolution, which has been demonstrated to be sensitive to prefrontal integrity in rodents. We sought to examine the effects of acute systemic d-amphetamine administration on the contextual control of response conflict in rats, and whether deficits were reversed through pre-treatment with clozapine or the D₁/D₂ antagonist α-flupenthixol. Acute d-amphetamine (1.5 mg/kg) disrupted the utilisation of contextual cues; therefore rats were impaired during presentation of stimulus compounds that require conflict resolution. Evidence suggested that this effect was attenuated through pre-treatment with the atypical antipsychotic clozapine (5.0 mg/kg), but not the typical antipsychotic α-flupenthixol (0.25 mg/kg), at doses previously shown to attenuate d-amphetamine-induced cognitive deficits. These studies therefore demonstrate a potentially viable model of disrupted executive function such as that seen in schizophrenia.

Conflict in Relationships and Perceived Support in Innovative Work Behavior

NASA Astrophysics Data System (ADS)

Battistelli, Adalgisa; Picci, Patrizia; Odoardi, Carlo

In recent years, the idea that innovation is one of the determining factors in the efficacy and survival of organizations has been strongly consolidated. Individuals and groups within the various organizations undertake specific creative activities with the express intention of deriving direct benefits from the changes with regard to the generational phase of ideas. Innovative Work Behavior (IWB) is a complex behavioral pattern which consists of a set of three different tasks, namely, idea generation, idea promotion and idea realization. Considering the scant attention that has been paid to date to the potentially different role of antecedent factors in the various phases of innovative behavior, the aim of the present work was to examine the combined conflicting and supportive roles on innovation within the three stages of IWB. The results obtained from a sample of 110 Public Elementary School teachers confirm, as expected, that in the realization phase there are a positive influence from conflicting and supportive roles on innovation and a positive influence from support for innovation also in the phase of idea promotion; whereas, unexpectedly, a positive influence from conflicting is exercised in the phases of idea generation.

Response inhibition under alcohol: effects of cognitive and motivational conflict.

PubMed

Fillmore, M T; Vogel-Sprott, M

2000-03-01

This experiment tested the effect of cognitive and motivational conflict on response inhibition under alcohol. Fifty-six male social drinkers were randomly assigned to one of eight groups (n = 8). Four pairs of groups received 0.62 g/kg of alcohol, or a placebo, and each pair performed a go/stop choice reaction time task under one of four conflict conditions. One condition (C) produced cognitive conflict by presenting "go" and "stop" signals in the task. Another condition (IR) added motivational conflict by administering an equal monetary reward for inhibiting responses to stop-signals, and for responding to go-signals. The remaining two conditions resolved the motivational conflict by administering the monetary reward only for inhibitions (I), or only for responses (R). Compared with placebo, alcohol reduced inhibitions (i.e., impaired inhibitory control) under cognitive conflict (C; p = .041) and under motivational conflict (IR; p = .012). No significant effect of alcohol on inhibitions was observed in conditions where conflict was resolved (i.e., I and R). The study shows that alcohol can reduce the ability to inhibit a response. However, impaired inhibitory control is not an inevitable outcome of the drug action, because it can be counteracted by the consequences of behavior in the situation.

Mismatch and conflict: neurophysiological and behavioral evidence for conflict priming.

PubMed

Mager, Ralph; Meuth, Sven G; Kräuchi, Kurt; Schmidlin, Maria; Müller-Spahn, Franz; Falkenstein, Michael

2009-11-01

Conflict-related cognitive processes are critical for adapting to sudden environmental changes that confront the individual with inconsistent or ambiguous information. Thus, these processes play a crucial role to cope with daily life. Generally, conflicts tend to accumulate especially in complex and threatening situations. Therefore, the question arises how conflict-related cognitive processes are modulated by the close succession of conflicts. In the present study, we investigated the effect of interactions between different types of conflict on performance as well as on electrophysiological parameters. A task-irrelevant auditory stimulus and a task-relevant visual stimulus were presented successively. The auditory stimulus consisted of a standard or deviant tone, followed by a congruent or incongruent Stroop stimulus. After standard prestimuli, performance deteriorated for incongruent compared to congruent Stroop stimuli, which were accompanied by a widespread negativity for incongruent versus congruent stimuli in the event-related potentials (ERPs). However, after deviant prestimuli, performance was better for incongruent than for congruent Stroop stimuli and an additional early negativity in the ERP emerged with a fronto-central maximum. Our data show that deviant auditory prestimuli facilitate specifically the processing of stimulus-related conflict, providing evidence for a conflict-priming effect.

Reduced prefrontal cortex activation in the color-word Stroop task for Chinese dyslexic children: a near-infrared spectroscopy study

NASA Astrophysics Data System (ADS)

Sun, Jinyan; Zhai, Jiahuan; Song, Ranran; Zou, Li; Gong, Hui

2011-01-01

Behavioral studies have investigated the performance of children with developmental dyslexia in conflict resolution, a function connected with the prefrontal cortex (PFC) closely. However, little is known about the prefrontal activation in conflict resolution for dyslexic children. In the present study, the involvement of the PFC in resolving conflict was evaluated for Chinese dyslexic children by means of near-infrared spectroscopy (NIRS). The NIRS instrument is a portable, continuous-wave system and can measure concentration changes of hemodynamic parameters (including oxy-, deoxy-, and total hemoglobin). Considering better sensitivity, the oxy-hemoglobin (oxy-Hb) was chosen to indicate the prefrontal activation. Ten dyslexic children and 11 normal children were recruited to perform the Chinese-character color-word Stroop task, which included the neutral and color (incongruent) tasks. In behavioral performance, both groups showed significant Stroop effect, longer response time or higher error rate for the color task. In particular, the Stroop interference effect was marginally larger for dyslexic children than normal children in response time. What's more, the two groups showed distinct pattern of oxy-Hb activation during the Stroop tasks. The normal group recruited the bilateral PFC to perform the tasks, while the dyslexic group couldn't activate the bilateral PFC in the difficult color task. Moreover, significantly less color Stroop effect was found in the left PFC for the dyslexic group, showing their disability in coping with the Stroop interference. These findings suggest that the PFC is dysfunctional in conflict resolution for Chinese dyslexic children and that NIRS can be an effective tool in neurological research and clinical application.

Faces in-between: evaluations reflect the interplay of facial features and task-dependent fluency.

PubMed

Winkielman, Piotr; Olszanowski, Michal; Gola, Mateusz

2015-04-01

Facial features influence social evaluations. For example, faces are rated as more attractive and trustworthy when they have more smiling features and also more female features. However, the influence of facial features on evaluations should be qualified by the affective consequences of fluency (cognitive ease) with which such features are processed. Further, fluency (along with its affective consequences) should depend on whether the current task highlights conflict between specific features. Four experiments are presented. In 3 experiments, participants saw faces varying in expressions ranging from pure anger, through mixed expression, to pure happiness. Perceivers first categorized faces either on a control dimension, or an emotional dimension (angry/happy). Thus, the emotional categorization task made "pure" expressions fluent and "mixed" expressions disfluent. Next, participants made social evaluations. Results show that after emotional categorization, but not control categorization, targets with mixed expressions are relatively devalued. Further, this effect is mediated by categorization disfluency. Additional data from facial electromyography reveal that on a basic physiological level, affective devaluation of mixed expressions is driven by their objective ambiguity. The fourth experiment shows that the relative devaluation of mixed faces that vary in gender ambiguity requires a gender categorization task. Overall, these studies highlight that the impact of facial features on evaluation is qualified by their fluency, and that the fluency of features is a function of the current task. The discussion highlights the implications of these findings for research on emotional reactions to ambiguity. (c) 2015 APA, all rights reserved).

Cognitive states influence dopamine-driven aberrant learning in Parkinson’s disease

PubMed Central

Cavanagh, James F.; Mueller, Andrea A.; Brown, Darin R.; Janowich, Jacqueline R.; Story-Remer, Jacqueline H.; Wegele, Ashley; Richardson, Sarah Pirio

2017-01-01

Individual differences in dopaminergic tone underlie tendencies to learn from reward versus punishment. These effects are well documented in Parkinson’s patients, who vacillate between low and high tonic dopaminergic states as a function of medication. Yet very few studies have investigated the influence of higher-level cognitive states known to affect downstream dopaminergic learning in Parkinson’s patients. A dopamine-dependent cognitive influence over learning would provide a candidate mechanism for declining cognitive integrity and motivation in Parkinson’s patients. In this report we tested the influence of two high-level cognitive states (cost of conflict and value of volition) that have recently been shown to cause predictable learning biases in healthy young adults as a function of dopamine receptor subtype and dopaminergic challenge. It was hypothesized that Parkinson’s patients OFF medication would have an enhanced cost of conflict and a decreased value of volition, and that these effects would be remediated or reversed ON medication. Participants included N=28 Parkinson’s disease patients who were each tested ON and OFF dopaminergic medication and 28 age- and sex-matched controls. The expected cost of conflict effect was observed in Parkinson’s patients OFF versus ON medication, but only in those that were more recently diagnosed (<5 years). We found an unexpected effect in the value of volition task: medication compromised the ability to learn from difficult a-volitional (instructed) choices. This novel finding was also enhanced in recently diagnosed patients. The difference in learning biases ON vs. OFF medication between these two tasks was strongly correlated, bolstering the idea that they tapped into a common underlying imbalance in dopaminergic tone that is particularly variable in earlier stage Parkinsonism. The finding that these decision biases are specific to earlier but not later stage disease may offer a chance for future studies to quantify phenotypic expressions of idiosyncratic disease progression. PMID:28384481

What makes your brain suggestible? Hypnotizability is associated with differential brain activity during attention outside hypnosis.

PubMed

Cojan, Yann; Piguet, Camille; Vuilleumier, Patrik

2015-08-15

Theoretical models of hypnosis have emphasized the importance of attentional processes in accounting for hypnotic phenomena but their exact nature and brain substrates remain unresolved. Individuals vary in their susceptibility to hypnosis, a variability often attributed to differences in attentional functioning such as greater ability to filter irrelevant information and inhibit prepotent responses. However, behavioral studies of attentional performance outside the hypnotic state have provided conflicting results. We used fMRI to investigate the recruitment of attentional networks during a modified flanker task in High and Low hypnotizable participants. The task was performed in a normal (no hypnotized) state. While behavioral performance did not reliably differ between groups, components of the fronto-parietal executive network implicated in monitoring (anterior cingulate cortex; ACC), adjustment (lateral prefrontal cortex; latPFC), and implementation of attentional control (intraparietal sulcus; IPS) were differently activated depending on the hypnotizability of the subjects: the right inferior frontal gyrus (rIFG) was more recruited, whereas IPS and ACC were less recruited by High susceptible individuals compared to Low. Our results demonstrate that susceptibility to hypnosis is associated with particular executive control capabilities allowing efficient attentional focusing, and point to specific neural substrates in right prefrontal cortex. We demonstrated that outside hypnosis, low hypnotizable subjects recruited more parietal cortex and anterior cingulate regions during selective attention conditions suggesting a better detection and implementation of conflict. However, outside hypnosis the right inferior frontal gyrus (rIFG) was more recruited by highly hypnotizable subjects during selective attention conditions suggesting a better control of conflict. Furthermore, in highly hypnotizable subjects this region was more connected to the default mode network suggesting a tight dialogue between internally and externally driven processes that may permit higher flexibility in attention and underlie a greater ability to dissociate. Copyright © 2015 Elsevier Inc. All rights reserved.

Cognitive states influence dopamine-driven aberrant learning in Parkinson's disease.

PubMed

Cavanagh, James F; Mueller, Andrea A; Brown, Darin R; Janowich, Jacqueline R; Story-Remer, Jacqueline H; Wegele, Ashley; Richardson, Sarah Pirio

2017-05-01

Individual differences in dopaminergic tone underlie tendencies to learn from reward versus punishment. These effects are well documented in Parkinson's patients, who vacillate between low and high tonic dopaminergic states as a function of medication. Yet very few studies have investigated the influence of higher-level cognitive states known to affect downstream dopaminergic learning in Parkinson's patients. A dopamine-dependent cognitive influence over learning would provide a candidate mechanism for declining cognitive integrity and motivation in Parkinson's patients. In this report we tested the influence of two high-level cognitive states (cost of conflict and value of volition) that have recently been shown to cause predictable learning biases in healthy young adults as a function of dopamine receptor subtype and dopaminergic challenge. It was hypothesized that Parkinson's patients OFF medication would have an enhanced cost of conflict and a decreased value of volition, and that these effects would be remediated or reversed ON medication. Participants included N = 28 Parkinson's disease patients who were each tested ON and OFF dopaminergic medication and 28 age- and sex-matched controls. The expected cost of conflict effect was observed in Parkinson's patients OFF versus ON medication, but only in those that were more recently diagnosed (<5 years). We found an unexpected effect in the value of volition task: medication compromised the ability to learn from difficult a-volitional (instructed) choices. This novel finding was also enhanced in recently diagnosed patients. The difference in learning biases ON versus OFF medication between these two tasks was strongly correlated, bolstering the idea that they tapped into a common underlying imbalance in dopaminergic tone that is particularly variable in earlier stage Parkinsonism. The finding that these decision biases are specific to earlier but not later stage disease may offer a chance for future studies to quantify phenotypic expressions of idiosyncratic disease progression. Copyright © 2017 Elsevier Ltd. All rights reserved.

Did I read or did I name? Diminished awareness of processes yielding identical 'outputs'.

PubMed

Molapour, Tanaz; Berger, Christopher C; Morsella, Ezequiel

2011-12-01

It has been proposed that incompatible intentions (e.g., to inhale and not inhale while holding one's breath while underwater) are an essential ingredient of conscious conflict. Laboratory tasks such as the Stroop color naming task can instantiate conscious conflict innocuously. However, little research has explored what occurs subjectively at the other end of conflict, when intentions are harmonious. The hypothesis of synchrony blindness proposes that, during harmonious processing, not only may one not experience any conflict, but one may also be unaware that more than one process yielded the same intention/action plan. Accordingly, in the Stroop task, participants reported less of an urge to err (by reading) when words were presented in the congruent condition (e.g., RED presented in red) than when the very same words were presented in standard font color, suggesting that awareness of word-reading was diminished experimentally. The implications of this finding for theories about consciousness are discussed. Copyright © 2011 Elsevier Inc. All rights reserved.

Board task performance: An exploration of micro- and macro-level determinants of board effectiveness

PubMed Central

Minichilli, Alessandro; Zattoni, Alessandro; Nielsen, Sabina; Huse, Morten

2012-01-01

This paper addresses recent calls to narrow the micro–macro gap in management research (Bamberger, 2008), by incorporating a macro-level context variable (country) in exploring micro-level determinants of board effectiveness. Following the integrated model proposed by Forbes and Milliken (1999), we identify three board processes as micro-level determinants of board effectiveness. Specifically, we focus on effort norms, cognitive conflicts and the use of knowledge and skills as determinants of board control and advisory task performance. Further, we consider how two different institutional settings influence board tasks, and how the context moderates the relationship between processes and tasks. Our hypotheses are tested on a survey-based dataset of 535 medium-sized and large industrial firms in Italy and Norway, which are considered to substantially differ along legal and cultural dimensions. The findings show that: (i) Board processes have a larger potential than demographic variables to explain board task performance; (ii) board task performance differs significantly between boards operating in different contexts; and (iii) national context moderates the relationships between board processes and board task performance. Copyright © 2010 John Wiley & Sons, Ltd. PMID:23365485

Conflict Frequency within Mother-Child Dyads across Contexts: Links with Attachment Security and Gender

ERIC Educational Resources Information Center

Panfile, Tia M.; Laible, Deborah J.; Eye, Jessica L.

2012-01-01

The current study examined context, attachment, temperament, and gender as predictors of conflict frequency between mothers and their young children. Conflict between 40 mothers and their 36-month-old children was observed during multiple laboratory tasks with varying levels of structure, and the number of dyadic conflict episodes was totaled for…

Children's Perceived Agency in the Context of Marital Conflict: Relations with Marital Conflict over Time

ERIC Educational Resources Information Center

Schermerhorn, Alice C.; Cummings, E. Mark; Davies, Patrick T.

2005-01-01

Consistent with the bidirectional perspective on parent-child relations, the current study examined children's perceptions of agency in the context of marital conflict. A storytelling task was completed by 11 5 five-year-old children, tapping perceived agency. These children and their mothers and fathers completed measures of marital conflict at…

48 CFR 1309.507-2 - Contract clauses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Organizational and Consultant Conflicts of Interest 1309.507-2... systems for which task orders may be issued and indicate which organizational conflict of interest... order which organizational conflict of interest provision in paragraph (a)(2) of this clause shall apply...