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Sample records for 1987a focused attention

  1. Focusing, Sustaining, and Switching Attention

    DTIC Science & Technology

    2013-09-12

    scene analysis 16. SECURITY CLASSIFICATION OF: U a. REPORT u b. ABSTRACT u c. THIS PAGE u 17. LIMITATION OF ABSTRACT uu 18. NUMBER OF...humans can communicate in complex acoustic scenes , we must understand the dynamics of focusing, sustaining, and switching selective auditory ...many of whom deal with complex acoustic scenes full of competing sources (where selective auditory attention is challenging in the best of

  2. Attentional Focus Effects in Balance Acrobats

    ERIC Educational Resources Information Center

    Wulf, Gabriele

    2008-01-01

    Performing and learning motor skills has been shown to be enhanced if the performer adopts an external relative to internal focus (or no focus) of attention (Wulf, 2007). The present study examined the generalizability of this effect to top-level performers (balance acrobats). Participants performed a balance task (standing on an inflated rubber…

  3. Focus of Attention and Putting Performance.

    ERIC Educational Resources Information Center

    Boutcher, Stephen H.; Crews, Debra J.

    The effect of a preshot attentional/behavioral routine on putting performance was investigated. Subjects were randomly assigned to four groups: (1) Male Routine (MR); (2) Female Routine (FR); (3) Male Control (MC); and (4) Female Control (FC). Subjects in the FR and MR groups were given individualized putting routines which focused on specific…

  4. Self-focused Attention in Anorexia Nervosa

    PubMed Central

    Zucker, Nancy; Wagner, H. Ryan; Merwin, Rhonda; Bulik, Cynthia M.; Moskovich, Ashley; Keeling, Lori; Hoyle, Rick

    2015-01-01

    Objective The clinical presentation of anorexia nervosa (AN) is characterized by preoccupation with body experience, intrusive concerns regarding shape, and pathological fears of weight gain. These symptoms are suggestive of unrelenting self-focused attention. No research to date has characterized self-focused attention (SFA) in AN nor examined neurocognitive features that may facilitate an excessive, rigid, or sustained focus on one’s appearance. Method This study examined SFA, body image disturbance, and executive functioning in women with current anorexia nervosa (AN-C; n = 24), a history of AN who were weight-restored at the time of the study weight-restored (WR; n = 19), and healthy controls (n = 24). Results Private and public SFA were highest among WR and lowest among AN-C. Shape concerns were negatively correlated with SFA, especially among AN-C, after controlling for depression and social anxiety symptoms. Discussion Lower levels of SFA among AN-C were unexpected and suggest the acute state of AN may lessen pathological self-focus, negatively reinforcing symptoms. In addition, body image concerns may distract from general SFA. Deficits in executive attention may explain these findings, as each one unit increase in perseverative errors among AN-C participants was associated with an almost one-half unit decrease in public SFA. PMID:24899215

  5. Neuroticism focuses attention: evidence from SSVEPs.

    PubMed

    Dhinakaran, Janani; De Vos, Maarten; Thorne, Jeremy D; Kranczioch, Cornelia

    2014-06-01

    Neuroticism and negative affect have been associated with an increase in attentional investment and the greater processing of irrelevant stimuli. Previous research proposes the overinvestment of attention and a focused mental state as the mechanism of this effect. We investigated the neural correlates of this idea using a dual-stream rapid serial visual presentation paradigm with centrally presented, overlapping streams of letters that changed at different frequencies. Participants attended one stream at a time. We predicted that the more focused cognitive style associated with higher neuroticism would be reflected in the overinvestment of attention in the irrelevant stream of to-be-ignored letters, in particular, when the ignored stream was the more salient one. This was expected to lead to a smaller difference in power between the attended and unattended frequencies. Results showed that power differences between attended and unattended streams were negatively correlated with neuroticism scores in direct support of our hypothesis. Exploratory correlations also showed that extraversion was positively related to the attention difference. As extraversion has been contrasted to neuroticism and linked to increased cognitive flexibility and control in previous studies, it is possible that this trait may help in disengagement from salient stimuli. Together, these results provide the first neural correlates of the focused cognitive style idea. That the effect of extraversion is seen in the centro-parietal region and the effect of neuroticism is seen in the occipital region, indicate that these personality traits may affect the hierarchy of visual information processing. These findings provide new insight into the influence of personality traits on attention mechanisms and open up questions regarding the relationship between neuroticism, extraversion and information processing.

  6. Distributed vs. Focused Attention (count vs. estimate)

    PubMed Central

    Chong, Sang Chul; Evans, Karla K.

    2010-01-01

    Quantity or numerosity is one of the basic properties of our environment. Humans and animals both have the neural representation of quantity or “number sense”. The ability to extract and to manipulate numbers is closely related to our various cognitive functions such as the capacity of working memory, mathematical achievement, and texture perception. Evidence shows that the sense of number is not a unitary mechanism but rather a composition of two distinct processes; enumeration and estimation. The review examines how numerosity is represented in the visual domain and its relation to different modes of attention. Enumeration or counting permits an exact representation of a distinct number of objects, with an awareness of each object achieved through focal deployment of attention to each object serially. On the other hand, estimation involves an approximation of the number of different items or a sense of ensemble statistics, achieved through fast deployment of distributed attention over a set of objects as a whole. In this overview we suggest that a focused attention mode is more suitable for enumeration, whereas a distributed attention mode is better for estimation. PMID:22121459

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

    ERIC Educational Resources Information Center

    Sawaki, Risa; Katayama, Jun'ichi

    2009-01-01

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

  8. Brain oscillations in switching vs. focusing audio-visual attention.

    PubMed

    Rapela, Joaquin; Gramann, Klaus; Westerfield, Marissa; Townsend, Jeanne; Makeig, Scott

    2012-01-01

    Selective attention contributes to perceptual efficiency by modulating cortical activity according to task demands. The majority of attentional research has focused on the effects of attention to a single modality, and little is known about the role of attention in multimodal sensory processing. Here we employ a novel experimental design to examine the electrophysiological basis of audio-visual attention shifting. We use electroencephalography (EEG) to study differences in brain dynamics between quickly shifting attention between modalities and focusing attention on a single modality for extended periods of time. We also address interactions between attentional effects generated by the attention-shifting cue and those generated by subsequent stimuli. The conclusions from these examinations address key issues in attentional research, including the supramodal theory of attention, or the role of attention in foveal vision. The experimental design and analysis methods used here may suggest new directions in the study of the physiological basis of attention.

  9. Focus of Attention and Aesthetic Response.

    ERIC Educational Resources Information Center

    Madsen, Clifford K.

    1997-01-01

    Presents the results of a study where musicians listened to 20 minutes of Puccini's, "La Boheme," and indicated which of the five musical elements (melody, rhythm, timbre, dynamics, or everything) commanded their attention. Two groups responded using differing instructions for the Continuous Response Digital Interface. Analyzes the different…

  10. Exploring Insight: Focus on Shifts of Attention

    ERIC Educational Resources Information Center

    Palatnik, Alik; Koichu, Boris

    2015-01-01

    The paper presents and analyses a sequence of events that preceded an insight solution to a challenging problem in the context of numerical sequences. A three­week long solution process by a pair of ninth­-grade students is analysed by means of the theory of shifts of attention. The goal for this article is to reveal the potential of this theory…

  11. Fixing our focus: Training attention to regulate emotion

    PubMed Central

    Wadlinger, Heather A.; Isaacowitz, Derek M.

    2010-01-01

    Empirical studies have frequently linked negative attentional biases with attentional dysfunction and negative moods; however, far less research has focused on how attentional deployment can be an adaptive strategy that regulates emotional experience. We argue that attention may be an invaluable tool for promoting emotion regulation. Accordingly, we present evidence that selective attention to positive information reflects emotion regulation, and that regulating attention is a critical component of the emotion regulatory process. Furthermore, attentional regulation can be successfully trained through repeated practice. We ultimately propose a model of attention training methodologies integrating attention-dependent emotion regulation strategies with attention networks. While additional interdisciplinary research is needed to bolster these nascent findings, meditative practices appear to be among the most effective training methodologies in enhancing emotional well-being. Further exploration of the positive and therapeutic qualities of attention warrants the empirical attention of social and personality psychologists. PMID:20435804

  12. A focused attention intervention for coping with ostracism.

    PubMed

    Molet, Mikaël; Macquet, Benjamin; Lefebvre, Olivier; Williams, Kipling D

    2013-12-01

    Ostracism-being excluded and ignored-thwarts satisfaction of four fundamental needs: belonging, self-esteem, control, and meaningful existence. The current study investigated whether training participants to focus their attention on the here-and-now (i.e., focused attention) reduces distress from an ostracism experience. Participants were first trained in either focused or unfocused attention, and then played Cyberball, an online ball-tossing game for which half the participants were included or ostracized. Participants reported their levels of need satisfaction during the game, and after a short delay. Whereas both training groups experienced the same degree of need-threat in the immediate measure, participants who were trained in focused attention showed more recovery for the delayed measure. We reason that focused attention would not reduce the distress during the ostracism experience, but it aided in recovery by preventing participants from reliving the ostracism experience after it concludes.

  13. Neural correlates of self-focused attention in social anxiety.

    PubMed

    Boehme, Stephanie; Miltner, Wolfgang H R; Straube, Thomas

    2015-06-01

    Socially anxious individuals tend to shift their attention away from external socially threatening cues and instead become highly self-focused. Such heightened self-focused attention has been suggested to be involved in the development and maintenance of social anxiety disorder. This study used functional magnetic resonance imaging to investigate the neural correlates of self-focused attention in 16 high socially anxious (HSA) and 16 low socially anxious (LSA) individuals. Participants were instructed to focus their attention either inwardly or outwardly during a simulated social situation. Results indicate hyperactivation of medial prefrontal cortex (mPFC), temporo-parietal junction (TPJ) and temporal pole during inward vs outward attention in HSA compared with LSA participants. Furthermore, activation of mPFC, right anterior insula, TPJ and posterior cingulate cortex was positively correlated with the trait of self-focused attention in HSA subjects. Results highlight the prominent role of the mPFC and other cortical structures in abnormal self-focused attention in social anxiety. Finally, findings for the insula suggest increased processing of bodily states that is related to the amount of habitual self-focused attention in social anxiety.

  14. On the neural basis of focused and divided attention.

    PubMed

    Nebel, Katharina; Wiese, Holger; Stude, Philipp; de Greiff, Armin; Diener, Hans-Christoph; Keidel, Matthias

    2005-12-01

    Concepts of higher attention functions distinguish focused and divided attention. The present study investigated whether these mental abilities are mediated by common or distinct neural substrates. In a first experiment, 19 healthy subjects were examined with functional brain imaging (fMRI) while they attended to either one or both of two simultaneously presented visual information streams and responded to repetitive stimuli. This experiment resembled a typical examination of these mental functions with the single task demanding focused and the dual task conditions requiring divided attention. Both conditions activated a widespread, mainly right-sided network including dorso- and ventrolateral prefrontal structures, superior and inferior parietal cortex, and anterior cingulate gyrus. Under higher cognitive demands of divided attention, activity in these structures was enhanced and left-sided homologues were recruited. In a second experiment investigating another 17 subjects with almost the same paradigm, it was accounted for that in most dual task investigations of focused and divided attention the single tasks are easier to process than their combined presentation. Therefore, the task difficulty of focused attention tasks was increased. Almost the same activity pattern observed during division of attention was now found during focusing attention. Comparing both attentional states matched for task difficulty, differences were found in visual but not in prefrontal or parietal cortex areas. Our results suggest that focused and divided attention depend on largely overlapping neuronal substrates. Differences in activation patterns, especially in prefrontal and parietal areas, may result from unequal demands on executive control due to disparate processing requirements in typical tasks of focused and divided attention: Easier conditions begin with mainly right-sided activity within the attention network. As conditions become more difficult, left-lateralized homologue

  15. Sustained and Focused Attention Deficits in Adult ADHD

    ERIC Educational Resources Information Center

    Marchetta, Natalie D. J.; Hurks, Petra P. M.; De Sonneville, Leo M. J.; Krabbendam, Lydia; Jolles, Jelle

    2008-01-01

    Objective: To examine the specificity of deficits in focused attention and sustained attention in adults with ADHD and to evaluate the effect of comorbidity. Method: Twenty-eight adults with ADHD without comorbidity were compared with 28 ADHD outpatients with comorbidity. Two control groups were used: 68 adults referred for ADHD but with another…

  16. Focus of Attention Affects Performance of Motor Skills in Music

    ERIC Educational Resources Information Center

    Duke, Robert A.; Cash, Carla Davis; Allen, Sarah E.

    2011-01-01

    To test the extent to which learners performing a simple keyboard passage would be affected by directing their focus of attention to different aspects of their movements, 16 music majors performed a brief keyboard passage under each of four focus conditions arranged in a counterbalanced design--a total of 64 experimental sessions. As they…

  17. Defining the Focus of Attention: Effects of Attention on Perceived Exertion and Fatigue

    PubMed Central

    Lohse, Keith R.; Sherwood, David E.

    2011-01-01

    This manuscript presents two experiments designed to explore the effects of attention on perceived exertion and time to failure in a fatiguing athletic task. There were two major motivating factors for these experiments. First, there are few studies evaluating attentional focus effects in endurance tasks and, second, there is a lack of integration between studies of attentional focus as external/internal (e.g., Wulf, 2007a) compared to associative/dissociative (e.g., Stevinson and Biddle, 1998). In Experiment 1, we used a fatiguing wall-sit posture (essentially a complex, isometric task) to compare two different types of external attention with an internal focus on the position of the legs. An external focus (regardless of type) increased the time taken to failure and reduced perceived exertion. In Experiment 2, we manipulated subjects’ expectancy of fatigue to test the interaction of attention and expectancy (both top-down factors) in this highly fatiguing task. Previous theories of attention during endurance tasks have suggested that as fatigue/pain increase, bottom-up factors begin to dominate subjects’ attention. While this may be true, Experiment 2 showed that even in a highly fatiguing task, attentional strategies, and expectancies affected the time to failure and perceived exertion. PMID:22102843

  18. Supernova 1987A

    NASA Astrophysics Data System (ADS)

    McCray, R.; Murdin, P.

    2002-10-01

    Supernova 1987A (SN1987A) in the LARGE MAGELLANIC CLOUD (LMC) is the brightest supernova to be observed since SN1604 (Kepler), the first to be observed in every band of the ELECTROMAGNETIC SPECTRUM and the first to be detected through its initial burst of NEUTRINOS. Although the bolometric luminosity of SN1987A today is ≈10-6 of its value at maximum light (Lmax≈2.5×108L⊙), it ...

  19. Attentional Focus in Classical Ballet: A Survey Of Professional Dancers.

    PubMed

    Guss-West, Clare; Wulf, Gabriele

    2016-03-01

    Focus of attention and its effects on skilled motor performance has become an important line of research in the motor learning domain. Numerous studies have demonstrated that an external focus of attention (i.e., on the movement effect) enhances motor performance and learning relative to an internal focus (i.e., on body movements). Thus, small differences in the wording of instructions or feedback given by teachers can have a significant impact on the effectiveness and efficiency of motor skill performance. In this paper, we review some of the attentional focus studies that are relevant to ballet performance. In addition, we report the findings of a survey among professional ballet dancers (N = 53) that we conducted to determine their typical attentional focus while performing certain movements. The results showed that the majority adopted internal foci, or combinations of internal and external foci, most of the time. This suggests that there is room for improvement for performance and teaching. We provide examples of how external foci can be promoted in ballet practice.

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

    ERIC Educational Resources Information Center

    Gilchrist, Amanda L.; Cowan, Nelson

    2011-01-01

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

  1. The effect of focused attention and open monitoring meditation on attention network function in healthy volunteers.

    PubMed

    Ainsworth, Ben; Eddershaw, Rachael; Meron, Daniel; Baldwin, David S; Garner, Matthew

    2013-12-30

    Mindfulness meditation techniques are increasingly popular both as a life-style choice and therapeutic adjunct for a range of mental and physical health conditions. However, little is known about the mechanisms through which mindfulness meditation and its constituent practices might produce positive change in cognition and emotion. Our study directly compared the effects of Focused Attention (FA) and Open-Monitoring (OM) meditation on alerting, orienting and executive attention network function in healthy individuals. Participants were randomized to three intervention groups: open-focused meditation, focused attention, and relaxation control. Participants completed an emotional variant of the Attention Network Test (ANT) at baseline and post-intervention. OM and FA practice improved executive attention, with no change observed in the relaxation control group. Improvements in executive attention occurred in the absence of change in subjective/self-report mood and cognitive function. Baseline levels of dispositional/trait mindfulness were positively correlated with executive control in the ANT at baseline. Our results suggest that mindfulness meditation might usefully target deficits in executive attention that characterise mood and anxiety disorders.

  2. Does Focus of Attention Improve Snatch Lift Kinematics?

    PubMed

    Schutts, Kyle S; Wu, Will; Vidal, Anthony; Hiegel, Jamie; Becker, James

    2016-12-24

    Recent motor control literature has demonstrated that using verbal instructions to direct a performer's attention externally (i.e. toward the movement outcome) enhances motor skill performance. The purpose of this study was to investigate how an athlete's focus of attention impacts kinematic performance of the snatch. Using a counterbalanced within-participant design, 12 competitively trained athletes (8 male, 4 female) performed 2 instructional blocks of 3 snatch repetitions at 80% of their most recent training 1RM. Blocks of internal and external instructions were given to the athlete in a random fashion. Results showed that, when focusing internally, athletes significantly (p <0.05) increased elbow velocity relative to focusing externally, while the external instructions significantly increased horizontal barbell velocity, relative to internal instructions (see table 2). Additionally an internal focus resulted in significantly larger Barbell-Cervical-Hip (BCH) angles at maximum height of the barbell (MH) (see table 1) compared to an external focus, indicating that the athletes squatted under the barbell too soon. This information adds to the literature suggesting small changes in coaching instructions can impact performance significantly. It is recommended that coaches use instructions that direct an athlete's attention externally, toward the movement outcome, rather than the action itself.

  3. Attention focusing and anomaly detection in systems monitoring

    NASA Technical Reports Server (NTRS)

    Doyle, Richard J.

    1994-01-01

    Any attempt to introduce automation into the monitoring of complex physical systems must start from a robust anomaly detection capability. This task is far from straightforward, for a single definition of what constitutes an anomaly is difficult to come by. In addition, to make the monitoring process efficient, and to avoid the potential for information overload on human operators, attention focusing must also be addressed. When an anomaly occurs, more often than not several sensors are affected, and the partially redundant information they provide can be confusing, particularly in a crisis situation where a response is needed quickly. The focus of this paper is a new technique for attention focusing. The technique involves reasoning about the distance between two frequency distributions, and is used to detect both anomalous system parameters and 'broken' causal dependencies. These two forms of information together isolate the locus of anomalous behavior in the system being monitored.

  4. Attention focusing versus distraction during exposure in dental phobia.

    PubMed

    Schmid-Leuz, Barbara; Elsesser, Karin; Lohrmann, Thomas; Jöhren, Peter; Sartory, Gudrun

    2007-11-01

    A survey of the discrepant findings regarding the effects of attention focusing and distraction on exposure suggested that subjective measures of anxiety and avoidance respond better to the latter condition, and heart rate (HR) reaction responds to the former. To test this hypothesis, 63 dental phobics were recruited who had not visited a dentist for a mean of 6.6 (1.5-25) years. Participants received a 1-h exposure session with either attention focusing or distraction. Subjective anxiety and HR to phobia-related pictures were assessed before and after the treatment session and again after 1 week. Avoidance was recorded in terms of adherence to the dental treatment schedule in the following 6 months. Contrary to expectation, state anxiety showed a greater decrease in the attention focusing than the distraction condition after 1 week. Both treatment conditions were similarly effective with regard to HR and avoidance. HR habituated in both groups after exposure and 73% of followed-up patients adhered to the dental treatment schedule. Comparison of the present with previous results suggests that the differences between attentional conditions tend to be more pronounced during shorter exposure sessions than were employed in the present study.

  5. Modeling the Evolution of Beliefs Using an Attentional Focus Mechanism

    PubMed Central

    Marković, Dimitrije; Gläscher, Jan; Bossaerts, Peter; O’Doherty, John; Kiebel, Stefan J.

    2015-01-01

    For making decisions in everyday life we often have first to infer the set of environmental features that are relevant for the current task. Here we investigated the computational mechanisms underlying the evolution of beliefs about the relevance of environmental features in a dynamical and noisy environment. For this purpose we designed a probabilistic Wisconsin card sorting task (WCST) with belief solicitation, in which subjects were presented with stimuli composed of multiple visual features. At each moment in time a particular feature was relevant for obtaining reward, and participants had to infer which feature was relevant and report their beliefs accordingly. To test the hypothesis that attentional focus modulates the belief update process, we derived and fitted several probabilistic and non-probabilistic behavioral models, which either incorporate a dynamical model of attentional focus, in the form of a hierarchical winner-take-all neuronal network, or a diffusive model, without attention-like features. We used Bayesian model selection to identify the most likely generative model of subjects’ behavior and found that attention-like features in the behavioral model are essential for explaining subjects’ responses. Furthermore, we demonstrate a method for integrating both connectionist and Bayesian models of decision making within a single framework that allowed us to infer hidden belief processes of human subjects. PMID:26495984

  6. Focus of attention in systems for visual monitoring of experiments

    NASA Technical Reports Server (NTRS)

    Blank, G. E.; Martin, W. N.

    1987-01-01

    The problem of designing a computerized experiment monitoring system for use in a space station or elsewhere is examined. It is shown that the essential challenge of such a system - attaining a reasonable expected running time - can be attacked using the concept of focus of attention and by exploiting parallelism. The use of the Contract Net Protocol for the latter purpose is discussed. The use of ideas from information science to help focus a programs's efforts on those computations likely to bring results is addressed, and the incorporation of those ideas into a design in order to aid the system in deciding upon the best course of action is considered.

  7. Focus-of-attention for human activity recognition from UAVs

    NASA Astrophysics Data System (ADS)

    Burghouts, G. J.; van Eekeren, A. W. M.; Dijk, J.

    2014-10-01

    This paper presents a system to extract metadata about human activities from full-motion video recorded from a UAV. The pipeline consists of these components: tracking, motion features, representation of the tracks in terms of their motion features, and classification of each track as one of the human activities of interest. We consider these activities: walk, run, throw, dig, wave. Our contribution is that we show how a robust system can be constructed for human activity recognition from UAVs, and that focus-of-attention is needed. We find that tracking and human detection are essential for robust human activity recognition from UAVs. Without tracking, the human activity recognition deteriorates. The combination of tracking and human detection is needed to focus the attention on the relevant tracks. The best performing system includes tracking, human detection and a per-track analysis of the five human activities. This system achieves an average accuracy of 93%. A graphical user interface is proposed to aid the operator or analyst during the task of retrieving the relevant parts of video that contain particular human activities. Our demo is available on YouTube.

  8. Focus of attention in an activity-based scheduler

    NASA Technical Reports Server (NTRS)

    Sadeh, Norman; Fox, Mark S.

    1989-01-01

    Earlier research in job shop scheduling has demonstrated the advantages of opportunistically combining order-based and resource-based scheduling techniques. An even more flexible approach is investigated where each activity is considered a decision point by itself. Heuristics to opportunistically select the next decision point on which to focus attention (i.e., variable ordering heuristics) and the next decision to be tried at this point (i.e., value ordering heuristics) are described that probabilistically account for both activity precedence and resource requirement interactions. Preliminary experimental results indicate that the variable ordering heuristic greatly increases search efficiency. While least constraining value ordering heuristics have been advocated in the literature, the experimental results suggest that other value ordering heuristics combined with our variable-ordering heuristic can produce much better schedules without significantly increasing search.

  9. The Effects of Focused Attention on Inhibition and State Regulation in Children with and without Attention Deficit Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Ketch, Karen M.; Brodeur, Darlene A.; McGee, Robin

    2009-01-01

    This study investigated the effects of response rate and attention focusing on performance of ADHD, clinical-control (CRNA) and non-clinical control children in response inhibition tasks. All children completed the "Go-NoGo" task, a computer-based task of attention and impulsivity. Focused attention on this task was manipulated using a priming…

  10. Attentional Focus Effects in Standing Long Jump Performance: Influence of a Broad and Narrow Internal Focus.

    PubMed

    Becker, Kevin A; Smith, Peter J K

    2015-07-01

    The content of instructions that strength coaches give can have a significant impact on how an athlete or client performs. Research on motor learning has shown an advantage of instructions focusing on the effects of movements (external focus) over those focusing on the movements themselves (internal focus) in the performance of motor skills. Internally focused cues are abundant in coaching, therefore the purpose of this study was to test whether some internally focused cues might be more helpful than others. Participants (68) were randomly assigned to either an external focus (EX), broad internal focus (B-IN), narrow internal focus (N-IN), or a control group (CON), and performed 5 standing long jumps. All groups were instructed that the goal was to jump as far as possible. In addition, the EX group was told to "jump as far past the start line as possible." The B-IN group was told to "use your legs." The N-IN group was told to "extend your knees as rapidly as possible," and the CON group received no additional instruction. An analysis of covariance showed that the EX group (198.09 ± 31.89 cm) jumped significantly farther than both the B-IN group (173.74 ± 35.36 cm), p = 0.010 and the N-IN group (178.53 ± 31.17 cm), p = 0.049, with no group different from the CON group. The results suggest that a broad internal focus is no more effective than a narrow internal focus, and that an external focus leads to the greatest jump distance. Strength and conditioning professionals should carefully word their instructions to induce an external focus of attention whenever possible.

  11. Focusing attention on objects of interest using multiple matched filters.

    PubMed

    Stough, T M; Brodley, C E

    2001-01-01

    In order to be of use to scientists, large image databases need to be analyzed to create a catalog of the objects of interest. One approach is to apply a multiple tiered search algorithm that uses reduction techniques of increasing computational complexity to select the desired objects from the database. The first tier of this type of algorithm, often called a focus of attention (FOA) algorithm, selects candidate regions from the image data and passes them to the next tier of the algorithm. In this paper we present a new approach to FOA that employs multiple matched filters (MMF), one for each object prototype, to detect the regions of interest. The MMFs are formed using k-means clustering on a set of image patches identified by domain experts as positive examples of objects of interest. An innovation of the approach is to radically reduce the dimensionality of the feature space, used by the k-means algorithm, by taking block averages (spoiling) the sample image patches. The process of spoiling is analyzed and its applicability to other domains is discussed. The combination of the output of the MMFs is achieved through the projection of the detections back into an empty image and then thresholding. This research was motivated by the need to detect small volcanos in the Magellan probe data from Venus. An empirical evaluation of the approach illustrates that a combination of the MMF plus the average filter results in a higher likelihood of 100% detection of the objects of interest at a lower false positive rate than a single matched filter alone.

  12. Effects of a Coactor's Focus of Attention on Task Performance

    ERIC Educational Resources Information Center

    Bockler, Anne; Knoblich, Gunther; Sebanz, Natalie

    2012-01-01

    Coactors take into account certain aspects of each other's tasks even when this is not required to perform their own task. The present experiments investigated whether the way a coactor allocates attention affects one's own attentional relation to stimuli that are attended jointly (Experiment 1), individually (Experiment 2), or in parallel…

  13. Supernova 1987A

    NASA Technical Reports Server (NTRS)

    Mccray, Richard; Li, Hong Wei

    1988-01-01

    Supernova 1987A (February 23, 1987) in the Large Magellanic Cloud is the brightest supernova to be observed since SN 1604 AD (Kepler). Detection of a burst of neutrinos indicates that a neutron star was formed. Radioactive decay of about 0.07 solar mass of Co-56 is responsible for the observed optical light as well as hard X-rays and gamma-ray lines. Ultraviolet, optical, and infrared 'light echoes' and soft X-rays provide information on the distribution of circumstellar matter and the evolution of the progenitor star.

  14. Discovering Focus: Helping Students with ADD (Attention Deficit Disorder)

    ERIC Educational Resources Information Center

    Valkenburg, Jim

    2012-01-01

    Attention Deficit Disorder (ADD) is a neurological disorder which effects learning and that has a confusing set of diagnostic symptoms and an even more confusing set of remedies ranging from medication to meditation to nothing at all. Current neurological research suggests, however, that there are strategies that the individual with ADD can use to…

  15. Prenatal cocaine exposure and prolonged focus attention. Poor infant information processing ability or precocious maturation of attentional systems?

    PubMed

    Chiriboga, Claudia A; Starr, Denise; Kuhn, Louise; Wasserman, Gail A

    2009-01-01

    In experimental models, prenatal cocaine exposure has been found to perturb monoaminergic development of systems implicated in modulating attention. To determine whether prenatal cocaine exposure affects infant attention, we assessed visual recognition memory and focused attention during free play. We enrolled at birth 380 infants, 113 cocaine exposed, using multiple biomarkers to assess drug exposure. Behavior was videotaped and coded off-line for sustained looking time (i.e. focused attention), banging and intrusion. Prenatal cocaine exposure was not associated with visual recognition memory, but was significantly associated with longer sustained looking times (average focused attention) at ages 6 months (p = 0.02) and 12 months (p = 0.04) in analyses that adjusted for variables, including maternal intelligence, education, depressive scores and other exposures (alcohol, tobacco and marijuana). Cocaine-exposed infants at age 12 months also spent significantly less time in banging activity (p = 0.02) after adjusting for confounding variables. This finding was not explained through cocaine effects on motor development, neurological findings or time spent in focused attention. Prenatal cocaine exposure was significantly associated with longer periods of sustained looking or focused attention in infancy, a finding that could interpreted as a measure of poor processing efficiency, or alternatively as precocious maturation of attentional systems. Either interpretation has implications for later cognitive development. Lower banging activity among cocaine exposed was not explained through cocaine effects on motor development or neurological findings, suggesting that activity level itself is diminished in these infants. Whether focused attention findings impact long term development awaits further study.

  16. The Interaction of Focused Attention with Flow-field Sensitivity

    NASA Technical Reports Server (NTRS)

    Stoffregen, T.

    1984-01-01

    Two studies were performed to determine whether a subject's response to naturalistic optical flow specifying egomotion would be affected by a concurrent attention task. In the first study subjects stood in a moving room in which various areas of the optical flow generated by room movement were visible. Subjects responded to room motion with strong compensatory sway when the entire room was visible. When the side walls of the room were completely obscured by stationary screens, leaving only the front wall visible, sway was significantly reduced, though it remained greater than in an eyes-closed control. In Exp. 2 subjects were presented with either the full room (large sway response) or the room with only the front wall visible (moderate response), each in combination with either a hard or easy verbal addition task. Preliminary results show that swaying in the fully visible room and in the room with only the front wall visible increased when combined with either the hard or easy tasks. These preliminary results suggest that at the least the pick-up of optical flow specifying egomotion is not affected by concurrent attentional activity.

  17. Pupil size reflects the focus of feature-based attention.

    PubMed

    Binda, Paola; Pereverzeva, Maria; Murray, Scott O

    2014-12-15

    We measured pupil size in adult human subjects while they selectively attended to one of two surfaces, bright and dark, defined by coherently moving dots. The two surfaces were presented at the same location; therefore, subjects could select the cued surface only on the basis of its features. With no luminance change in the stimulus, we find that pupil size was smaller when the bright surface was attended and larger when the dark surface was attended: an effect of feature-based (or surface-based) attention. With the same surfaces at nonoverlapping locations, we find a similar effect of spatial attention. The pupil size modulation cannot be accounted for by differences in eye position and by other variables known to affect pupil size such as task difficulty, accommodation, or the mere anticipation (imagery) of bright/dark stimuli. We conclude that pupil size reflects not just luminance or cognitive state, but the interaction between the two: it reflects which luminance level in the visual scene is relevant for the task at hand.

  18. Attentional Focus Effects as a Function of Task Difficulty

    ERIC Educational Resources Information Center

    Wulf, Gabriele; Tollner, Thomas; Shea, Charles H.

    2007-01-01

    The purpose of the present study was to examine whether the advantages of adopting an external focus would be seen primarily for relatively challenging (postural stability) tasks but not less demanding tasks. To examine this, the authors used balance tasks that imposed increased challenges to maintaining stability. The present results support the…

  19. Direction of Attentional Focus in Biofeedback Treatment for /R/ Misarticulation

    ERIC Educational Resources Information Center

    McAllister Byun, Tara; Swartz, Michelle T.; Halpin, Peter F.; Szeredi, Daniel; Maas, Edwin

    2016-01-01

    Background: Maintaining an external direction of focus during practice is reported to facilitate acquisition of non-speech motor skills, but it is not known whether these findings also apply to treatment for speech errors. This question has particular relevance for treatment incorporating visual biofeedback, where clinician cueing can direct the…

  20. Organizational and Spatial Dynamics of Attentional Focusing in Hierarchically Structured Objects

    ERIC Educational Resources Information Center

    Yeari, Menahem; Goldsmith, Morris

    2011-01-01

    Is the focusing of visual attention object-based, space-based, both, or neither? Attentional focusing latencies in hierarchically structured compound-letter objects were examined, orthogonally manipulating global size (larger vs. smaller) and organizational complexity (two-level structure vs. three-level structure). In a dynamic focusing task,…

  1. [A valid proposal to focus attention on primary health].

    PubMed

    Aurelius, S

    1990-10-01

    Local Systems of Health (SILOS) evolved as a response to the Alma Ata Declaration to integrate strategies for primary health care (PHC) at primary, secondary and tertiary levels of all national health systems. PHC contains 3 basic concepts: 1) that health is a fundamental right of all human beings; 2) that all governments have the obligation of providing health services to all, irregardless of people's financial status; and 3) citizens, individuals and communities in the aggregate are responsible for their own health. SILOS through Ministries of Health provide the vehicle for spreading PHC and are based on the following: 1) decentralization and disaggregation; 2) community participation and social mobilization; 3) intersectorial coordination; 4) adjustments in finances; 5) development of new models of attention; 6) integration of preventive with curative strategies; 7) strengthening administrative capabilities; and 8) training health personnel. It is recommended that social and community-based organizations maintain their independence from the government's administrative system while respecting those organizations already in place.

  2. Focus-of-attention behavioral experiment: an examination of a therapeutic procedure to reduce social anxiety.

    PubMed

    Renner, Kerry A; Valentiner, David P; Holzman, Jacob B

    2017-01-01

    A clinical protocol based on contemporary cognitive behavioral treatment for social anxiety was developed and examined. Previously published instructions for conducting a focus-of-attention behavioral experiment targeting self-focused attention and safety behaviors during exposure were used to create a structured protocol. Individuals (n = 45) with high levels of social anxiety and public-speaking anxiety were randomly assigned to either a focus-of-attention behavioral experiment (FABE) or an Exposure-Only Control (EOC) condition. During four exposure trials, those in the FABE condition (n = 24) were alternately instructed to engage in self-focused attention vs. externally focused attention and to eliminate safety behaviors. Those in the EOC condition (n = 21) were not so instructed. At post-intervention, individuals in the FABE condition showed significantly less self-focused attention and anxiety, and better observed performance as rated by audience members. Focus-of-attention statistically mediated the effect of condition on anxiety. For those in the FABE condition, the degree of association between focus-of-attention and anxiety during the intervention predicted less self-focused attention post-intervention. The FABE appears to be a useful procedure for implementing part of the contemporary cognitive behavioral treatment model.

  3. Distributed and Focused Attention: Neuropsychological Evidence for Separate Attentional Mechanisms when Counting and Estimating

    ERIC Educational Resources Information Center

    Demeyere, Nele; Humphreys, Glyn W.

    2007-01-01

    Evidence is presented for 2 modes of attention operating in simultanagnosia. The authors examined visual enumeration in a patient, GK, who has severe impairments in serially scanning across a scene and is unable to count the numbers of items in visual displays. However, GK's ability to judge the relative magnitude of 2 displays was consistently…

  4. UN food summit tries to focus world attention on hunger.

    PubMed

    Scommegna, P

    1996-11-01

    This article discusses the November 1996 World Food Summit in Rome, women's role as food producers, overconsumption, and justification for a world conference focus. The Summit was planned by the UN Food and Agriculture Organization and is to focus on how to provide people with food security and how to keep pace with growing needs without causing environmental damage. The Summit takes place during a time when 841 million of the world population are chronically undernourished, of which 200 million are children. Millions more suffer from contaminated food and water, micronutrient deficiencies, and blindness due to lack of vitamin A. Agricultural production in 88 countries is deficient. These countries cannot produce enough food to feed their populations an adequate diet and cannot afford to import needed food. These countries include China, India, and most of sub-Saharan Africa. World grain stocks have dropped to low levels, export prices for cereals have risen, and the world fish harvest has leveled off. Over the next 50 years the world must raise food for about 4 billion more people with a limited supply of land and uneven water resources. African countries must increase food production by 300%, Latin America by 80%, Asia by 69%, and North America by 30%. The former strategy of increasing yields with fertilizers is no longer effective and there is no other alternative. In developing countries women are the main producers of food for the family. Future policies must recognize women's role in food production. Poverty would decrease and food supplies increase if poor women were given access to credit and technical advice, education and health care, and a place in the center of the world agenda for increasing food productivity. The global food system is inequitably concentrated among few, and the food trade is increasingly controlled by multinationals. Overconsumption is as serious a problem as overpopulation.

  5. An External Focus of Attention Enhances Golf Shot Accuracy in Beginners and Experts

    ERIC Educational Resources Information Center

    Wulf, Gabriele; Su, Jiang

    2007-01-01

    This article presents two experiments examining the effects of external focus of attention on motor performance and learning. Two main findings resulted from the present studies. First, directing learners' attention to the movement effect (external focus) can enhance learning complex, real-life skills. In contrast, wording instructions in a way…

  6. Perceptual and Cognitive Load Interact to Control the Spatial Focus of Attention

    ERIC Educational Resources Information Center

    Linnell, Karina J.; Caparos, Serge

    2011-01-01

    Caparos and Linnell (2009, 2010) used a variable-separation flanker paradigm to show that (a) when cognitive load is low, increasing perceptual load causes spatial attention to focus and (b) when perceptual load is high, decreasing cognitive load causes spatial attention to focus. Here, we tested whether the effects of perceptual and cognitive…

  7. Internal versus External: Oral-Motor Performance as a Function of Attentional Focus

    ERIC Educational Resources Information Center

    Freedman, Skott E.; Maas, Edwin; Caligiuri, Michael P.; Wulf, Gabriele; Robin, Donald A.

    2007-01-01

    Purpose: Previous studies (e.g., G. Wulf, M. HoB, & W. Prinz, 1998; G. Wulf, B. Lauterbach, & T. Toole, 1999; for a review, see G. Wulf & W. Prinz, 2001) have reported that limb motor performance is enhanced when individuals adopt an external focus (focusing on the effect of the movement) versus an internal focus of attention (focusing on body…

  8. Stay Focused! The Effects of Internal and External Focus of Attention on Movement Automaticity in Patients with Stroke

    PubMed Central

    Kal, E. C.; van der Kamp, J.; Houdijk, H.; Groet, E.; van Bennekom, C. A. M.; Scherder, E. J. A.

    2015-01-01

    Dual-task performance is often impaired after stroke. This may be resolved by enhancing patients’ automaticity of movement. This study sets out to test the constrained action hypothesis, which holds that automaticity of movement is enhanced by triggering an external focus (on movement effects), rather than an internal focus (on movement execution). Thirty-nine individuals with chronic, unilateral stroke performed a one-leg-stepping task with both legs in single- and dual-task conditions. Attentional focus was manipulated with instructions. Motor performance (movement speed), movement automaticity (fluency of movement), and dual-task performance (dual-task costs) were assessed. The effects of focus on movement speed, single- and dual-task movement fluency, and dual-task costs were analysed with generalized estimating equations. Results showed that, overall, single-task performance was unaffected by focus (p = .341). Regarding movement fluency, no main effects of focus were found in single- or dual-task conditions (p’s ≥ .13). However, focus by leg interactions suggested that an external focus reduced movement fluency of the paretic leg compared to an internal focus (single-task conditions: p = .068; dual-task conditions: p = .084). An external focus also tended to result in inferior dual-task performance (β = -2.38, p = .065). Finally, a near-significant interaction (β = 2.36, p = .055) suggested that dual-task performance was more constrained by patients’ attentional capacity in external focus conditions. We conclude that, compared to an internal focus, an external focus did not result in more automated movements in chronic stroke patients. Contrary to expectations, trends were found for enhanced automaticity with an internal focus. These findings might be due to patients’ strong preference to use an internal focus in daily life. Future work needs to establish the more permanent effects of learning with different attentional foci on re-automating motor

  9. Thoughts and attention of athletes under pressure: skill-focus or performance worries?

    PubMed

    Oudejans, Raoul R D; Kuijpers, Wilma; Kooijman, Chris C; Bakker, Frank C

    2011-01-01

    Choking under pressure in sport has been explained by either explicit attention to skill execution (self-focus theories), or attention to performance worries (distraction theories). The aim of the present study was to find out which focus of attention occurs most often when expert athletes perform under pressure. Two retrospective methods were employed, namely, verbal reports and concept mapping. In the verbal reports, 70 expert athletes indicated their main focus of attention when performing under high pressure in competition. For concept mapping seven expert athletes generated statements about their focus of attention in such high-pressure situations. These statements were clustered and rated on how often they occurred and how important they were for choking. Both methods revealed that under pressure attention of expert athletes was often focused on worries and hardly ever on movement execution. Furthermore, the athletes reported that they focused attention on external factors and that they reverted to positive monitoring in an attempt to maintain performance. These results are more in line with distraction theories than self-focus theories, suggesting that attention to performance worries rather than to skill execution generally explains choking.

  10. Effects of varying attentional focus on health-related physical fitness performance.

    PubMed

    Bredin, Shannon S D; Dickson, Danika B; Warburton, Darren E R

    2013-02-01

    Assessing health-related physical fitness is important for determining health status. However, verbal instructions provided during an assessment generally do not specify direction of attentional focus. This investigation examined the effect of attentional focus on performance outcomes during appraisals of health-related physical fitness. Eight females (25.0 ± 4.0 years) and 8 males (26.3 ± 3.9 years) completed 7 physical fitness tests of the Canadian Physical Activity, Fitness and Lifestyle Approach (modified Canadian Aerobic Fitness Test, grip strength, push-ups, sit and reach, partial curl-ups, vertical jump, and back extension) on 3 different days, each separated by 1 week. On day 1, no attentional focus was specified. On days 2 and 3, participants were asked to adopt an external focus (instructions focused attention away from the body) or an internal focus (instructions focused attention on the body's movement) in randomized order. Irrespective of sex, adopting an external focus resulted in significantly better performance on all tests when compared with no focus or internal-focus conditions. An internal focus also resulted in performance decrements for grip strength, push-ups, and vertical jump vs. no focus. These results demonstrate that instructing individuals to adopt an external focus provides a performance advantage on appraisals of aerobic and musculoskeletal fitness, whereas an internal focus may hinder performance. In some participants, these scores may convert to a rating of health status that is 1 health benefit zone higher or lower, respectively. This highlights further the importance of formulating verbal instructions that incorporate attentional focus for optimal performance on appraisals of physical fitness.

  11. Effects of Attentional Focus and Age on Suprapostural Task Performance and Postural Control

    ERIC Educational Resources Information Center

    McNevin, Nancy; Weir, Patricia; Quinn, Tiffany

    2013-01-01

    Purpose: Suprapostural task performance (manual tracking) and postural control (sway and frequency) were examined as a function of attentional focus, age, and tracking difficulty. Given the performance benefits often found under external focus conditions, it was hypothesized that external focus instructions would promote superior tracking and…

  12. The flexible focus: whether spatial attention is unitary or divided depends on observer goals.

    PubMed

    Jefferies, Lisa N; Enns, James T; Di Lollo, Vincent

    2014-04-01

    The distribution of visual attention has been the topic of much investigation, and various theories have posited that attention is allocated either as a single unitary focus or as multiple independent foci. In the present experiment, we demonstrate that attention can be flexibly deployed as either a unitary or a divided focus in the same experimental task, depending on the observer's goals. To assess the distribution of attention, we used a dual-stream Attentional Blink (AB) paradigm and 2 target pairs. One component of the AB, Lag-1 sparing, occurs only if the second target pair appears within the focus of attention. By varying whether the first-target-pair could be expected in a predictable location (always in-stream) or not (unpredictably in-stream or between-streams), observers were encouraged to deploy a divided or a unitary focus, respectively. When the second-target-pair appeared between the streams, Lag-1 sparing occurred for the Unpredictable group (consistent with a unitary focus) but not for the Predictable group (consistent with a divided focus). Thus, diametrically different outcomes occurred for physically identical displays, depending on the expectations of the observer about where spatial attention would be required.

  13. More attentional focusing through binaural beats: evidence from the global-local task.

    PubMed

    Colzato, Lorenza S; Barone, Hayley; Sellaro, Roberta; Hommel, Bernhard

    2017-01-01

    A recent study showed that binaural beats have an impact on the efficiency of allocating attention over time. We were interested to see whether this impact affects attentional focusing or, even further, the top-down control over irrelevant information. Healthy adults listened to gamma-frequency (40 Hz) binaural beats, which are assumed to increase attentional concentration, or a constant tone of 340 Hz (control condition) for 3 min before and during a global-local task. While the size of the congruency effect (indicating the failure to suppress task-irrelevant information) was unaffected by the binaural beats, the global-precedence effect (reflecting attentional focusing) was considerably smaller after gamma-frequency binaural beats than after the control condition. Our findings suggest that high-frequency binaural beats bias the individual attentional processing style towards a reduced spotlight of attention.

  14. Out of sight, out of mind: cognitive states alter the focus of attention.

    PubMed

    den Daas, Chantal; Häfner, Michael; de Wit, John

    2013-01-01

    People in an impulsive state are influenced mainly by the immediate incentive value of appetitive stimuli, whereas people in a reflective state usually also consider the (sometimes negative) long-term consequences of such stimuli. In order to consider all information, we hypothesize that, people in reflective states distribute their attention over all available information, whereas people in impulsive states focus their attention on the most salient information. We measured cognitive states using eye-blink rate (Experiment 1) or induced them with a procedural priming manipulation (Experiments 2 and 3). In eye-tracking Experiments 1 and 2, we established that people in an impulsive state indeed focus their attention on the salient information, whereas people in a reflective state distribute their attention. Moreover, we show that this attentional difference extends to evaluative judgments (Experiment 3), which could potentially contribute to people's increased propensity to risk in impulsive states.

  15. An External Focus of Attention Enhances Motor Learning in Children with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Chiviacowsky, S.; Wulf, G.; Avila, L. T. G.

    2013-01-01

    Background: The present study examined whether the learning benefits of an external focus of attention (i.e. on the movement effect) relative to an internal focus (i.e. on the movement), found previously in non-disabled children and adults would also be found in children with intellectual disabilities (IDs). Methods: Participants ("n" =…

  16. Effects of Focus of Attention on Tone Production in Trained Singers

    ERIC Educational Resources Information Center

    Atkins, Rebecca L.

    2017-01-01

    Motor performance in familiar tasks is often advantaged when performers focus on the effects of their movements rather than on the movements themselves. But, this phenomenon has yet to be studied systematically in the context of vocal production. I evaluated 20 trained singers' vocal tone as they varied their focus of attention. Each participant…

  17. Internal and External Focus of Attention in a Novice Form Sport

    ERIC Educational Resources Information Center

    Lawrence, Gavin P.; Gottwald, Vicky M.; Hardy, James; Khan, Michael A.

    2011-01-01

    In the current experiment, we examined optimal focus for novices during a movement sequence in which performance was measured on accurate movement form/technique. A novel gymnastics routine was practiced under either an internal skill-relevant, internal skill-irrelevant, external, or no attention focus. Retention and transfer tests were then…

  18. Focus of Attention in Children's Motor Learning: Examining the Role of Age and Working Memory.

    PubMed

    Brocken, J E A; Kal, E C; van der Kamp, J

    2016-01-01

    The authors investigated the relative effectiveness of different attentional focus instructions on motor learning in primary school children. In addition, we explored whether the effect of attentional focus on motor learning was influenced by children's age and verbal working memory capacity. Novice 8-9-year old children (n = 30) and 11-12-year-old children (n = 30) practiced a golf putting task. For each age group, half the participants received instructions to focus (internally) on the swing of their arm, while the other half was instructed to focus (externally) on the swing of the club. Children's verbal working memory capacity was assessed with the Automated Working Memory Assessment. Consistent with many reports on adult's motor learning, children in the external groups demonstrated greater improvements in putting accuracy than children who practiced with an internal focus. This effect was similar across age groups. Verbal working memory capacity was not found to be predictive of motor learning, neither for children in the internal focus groups nor for children in the external focus groups. In conclusion, primary school children's motor learning is enhanced by external focus instructions compared to internal focus instructions. The purported modulatory roles of children's working memory, attentional capacity, or focus preferences require further investigation.

  19. Revisiting the relation between contingency awareness and attention: evaluative conditioning relies on a contingency focus.

    PubMed

    Kattner, Florian

    2012-01-01

    Although evaluative conditioning has occasionally been demonstrated in the absence of contingency awareness, many recent studies imply that its acquisition depends on the availability of attentional resources during conditioning. In previous experiments attention has typically been manipulated in a general way rather than looking at the particular focus of attention. The present study investigated the role of a focus on the CS-US contingency. Two separate distraction tasks were designed that either diverted attention from the stimuli or directed it to the stimuli while drawing attention away from the contingency between the stimuli. Both types of distraction were shown to eliminate evaluative conditioning. Significant evaluative conditioning was observed in a third group of participants who were required to attend the contingencies. A mediation analysis showed that the observed discrepancy in evaluative conditioning effects between groups was mediated by contingency awareness. The results imply that attention in terms of a stimulus focus is not sufficient for evaluative conditioning to occur. Rather, attention to the contingencies between stimuli appears to be crucial in evaluative conditioning, because it is supposed to foster the acquisition of contingency awareness.

  20. Focused attention, open monitoring and loving kindness meditation: effects on attention, conflict monitoring, and creativity - A review.

    PubMed

    Lippelt, Dominique P; Hommel, Bernhard; Colzato, Lorenza S

    2014-01-01

    Meditation is becoming increasingly popular as a topic for scientific research and theories on meditation are becoming ever more specific. We distinguish between what is called focused Attention meditation, open Monitoring meditation, and loving kindness (or compassion) meditation. Research suggests that these meditations have differential, dissociable effects on a wide range of cognitive (control) processes, such as attentional selection, conflict monitoring, divergent, and convergent thinking. Although research on exactly how the various meditations operate on these processes is still missing, different kinds of meditations are associated with different neural structures and different patterns of electroencephalographic activity. In this review we discuss recent findings on meditation and suggest how the different meditations may affect cognitive processes, and we give suggestions for directions of future research.

  1. Focused attention, open monitoring and loving kindness meditation: effects on attention, conflict monitoring, and creativity – A review

    PubMed Central

    Lippelt, Dominique P.; Hommel, Bernhard; Colzato, Lorenza S.

    2014-01-01

    Meditation is becoming increasingly popular as a topic for scientific research and theories on meditation are becoming ever more specific. We distinguish between what is called focused Attention meditation, open Monitoring meditation, and loving kindness (or compassion) meditation. Research suggests that these meditations have differential, dissociable effects on a wide range of cognitive (control) processes, such as attentional selection, conflict monitoring, divergent, and convergent thinking. Although research on exactly how the various meditations operate on these processes is still missing, different kinds of meditations are associated with different neural structures and different patterns of electroencephalographic activity. In this review we discuss recent findings on meditation and suggest how the different meditations may affect cognitive processes, and we give suggestions for directions of future research. PMID:25295025

  2. Focused and Sustained Attention Is Modified by a Goal-Based Rehabilitation in Parkinsonian Patients

    PubMed Central

    Ferrazzoli, Davide; Ortelli, Paola; Maestri, Roberto; Bera, Rossana; Gargantini, Roberto; Palamara, Grazia; Zarucchi, Marianna; Giladi, Nir; Frazzitta, Giuseppe

    2017-01-01

    Rehabilitation for patients with Parkinson’s disease (PD) is based on cognitive strategies that exploit attention. Parkinsonians exhibit impairments in divided attention and interference control. Nevertheless, the effectiveness of specific rehabilitation treatments based on attention suggests that other attentional functions are preserved. Data about attention are conflicting in PD, and it is not clear whether rehabilitative treatments that entail attentional strategies affect attention itself. Reaction times (RTs) represent an instrument to explore attention and investigate whether changes in attentional performances parallel rehabilitation induced-gains. RTs of 103 parkinsonian patients in “on” state, without cognitive deficits, were compared with those of a population of 34 healthy controls. We studied those attentional networks that subtend the use of cognitive strategies in motor rehabilitation: alertness and focused and sustained attention, which is a component of the executive system. We used visual and auditory RTs to evaluate alertness and multiple choices RTs (MC RTs) to explore focused and sustained attention. Parkinsonian patients underwent these tasks before and after a 4-week multidisciplinary, intensive and goal-based rehabilitation treatment (MIRT). Unified Parkinson’s Disease Rating Scale (UPDRS) III and Timed Up and Go test (TUG) were assessed at the enrollment and at the end of MIRT to evaluate the motor-functional effectiveness of treatment. We did not find differences in RTs between parkinsonian patients and controls. Further, we found that improvements in motor-functional outcome measures after MIRT (p < 0.0001) paralleled a reduction in MC RTs (p = 0.014). No changes were found for visual and auditory RTs. Correlation analysis revealed no association between changes in MC RTs and improvements in UPDRS-III and TUG. These findings indicate that alertness, as well as focused and sustained attention, are preserved in “on” state. This

  3. The influence of scene context on object recognition is independent of attentional focus.

    PubMed

    Munneke, Jaap; Brentari, Valentina; Peelen, Marius V

    2013-01-01

    Humans can quickly and accurately recognize objects within briefly presented natural scenes. Previous work has provided evidence that scene context contributes to this process, demonstrating improved naming of objects that were presented in semantically consistent scenes (e.g., a sandcastle on a beach) relative to semantically inconsistent scenes (e.g., a sandcastle on a football field). The current study was aimed at investigating which processes underlie the scene consistency effect. Specifically, we tested: (1) whether the effect is due to increased visual feature and/or shape overlap for consistent relative to inconsistent scene-object pairs; and (2) whether the effect is mediated by attention to the background scene. Experiment 1 replicated the scene consistency effect of a previous report (Davenport and Potter, 2004). Using a new, carefully controlled stimulus set, Experiment 2 showed that the scene consistency effect could not be explained by low-level feature or shape overlap between scenes and target objects. Experiments 3a and 3b investigated whether focused attention modulates the scene consistency effect. By using a location cueing manipulation, participants were correctly informed about the location of the target object on a proportion of trials, allowing focused attention to be deployed toward the target object. Importantly, the effect of scene consistency on target object recognition was independent of spatial attention, and was observed both when attention was focused on the target object and when attention was focused on the background scene. These results indicate that a semantically consistent scene context benefits object recognition independently of the focus of attention. We suggest that the scene consistency effect is primarily driven by global scene properties, or "scene gist", that can be processed with minimal attentional resources.

  4. Effect of Music Tempo on Attentional Focus and Perceived Exertion during Self-selected Paced Walking.

    PubMed

    Silva, Aldo Coelho; Dos Santos Ferreira, Sandro; Alves, Ragami Chaves; Follador, Lucio; DA Silva, Sergio Gregorio

    2016-01-01

    This study investigated the influence of music on the rating of perceived exertion (RPE) and attentional focus during walking at a self-selected pace. Fifteen overweight and obese women volunteered to participate in the study. They underwent four sessions: the first for incremental maximal test and anthropometric measurement followed by three experimental sessions. After the first session, they were exposed to three 30-minute walking sessions at a self-selected pace in a counterbalanced order: fast-tempo music (FT), medium-tempo music (MT) and no-music control (NM). Borg's RPE Scale and an Attentional Focus Questionnaire were used to measure the perceptual response and attentional focus, respectively. Results showed that the RPE was higher in the no-music control than in the medium-tempo music (12.05 ± 0.6 vs. 10.5 ± 0.5). Furthermore, dissociative attentional focus was greater for both conditions with music in comparison with the no-music control (NM= 39.0 ± 4.1; MT= 48.4 ± 4.1 and FT= 47.9 ± 4.5). The results indicated that the use of music during walking can modulate attentional focus, increasing dissociative thought, and medium-tempo music can reduce the RPE.

  5. Effect of Music Tempo on Attentional Focus and Perceived Exertion during Self-selected Paced Walking

    PubMed Central

    SILVA, ALDO COELHO; DOS SANTOS FERREIRA, SANDRO; ALVES, RAGAMI CHAVES; FOLLADOR, LUCIO; DA SILVA, SERGIO GREGORIO

    2016-01-01

    This study investigated the influence of music on the rating of perceived exertion (RPE) and attentional focus during walking at a self-selected pace. Fifteen overweight and obese women volunteered to participate in the study. They underwent four sessions: the first for incremental maximal test and anthropometric measurement followed by three experimental sessions. After the first session, they were exposed to three 30-minute walking sessions at a self-selected pace in a counterbalanced order: fast-tempo music (FT), medium-tempo music (MT) and no-music control (NM). Borg’s RPE Scale and an Attentional Focus Questionnaire were used to measure the perceptual response and attentional focus, respectively. Results showed that the RPE was higher in the no-music control than in the medium-tempo music (12.05 ± 0.6 vs. 10.5 ± 0.5). Furthermore, dissociative attentional focus was greater for both conditions with music in comparison with the no-music control (NM= 39.0 ± 4.1; MT= 48.4 ± 4.1 and FT= 47.9 ± 4.5). The results indicated that the use of music during walking can modulate attentional focus, increasing dissociative thought, and medium-tempo music can reduce the RPE. PMID:27990220

  6. On the advantage of an external focus of attention: a benefit to learning or performance?

    PubMed

    Lohse, Keith R; Sherwood, David E; Healy, Alice F

    2014-02-01

    Although there is general agreement in the sport science community that the focus of attention (FOA) has significant effects on performance, there is some debate about whether or not the FOA adopted during training affects learning. A large number of studies on the focus of attention have shown that subjects who train with an external FOA perform better on subsequent retention and transfer tests. However, the FOA in these studies was not experimentally controlled during testing. Therefore, the current study used a dart-throwing paradigm in which the FOA was experimentally manipulated at both acquisition and testing over very short and long training times. Performance at test, in terms of accuracy and precision, was improved by adopting an external focus at test regardless of the focus instructed during acquisition, in both Experiment 1 and 2. Although an effect of acquisition focus during testing in Experiment 2 provides some evidence that FOA affects learning, the current data demonstrate a much stronger effect for performance than learning, and stronger effects of attention on precision than accuracy. Theoretical implications of these results are discussed, but in general these data provide a more nuanced understanding of how attentional focus instructions influence motor learning and performance.

  7. Self-Awareness Without Awareness? Implicit Self-Focused Attention and Behavioral Self-Regulation.

    PubMed

    Silvia, Paul J; Phillips, Ann G

    2013-04-01

    Objective self-awareness theory contends that focusing attention on the self initiates an automatic comparison of self to standards. To gain evidence for automatic self-standard comparison processes, two experiments manipulated attention to self with subliminal first-name priming. People completed a computer-based parity task after being instructed that the standard was to be fast or to be accurate. Subliminal first name priming increased behavioral adherence to the explicit standard. When told to be fast, self-focused people made more mistakes and had faster response times; when told to be accurate, self-focused people made fewer mistakes. A manipulation of conscious self-awareness (via a mirror) had the same self-regulatory effects. The findings suggest that comparing self to standards can occur automatically and that it is attention to self, not awareness of the self per se, that evokes self-evaluation.

  8. Object selection costs in visual working memory: A diffusion model analysis of the focus of attention.

    PubMed

    Sewell, David K; Lilburn, Simon D; Smith, Philip L

    2016-11-01

    A central question in working memory research concerns the degree to which information in working memory is accessible to other cognitive processes (e.g., decision-making). Theories assuming that the focus of attention can only store a single object at a time require the focus to orient to a target representation before further processing can occur. The need to orient the focus of attention implies that single-object accounts typically predict response time costs associated with object selection even when working memory is not full (i.e., memory load is less than 4 items). For other theories that assume storage of multiple items in the focus of attention, predictions depend on specific assumptions about the way resources are allocated among items held in the focus, and how this affects the time course of retrieval of items from the focus. These broad theoretical accounts have been difficult to distinguish because conventional analyses fail to separate components of empirical response times related to decision-making from components related to selection and retrieval processes associated with accessing information in working memory. To better distinguish these response time components from one another, we analyze data from a probed visual working memory task using extensions of the diffusion decision model. Analysis of model parameters revealed that increases in memory load resulted in (a) reductions in the quality of the underlying stimulus representations in a manner consistent with a sample size model of visual working memory capacity and (b) systematic increases in the time needed to selectively access a probed representation in memory. The results are consistent with single-object theories of the focus of attention. The results are also consistent with a subset of theories that assume a multiobject focus of attention in which resource allocation diminishes both the quality and accessibility of the underlying representations. (PsycINFO Database Record

  9. Decoding and Reconstructing the Focus of Spatial Attention from the Topography of Alpha-band Oscillations

    PubMed Central

    Samaha, Jason; Sprague, Thomas C.; Postle, Bradley R.

    2016-01-01

    Many aspects of perception and cognition are supported by activity in neural populations that are tuned to different stimulus features (e.g., orientation, spatial location, color). Goal-directed behavior, such as sustained attention, requires a mechanism for the selective prioritization of contextually appropriate representations. A candidate mechanism of sustained spatial attention is neural activity in the alpha band (8–13 Hz), whose power in the human EEG covaries with the focus of covert attention. Here, we applied an inverted encoding model to assess whether spatially selective neural responses could be recovered from the topography of alpha-band oscillations during spatial attention. Participants were cued to covertly attend to one of six spatial locations arranged concentrically around fixation while EEG was recorded. A linear classifier applied to EEG data during sustained attention demonstrated successful classification of the attended location from the topography of alpha power, although not from other frequency bands. We next sought to reconstruct the focus of spatial attention over time by applying inverted encoding models to the topography of alpha power and phase. Alpha power, but not phase, allowed for robust reconstructions of the specific attended location beginning around 450 msec postcue, an onset earlier than previous reports. These results demonstrate that posterior alpha-band oscillations can be used to track activity in feature-selective neural populations with high temporal precision during the deployment of covert spatial attention. PMID:27003790

  10. Bottom-up influences of voice continuity in focusing selective auditory attention.

    PubMed

    Bressler, Scott; Masud, Salwa; Bharadwaj, Hari; Shinn-Cunningham, Barbara

    2014-01-01

    Selective auditory attention causes a relative enhancement of the neural representation of important information and suppression of the neural representation of distracting sound, which enables a listener to analyze and interpret information of interest. Some studies suggest that in both vision and in audition, the "unit" on which attention operates is an object: an estimate of the information coming from a particular external source out in the world. In this view, which object ends up in the attentional foreground depends on the interplay of top-down, volitional attention and stimulus-driven, involuntary attention. Here, we test the idea that auditory attention is object based by exploring whether continuity of a non-spatial feature (talker identity, a feature that helps acoustic elements bind into one perceptual object) also influences selective attention performance. In Experiment 1, we show that perceptual continuity of target talker voice helps listeners report a sequence of spoken target digits embedded in competing reversed digits spoken by different talkers. In Experiment 2, we provide evidence that this benefit of voice continuity is obligatory and automatic, as if voice continuity biases listeners by making it easier to focus on a subsequent target digit when it is perceptually linked to what was already in the attentional foreground. Our results support the idea that feature continuity enhances streaming automatically, thereby influencing the dynamic processes that allow listeners to successfully attend to objects through time in the cacophony that assails our ears in many everyday settings.

  11. SN1987A's Twentieth Anniversary

    NASA Astrophysics Data System (ADS)

    2007-02-01

    Looking back at 20 Years of Observations of this Supernova with ESO telescopes The unique supernova SN 1987A has been a bonanza for astrophysicists. It provided several observational 'firsts,' like the detection of neutrinos from an exploding star, the observation of the progenitor star on archival photographic plates, the signatures of a non-spherical explosion, the direct observation of the radioactive elements produced during the blast, observation of the formation of dust in the supernova, as well as the detection of circumstellar and interstellar material. ESO PR Photo 08a/07 ESO PR Photo 08a/07 SN1987A in the Large Magellanic Cloud Today, it is exactly twenty years since the explosion of Supernova 1987A in the Large Magellanic Cloud was first observed, at a distance of 163,000 light-years. It was the first naked-eye supernova to be seen for 383 years. Few events in modern astronomy have met with such an enthusiastic response by the scientists and now, after 20 years, it continues to be an extremely exciting object that is further studied by astronomers around the world, in particular using ESO's telescopes. When the first signs of Supernova 1987A, the first supernova of the year 1987, were noticed early on 24 February of that year, it was clear that this would be an unusual event. It was discovered by naked-eye and on a panoramic photographic plate taken with a 10-inch astrograph on Las Campanas in Chile by Oscar Duhalde and Ian Shelton, respectively. A few hours earlier, still on 23 February, two large underground detectors - in Japan and the USA - had registered the passage of high-energy neutrinos. Since SN 1987A exploded in the Large Magellanic Cloud (LMC), it was only accessible to telescopes in the Southern Hemisphere, more particularly in Australia, South Africa, and South America. In Chile, ESO's observatory at La Silla with its armada of telescopes with sizes between 0.5 and 3.6-m, played an important role. ESO PR Photo 08c/07 ESO PR Photo 08c/07 The

  12. A self-novelty manipulation of self-focused attention for internet and laboratory experiments.

    PubMed

    Silvia, Paul J; Eichstaedt, Jan

    2004-05-01

    Conventional manipulations of self-focused attention are poorly suited for Internet experiments and for group-based administration. The authors present a self-novelty manipulation that effectively induces self-awareness for such contexts. In the high self-focus condition, people write about how they differ from their family and friends and from people in general. In the control conditions, people write about neutral topics or do no writing. Three experiments using different measures of self-focus (the situational self-awareness scale, a pronoun selection task, and the private self-consciousness scale) showed that the self-novelty manipulation significantly increased self-focused attention. This effect appeared in Internet-based experiments (Experiment 1) and in laboratory experiments with groups (Experiments 2 and 3). The self-novelty manipulation appears promising for self-awareness research conducted outside of conventional laboratory contexts.

  13. Salience in Second Language Acquisition: Physical Form, Learner Attention, and Instructional Focus

    PubMed Central

    Cintrón-Valentín, Myrna C.; Ellis, Nick C.

    2016-01-01

    We consider the role of physical form, prior experience, and form focused instruction (FFI) in adult language learning. (1) When presented with competing cues to interpretation, learners are more likely to attend to physically more salient cues in the input. (2) Learned attention is an associative learning phenomenon where prior-learned cues block those that are experienced later. (3) The low salience of morphosyntactic cues can be overcome by FFI, which leads learners to attend cues which might otherwise be ignored. Experiment 1 used eye-tracking to investigate how language background influences learners’ attention to morphological cues, as well as the attentional processes whereby different types of FFI overcome low cue salience, learned attention and blocking. Chinese native speakers (no L1 verb-tense morphology) viewed Latin utterances combining lexical and morphological cues to temporality under control conditions (CCs) and three types of explicit FFI: verb grammar instruction (VG), verb salience with textual enhancement (VS), and verb pretraining (VP), and their use of these cues was assessed in a subsequent comprehension test. CC participants were significantly more sensitive to the adverbs than verb morphology. Instructed participants showed greater sensitivity to the verbs. These results reveal attentional processes whereby learners’ prior linguistic experience can shape their attention toward cues in the input, and whereby FFI helps learners overcome the long-term blocking of verb-tense morphology. Experiment 2 examined the role of modality of input presentation – aural or visual – in L1 English learners’ attentional focus on morphological cues and the effectiveness of different FFI manipulations. CC participants showed greater sensitivity toward the adverb cue. FFI was effective in increasing attention to verb-tense morphology, however, the processing of morphological cues was considerably more difficult under aural presentation. From visual

  14. Salience in Second Language Acquisition: Physical Form, Learner Attention, and Instructional Focus.

    PubMed

    Cintrón-Valentín, Myrna C; Ellis, Nick C

    2016-01-01

    We consider the role of physical form, prior experience, and form focused instruction (FFI) in adult language learning. (1) When presented with competing cues to interpretation, learners are more likely to attend to physically more salient cues in the input. (2) Learned attention is an associative learning phenomenon where prior-learned cues block those that are experienced later. (3) The low salience of morphosyntactic cues can be overcome by FFI, which leads learners to attend cues which might otherwise be ignored. Experiment 1 used eye-tracking to investigate how language background influences learners' attention to morphological cues, as well as the attentional processes whereby different types of FFI overcome low cue salience, learned attention and blocking. Chinese native speakers (no L1 verb-tense morphology) viewed Latin utterances combining lexical and morphological cues to temporality under control conditions (CCs) and three types of explicit FFI: verb grammar instruction (VG), verb salience with textual enhancement (VS), and verb pretraining (VP), and their use of these cues was assessed in a subsequent comprehension test. CC participants were significantly more sensitive to the adverbs than verb morphology. Instructed participants showed greater sensitivity to the verbs. These results reveal attentional processes whereby learners' prior linguistic experience can shape their attention toward cues in the input, and whereby FFI helps learners overcome the long-term blocking of verb-tense morphology. Experiment 2 examined the role of modality of input presentation - aural or visual - in L1 English learners' attentional focus on morphological cues and the effectiveness of different FFI manipulations. CC participants showed greater sensitivity toward the adverb cue. FFI was effective in increasing attention to verb-tense morphology, however, the processing of morphological cues was considerably more difficult under aural presentation. From visual exposure

  15. Other-regarding attention focus modulates third-party altruistic choice: An fMRI study

    PubMed Central

    David, Bastian; Hu, Yang; Krüger, Frank; Weber, Bernd

    2017-01-01

    Third-party altruistic decision-making has been shown to be modulated by other-regarding attention (e.g., focusing on the offender’s crime or the victim’s situation especially in judicial judgment). However, the neural mechanisms underlying this modulation remain poorly understood. In this fMRI study, participants voluntarily decided if they wanted to punish the first-party offender or help the second-party victim using their own monetary endowment in an unfair context. Particularly, before deciding they were asked to focus on the (un)fairness of the offender proposing the offer (offender-focused block, OB), the feeling of the victim receiving this offer (victim-focused block, VB), or without any specific focus (baseline block, BB). We found that compared to BB participants punished more frequently and prolonged help choices in OB, whereas they helped more frequently in VB. These findings were accompanied by an increased activation in the temporo-parietal junction (TPJ) during decision making in OB and VB. Moreover, regions relevant to cognitive control (esp. IFG/AI and the dorsal anterior cingulate cortex) were strongly recruited during specific choices conflicting the attention focus (e.g., choosing help in OB). Our findings revealed how other-regarding attention modulates third-party altruistic decision-making at the neural level. PMID:28220867

  16. SN 1987A Transforms into SN Remnant 1987A

    NASA Astrophysics Data System (ADS)

    Crotts, Arlin; Heathcote, Stephen; Lawrence, Stephen

    2014-08-01

    The ejecta and circumstellar ring of SN 1987A are colliding violently. Over several years, we have seen radical changes in the circumstellar nebula as it is overrun by high-speed ejecta, giving birth to a supernova remnant (SNR). We have already discovered (and published), via this observational program, new interactions between ejecta and nebula, as several hot spots appearing every year, and see now the whole innermost nebula interacting. This means that observations, especially spectroscopy, of SNR 1987A have entered a new phase in which ground-based observations can reveal the collective behavior of the SNR, especially when combined with HST data. The collision is predicted (and observed) to produce intense IR/optical emission, in new and previously-observed lines. Depending on whether these arise in the ejecta or nebula, and whether shock or EUV-excited, they have linewidths ~10 to 15,000 km/s; frequent moderate- dispersion spectra are required. With the interaction region now enveloping the inner ring, ionizing radiation has started flooding the entire structure. SOAR/Goodman is ideal for this, covering velocity scales, wavelengths and time intervals unavailable to HST, allowing the first ever study of the creation of a nearby SNR. In particular we need timely, good-seeing Goodman spectra of the reverse shock of SN 1987A's circumstellar/ejecta interaction this semester to combine with our scheduled HST/STIS spectra and WFC3 images (in August 2014) and thereby measure of the compositon of deep layers in the SN progenitor star by studying ionic species measurements not seen by HST data alone.

  17. Effects of Internal and External Focus of Attention during Novices' Instructional Preparation on Subsequent Rehearsal Behaviors

    ERIC Educational Resources Information Center

    Montemayor, Mark; Silvey, Brian A.; Adams, Amy L.; Witt, Kay L.

    2016-01-01

    The purpose of this study was to investigate the effects of internal versus external focus of attention during novice teachers' instructional preparation on their subsequent rehearsal behaviors. Thirty-two undergraduate instrumental music education students led bands in a series of three, 6-minute rehearsals on their assigned excerpt. Prior to…

  18. Decreasing Internal Focus of Attention Improves Postural Control during Quiet Standing in Young Healthy Adults

    ERIC Educational Resources Information Center

    Nafati, Gilel; Vuillerme, Nicolas

    2011-01-01

    This experiment was designed to investigate whether and how decreasing the amount of attentional focus invested in postural control could affect bipedal postural control. Twelve participants were asked to stand upright as immobile as possible on a force platform in one control condition and one cognitive condition. In the latter condition, they…

  19. Focus of Attention to Melody or Harmony and Perception of Music Tension: An Exploratory Study

    ERIC Educational Resources Information Center

    Williams, Lindsey R.; Fredrickson, William E.; Atkinson, Sean

    2011-01-01

    This project represents an initial investigation into utilizing the two-dimensional Continuous Response Digital Interface (CRDI) to track listener perceptions related to the possible relationships between focus of attention to musical elements and perceived musical tension. The two-dimensional CRDI software creates an environment in which the…

  20. Effect of Music Training and Musical Complexity on Focus of Attention to Melody or Harmony

    ERIC Educational Resources Information Center

    Williams, Lindsey R.

    2005-01-01

    The purpose of this study was to investigate the relationships between music training and musical complexity and focus of attention to melody or harmony. Participants (N = 192) were divided into four groups: university jazz majors (n = 64), other university music majors (n = 64), high school instrumentalists (n = 32), and junior high…

  1. The Effect of Asterisks as an Attention Focusing Device on Test Performance of Undergraduate Students.

    ERIC Educational Resources Information Center

    Perrin, David W.; Kerasotes, Dean L.

    It was hypothesized that using asterisks as attention focusing devices would cause students to read all asteriked test items more carefully and would improve test scores of undergraduate education students. Sixty-three undergraduates majoring in elementary or special education were administered a 36-item objective test. Asterisks were used to…

  2. Focusing on Success: Teaching Students with Attention Deficit/Hyperactivity Disorder, Grades 1-12

    ERIC Educational Resources Information Center

    Price, Anne; Crawford, Shawn; Tottle, Johanne; Maunula, Susan

    2006-01-01

    This publication focuses on teaching students with attention deficit/hyperactivity disorder (AD/HD). The first chapter identifies and explains AD/HD: its causes, characteristics, its diagnosis and assessment process, related conditions, and what it looks in the classroom. The following chapters offer information and sample strategies supporting…

  3. Comparing Perception of Stroop Stimuli in Focused versus Divided Attention Paradigms: Evidence for Dramatic Processing Differences

    ERIC Educational Resources Information Center

    Eidels, Ami; Townsend, James T.; Algom, Daniel

    2010-01-01

    A huge set of focused attention experiments show that when presented with color words printed in color, observers report the ink color faster if the carrier word is the name of the color rather than the name of an alternative color, the Stroop effect. There is also a large number (although not so numerous as the Stroop task) of so-called…

  4. Neural Evidence for a Distinction between Short-Term Memory and the Focus of Attention

    ERIC Educational Resources Information Center

    Lewis-Peacock, Jarrod A.; Drysdale, Andrew T.; Oberauer, Klaus; Postle, Bradley R.

    2012-01-01

    It is widely assumed that the short-term retention of information is accomplished via maintenance of an active neural trace. However, we demonstrate that memory can be preserved across a brief delay despite the apparent loss of sustained representations. Delay period activity may, in fact, reflect the focus of attention, rather than STM. We…

  5. Focused Attention Deficits in Patients with Alzheimer's Disease and Mild Cognitive Impairment

    ERIC Educational Resources Information Center

    Levinoff, E.J.; Saumier, D.; Chertkow, H.

    2005-01-01

    Reaction time (RT) tasks take various forms, and can assess psychomotor speed, (i.e., simple reaction time task), and focused attention (i.e., choice reaction time (CRT) task). If cues are provided before stimulus presentation (i.e., cued choice reaction time (CCRT) task), then a cueing effect can also be assessed. A limited number of studies have…

  6. Effects of Internal and External Focus of Attention on Novices' Rehearsal Evaluations

    ERIC Educational Resources Information Center

    Silvey, Brian A.; Montemayor, Mark

    2014-01-01

    The purpose of this study was to investigate the effects of internal and external focus of attention on novices' rehearsal evaluations. Thirty-two undergraduate instrumental music education students led bands in a series of three 6-minute rehearsals on their assigned excerpt. Prior to these rehearsals, participants were led in score study and…

  7. Age-dependent impairment of auditory processing under spatially focused and divided attention: an electrophysiological study.

    PubMed

    Wild-Wall, Nele; Falkenstein, Michael

    2010-01-01

    By using event-related potentials (ERPs) the present study examines if age-related differences in preparation and processing especially emerge during divided attention. Binaurally presented auditory cues called for focused (valid and invalid) or divided attention to one or both ears. Responses were required to subsequent monaurally presented valid targets (vowels), but had to be suppressed to non-target vowels or invalidly cued vowels. Middle-aged participants were more impaired under divided attention than young ones, likely due to an age-related decline in preparatory attention following cues as was reflected in a decreased CNV. Under divided attention, target processing was increased in the middle-aged, likely reflecting compensatory effort to fulfill task requirements in the difficult condition. Additionally, middle-aged participants processed invalidly cued stimuli more intensely as was reflected by stimulus ERPs. The results suggest an age-related impairment in attentional preparation after auditory cues especially under divided attention and latent difficulties to suppress irrelevant information.

  8. Meditation Breath Attention Scores (MBAS): Development and investigation of an internet-based assessment of focused attention during meditation practice.

    PubMed

    Frewen, Paul; Hargraves, Heather; DePierro, Jonathan; D'Andrea, Wendy; Flodrowski, Les

    2016-07-01

    Meditation Breath Attention Scores (MBAS) represent a self-report, state measure of focused attention (FA) during the practice of meditation. The MBAS assessment procedure involves sounding a bell at periodic intervals during meditation practice, at which times participants indicate if they were attending toward breathing (scored 1) or if instead they had become distracted (e.g., by mind wandering; scored 0); scores are then tallied to yield participants' MBAS for that meditation. The current study developed and evaluated a fully automated and Internet-based version of MBAS in 1,101 volunteers. Results suggested that: (a) MBAS are internally consistent across bell rings; (b) MBAS total scores exhibit a non-normal distribution identifying subgroups of participants with particularly poor or robust FA during meditation; (c) MBAS decrease linearly with the duration of meditation practices, indicating that participants tend to experience less FA later as opposed to earlier in the meditation; (d) in the case of eyes-open meditation, MBAS are higher when the amount of time between bells is shorter; (e) MBAS correlate with various self-reported subjective experiences occurring during meditation; and (f) MBAS are weakly associated with higher trait mindful "acting with awareness," lesser ADHD-related symptoms of inattentiveness, and estimated minutes of meditation practiced in the past month. In sum, results provide further support for the construct validity of MBAS and serve to further characterize the dynamics of individual differences in FA during meditation. (PsycINFO Database Record

  9. Trait self-focused attention, task difficulty, and effort-related cardiovascular reactivity.

    PubMed

    Silvia, Paul J; Jones, Hannah C; Kelly, Casey S; Zibaie, Alireza

    2011-03-01

    Using motivational intensity theory as a framework, the present experiment examined how individual differences in self-focused attention interact with task difficulty to predict effort, assessed via cardiovascular reactivity. Participants (n = 50) worked on a cognitive task fixed at an easy, medium, or hard level of difficulty, and individual differences in private self-consciousness and self-reflection were measured. Regression models indicated that trait self-focus interacted with task difficulty to predict cardiovascular reactivity, particularly systolic blood pressure (SBP) reactivity. Participants low and high in trait self-focus showed similar SBP reactivity in the easy and medium conditions, but they diverged in the hard condition: High trait focus was associated with higher SBP reactivity, indicating greater effort, whereas low trait self-focus was associated with low SBP reactivity, indicating disengagement. The findings thus support the motivational intensity approach to effort and its interpretation of self-focus's role in effort mobilization.

  10. Influence of varying focus of attention conditions on dart throwing performance in experts and novices.

    PubMed

    Schorer, J; Jaitner, T; Wollny, R; Fath, F; Baker, J

    2012-03-01

    Research suggests an external focus of attention positively affects motor learning more than an internal focus; however, little research has considered this relationship in motor control situations. The present study examined the role of varying focus of attention conditions on dart throwing performance. Experts (n = 6) and novices (n = 6) performed 84 throws under two internal and one external conditions and in the presence and absence of knowledge of results (KR). Results indicated clear differences between experts and novices on both performance and motor control outcomes. Further, there was some evidence that movement execution was slowed in experts but not in novices, although results were somewhat inconclusive. Our analyses suggest that varying focus of attention affects temporal parameters of movement execution in experts but not spatial parameters. Interestingly, both experts and novices generally perceived all instruction conditions to be hindrances to performance, with the exception of the external focus with KR condition. Further work is necessary to determine the extent to which these results apply to other open and closed skills.

  11. A Distance Measure for Attention Focusing and Anomaly Detection in Systems Monitoring

    NASA Technical Reports Server (NTRS)

    Doyle, R.

    1994-01-01

    Any attempt to introduce automation into the monitoring of complex physical systems must start from a robust anomaly detection capability. This task is far from straightforward, for a single definition of what constitutes an anomaly is difficult to come by. In addition, to make the monitoring process efficient, and to avoid the potential for information overload on human operators, attention focusing must also be addressed. When an anomaly occurs, more often than not several sensors are affected, and the partially redundant information they provide can be confusing, particularly in a crisis situation where a response is needed quickly. Previous results on extending traditional anomaly detection techniques are summarized. The focus of this paper is a new technique for attention focusing.

  12. Effect of progressive self-focus meditation on attention, anxiety, and depression scores.

    PubMed

    Leite, José Roberto; Ornellas, Felipe Leite de Moraes; Amemiya, Tascila Mary; de Almeida, Anna Alice F; Dias, Arnaldo Aparecido; Afonso, Rui; Little, Stephen; Kozasa, Elisa Harumi

    2010-06-01

    This study evaluated the effects of Progressive Self-focus Meditation with 42 volunteers (M age = 46.0 yr., SD = 14.1) allocated to two groups: one that had weekly 1-hr. training sessions in the practice for 5 wk. and one waiting-list group. Participants were evaluated before and after 5 wk. on the Beck Anxiety Inventory, Beck Depression Inventory, the Digit Symbol subtest of the Wechsler Adult Intelligence Scale, and the Mindfulness Attention Awareness Scale. After 5 wk., a significant reduction in scores on depression was found in the Meditation group as well as an increase in attention in comparison with the waiting-list Control group.

  13. Performance of gymnastics skill benefits from an external focus of attention.

    PubMed

    Abdollahipour, Reza; Wulf, Gabriele; Psotta, Rudolf; Palomo Nieto, Miriam

    2015-01-01

    The present study was designed to fill a gap in the literature on attentional focus and sports performance. Specifically, in contrast to most previous studies in which an external focus was directed at an implement, we used a gymnastics skill that did not involve the use of an implement. Furthermore, while most studies used only outcome measures of performance, we also assessed movement quality. Twelve-year-old gymnasts performed a maximum vertical jump with a 180-degree turn while airborne, with their hands crossing in front of their chest during the turn under three different focus conditions. Under the external focus condition, participants were asked to focus on the direction in which a tape marker, which was attached to their chest, was pointing after the turn. Under the internal focus condition, they were asked to focus on the direction in which their hands were pointing after the turn. Under the control condition, no focus instructions were given. The external focus condition resulted in both superior movement form and greater jump height than did the other two conditions, which produced comparable results. The present findings show that, similar to other tasks, the performance of form-based skills can be enhanced relatively easily by appropriate external focus instructions.

  14. Optimal attentional focus during exposure in specific phobia: a meta-analysis.

    PubMed

    Podină, Ioana R; Koster, Ernst H W; Philippot, Pierre; Dethier, Vincent; David, Daniel O

    2013-12-01

    Over the last 30 years, researchers have disagreed over the consequences of diverting attention from threat for exposure efficacy, which is an important theoretical and clinical debate. Therefore, the present meta-analysis assessed the efficacy of attentionally focused exposure against distracted and attentionally uninstructed exposure regarding distress, behavioral, and physiological outcomes. We included 15 randomized studies with specific phobia, totaling 444 participants and targeting outcomes at post-exposure and follow-up. Results indicated no difference between the efficacy of distracted exposure as opposed to focused or uninstructed exposure for distress and physiology. For behavior, at post-exposure, results were marginally significant in favor of distracted as opposed to focused exposure, while at follow-up results significantly favored distraction. However, concerning behavior, uninstructed exposure was superior to distraction. Moderation analyses revealed that, regarding distress reduction and approach behavior, distracted exposure significantly outperformed focused exposure when the distracter was interactive (g=1.010/g=1.128) and exposure was spread over the course of multiple sessions (g=1.527/g=1.606). No moderation analysis was significant for physiological measures. These findings suggest that distraction during exposure could be less counterproductive than previously considered and even beneficial under certain circumstances. Theoretical implications and future directions for research are discussed.

  15. Focusing of visual attention at rest and during physical exercise in soccer players.

    PubMed

    Pesce, Caterina; Tessitore, Antonio; Casella, Rita; Pirritano, Mirella; Capranica, Laura

    2007-09-01

    In this study, we investigated the focus of visual attention in expert soccer players together with the effects of acute bouts of physical exercise on performance. In two discriminative reaction time experiments, which were performed both at rest and under submaximal physical workload, visual attention was cued by means of spatial cues of different size followed by compound stimuli with local and global target features. Soccer players were slower than non-athletes in reacting to local compared with global targets, but were faster in switching from local to global attending. Thus, soccer players appear to be less skilled in local attending, but better able than non-athletes to rapidly "zoom out" the focus of attention. Non-athletes generally showed faster performance under physical load, as expected according to the hypothesis of exercise-induced increases in arousal and/or activation and in resource allocation. In contrast, soccer players showed a more differentiated pattern of exercise-induced facilitation that selectively affects specific components of the attentional performance and is interpreted by referring to the role played by individual expertise and cognitive effort.

  16. An External Focus of Attention Enhances Manual Tracking of Occluded and Visible Targets

    PubMed Central

    Schlesinger, Matthew; Porter, Jared; Russell, Robert

    2013-01-01

    The present study investigated the enhancement effects of an external focus of attention (FOA) in the context of a manual tracking task, in which participants tracked both visible and occluded targets. Three conditions were compared, which manipulated the distance of the FOA from the participant as well as the external/internal dimension. As expected, an external FOA resulted in lower tracking errors than an internal FOA. In addition, analyses of participants’ movement patterns revealed a systematic shift toward higher-frequency movements in the external FOA condition, consistent with the idea that an external FOA exploits the natural movement dynamics available during skilled action. Finally, target visibility did not influence the effect of focused attention on tracking performance, which provides evidence for the proposal that the mechanisms that underlie FOA do not depend directly on vision. PMID:23346062

  17. Top-down modulation of auditory processing: effects of sound context, musical expertise and attentional focus.

    PubMed

    Tervaniemi, M; Kruck, S; De Baene, W; Schröger, E; Alter, K; Friederici, A D

    2009-10-01

    By recording auditory electrical brain potentials, we investigated whether the basic sound parameters (frequency, duration and intensity) are differentially encoded among speech vs. music sounds by musicians and non-musicians during different attentional demands. To this end, a pseudoword and an instrumental sound of comparable frequency and duration were presented. The accuracy of neural discrimination was tested by manipulations of frequency, duration and intensity. Additionally, the subjects' attentional focus was manipulated by instructions to ignore the sounds while watching a silent movie or to attentively discriminate the different sounds. In both musicians and non-musicians, the pre-attentively evoked mismatch negativity (MMN) component was larger to slight changes in music than in speech sounds. The MMN was also larger to intensity changes in music sounds and to duration changes in speech sounds. During attentional listening, all subjects more readily discriminated changes among speech sounds than among music sounds as indexed by the N2b response strength. Furthermore, during attentional listening, musicians displayed larger MMN and N2b than non-musicians for both music and speech sounds. Taken together, the data indicate that the discriminative abilities in human audition differ between music and speech sounds as a function of the sound-change context and the subjective familiarity of the sound parameters. These findings provide clear evidence for top-down modulatory effects in audition. In other words, the processing of sounds is realized by a dynamically adapting network considering type of sound, expertise and attentional demands, rather than by a strictly modularly organized stimulus-driven system.

  18. Subjective Somatosensory Experiences Disclosed by Focused Attention: Cortical-Hippocampal-Insular and Amygdala Contributions

    PubMed Central

    Bauer, Clemens C. C.; Barrios, Fernando A.; Díaz, José-Luis

    2014-01-01

    In order to explore the neurobiological foundations of qualitative subjective experiences, the present study was designed to correlate objective third-person brain fMRI measures with subjective first-person identification and scaling of local, subtle, and specific somatosensory sensations, obtained directly after the imaging procedure. Thus, thirty-four volunteers were instructed to focus and sustain their attention to either provoked or spontaneous sensations of each thumb during the fMRI procedure. By means of a Likert scale applied immediately afterwards, the participants recalled and evaluated the intensity of their attention and identified specific somatosensory sensations (e.g. pulsation, vibration, heat). Using the subject's subjective scores as covariates to model both attention intensity and general somatosensory experiences regressors, the whole-brain random effect analyses revealed activations in the frontopolar prefrontal cortex (BA10), primary somatosensory cortex (BA1), premotor cortex (BA 6), precuneus (BA 7), temporopolar cortex (BA 38), inferior parietal lobe (BA 39), hippocampus, insula and amygdala. Furthermore, BA10 showed differential activity, with ventral BA10 correlating exclusively with attention (r(32) = 0.54, p = 0.0013) and dorsal BA10 correlating exclusively with somatosensory sensation (r(32) = 0.46, p = 0.007). All other reported brain areas showed significant positive correlations solely with subjective somatosensory experiences reports. These results provide evidence that the frontopolar prefrontal cortex has dissociable functions depending on specific cognitive demands; i.e. the dorsal portion of the frontopolar prefrontal cortex in conjunction with primary somatosensory cortex, temporopolar cortex, inferior parietal lobe, hippocampus, insula and amygdala are involved in the processing of spontaneous general subjective somatosensory experiences disclosed by focused and sustained attention. PMID:25166875

  19. Supernova 1987A at 30

    NASA Astrophysics Data System (ADS)

    Spyromilio, J.; Leibundgut, B.; Fransson, C.; Larsson, J.; Migotto, K.; Girard, J.

    2017-03-01

    Thirty years on, SN 1987A continues to develop and, over the last decade in particular, has: revealed the presence of a large centrally concentrated reservoir of dust; shown the presence of molecular species within the ejecta; expanded such that the ejecta structure is angularly resolved; begun the destruction of the circumstellar ring and transitioned to being dominated by energy sources external to the ejecta. We are participating in a live experiment in the creation of a supernova remnant and here the recent progress is briefly overviewed. Exciting developments can be expected as the ejecta and the reverse shock continue their interaction, the X-rays penetrate into the cold molecular core and we observe the return of the material into the interstellar medium. We anticipate that the nature of the remnant of the leptonisation event in the centre will also be revealed.

  20. Axions and SN1987A

    NASA Technical Reports Server (NTRS)

    Burrows, Adam; Turner, Michael S.; Brinkmann, R. P.

    1988-01-01

    The effect of free-streaming axion emission on numerical models for the cooling of the newly born neutron star associated with SN1987A is considered. It is found that for an axion mass of greater than approximately 10 to the -3 eV, axion emission shortens the duration of the expected neutrino burst so significantly that it would be inconsistent with the neutrino observations made by the Kamiokande II and Irvine-Michigan-Brookhaven detectors. However, the possibility has not been investigated that axion trapping (which should occur for masses greater than or equal to 0.02 eV) sufficiently reduces axion emission so that axion masses greater than approximately 2 eV would be consistent with the neutrino observations.

  1. The effects of attentional focus instructions on punching velocity and impact forces among trained combat athletes.

    PubMed

    Halperin, Israel; Chapman, Dale W; Martin, David T; Abbiss, Chris

    2017-03-01

    Research indicates that instructing athlete's to focus on bodily movements (internal focus of attention [IFA]) may hinder performance, whereas instructing them to focus on the movement outcome (external focus of attention [EFA]) often enhances performance. Despite the importance of instructions in striking combat sports, limited research has examined the influence of IFA and EFA on performance in well-trained combat athletes. This study investigated the effects of different instructional cues on punching velocity (m · s(-1)) and normalised impact forces (N · kg(-1)) among intermediate (n = 8) and expert (n = 7) competitive boxers and kickboxers. Athletes completed three rounds of 12 maximal effort punches delivered to a punching integrator on three separate days. Day one was a familiarisation session with only control instructions provided. In the following two days athletes randomly received IFA, EFA or control instructions prior to each of the three rounds. Athletes punching with EFA were 4% faster and 5% more forceful than IFA (P < 0.05), and 2% faster and 3% more forceful than control (P < 0.05). Furthermore, experts punched 11% faster and with 13% greater force compared with intermediate athletes (P < 0.05). EFA led to a positive effect on punching performance and should be favoured over IFA and control instructions.

  2. Children's reasoning about self-presentation following rule violations: the role of self-focused attention.

    PubMed

    Banerjee, Robin; Bennett, Mark; Luke, Nikki

    2012-01-01

    Rule violations are likely to serve as key contexts for learning to reason about public identity. In an initial study with 91 children aged 4-9years, social emotions and self-presentational concerns were more likely to be cited when children were responding to hypothetical vignettes involving social-conventional rather than moral violations. In 2 further studies with 376 children aged 4-9years, experimental manipulations of self-focused attention (either by leading children to believe they were being video-recorded or by varying audience reactions to transgressions) were found to elicit greater attention to social evaluation following moral violations, although self-presentational concerns were consistently salient in the context of social-conventional violations. The role of rule transgressions in children's emerging self-awareness and social understanding is discussed.

  3. Attitude-behavior congruity, mindfulness, and self-focused attention: A behavior-analytic reconstruction

    PubMed Central

    Street, Warren R.

    1994-01-01

    Social psychologists have responded to research reporting low agreement between attitude measures and related behavior with attempts to explain the incongruities and enhance agreement. This article examines attitude-behavior incongruity from a behavior-analytic point of view. Traditional and behavior-analytic views of attitudes and behaviors are compared. In the behavior-analytic view, answering an attitude scale should be considered as behavior displayed by a person under rather unusual social conditions, not as a reflection of an enduring personal disposition. Reasons why questionnaire-answering behavior will not resemble behavior in other functionally different social conditions are reviewed. Special attention is extended to two representative lines of attitude-behavior research: mindfulness and self-focused attention. Discriminative stimuli in both areas of study have produced more predictable agreement between questionnaire-answering behavior and behavior in other settings. PMID:22478180

  4. Improving Facial Emotion Recognition in Schizophrenia: a Controlled Study Comparing Specific and Attentional Focused Cognitive Remediation

    PubMed Central

    Gaudelus, Baptiste; Virgile, Jefferson; Geliot, Sabrina; Dupuis, M.; Franck, Nicolas

    2016-01-01

    Cognitive impairments associated with schizophrenia are very frequent. They concern both neurocognition and social cognition, including facial emotion recognition. These impairments have a negative impact on the daily functioning, in particular the social and vocational rehabilitation of people with schizophrenia. Previous studies in this area clearly demonstrated the interest of cognitive remediation to improve neurocognitive and social cognitive functioning in schizophrenia. They also established clear links between facial emotion recognition skills and attentional processes. The present study compares the GAÏA s-face program (GAÏA arm), which focuses on facial emotion recognition processes, with the RECOS program (RECOS arm), a neurocognitive remediation therapy focusing on selective attention. Forty people with schizophrenia were randomly distributed between each study arm and assessed pre- (T1) and post- (T2) therapy. The single-blind assessment focused on facial emotion recognition (the main criteria), symptoms, social and subjective functioning, and neurocognitive and social cognitive performance. Both programs were conducted by nurses after a 3-day training session. The study showed a significant improvement in facial emotion recognition performance in both groups, with a significantly larger effect in the GAÏA arm. Symptoms and social functioning also improved in the GAÏA arm, and certain neurocognitive and social cognitive processes improved in both study arms. Further studies are recommended, with larger population samples and a follow-up assessing the long-term preservation of these improvements. PMID:27445866

  5. Improving Facial Emotion Recognition in Schizophrenia: a Controlled Study Comparing Specific and Attentional Focused Cognitive Remediation.

    PubMed

    Gaudelus, Baptiste; Virgile, Jefferson; Geliot, Sabrina; Franck, Nicolas

    2016-01-01

    Cognitive impairments associated with schizophrenia are very frequent. They concern both neurocognition and social cognition, including facial emotion recognition. These impairments have a negative impact on the daily functioning, in particular the social and vocational rehabilitation of people with schizophrenia. Previous studies in this area clearly demonstrated the interest of cognitive remediation to improve neurocognitive and social cognitive functioning in schizophrenia. They also established clear links between facial emotion recognition skills and attentional processes. The present study compares the GAÏA s-face program (GAÏA arm), which focuses on facial emotion recognition processes, with the RECOS program (RECOS arm), a neurocognitive remediation therapy focusing on selective attention. Forty people with schizophrenia were randomly distributed between each study arm and assessed pre- (T1) and post- (T2) therapy. The single-blind assessment focused on facial emotion recognition (the main criteria), symptoms, social and subjective functioning, and neurocognitive and social cognitive performance. Both programs were conducted by nurses after a 3-day training session. The study showed a significant improvement in facial emotion recognition performance in both groups, with a significantly larger effect in the GAÏA arm. Symptoms and social functioning also improved in the GAÏA arm, and certain neurocognitive and social cognitive processes improved in both study arms. Further studies are recommended, with larger population samples and a follow-up assessing the long-term preservation of these improvements.

  6. Distinct neural activity associated with focused-attention meditation and loving-kindness meditation.

    PubMed

    Lee, Tatia M C; Leung, Mei-Kei; Hou, Wai-Kai; Tang, Joey C Y; Yin, Jing; So, Kwok-Fai; Lee, Chack-Fan; Chan, Chetwyn C H

    2012-01-01

    This study examined the dissociable neural effects of ānāpānasati (focused-attention meditation, FAM) and mettā (loving-kindness meditation, LKM) on BOLD signals during cognitive (continuous performance test, CPT) and affective (emotion-processing task, EPT, in which participants viewed affective pictures) processing. Twenty-two male Chinese expert meditators (11 FAM experts, 11 LKM experts) and 22 male Chinese novice meditators (11 FAM novices, 11 LKM novices) had their brain activity monitored by a 3T MRI scanner while performing the cognitive and affective tasks in both meditation and baseline states. We examined the interaction between state (meditation vs. baseline) and expertise (expert vs. novice) separately during LKM and FAM, using a conjunction approach to reveal common regions sensitive to the expert meditative state. Additionally, exclusive masking techniques revealed distinct interactions between state and group during LKM and FAM. Specifically, we demonstrated that the practice of FAM was associated with expertise-related behavioral improvements and neural activation differences in attention task performance. However, the effect of state LKM meditation did not carry over to attention task performance. On the other hand, both FAM and LKM practice appeared to affect the neural responses to affective pictures. For viewing sad faces, the regions activated for FAM practitioners were consistent with attention-related processing; whereas responses of LKM experts to sad pictures were more in line with differentiating emotional contagion from compassion/emotional regulation processes. Our findings provide the first report of distinct neural activity associated with forms of meditation during sustained attention and emotion processing.

  7. The short- and long-term fates of memory items retained outside the focus of attention

    PubMed Central

    Eichenbaum, Adam S.; Starrett, Michael J.; Rose, Nathan S.; Emrich, Stephen M.; Postle, Bradley R.

    2015-01-01

    When a test of working memory (WM) requires the retention of multiple items, a subset of them can be prioritized. Recent studies have shown that, although prioritized (i.e., attended) items are associated with active neural representations, unprioritized (i.e., unattended) memory items can be retained in WM despite the absence of such active representations, and with no decrement in their recognition if they are cued later in the trial. These findings raise two intriguing questions about the nature of the short-term retention of information outside the focus of attention. First, when the focus of attention shifts from items in WM, is there a loss of fidelity for those unattended memory items? Second, could the retention of unattended memory items be accomplished by long-term memory mechanisms? We addressed the first question by comparing the precision of recall of attended versus unattended memory items, and found a significant decrease in precision for unattended memory items, reflecting a degradation in the quality of those representations. We addressed the second question by asking subjects to perform a WM task, followed by a surprise memory test for the items that they had seen in the WM task. Long-term memory for unattended memory items from the WM task was not better than memory for items that had remained selected by the focus of attention in the WM task. These results show that unattended WM representations are degraded in quality and are not preferentially represented in long-term memory, as compared to attended memory items. PMID:25472902

  8. The short- and long-term fates of memory items retained outside the focus of attention.

    PubMed

    LaRocque, Joshua J; Eichenbaum, Adam S; Starrett, Michael J; Rose, Nathan S; Emrich, Stephen M; Postle, Bradley R

    2015-04-01

    When a test of working memory (WM) requires the retention of multiple items, a subset of them can be prioritized. Recent studies have shown that, although prioritized (i.e., attended) items are associated with active neural representations, unprioritized (i.e., unattended) memory items can be retained in WM despite the absence of such active representations, and with no decrement in their recognition if they are cued later in the trial. These findings raise two intriguing questions about the nature of the short-term retention of information outside the focus of attention. First, when the focus of attention shifts from items in WM, is there a loss of fidelity for those unattended memory items? Second, could the retention of unattended memory items be accomplished by long-term memory mechanisms? We addressed the first question by comparing the precision of recall of attended versus unattended memory items, and found a significant decrease in precision for unattended memory items, reflecting a degradation in the quality of those representations. We addressed the second question by asking subjects to perform a WM task, followed by a surprise memory test for the items that they had seen in the WM task. Long-term memory for unattended memory items from the WM task was not better than memory for items that had remained selected by the focus of attention in the WM task. These results show that unattended WM representations are degraded in quality and are not preferentially represented in long-term memory, as compared to attended memory items.

  9. Real-time fMRI links subjective experience with brain activity during focused attention

    PubMed Central

    Garrison, Kathleen A.; Scheinost, Dustin; Worhunsky, Patrick D.; Elwafi, Hani M.; Thornhill, Thomas A.; Thompson, Evan; Saron, Clifford; Desbordes, Gaëlle; Kober, Hedy; Hampson, Michelle; Gray, Jeremy R.; Constable, R. Todd; Papademetris, Xenophon; Brewer, Judson A.

    2013-01-01

    Recent advances in brain imaging have improved the measure of neural processes related to perceptual, cognitive and affective functions, yet the relation between brain activity and subjective experience remains poorly characterized. In part, it is a challenge to obtain reliable accounts of participant’s experience in such studies. Here we addressed this limitation by utilizing experienced meditators who are expert in introspection. We tested a novel method to link objective and subjective data, using real-time fMRI (rt-fMRI) to provide participants with feedback of their own brain activity during an ongoing task. We provided real-time feedback during a focused attention task from the posterior cingulate cortex, a hub of the default mode network shown to be activated during mind-wandering and deactivated during meditation. In a first experiment, both meditators and non-meditators reported significant correspondence between the feedback graph and their subjective experience of focused attention and mind-wandering. When instructed to volitionally decrease the feedback graph, meditators, but not non-meditators, showed significant deactivation of the posterior cingulate cortex. We were able to replicate these results in a separate group of meditators using a novel step-wise rt-fMRI discovery protocol in which participants were not provided with prior knowledge of the expected relationship between their experience and the feedback graph (i.e., focused attention versus mind-wandering). These findings support the feasibility of using rt-fMRI to link objective measures of brain activity with reports of ongoing subjective experience in cognitive neuroscience research, and demonstrate the generalization of expertise in introspective awareness to novel contexts. PMID:23684866

  10. The Relationship Between Focused Attention Meditation Practice Habits, Psychological Symptoms, and Quality of Life.

    PubMed

    Bilican, F Isil

    2016-12-01

    This study examined the relationship between focused attention meditation practice habits, psychological symptoms, and quality of life. The participants were 30 adults from New York, NY, practicing Ananda Marga spirituality. They were administered the Symptom Check List-90-R and the Quality of Life Index. The findings pointed out while Ananda Marga meditation practice habits were not associated with improvements in psychological symptoms, longer years in meditation practice was associated with improvements in overall, social and psychological/spiritual quality of life. Longer periods of meditation practice per session were related to lower levels of overall quality of life and economic quality of life.

  11. Working memory benefits creative insight, musical improvisation, and original ideation through maintained task-focused attention.

    PubMed

    De Dreu, Carsten K W; Nijstad, Bernard A; Baas, Matthijs; Wolsink, Inge; Roskes, Marieke

    2012-05-01

    Anecdotes from creative eminences suggest that executive control plays an important role in creativity, but scientific evidence is sparse. Invoking the Dual Pathway to Creativity Model, the authors hypothesize that working memory capacity (WMC) relates to creative performance because it enables persistent, focused, and systematic combining of elements and possibilities (persistence). Study 1 indeed showed that under cognitive load, participants performed worse on a creative insight task. Study 2 revealed positive associations between time-on-task and creativity among individuals high but not low in WMC, even after controlling for general intelligence. Study 3 revealed that across trials, semiprofessional cellists performed increasingly more creative improvisations when they had high rather than low WMC. Study 4 showed that WMC predicts original ideation because it allows persistent (rather than flexible) processing. The authors conclude that WMC benefits creativity because it enables the individual to maintain attention focused on the task and prevents undesirable mind wandering.

  12. Comparing perception of Stroop stimuli in focused versus divided attention paradigms: evidence for dramatic processing differences.

    PubMed

    Eidels, Ami; Townsend, James T; Algom, Daniel

    2010-02-01

    A huge set of focused attention experiments show that when presented with color words printed in color, observers report the ink color faster if the carrier word is the name of the color rather than the name of an alternative color, the Stroop effect. There is also a large number (although not so numerous as the Stroop task) of so-called "redundant targets studies" that are based on divided attention instructions. These almost always indicate that observers report the presence of a visual target ('redness' in the stimulus) faster if there are two replications of the target (the word RED in red ink color) than if only one is present (RED in green or GREEN in red). The present set of four experiments employs the same stimuli and same participants in both designs. Evidence supports the traditional interference account of the Stroop effect, but also supports a non-interference parallel processing account of the word and the color in the divided attention task. Theorists are challenged to find a unifying model that parsimoniously explains both seemingly contradictory results.

  13. Focused attention, open monitoring and automatic self-transcending: Categories to organize meditations from Vedic, Buddhist and Chinese traditions.

    PubMed

    Travis, Fred; Shear, Jonathan

    2010-12-01

    This paper proposes a third meditation-category--automatic self-transcending--to extend the dichotomy of focused attention and open monitoring proposed by Lutz. Automatic self-transcending includes techniques designed to transcend their own activity. This contrasts with focused attention, which keeps attention focused on an object; and open monitoring, which keeps attention involved in the monitoring process. Each category was assigned EEG bands, based on reported brain patterns during mental tasks, and meditations were categorized based on their reported EEG. Focused attention, characterized by beta/gamma activity, included meditations from Tibetan Buddhist, Buddhist, and Chinese traditions. Open monitoring, characterized by theta activity, included meditations from Buddhist, Chinese, and Vedic traditions. Automatic self-transcending, characterized by alpha1 activity, included meditations from Vedic and Chinese traditions. Between categories, the included meditations differed in focus, subject/object relation, and procedures. These findings shed light on the common mistake of averaging meditations together to determine mechanisms or clinical effects.

  14. Three-dimensional focus of attention for iterative cone-beam micro-CT reconstruction

    NASA Astrophysics Data System (ADS)

    Benson, T. M.; Gregor, J.

    2006-09-01

    Three-dimensional iterative reconstruction of high-resolution, circular orbit cone-beam x-ray CT data is often considered impractical due to the demand for vast amounts of computer cycles and associated memory. In this paper, we show that the computational burden can be reduced by limiting the reconstruction to a small, well-defined portion of the image volume. We first discuss using the support region defined by the set of voxels covered by all of the projection views. We then present a data-driven preprocessing technique called focus of attention that heuristically separates both image and projection data into object and background before reconstruction, thereby further reducing the reconstruction region of interest. We present experimental results for both methods based on mouse data and a parallelized implementation of the SIRT algorithm. The computational savings associated with the support region are substantial. However, the results for focus of attention are even more impressive in that only about one quarter of the computer cycles and memory are needed compared with reconstruction of the entire image volume. The image quality is not compromised by either method.

  15. Default mode network activation and Transcendental Meditation practice: Focused Attention or Automatic Self-transcending?

    PubMed

    Travis, Frederick; Parim, Niyazi

    2017-02-01

    This study used subjective reports and eLORETA analysis to assess to what extent Transcendental Meditation (TM) might involve focused attention-voluntary control of mental content. Eighty-seven TM subjects with one month to five years TM experience participated in this study. Regression analysis of years TM practice and self-reported transcendental experiences (lack of time, space and body sense) during meditation practice was flat (r=.07). Those practicing Transcendental Meditation for 1month reported as much transcending as those with 5years of practice. The eLORETA comparison of eyes-closed rest/task and TM practice/task identified similar areas of activation: theta and alpha activation during rest and TM in the posterior cingulate and precuneus, part of the default mode network, and beta2 and beta3 activation during the task in anterior cingulate, ventral lateral and dorsolateral prefrontal cortices, part of the central executive network. In addition, eLORETA comparison of rest and TM identified higher beta temporal activation during rest and higher theta orbitofrontal activation during TM. Thus, it does not seem accurate to include TM practice with meditations in the catgory of Focused Attention, which are characterized by gamma EEG and DMN deactivation. Mixing meditations with different procedures into a single study confounds exploration of meditation effects and confounds application of meditation practices to different subject populations.

  16. Focusing Attention to Deep Structure in Math Problems: Effects on Elementary Education Students with and without Attentional Deficits

    ERIC Educational Resources Information Center

    Kercood, Suneeta; Zentall, Sydney S.; Lee, David L.

    2004-01-01

    The purpose of this study was to examine the effects of actively categorizing math problems on the math problem solving performance of students with and without attention deficit disorder (ADD). To this purpose, 52 fifth and sixth grade students were involved in actively categorizing or noncategorizing (control) tasks followed by two problem…

  17. Developmental changes in anger expression and attention focus: learning to wait.

    PubMed

    Cole, Pamela M; Tan, Patricia Z; Hall, Sarah E; Zhang, Yiyun; Crnic, Keith A; Blair, Clancy B; Li, Runze

    2011-07-01

    Being able to wait is an essential part of self-regulation. In the present study, the authors examined the developmental course of changes in the latency to and duration of target-waiting behaviors by following 65 boys and 55 girls from rural and semirural economically strained homes from ages 18 months to 48 months. Age-related changes in latency to and duration of children's anger expressions and attention focus (e.g., self-initiated distraction) during an 8-min wait for a gift were found. On average, at 18 and 24 months of age, children were quick to react angrily and slower to shift attention away from the desired object than they were at later ages. Over time, children were quicker to distract themselves. By 36 months, distractions occurred before children expressed anger, and anger expressions were briefer. At 48 months, children typically made a quick bid to their mothers about having to wait before distracting themselves; on average, they did not appear angry until the latter half of the wait. Unexpectedly, children bid to their mothers as much at age 48 months as they had at 18 months; however, bids became less angry as children got older. Developmental changes in distraction and bidding predicted age-related changes in the latency to anger. Findings are discussed in terms of the neurocognitive control of attention around age 30 months, the limitations of children's self-regulatory efforts at age 48 months, and the importance of fostering children's ability to forestall, as well as modulate, anger.

  18. Alpha power increases in right parietal cortex reflects focused internal attention.

    PubMed

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

    2014-04-01

    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.

  19. Real-time high-performance attention focusing in outdoors color video streams

    NASA Astrophysics Data System (ADS)

    Itti, Laurent

    2002-06-01

    When confronted with cluttered natural environments, animals still perform orders of magnitude better than artificial vision systems in visual tasks such as orienting, target detection, navigation and scene understanding. To better understand biological visual processing, we have developed a neuromorphic model of how our visual attention is attracted towards conspicuous locations in a visual scene. It replicates processing in the dorsal ('where') visual stream in the primate brain. The model includes a bottom-up (image-based) computation of low-level color, intensity, orientation and flicker features, as well as a nonlinear spatial competition that enhances salient locations in each feature channel. All feature channels feed into a unique scalar 'saliency map' which controls where to next focus attention onto. In this article, we discuss a parallel implementation of the model which runs at 30 frames/s on a 16-CPU Beowulf cluster, and the role of flicker (temporal derivatives) cues in computing salience. We show how our simple within-feature competition for salience effectively suppresses strong but spatially widespread motion transients resulting from egomotion. The model robustly detects salient targets in live outdoors video streams, despite large variations in illumination, clutter, and rapid egomotion. The success of this approach suggests that neuromorphic vision algorithms may prove unusually robust for outdoors vision applications.

  20. A positive influence of vision on motor symptoms during sensory attention focused exercise for Parkinson's disease.

    PubMed

    Sage, Michael D; Almeida, Quincy J

    2010-01-15

    This study evaluated the effect of increased attention to sensory feedback during exercise. Two 12-week exercise programs that differed only in the presence (PD SAFEx) or absence (non-SAFE control group) of increased attention focused on sensory feedback were compared. Participants were assessed symptomatically using the Unified Parkinson's Disease Rating Scale (UPDRS) before the start of the exercise program, immediately following the 12-week program and after a 6-week nonexercise washout period. Secondary outcome measures included the Timed-Up-and-Go (TUG), Grooved Pegboard (GP) and velocity and step length of self-paced gait. Both groups significantly improved on the TUG, GP, velocity, and step length, and this was maintained after a 6-week washout period. Of additional interest, only the PD SAFEx program significantly improved motor symptoms (UPDRS). These gains were maintained in the PD SAFEx group 6 weeks after the exercise was stopped, while motor symptoms significantly worsened in the non-SAFE group. These results suggest that increasing awareness of sensory feedback may be a critical factor that specifically impacts motor symptoms. Future work should strive to uncover the underlying neurophysiological mechanism behind this effect.

  1. The attention to body shape scale: a new measure of body focus.

    PubMed

    Beebe, D W

    1995-12-01

    An abnormal degree of attention to one's body shape has been implicated in the development and maintenance of eating pathology. This article reports on three preliminary reliability and validity studies of the Attention to Body Shape Scale (ABS). Although brief, the ABS was found to be internally consistent and relatively stable over 2 weeks for both women and men. As expected, women were more body-focused on the ABS than were men. Preliminary validation studies on college women had encouraging results. Lending evidence of convergent validity, the ABS correlated with measures of eating pathology and dietary restraint. Moreover, although the ABS correlated with a measure of general-appearance orientation, regression analyses showed that the former was more closely linked than the latter to eating pathology. As evidence of discriminant validity, the ABS failed to correlate with dysphoria, body weight, or the tendency to eat in response to emotional or environmental pressures. As predicted by theory, high scores on the ABS were associated with body-image distortion. However, contrary to predictions, the ABS failed to moderate the impact of induced anxiety on body image on two of three measures. The implications of these findings and suggestions for future work are discussed.

  2. 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

  3. Attentional focus during exposure in spider phobia: the role of schematic versus non-schematic imagery.

    PubMed

    Dethier, Vincent; Bruneau, Nicolas; Philippot, Pierre

    2015-02-01

    Research has provided controversial results regarding the role of distraction (vs. attentional focus) during exposure therapy. In the present study, we manipulated the nature of the concepts activated during exposure. Sixty-six spider phobics were exposed to pictures of spiders and asked, or not, to form mental images of concepts that were either related or unrelated to spiders. At pre-exposure, mid-exposure, post-exposure, and follow-up, subjective distress, heart rate variability, and skin conductance responses were measured and the Fear of Spiders Questionnaire and a Behavioural Avoidance Test were performed. Results showed that the activation of concepts unrelated to spiders led to return of distress at follow-up. Moreover, the activation of concepts related to spiders decreased emotional and avoidance responses between sessions. This pattern of results suggests that the nature of the activated concepts does not influence subjective distress during exposure, but plays an important role in the maintenance of distress reduction between sessions.

  4. Effect of Virtual Reality Exposure and Aural Stimuli on Eye Contact, Directional Focus, and Focus of Attention of Novice Wind Band Conductors

    ERIC Educational Resources Information Center

    Orman, Evelyn K.

    2016-01-01

    This study examined the effects of virtual reality immersion with audio on eye contact, directional focus and focus of attention for novice wind band conductors. Participants (N = 34) included a control group (n = 12) and two virtual reality groups with (n = 10) and without (n = 12) head tracking. Participants completed conducting/score study…

  5. Exploring the Interface: Explicit Focus-on-Form Instruction and Learned Attentional Biases in L2 Latin

    ERIC Educational Resources Information Center

    Cintrón-Valentín, Myrna; Ellis, Nick C.

    2015-01-01

    Eye-tracking was used to investigate the attentional processes whereby different types of focus on form (FonF) instruction assist learners in overcoming learned attention and blocking effects in their online processing of second language input. English native speakers viewed Latin utterances combining lexical and morphological cues to temporality…

  6. Focused and divided attention in a simulated cocktail-party situation: ERP evidence from younger and older adults.

    PubMed

    Getzmann, Stephan; Golob, Edward J; Wascher, Edmund

    2016-05-01

    Speech perception under complex listening conditions usually decreases in aging. This is especially true for listening conditions requiring divided attention among 2 and more relevant speakers. Using a speech perception task and event-related potential measures, we studied the ability of younger and older adults to attend to speech information from a single-target speaker (focused attention) or from 2 different (alternative) target speakers (divided attention). The focused and divided attention conditions were presented either in silence or in the presence of 3 concurrent speakers. In the presence of concurrent speakers, older participants showed worse performance with divided versus focused attention. In contrast, there was no effect of attention condition for the younger adults. Relative to the young, event-related potential analysis in older subjects indicated a decline in preparatory activity for the critical speech information (a delayed and smaller contingent negative variation), and delayed attentional control (indicated by a longer P2 latency). Standardized low-resolution brain electromagnetic tomography revealed that the age-related decline in preparatory activity was associated with reduced activation of medial and superior frontal gyrus and anterior cingulate gyrus. The results suggest that age-related differences in these prefrontal brain areas reflect declines in preparatory attention and gating of subsequent task-related speech information, especially under conditions of divided attention. These findings may reflect mechanisms relating to impaired speech perception by older people in "cocktail-party" listening situations.

  7. Dirac neutrinos and SN 1987A

    NASA Technical Reports Server (NTRS)

    Turner, Michael S.

    1991-01-01

    Previous work has shown that the cooling of SN 1987A excludes a Dirac-neutrino mass greater than theta(20 keV) for nu(sub e), nu(sub mu), or nu(sub tau). The emission of wrong-helicity, Dirac neutrinos from SN 1987A, is re-examined. It is concluded that the effect of a Dirac neutrino on the cooling of SN 1987A has been underestimated due to neutrino degeneracy and additional emission processes. The limit that follows from the cooling of SN 1987A is believed to be greater (probably much greater) than 10 keV. This result is significant in light of the recent evidence for a 17 keV mass eigenstate that mixes with the electron neutrino.

  8. How can comprehension adjunct questions focus students' attention and enhance concept learning of a computer-animated science lesson?

    NASA Astrophysics Data System (ADS)

    Holliday, William G.; McGuire, Barry

    Two focusing hypotheses were evaluated. First, do adjunct questions, focusing on science concepts and inserted after computer-animated sequences, selectively alter students' attentional or practice processing and thus produce differential learning effects? Theoretically, such questions selectively focus students' attention and enhance concept learning of focused concepts. Second, do these questions still provide enough metacognitive scaffolding to produce differential learning effects when only the first 8 out of 12 sequences are followed by focusing questions? Eighth-grade students (n = 160) were randomly assigned to a control group (lesson alone) or one of four treatment groups (lesson plus 12 questions focusing either on heat or on temperature, or lesson plus the same first 8 questions on heat or temperature followed by 4 placebo questions). Two significant two-way interactions with widely varying F ratios supported the differential focusing hypotheses (12 questions - more robust interaction, 8 - less robust interaction).

  9. Anger and Positive Reactivity in Infancy: Effects on Maternal Report of Surgency and Attention Focusing in Early Childhood.

    PubMed

    He, Jie; Hane, Amie Ashley; Degnan, Kathryn Amey; Henderson, Heather A; Xu, Qinmei; Fox, Nathan A

    2013-01-01

    We examined two aspects of temperamental approach in early infancy, positive reactivity and anger, and their unique and combined influences on maternal reports of child surgency and attention focusing at 4 years of age. One hundred and fourteen infants were observed for their positive reactions to novel stimuli at 4 months, and their anger expressions during arm restraint at 9 months. Child surgency and attention focusing at age 4 years were assessed by maternal report. Infants who expressed more anger to restraint were rated higher in surgency during early childhood relative to infants who expressed less anger. The effects of positive reactivity to novelty on attention focusing were moderated by anger to restraint. These findings suggest that infant temperamental approach tendencies are multifaceted and have both unique and combined influences on later maternal report of attention and social behavior.

  10. Mind wandering and attention during focused meditation: a fine-grained temporal analysis of fluctuating cognitive states.

    PubMed

    Hasenkamp, Wendy; Wilson-Mendenhall, Christine D; Duncan, Erica; Barsalou, Lawrence W

    2012-01-02

    Studies have suggested that the default mode network is active during mind wandering, which is often experienced intermittently during sustained attention tasks. Conversely, an anticorrelated task-positive network is thought to subserve various forms of attentional processing. Understanding how these two systems work together is central for understanding many forms of optimal and sub-optimal task performance. Here we present a basic model of naturalistic cognitive fluctuations between mind wandering and attentional states derived from the practice of focused attention meditation. This model proposes four intervals in a cognitive cycle: mind wandering, awareness of mind wandering, shifting of attention, and sustained attention. People who train in this style of meditation cultivate their abilities to monitor cognitive processes related to attention and distraction, making them well suited to report on these mental events. Fourteen meditation practitioners performed breath-focused meditation while undergoing fMRI scanning. When participants realized their mind had wandered, they pressed a button and returned their focus to the breath. The four intervals above were then constructed around these button presses. We hypothesized that periods of mind wandering would be associated with default mode activity, whereas cognitive processes engaged during awareness of mind wandering, shifting of attention and sustained attention would engage attentional subnetworks. Analyses revealed activity in brain regions associated with the default mode during mind wandering, and in salience network regions during awareness of mind wandering. Elements of the executive network were active during shifting and sustained attention. Furthermore, activations during these cognitive phases were modulated by lifetime meditation experience. These findings support and extend theories about cognitive correlates of distributed brain networks.

  11. The focus of attention is similar to other memory systems rather than uniquely different

    PubMed Central

    Beaudry, Olivia; Neath, Ian; Surprenant, Aimée M.; Tehan, Gerald

    2014-01-01

    According to some current theories, the focus of attention (FOA), part of working memory, represents items in a privileged state that is more accessible than items stored in other memory systems. One line of evidence supporting the distinction between the FOA and other memory systems is the finding that items in the FOA are immune to proactive interference (when something learned earlier impairs the ability to remember something learned more recently). The FOA, then, is held to be unique: it is the only memory system that is not susceptible to proactive interference. We review the literature used to support this claim, and although there are many studies in which proactive interference was not observed, we found more studies in which it was observed. We conclude that the FOA is not immune to proactive interference: items in the FOA are susceptible to proactive interference just like items in every other memory system. And, just as in all other memory systems, it is how the items are represented and processed that plays a critical role in determining whether proactive interference will be observed. PMID:24574996

  12. Can sensory attention focused exercise facilitate the utilization of proprioception for improved balance control in PD?

    PubMed

    Lefaivre, Shannon C; Almeida, Quincy J

    2015-02-01

    Impaired sensory processing in Parkinson's disease (PD) has been argued to contribute to balance deficits. Exercises aimed at improving sensory feedback and body awareness have the potential to ameliorate balance deficits in PD. Recently, PD SAFEx™, a sensory and attention focused rehabilitation program, has been shown to improve motor deficits in PD, although balance control has never been evaluated. The objective of this study was to measure the effects of PD SAFEx™ on balance control in PD. Twenty-one participants with mild to moderate idiopathic PD completed 12 weeks of PD SAFEx™ training (three times/week) in a group setting. Prior to training, participants completed a pre-assessment evaluating balance in accordance with an objective, computerized test of balance (modified clinical test of sensory integration and balance (m-CTSIB) and postural stability testing (PST)) protocols. The m-CTSIB was our primary outcome measure, which allowed assessment of balance in both eyes open and closed conditions, thus enabling evaluation of specific sensory contributions to balance improvement. At post-test, a significant interaction between time of assessment and vision condition (p=.014) demonstrated that all participants significantly improved balance control, specifically when eyes were closed. Balance control did not change from pre to post with eyes open. These results provide evidence that PD SAFEx™ is effective at improving the ability to utilize proprioceptive information, resulting in improved balance control in the absence of vision. Enhancing the ability to utilize proprioception for individuals with PD is an important intermediary to improving balance deficits.

  13. Accessing Information in Working Memory: Can the Focus of Attention Grasp Two Elements at the Same Time?

    ERIC Educational Resources Information Center

    Oberauer, Klaus; Bialkova, Svetlana

    2009-01-01

    Processing information in working memory requires selective access to a subset of working-memory contents by a focus of attention. Complex cognition often requires joint access to 2 items in working memory. How does the focus select 2 items? Two experiments with an arithmetic task and 1 with a spatial task investigate time demands for successive…

  14. Possible binary star progenitor for SN1987A

    NASA Astrophysics Data System (ADS)

    White, Graeme L.; Malin, D. F.

    1987-05-01

    Accurate optical astrometry gives a position (B1950.0) for the Large Magellanic Cloud supernova, SN 1987A, relative to the FK 4 system as right ascension, RA = 05h 35min 49.95 s±0.039 s, declination δ = -69°17arcmin57.9arcsec±0.27arcsec. Differential astrometry carried out on prime-focus plates taken with the AAT indicates that the component, star 1, of Sanduleak's star Sk -69202 is within 0.05±0.13 arc s of the supernova. The authors conclude that the progenitor of SN 1987A was star 1 or a fainter binary companion.

  15. Linear Changes in the Spatial Extent of the Focus of Attention across Time

    ERIC Educational Resources Information Center

    Jefferies, Lisa N.; Di Lollo, Vincent

    2009-01-01

    This research examined changes in the spatial extent of focal attention over time. The Attentional Blink (impaired perception of the second of two targets) and Lag-1 sparing (the seemingly paradoxical finding that second-target accuracy is high when the second target immediately follows the first) were employed in a dual-stream paradigm to index…

  16. The Progenitor of SN 1987A. [IUE

    NASA Technical Reports Server (NTRS)

    Sonneborn, G.

    1988-01-01

    Spatially resolved IUE spectra (1150 to 2000 A) taken at the position of SN 1987A in March 1987 show that the 12th mag B3 I star Sk -69 deg 202 disappeared. Only the fainter companion stars (Star 2 and Star 3) are present near the site of the supernova. It is concluded that Sk -69 deg 202 exploded to produce SN 1987A. The known characteristics of Sk -69 deg 202 are consistent with the interpretation that the progenitor was a relatively compact star, having a high-velocity low-density stellar wind prior to the outburst. Recent IUE spectra of SN 1987A (May 1988) show no evidence that Sk -69 deg 202 still exists inside the expanding ejecta.

  17. A single bout of meditation biases cognitive control but not attentional focusing: Evidence from the global-local task.

    PubMed

    Colzato, Lorenza S; van der Wel, Pauline; Sellaro, Roberta; Hommel, Bernhard

    2016-01-01

    Recent studies show that a single bout of meditation can impact information processing. We were interested to see whether this impact extends to attentional focusing and the top-down control over irrelevant information. Healthy adults underwent brief single bouts 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 global-local task. While the size of the global-precedence effect (reflecting attentional focusing) was unaffected by type of meditation, the congruency effect (indicating the failure to suppress task-irrelevant information) was considerably larger after OMM than after FAM. Our findings suggest that engaging in particular kinds of meditation creates particular cognitive-control states that bias the individual processing style toward either goal-persistence or cognitive flexibility.

  18. The Improvement of Emotion and Attention Regulation after a 6-Week Training of Focused Meditation: A Randomized Controlled Trial

    PubMed Central

    Menezes, Carolina Baptista; Buratto, Luciano G.; Erthal, Fátima; Pereira, Mirtes G.; Bizarro, Lisiane

    2013-01-01

    Self-regulatory trainings can be an effective complementary treatment for mental health disorders. We investigated the effects of a six-week-focused meditation training on emotion and attention regulation in undergraduates randomly allocated to a meditation, a relaxation, or a wait-list control group. Assessment comprised a discrimination task that investigates the relationship between attentional load and emotional processing and self-report measures. For emotion regulation, results showed greater reduction in emotional interference in the low attentional load condition in meditators, particularly compared to relaxation. Only meditators presented a significant association between amount of weekly practice and the reduction in emotion interference in the task and significantly reduced image ratings of negative valence and arousal, perceived anxiety and difficulty during the task, and state and trait-anxiety. For attention regulation, response bias during the task was analyzed through signal detection theory. After training, meditation and relaxation significantly reduced bias in the high attentional load condition. Importantly, there was a dose-response effect on general bias: the lowest in meditation, increasing linearly across relaxation and wait-list. Only meditators reduced omissions in a concentrated attention test. Focused meditation seems to be an effective training for emotion and attention regulation and an alternative for treatments in the mental health context. PMID:23935694

  19. Attentional focus influences postural control and reaction time performances only during challenging dual-task conditions in healthy young adults.

    PubMed

    Remaud, Anthony; Boyas, Sébastien; Lajoie, Yves; Bilodeau, Martin

    2013-11-01

    The dual-task paradigm has previously been used to investigate the attentional demands associated with postural control. Previous studies have identified both the focus of attention and the difficulty of a postural task as potential factors influencing dual-task performance. The aim of this study was to examine how the instructed focus of attention influences dual-task performance during quiet standing tasks of various levels of difficulty. Thirteen young adults participated in two testing sessions consisting of standing as still as possible on a force platform in different postural conditions, while simultaneously performing a simple reaction time (RT) task. Postural task difficulty was manipulated by various combinations of three bases of support (feet together, tandem and single leg) and two visual conditions (eyes opened and closed). Participants were instructed to focus on either their balance or their RT performance, depending on the testing session. When comparing postural control with respect to session focus, anterior-posterior sway velocity decreased with the addition of the simple RT task when the focus was on balance, but only during the more difficult dual-task conditions. In contrast, sway area and medial-lateral sway velocity did not change between the two instructed focus sessions. Participants responded faster in all dual-task conditions when focusing on RT performance than on balance. The modified attention allocation index indicated that participants' ability to modulate their allocation of attentional resources to respond positively to instruction was more pronounced in the most challenging postural condition. The present findings could have important implications for the interpretation of dual-task performance in both clinical and research settings.

  20. The effects of state and trait self-focused attention on sexual arousal in sexually functional and dysfunctional women.

    PubMed

    Meston, Cindy M

    2006-04-01

    This study examined the effects of state self-focused attention on sexual arousal and trait self-consciousness on sexual arousal and function in sexually functional (n=16) and dysfunctional (n=16) women. Self-focused attention was induced using a 50% reflectant television screen in one of two counterbalanced sessions during which self-report and physiological sexual responses to erotic films were measured. Self-focused attention significantly decreased vaginal pulse amplitude (VPA) responses among sexually functional but not dysfunctional women, and substantially decreased correlations between self-report and VPA measures of sexual arousal. Self-focused attention did not significantly impact subjective sexual arousal in sexually functional or dysfunctional women. Trait private self-consciousness was positively related to sexual desire, orgasm, compatibility, contentment and sexual satisfaction. Public self-consciousness was correlated with sexual pain. The findings are discussed in terms of Masters and Johnson's [Masters, W. H. & Johnson, V. E. (1970). Human sexual inadequacy. Boston: Little, Brown) concepts of "spectatoring" and "sensate focus."

  1. SAINTS - The SN 1987A Intensive Study

    NASA Astrophysics Data System (ADS)

    Kirshner, Robert

    2010-09-01

    SAINTS is a program to observe SN 1987A, the brightest supernova since 1604, as it matures into the youngest supernova remnant at age 23. HST is the essential tool for observing SN 1987A's many physical components. A violent encounter is underway between the fastest-moving debris and the circumstellar ring: shocks excite "hotspots." Radio, optical, infrared and X-ray fluxes have been rising rapidly: we have organized VLT, Spitzer, and Chandra observations to understand the several emission mechanisms at work. The inner debris, excited by radioactive isotopes from the explosion, is now resolved and seen to be aspherical, providing direct evidence on the shape of the explosion itself and on dust that formed in the debris. Questions about SN 1987A remain unanswered. For example, whereis the compact object whose formation sent neutrinos our way in February 1987 ? A rich and unbroken data set from SAINTS will help answer these central questions and will build an archive for the future to help answer questions we have not yet thought to ask. For Cycle 18, these data will include novel observations with the IR channel of WFC3 and UV observations with COS.

  2. Neural mechanisms of human perceptual choice under focused and divided attention.

    PubMed

    Wyart, Valentin; Myers, Nicholas E; Summerfield, Christopher

    2015-02-25

    Perceptual decisions occur after the evaluation and integration of momentary sensory inputs, and dividing attention between spatially disparate sources of information impairs decision performance. However, it remains unknown whether dividing attention degrades the precision of sensory signals, precludes their conversion into decision signals, or dampens the integration of decision information toward an appropriate response. Here we recorded human electroencephalographic (EEG) activity while participants categorized one of two simultaneous and independent streams of visual gratings according to their average tilt. By analyzing trial-by-trial correlations between EEG activity and the information offered by each sample, we obtained converging behavioral and neural evidence that dividing attention between left and right visual fields does not dampen the encoding of sensory or decision information. Under divided attention, momentary decision information from both visual streams was encoded in slow parietal signals without interference but was lost downstream during their integration as reflected in motor mu- and beta-band (10-30 Hz) signals, resulting in a "leaky" accumulation process that conferred greater behavioral influence to more recent samples. By contrast, sensory inputs that were explicitly cued as irrelevant were not converted into decision signals. These findings reveal that a late cognitive bottleneck on information integration limits decision performance under divided attention, and places new capacity constraints on decision-theoretic models of information integration under cognitive load.

  3. Effect of Voice-Part Training and Music Complexity on Focus of Attention to Melody or Harmony

    ERIC Educational Resources Information Center

    Williams, Lindsey R.

    2009-01-01

    The purpose of this study was to investigate the possible effects of choral voice-part training/experience and music complexity on focus of attention to melody or harmony. Participants (N = 150) were members of auditioned university choral ensembles divided by voice-part (sopranos, n = 44; altos, n = 33; tenors, n = 35; basses, n = 38). The music…

  4. The Effect of Different Attentional Focus Instructions during Finger Movement Tasks in Healthy Subjects: An Exploratory Study.

    PubMed

    Rossettini, Giacomo; Testa, Marco; Vicentini, Marco; Manganotti, Paolo

    2017-01-01

    External focus of attention (EFA) and internal focus of attention (IFA) represent commonly used strategies to instruct subjects during exercise. Several studies showed EFA to be more effective than IFA to improve motor performance and learning. To date the role of these strategies on motor performance during finger movement was less studied. The objective of the study was to investigate motor performance, patient's preference induced by IFA and EFA, and the focus during control condition. Ten healthy right-handed participants performed a finger movement task in control, EFA, and IFA conditions (counterbalanced). Errors, patient's preference, and type of attentional focus spontaneously adopted during the control condition were recorded. EFA determined less error (p < 0.01) compared to control and IFA. Participants preferred EFA against IFA and control condition. In the control group 10% of subjects adopted a purely EFA, 70% of subjects adopted a purely IFA, and 20% of subjects adopted a mixture of the two foci. Our results confirm that EFA is more effective than IFA and control in finger movement task. Due its clinical relevance, the interaction between attention and finger movement should be further investigated.

  5. Anger and Positive Reactivity in Infancy: Effects on Maternal Report of Surgency and Attention Focusing in Early Childhood

    ERIC Educational Resources Information Center

    He, Jie; Hane, Amie Ashley; Degnan, Kathryn Amey; Henderson, Heather A.; Xu, Qinmei; Fox, Nathan A.

    2013-01-01

    We examined two aspects of temperamental approach in early infancy, positive reactivity and anger, and their unique and combined influences on maternal reports of child surgency and attention focusing at 4 years of age. One hundred and fourteen infants were observed for their positive reactions to novel stimuli at 4 months, and their anger…

  6. The Effect of Different Attentional Focus Instructions during Finger Movement Tasks in Healthy Subjects: An Exploratory Study

    PubMed Central

    Rossettini, Giacomo; Vicentini, Marco; Manganotti, Paolo

    2017-01-01

    External focus of attention (EFA) and internal focus of attention (IFA) represent commonly used strategies to instruct subjects during exercise. Several studies showed EFA to be more effective than IFA to improve motor performance and learning. To date the role of these strategies on motor performance during finger movement was less studied. The objective of the study was to investigate motor performance, patient's preference induced by IFA and EFA, and the focus during control condition. Ten healthy right-handed participants performed a finger movement task in control, EFA, and IFA conditions (counterbalanced). Errors, patient's preference, and type of attentional focus spontaneously adopted during the control condition were recorded. EFA determined less error (p < 0.01) compared to control and IFA. Participants preferred EFA against IFA and control condition. In the control group 10% of subjects adopted a purely EFA, 70% of subjects adopted a purely IFA, and 20% of subjects adopted a mixture of the two foci. Our results confirm that EFA is more effective than IFA and control in finger movement task. Due its clinical relevance, the interaction between attention and finger movement should be further investigated. PMID:28286760

  7. Focus of Attention and Choice of Text Modality in Multimedia Learning

    ERIC Educational Resources Information Center

    Schnotz, Wolfgang; Mengelkamp, Christoph; Baadte, Christiane; Hauck, Georg

    2014-01-01

    The term "modality effect" in multimedia learning means that students learn better from pictures combined with spoken rather than written text. The most prominent explanations refer to the split attention between visual text reading and picture observation which could affect transfer of information into working memory, maintenance of…

  8. "No Child" Effect on English-Learners Mulled: Teachers Welcome Attention, Fault Focus on Test Scores

    ERIC Educational Resources Information Center

    Zehr, Mary Ann

    2006-01-01

    Educators who specialize in teaching English-language learners agree that the 4-year-old No Child Left Behind Act has brought unprecedented attention to those students by requiring schools to isolate test-score data for them. They disagree, though, on whether changes in instruction spurred by the law have been positive or negative overall. Such…

  9. Delineation of Early Attentional Control Difficulties in Fragile X Syndrome: Focus on Neurocomputational Changes

    ERIC Educational Resources Information Center

    Scerif, Gaia; Cornish, Kim; Wilding, John; Driver, Jon; Karmiloff-Smith, Annette

    2007-01-01

    Fragile X syndrome (FXS) is due to the silencing of a single X-linked gene and it is associated with striking attentional difficulties. As FXS is well characterised at the cellular level, the condition provides a unique opportunity to investigate how a genetic dysfunction can impact on the development of neurocomputational properties relevant to…

  10. The Effects of Reinvestment of Conscious Processing on Switching Focus of Attention

    ERIC Educational Resources Information Center

    Weiss, Stephen M.

    2011-01-01

    The effects of switching focusing strategies on complex motor skill learning were investigated using a dart-throwing task. Participants were screened for reinvestment of conscious processing by completing the Reinvestment Scale (RS) of Masters, Polman, and Hammond (1993). After an initial baseline phase, two focusing strategies were described. Low…

  11. Delineation of early attentional control difficulties in fragile X syndrome: focus on neurocomputational changes.

    PubMed

    Scerif, Gaia; Cornish, Kim; Wilding, John; Driver, Jon; Karmiloff-Smith, Annette

    2007-04-09

    Fragile X syndrome (FXS) is due to the silencing of a single X-linked gene and it is associated with striking attentional difficulties. As FXS is well characterised at the cellular level, the condition provides a unique opportunity to investigate how a genetic dysfunction can impact on the development of neurocomputational properties relevant to attention. Thirteen young boys with FXS and 13 mental-age-matched typically developing controls performed a touch-screen-based search task that manipulated the similarity between targets and distractors and their heterogeneity in size. Search speed, path and errors were recorded as multiple measures of performance. Children did not differ in overall search speed or path when searching amongst distractors, but striking error patterns distinguished children with FXS from controls. Firstly, although clear markers of previously found targets remained on screen, children with FXS perseverated on touching previous hits more than typically developing controls, consistent with the well-documented inhibitory deficits in adults with the disorder. Secondly, they could accurately discriminate single target-distractor pairs, but, when searching a complex display, they touched distractors more often than control children when distractors were similar to targets and especially so when these were infrequent, highlighting difficulties in judging relative size and allocate attentional weight independently of stimulus frequency. Thirdly, their performance was also characterised by inaccuracies in pointing, suggesting additional motor control deficits. Taken together, the findings suggest that fragile X syndrome affects the early development of multiple processes contributing to efficient attentional selection, as would be predicted from an understanding of the neurocomputational changes associated with the disorder.

  12. Linear polarimetric study of SN 1987A

    NASA Astrophysics Data System (ADS)

    Clocchiatti, A.; Mendez, M.; Benvenuto, O.; Feinstein, C.; Marraco, H.

    Linear polarization measurements of SN 1987A were made with 0.83-m and a 2.15-m telescopes. It is found that the polarization decreases with time (Benvenuto et al., 1987) Because the polarization produced by the interstellar matter is time independent and the wavelength dependence of the observed polarization is far from the interstellar relation (Serkowski et al., 1975) it is suggested that the time dependent characteristic is due to an intrinsic polarization vector.

  13. The Continuing Fall of SN 1987A

    NASA Astrophysics Data System (ADS)

    Dwek, Eli; Arendt, Richard; Bouchet, Patrice; Danziger, John; Frank, Kari; Gehrz, Robert; Park, Sangwook; Woodward, Charles

    2016-08-01

    We propose to use a total of 0.8 hr to obtain 3.6 and 4.5 micron photometry of SNR 1987A at four final epochs between 10900 and 11500 days after the explosion. SN 1987A has been monitored at approximately 6 month intervals throughout the Spitzer mission. The latest IRAC data clearly show that at 3.6 and 4.5 micron, the SN emission has peaked and is now in decline. Continued observation of SN 1987A will allow us to track the decline as the blast wave moves completely past the equatorial ring (ER). The rate at which new dust is swept up should be dropping to zero, and as the presently swept up dust is gradually destroyed (or cools) the emission should continue to fade. The dust traced at these wavelengths is thought to be collisionally-heated by the SN blast wave that also gives rise to the soft X-ray emission from the ER. Early in the mission, the intensity of the mid-IR emission (24 micron) was generally well correlated with that of the X-ray emission. However, the 3.6 and 4.5 micron emission are no longer tracking the brightness of the soft X-ray emission. These differences could stem from a variety of causes, including the sputtering of the dust or changes in the morphology of the ER. Ongoing X-ray observations of the remnant are taking place. Supplementing these with IR observations is essential for determining the spatial distribution, nature, and evolution of this hot dust component. Additionally, the observations may still reveal the appearance of a new emission component from the SN ejecta which is currently interacting with the reverse shock. These observations will complete the record of Spitzer's observations of SN 1987A, spanning more than 15 years from launch to end of mission.

  14. The pupil response reveals increased listening effort when it is difficult to focus attention

    PubMed Central

    Koelewijn, Thomas; de Kluiver, Hilde; Shinn-Cunningham, Barbara G.; Zekveld, Adriana A.; Kramer, Sophia E.

    2015-01-01

    Recent studies have shown that prior knowledge about where, when, and who is going to talk improves speech intelligibility. How related attentional processes affect cognitive processing load has not been investigated yet. In the current study, three experiments investigated how the pupil dilation response is affected by prior knowledge of target speech location, target speech onset, and who is going to talk. A total of 56 young adults with normal hearing participated. They had to reproduce a target sentence presented to one ear while ignoring a distracting sentence simultaneously presented to the other ear. The two sentences were independently masked by fluctuating noise. Target location (left or right ear), speech onset, and talker variability were manipulated in separate experiments by keeping these features either fixed during an entire block or randomized over trials. Pupil responses were recorded during listening and performance was scored after recall. The results showed an improvement in performance when the location of the target speech was fixed instead of randomized. Additionally, location uncertainty increased the pupil dilation response, which suggests that prior knowledge of location reduces cognitive load. Interestingly, the observed pupil responses for each condition were consistent with subjective reports of listening effort. We conclude that communicating in a dynamic environment like a cocktail party (where participants in competing conversations move unpredictably) requires substantial listening effort because of the demands placed on attentional processes. PMID:25732724

  15. The pupil response reveals increased listening effort when it is difficult to focus attention.

    PubMed

    Koelewijn, Thomas; de Kluiver, Hilde; Shinn-Cunningham, Barbara G; Zekveld, Adriana A; Kramer, Sophia E

    2015-05-01

    Recent studies have shown that prior knowledge about where, when, and who is going to talk improves speech intelligibility. How related attentional processes affect cognitive processing load has not been investigated yet. In the current study, three experiments investigated how the pupil dilation response is affected by prior knowledge of target speech location, target speech onset, and who is going to talk. A total of 56 young adults with normal hearing participated. They had to reproduce a target sentence presented to one ear while ignoring a distracting sentence simultaneously presented to the other ear. The two sentences were independently masked by fluctuating noise. Target location (left or right ear), speech onset, and talker variability were manipulated in separate experiments by keeping these features either fixed during an entire block or randomized over trials. Pupil responses were recorded during listening and performance was scored after recall. The results showed an improvement in performance when the location of the target speech was fixed instead of randomized. Additionally, location uncertainty increased the pupil dilation response, which suggests that prior knowledge of location reduces cognitive load. Interestingly, the observed pupil responses for each condition were consistent with subjective reports of listening effort. We conclude that communicating in a dynamic environment like a cocktail party (where participants in competing conversations move unpredictably) requires substantial listening effort because of the demands placed on attentional processes.

  16. Attentional Focus and Control Parameter: Effect on Throwing Pattern and Performance

    ERIC Educational Resources Information Center

    Southard, Dan

    2011-01-01

    In two separate experiments, this study examined changes in motor pattern and performance accuracy when low-level throwers focused on internal variables, external variables, and/or velocity of throw. In Experiment 1 the task goal was to improve the throwing pattern. In Experiment 2 the task goal was to throw as accurately as possible at a target.…

  17. Focusing Narrowly or Broadly Attention When Judging Categorical and Coordinate Spatial Relations: A MEG Study

    PubMed Central

    Franciotti, Raffaella; D’Ascenzo, Stefania; Di Domenico, Alberto; Onofrj, Marco; Tommasi, Luca; Laeng, Bruno

    2013-01-01

    We measured activity in the dorsal system of the human cortex with magnetoencephalography (MEG) during a matching-to-sample plus cueing paradigm, where participants judged the occurrence of changes in either categorical or coordinate spatial relations (e.g., exchanges of left versus right positions or changes in the relative distances) between images of pairs of animals. The attention window was primed in each trial to be either small or large by using cues that immediately preceded the matching image. In this manner, we could assess the modulatory effects of the scope of attention on the activity of the dorsal system of the human cortex during spatial relations processing. The MEG measurements revealed that large spatial cues yielded greater activations and longer peak latencies in the right inferior parietal lobe for coordinate trials, whereas small cues yielded greater activations and longer peak latencies in the left inferior parietal lobe for categorical trials. The activity in the superior parietal lobe, middle frontal gyrus, and visual cortex, was also modulated by the size of the spatial cues and by the type of spatial relation change. The present results support the theory that the lateralization of each kind of spatial processing hinges on differences in the sizes of regions of space attended to by the two hemispheres. In addition, the present findings are inconsistent with the idea of a right-hemispheric dominance for all kinds of challenging spatial tasks, since response times and accuracy rates showed that the categorical spatial relation task was more difficult than the coordinate task and the cortical activations were overall greater in the left hemisphere than in the right hemisphere. PMID:24386197

  18. Focus of attention strategies for finding discrete objects in multispectral imagery

    SciTech Connect

    Harvey, N. R.; Theiler, J. P.

    2004-01-01

    Tools that perform pixel-by-pixel classification of multispectral imagery are useful in broad area mapping applications such as terrain categorization, but are less well-suited to the detection of discrete objects. Pixel-by-pixel classifiers, however, have many advantages: they are relatively simple to design, they can readily employ formal machine learning tools, and they are widely available on a variety of platforms. We describe an approach that enables pixel-by-pixel classifiers to be more effectively used in object-detection settings. This is achieved by optimizing a metric which does not attempt to precisely delineate every pixel comprising the objects of interest, but instead focusses the attention of the analyst to these objects without the distraction of many false alarms. The approach requires only minor modification of exisiting pixel-by-pixel classifiers, and produces substantially improved performance. We will describe algorithms that employ this approach and show how they work on a varitety of object detection problems using remotely-sensed multispectral data.

  19. The effects of focused attention training on the duration of novice drivers' glances inside the vehicle.

    PubMed

    Pradhan, A K; Divekar, G; Masserang, K; Romoser, M; Zafian, T; Blomberg, R D; Thomas, F D; Reagan, I; Knodler, M; Pollatsek, A; Fisher, D L

    2011-10-01

    Several studies have documented that the failure of drivers to attend to the forward roadway for a period lasting longer than 2-3 s is a major cause of highway crashes. Moreover, several studies have demonstrated that novice drivers are more likely to glance away from the roadway than the experienced drivers for extended periods when attempting to do a task inside the vehicle. The present study examines the efficacy of a PC-based training programme (FOrward Concentration and Attention Learning, FOCAL) designed to teach novice drivers not to glance away forthese extended periods of time. A FOCAL-trained group was compared with a placebo-trained group in an on-road test, and the FOCAL-trained group made significantly fewer glances away from the roadway that were more than 2 s than the placebo-trained group. Other measures indicated an advantage for the FOCAL-trained group as well. Statement of relevance: Distracted driving is increasingly a problem, as cell phones, navigation systems, and other in-vehicle devices are introduced into the cabin of the automobile. A training programme is described that has beentested on the open road and can reduce the behaviours that lead to crashes caused by the distracted driving.

  20. The Infrared Evolution of SN1987A

    NASA Astrophysics Data System (ADS)

    Dwek, Eli; Arendt, Richard; Bouchet, Patrice; Burrows, David; Challis, Peter; Danziger, John; De Buizer, James; Gehrz, Robert; Kirshner, Robert; McCray, Richard; Park, Sangwook; Polomski, Elisha; Woodward, Charles

    2006-05-01

    We will use the SPITZER to continue the ongoing monitoring of SN1987A, the youngest supernova remnant that is undergoing noticable evolutionary changes during the lifetime of the Great Observatories. At infrared wavelengths SN1987A provides a unique complimentary view of the interaction of the SN blast wave with the equatorial ring (ER). Dust in theÊ ERÊ is being swept up by the expanding shock and collisionally heated by the X-ray emitting gas observed with CHANDRA, giving rise to IR emission that reveals the composition and amount of dust that formed in the outflow of the presupernova star. The IR observations also provide a unique tool for studying physical processes - the collisional heating and destruction of dust -Ê in dusty X-ray emitting plasmas. Parts of the blast wave has penetrated the denser regions of the ER, creating the "hotspots" observed with HUBBLE. IR line emission from these regions provide important information on the physical conditions and theÊelemental and dust composition in these cooling shocks. Additionally, the ejecta of the SN explosion contains dust that was observed to have formed about 530 days after the explosion. Its imminent interaction with the ring will heat up this dust, which will be observable with SPITZER. In addition to providing useful information on SN1987A and its environment, the proposed observations will address key global issues regarding the origin and evolution of dust in the universe: how much dust is formed in SN ejecta and in quiescent stellar outflows, and how efficiently grains are destroyed by interstellar shock waves.

  1. Verbal-motor attention-focusing instructions influence kinematics and performance on a golf-putting task.

    PubMed

    Munzert, Jörn; Maurer, Heiko; Reiser, Mathias

    2014-01-01

    The authors examined how varying the content of verbal-motor instructions and requesting an internal versus external focus influenced the kinematics and outcome of a golf putting task. On Day 1, 30 novices performed 120 trials with the instruction to focus attention either on performing a pendulum-like movement (internal) or on the desired ball path (external). After 20 retention trials on Day 2, they performed 20 transfer trials with the opposite instruction. Group differences for retention and a group by block interaction showed that external instruction enhanced movement outcome. Kinematic data indicated that specific instruction content influenced outcomes by eliciting changes in movement execution. Switching from the external to the internal focus instruction resulted in a more pendulum-like movement.

  2. Trait self-focused attention increases sensitivity to nonconscious primes: evidence from effort-related cardiovascular reactivity.

    PubMed

    Silvia, Paul J; Kelly, Casey S; Zibaie, Alireza; Nardello, Joseph L; Moore, Lance C

    2013-05-01

    A broad range of primes presented outside of awareness - ranging from emotional faces to people's first names - can influence the physiological mobilization of effort during active coping tasks. Who responds more strongly to implicit cues? Based on models of self-awareness, the present research examined how individual differences in self-focused attention influence sensitivity to nonconscious primes. Adults completed a challenging cognitive task in which two kinds of primes were presented (people's first names and words related to the task's difficulty). Trait self-focus significantly interacted with both primes to predict effort, measured as systolic blood pressure (SBP) reactivity. People high in trait self-focus had significantly higher SBP reactivity when primed with words that made the task seem more important (their first names) and harder (high difficulty words). These findings thus expand the evidence for motivational intensity theory's analysis of implicit processes.

  3. Unparticle constraints from supernova 1987A

    SciTech Connect

    Hannestad, Steen; Raffelt, Georg; Wong, Yvonne Y. Y.

    2007-12-15

    The existence of an unparticle sector, weakly coupled to the standard model, would have a profound impact on supernova (SN) physics. Emission of energy into the unparticle sector from the core of SN 1987A would have significantly shortened the observed neutrino burst. The unparticle interaction with nucleons, neutrinos, electrons and muons is constrained to be so weak that it is unlikely to provide any missing-energy signature at colliders. One important exception are models where scale invariance in the hidden sector is broken by the Higgs vacuum expectation value. In this case the SN emission is suppressed by threshold effects.

  4. IUE investigations of SN 1987A

    NASA Technical Reports Server (NTRS)

    Kirshner, Robert P.

    1989-01-01

    IUE observations of the SN 1987A began shortly after the discovery and have been frequent through 1988 and 1989, using the fine error sensor for photometry, low dispersion spectra for the supernova spectrum, and high dispersion observations for the interstellar medium when the supernova was bright and for circumstellar gas surrounding the supernova as the initial event faded. The UV data were very useful in determining which star exploded, assessing the ionizing pulse produced as the shock hit the surface of the star, and in constraining the stellar evolution that preceded the explosion through observations of a circumstellar shell.

  5. Massive Dirac neutrinos and SN 1987A

    NASA Technical Reports Server (NTRS)

    Burrows, Adam; Gandhi, Raj; Turner, Michael S.

    1992-01-01

    The wrong-helicity states of a Dirac neutrino can provide an important cooling mechanism for young neutron stars. Based on numerical models of the early cooling of the neutron star associated with SN 1987A which self-consistently incorporate wrong-helicity neutrino emission, it is argued that a Dirac neutrino of mass greater than 30 keV (25 keV if it is degenerate) leads to shortening of the neutrino burst that is inconsistent with the Irvine-Michigan-Brookhaven and Kamiokande II data. If pions are as abundant as nucleons in the cores of neutron stars, the present limit improves to 15 keV.

  6. Theoretical infrared spectra of SN 1987A

    NASA Technical Reports Server (NTRS)

    Colgan, Sean W. J.; Hollenbach, David J.

    1988-01-01

    A simple model for the ejecta of SN 1987A is used to show that the expected fluxes in infared fine structure lines from nickel, cobalt, iron, argon, sulfur, silicon, and neon are likely to be detectable for several years following the supernova explosion. Energy sources due to radioactive decay and a central pulsar are considered separately. Most of the mass of heavy elements resides in the inner, pure metal shells of the ejecta, so that the infrared lines will probe the temperature, ejecta masses, and dynamics of this region and not the overlying, hydrogen-rich envelope.

  7. Mirrors, masks, and motivation: implicit and explicit self-focused attention influence effort-related cardiovascular reactivity.

    PubMed

    Silvia, Paul J

    2012-07-01

    Using motivational intensity theory as a framework, three experiments examined how implicit self-focus (manipulated with masked first-name priming) and explicit self-focus (manipulated with a large mirror) influence effort-related cardiovascular activity, particularly systolic blood pressure reactivity. Theories of self-focused attention suggest that both implicit and explicit self-focus bring about self-evaluation and thus make meeting a goal more important. For a "do your best" task of unfixed difficulty, implicit and explicit self-focus both increased effort (Experiment 1) compared to a control condition. For a task that varied in difficulty, implicit and explicit self-focus promoted more effort as the task became increasingly hard (Experiments 2 and 3). Taken together, the findings suggest that implicit and explicit self-processes share a similar motivational architecture. The discussion explores the value of integrating motivational intensity theory with self-awareness theory and considers the emerging interest in implicit aspects of effort regulation.

  8. A psychotherapy researcher's perspective on therapist self-awareness and self-focused attention after a decade of research.

    PubMed

    Williams, Elizabeth Nutt

    2008-03-01

    In this Early Career Award paper, the interplay between quantitative and qualitative approaches to self-awareness in the psychotherapy literature is described. In addition, the linkages between therapist self-awareness and self-focused attention discussed in the cognitive and social psychology literatures are also addressed. Contradictory sets of findings are examined; for example, momentary states of therapist self-awareness have at times been associated with anxiety or poor performance and at other times with positive interpersonal processes and client perceptions. Some of the studies on the management of distracting self-awareness are also reviewed, and suggestions for future research in the areas of mindfulness, attentional flexibility, and the person of the therapist are provided.

  9. Hydrogen Molecules in SN 1987A

    NASA Technical Reports Server (NTRS)

    Culhane, Michael; McCray, Richard

    1995-01-01

    The observations of CO and SiO in the infrared spectrum of SN 1987A clearly indicate that molecules can form in the debris of a supernova explosion. Since H2 is not easily observable we compute its abundance theoretically. For conditions typical of the inner (v less than 2500 km/s) envelope of SN 1987A, the fraction of H that is in molecular form rises to approx. 1% by t approx. 800 days. For t less than 500 days the formation is dominated by the gas-phase reactions H + H(+) yields H2(+) + hv; H2(+) + H yields H2 + H(+). Thereafter, the formation is dominated by the reactions H + e yields H(-) + hv; H(-) + H yields H2 + e. At early times the H(-) may absorb approx. 10%-30% of visible photons, contributing to the apparent paucity of H alpha emission. For t greater than 1000 days the abundance of H2 'freezes out' due to the slowing of all reactions. The opacity of the supernova envelope in the range 912 less than lambda less than or approx. equal to 1400 A (the upper limit depending on temperature) is dominated by resonance scattering in the Lyman and Werner bands of H2. The resulting fluorescence emission bands of H2 in the range 1150 less than lambda less than 1650 A may be observable in the UV spectra of supernovae at late times.

  10. Frontal midline theta rhythm and gamma power changes during focused attention on mental calculation: an MEG beamformer analysis.

    PubMed

    Ishii, Ryouhei; Canuet, Leonides; Ishihara, Tsutomu; Aoki, Yasunori; Ikeda, Shunichiro; Hata, Masahiro; Katsimichas, Themistoklis; Gunji, Atsuko; Takahashi, Hidetoshi; Nakahachi, Takayuki; Iwase, Masao; Takeda, Masatoshi

    2014-01-01

    Frontal midline theta rhythm (Fmθ) appears widely distributed over medial prefrontal areas in EEG recordings, indicating focused attention. Although mental calculation is often used as an attention-demanding task, little has been reported on calculation-related activation in Fmθ experiments. In this study we used spatially filtered MEG and permutation analysis to precisely localize cortical generators of the magnetic counterpart of Fmθ, as well as other sources of oscillatory activity associated with mental calculation processing (i.e., arithmetic subtraction). Our results confirmed and extended earlier EEG/MEG studies indicating that Fmθ during mental calculation is generated in the dorsal anterior cingulate and adjacent medial prefrontal cortex. Mental subtraction was also associated with gamma event-related synchronization, as an index of activation, in right parietal regions subserving basic numerical processing and number-based spatial attention. Gamma event-related desynchronization appeared in the right lateral prefrontal cortex, likely representing a mechanism to interrupt neural activity that can interfere with the ongoing cognitive task.

  11. How do I look? Self-focused attention during a video chat of women with social anxiety (disorder).

    PubMed

    Vriends, Noortje; Meral, Yasemin; Bargas-Avila, Javier A; Stadler, Christina; Bögels, Susan M

    2017-03-03

    We investigated the role of self-focused attention (SFA) in social anxiety (disorder) in an ecologically valid way. In Experiment 1 high (n = 26) versus low (n = 25) socially anxious single women between 18 and 30 years had a video ("Skype") conversation with an attractive male confederate, while seeing themselves and the confederate on-screen. The conversation was divided in four phases: (I) warm-up, (II) positive (confederate was friendly to the participant), (III) critical (confederate was critical to the participant), and (IV) active (participant was instructed to ask questions to the confederate). Participant's SFA was measured by eye-tracked gaze duration at their own image relative to the confederates' video image and other places at the computer screen. Results show that high socially anxious participants were more self-focused in the critical phase, but less self-focused in the active phase than low socially anxious participants. In Experiment 2 women diagnosed with SAD (n = 32) and controls (n = 30) between 18 and 30 years conducted the same experiment. Compared to controls participants with SAD showed increased SFA across all four phases of the conversation, and SFA predicted increased self-rated anxiety during the conversation. In conclusion, in subclinical social anxiety SFA is high only when the interaction partner is critical, whereas instructions to ask questions to the confederate reduces subclinical socially anxious' SFA, while clinical SAD is characterized by heightened self-focused attention throughout the interaction. Results support theories that social anxiety disorder is maintained by SFA, and imply that interventions that lower SFA may help prevent and treat social anxiety disorder, but that SFA can also be adaptive in certain types of interaction, such as when receiving compliments.

  12. Magnetoencephalographic alpha band connectivity reveals differential default mode network interactions during focused attention and open monitoring meditation

    PubMed Central

    Marzetti, Laura; Di Lanzo, Claudia; Zappasodi, Filippo; Chella, Federico; Raffone, Antonino; Pizzella, Vittorio

    2014-01-01

    According to several conceptualizations of meditation, the interplay between brain systems associated to self-related processing, attention and executive control is crucial for meditative states and related traits. We used magnetoencephalography (MEG) to investigate such interplay in a highly selected group of “virtuoso” meditators (Theravada Buddhist monks), with long-term training in the two main meditation styles: focused attention (FA) and open monitoring (OM) meditation. Specifically, we investigated the differences between FA meditation, OM meditation and resting state in the coupling between the posterior cingulate cortex, core node of the Default Mode Network (DMN) implicated in mind wandering and self-related processing, and the whole brain, with a recently developed phase coherence approach. Our findings showed a state dependent coupling of posterior cingulate cortex (PCC) to nodes of the DMN and of the executive control brain network in the alpha frequency band (8–12 Hz), related to different attentional and cognitive control processes in FA and OM meditation, consistently with the putative role of alpha band synchronization in the functional mechanisms for attention and consciousness. The coupling of PCC with left medial prefrontal cortex (lmPFC) and superior frontal gyrus characterized the contrast between the two meditation styles in a way that correlated with meditation expertise. These correlations may be related to a higher mindful observing ability and a reduced identification with ongoing mental activity in more expert meditators. Notably, different styles of meditation and different meditation expertise appeared to modulate the dynamic balance between fronto-parietal (FP) and DMN networks. Our results support the idea that the interplay between the DMN and the FP network in the alpha band is crucial for the transition from resting state to different meditative states. PMID:25360102

  13. Magnetoencephalographic alpha band connectivity reveals differential default mode network interactions during focused attention and open monitoring meditation.

    PubMed

    Marzetti, Laura; Di Lanzo, Claudia; Zappasodi, Filippo; Chella, Federico; Raffone, Antonino; Pizzella, Vittorio

    2014-01-01

    According to several conceptualizations of meditation, the interplay between brain systems associated to self-related processing, attention and executive control is crucial for meditative states and related traits. We used magnetoencephalography (MEG) to investigate such interplay in a highly selected group of "virtuoso" meditators (Theravada Buddhist monks), with long-term training in the two main meditation styles: focused attention (FA) and open monitoring (OM) meditation. Specifically, we investigated the differences between FA meditation, OM meditation and resting state in the coupling between the posterior cingulate cortex, core node of the Default Mode Network (DMN) implicated in mind wandering and self-related processing, and the whole brain, with a recently developed phase coherence approach. Our findings showed a state dependent coupling of posterior cingulate cortex (PCC) to nodes of the DMN and of the executive control brain network in the alpha frequency band (8-12 Hz), related to different attentional and cognitive control processes in FA and OM meditation, consistently with the putative role of alpha band synchronization in the functional mechanisms for attention and consciousness. The coupling of PCC with left medial prefrontal cortex (lmPFC) and superior frontal gyrus characterized the contrast between the two meditation styles in a way that correlated with meditation expertise. These correlations may be related to a higher mindful observing ability and a reduced identification with ongoing mental activity in more expert meditators. Notably, different styles of meditation and different meditation expertise appeared to modulate the dynamic balance between fronto-parietal (FP) and DMN networks. Our results support the idea that the interplay between the DMN and the FP network in the alpha band is crucial for the transition from resting state to different meditative states.

  14. Neutrino astrophysics and SN 1987A

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Badino, G.; Bologna, G.; Castagnoli, C.; Castellina, A.

    1990-04-01

    The Mont Blanc observation of the Large Magellanic Cloud supernova, exploded on February 23, 1987 is summarized. The problem of two bursts, recorded in different underground detectors and separated in time by 4.7 hours, is also discussed. Since the different observations are not contradictory from the experimental point of view, some changes are required in the current predictions of the theoretical models of a gravitational stellar collapse in order to fit all the experimental data. Finally, the combined analysis of the data, recorded in all the neutrino and gravitational wave detectors running at the time of the supernova, clearly indicates a long duration of the phenomenon. Thus, any serious tentative to explain how a star ends its life as a supernova should be based on all the experimental data available, recorded in different, independent experiments running at intercontinental distances at the time of supernova 1987A.

  15. Axions and SN 1987A: Axion trapping

    NASA Technical Reports Server (NTRS)

    Burrows, Adam; Ressell, M. Ted; Turner, Michael S.

    1990-01-01

    If an axion of mass between about 10(exp -3) and 10 eV exists, axion emission would have significantly affected the cooling of the nascent neutron star associated with SN 1987A. For an axion of mass greater than about 10(exp -2) eV axions would, like neutrinos, have a mean-free path that is smaller than the size of a neutron star, and thus would become trapped and radiated from an axion sphere. The trapping regime is treated by using numerical models of the initial cooling of a hot neutron star that incorporate a diffusion approximation for axion-energy transport. The axion opacity due to inverse nucleon-nucleon, axion bremsstrahlung is computed; and then the numerical models are used to calculate the integrated axion luminosity, the temperature of the axion sphere, and the effect of axion emission on the neutrino bursts detected by the Kamiokande II (KII) and Irvine-Michigan-Brookhaven (IMB) water-Cherenkov detectors. The larger the axion mass, the stronger the trapping and the smaller the axion luminosity. The estimate of the axion mass is confirmed above which trapping is so strong that axion emission does not significantly affect the neutrino burst. Based upon the neutrino-burst duration - the most sensitive barometer of axion cooling - it is concluded that for an axion mass greater than about 3 eV axion emission would not have had a significant effect on the neutrino bursts detected by KII and IMB. It is strongly suggested that an axion with mass in the interval 10(exp -3) to 3 eV is excluded by the observation of neutrinos from SN 1987A.

  16. A randomised controlled trial investigating motor skill training as a function of attentional focus in old age

    PubMed Central

    de Bruin, Eling D; Swanenburg, Jaap; Betschon, Elsbeth; Murer, Kurt

    2009-01-01

    Background Motor learning research has had little impact on clinical applications and rarely extended to research about how older adults learn motor skills. There is consistent evidence that motor skill performance and learning can be enhanced by giving learners instructions that direct their attention. The aim of this study was to test whether elderly individuals that receive an external focus instruction during training of dynamic balance skills would learn in a different manner compared to individuals that received an internal focus instruction. Methods This randomised trial included 26 older persons (81 ± 6 years) that were training functional balance twice a week for the duration of 5 weeks. Learning outcomes were recorded after every training session. Weight shifting score and dynamic balance parameters (Biodex Balance System), components of the Extended Timed-Get-Up-and-Go test, five chair rises, and falls efficacy (FES-I) was assessed at baseline and post-intervention. Results Participation for training sessions was 94%. No differences between groups were found following 5 weeks of training for weight shifting score, dynamic balance index and dynamic balance time (p < 0.95, p = 0.16, p < 0.50), implying no learning differences between training groups. Extended Timed-Get-Up-and-Go components Sit-to-stand, p = .036; Gait initiation, p = .039; Slow down, stop, turnaround, and sit down, p = 0.011 and the Fes-I (p = 0.014) showed improvements for the total group, indicating that function improved compared to baseline. Conclusion A 5-week balance training improved weight shifting scores and dynamic balance parameters as well as functional abilities. The observed improvements were independent from the type of attentional focus instructions. The findings provide support for the proposition of different motor learning principles in older adults compared to younger adults. Trial Registration ISRCTN44627088 PMID:19426480

  17. Supernova 1987A in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Kafatos, Minas; Michalitsianos, Andrew G.

    2006-11-01

    Foreword; Acknowledgements; Workshop participants; 1. Images and spectrograms of Sanduleak - 69º202, the SN 1987a progenitor N. R. Walborn; 2. The progenitor of SN 1987A G. Sonneborn; 3. Another supernova with a blue progenitor C. M. Gaskell and W. C. Keel; 4. Optical and infrared observations of SN 1987A from Cerro Tololo Inter-American Observatory M. M. Phillips; 5. SN 1987A: observational results obtained at ESO I. J. Danziger, P. Bouchet, R. A. E. Fosbury, C. Gouiffes, L. B. Lucy, A. F. M. Moorwood, E. Oliva and F. Rufener; 6. Observations of SN 1987A at the South African Astronomical Observatory (SAAO) M. W. Feast; 7. Observations of SN 1987A at the Anglo-Australian Telescope W. J. Couch; 8. Linear polarimetric study of SN 1987A A. Clocchiatti, M. Méndez, O. Benvenuto, C. Feinstein, H. Marraco, B. García and N. Morrell; 9. Infrared spectroscopy of SN 1987A from the NASA Kuiper Airborne Observatory H. P. Larson, S. Drapatz, M. J. Mumma and H. A. Weaver; 10. Radio observations of SN 1987A N. Bartel et al.; 11. Ultraviolet observations of SN 1987A: clues to mass loss R. P. Kirshner; 12. On the energetics of SN 1987A N. Panagia; 13. On the nature and apparent uniqueness of SN 1987A A. V. Filippenko; 14. A comparison of the SN 1987A light curve with other type II supernovae, and the detectability of similar supernovae M. F. Schmitz and C. M. Gaskell; 15. P-Cygni features and photospheric velocities L. Bildsten and J. C. L. Wang; 16. The Neutrino burst from SN 1987A detected in the Mont Blanc LSD experiment M. Aglietta et al.; 17. Toward observational neutrino astrophysics M. Koshiba; 18. The discovery of neutrinos from SN 1987A with the IMB detector J. Matthews; 19. Peering into the abyss: the neutrinos from SN 1987A A. Burrows; 20. Phenomenological analysis of neutrino emission from SN 1987A J. N. Bahcall, D. N. Spergel and W. H. Press; 21. Mass determination of neutrinos H. Y. Chiu; 22. Neutrino transport in a type II supernova D. C. Ellison, P. M. Giovanoni

  18. Structural and Functional Abnormalities in Children with Attention-Deficit/Hyperactivity Disorder: A Focus on Subgenual Anterior Cingulate Cortex.

    PubMed

    Zhan, Chenyang; Liu, Yuhong; Wu, Kai; Gao, Yu; Li, Xiaobo

    2017-03-01

    Attention-deficit/hyperactivity disorder (ADHD), characterized by developmentally inappropriate inattention, hyperactivity/impulsivity, or a combination of both, is a major public health problem. Neuroimaging studies have revealed associations of these cognitive impairments with structural and functional deficits all over the brain. Existing findings are not fully consistent because of the heterogeneity of study samples and diversity of research techniques. In this study, we propose to utilize a multimodal magnetic resonance imaging (MRI) approach to study the structural and functional brain networks in children with ADHD-combined type (ADHD-C) with a focus on the subgenual anterior cingulate cortex (sgACC). Diffusion tensor imaging (DTI) and resting-state functional MRI (rs-fMRI) data from 32 children with ADHD-C and 32 group-matched controls were involved. Network-based statistic analysis of the rs-fMRI data revealed a disconnected functional network between the sgACC and multiple regions in the occipital lobe and cerebellum, whereas the DTI data showed disrupted white matter integrity in the subgenual cingulum bundle (sgCB). Post hoc region of interest (ROI)-based analyses showed significantly increased fluctuation of the spontaneous brain activity in the sgACC and higher radial diffusivity in the sgCB in the ADHD group. Both the rs-fMRI and DTI ROI-based measures were significantly correlated with clinical measures that examine behavioral capacities of attention and inhibitory control. Findings of this study suggest that functional alterations in the sgACC and white matter under development in the sgCB may impact each other, and together contribute to impaired attention and inhibitory control function in children with ADHD.

  19. Axions and SN 1987A: Axion trapping

    NASA Technical Reports Server (NTRS)

    Burrows, Adam; Ressell, M. Ted; Turner, Michael S.

    1990-01-01

    If an axion of mass between about 10(exp -3) eV and 1 eV exists, axion emission would have significantly affected the cooling of the nascent neutron star associated with SN 1987A. For an axion of mass less than about 10(exp -2) eV, axions produced deep inside the neutron star simply stream out; in a previous paper this case has been addressed. Remarkably, for an axion of mass greater than about 10(exp -2) eV axions would, like neutrinos, have a mean-free path that is smaller than the size of a neutron star, and thus would become 'trapped' and radiated from an axion sphere. In this paper the trapping regime is treated by using numerical models of the initial cooling of a hot neutron star that incorporate a leakage approximation scheme for axion-energy transport. The axion opacity is computed due to inverse nucleon-nucleon, axion bremsstrahlung, and numerical models are used to calculate the integrated axion luminosity, the temperature of the axion sphere, and the effect of axion emission on the neutrino bursts detected by the Kamiokande 2 (K2) and Irvine-Michigan-Brookhaven (IMB) water-Cherenkov detectors. The larger the axion mass, the stronger the trapping and the smaller the axion luminosity. The earlier estimate is confirmed and refined of the axion mass above which trapping is so strong that axion emission does not significantly affect the neutrino burst. Based upon the neutrino-burst duration--the most sensitive barometer of axion cooling--it is concluded that for an axion mass of greater than about 0.3 eV, axion emission would not have had a significant effect on the neutrino bursts detected by K2 and IMB. The present work, together with the previous work, strongly suggests that an axion with mass in the interval 10(exp -3) eV to 0.3 eV is excluded by SN 1987A.

  20. The circumstellar ring of SN 1987A

    NASA Astrophysics Data System (ADS)

    Fransson, Claes; Migotto, Katia; Larsson, Josefin; Pesce, Dominic; Challis, Peter; Chevalier, Roger A.; France, Kevin; Kirshner, Robert P.; Leibundgut, Bruno; Lundqvist, Peter; McCray, Richard; Spyromilio, Jason; Taddia, Francesco; Jerkstrand, Anders; Mattila, Seppo; Smith, Nathan; Sollerman, Jesper; Wheeler, J. Craig; Crotts, Arlin; Garnavich, Peter; Heng, Kevin; Lawrence, Stephen S.; Panagia, Nino; Pun, Chun S. J.; Sonneborn, George; Sugerman, Ben

    2016-06-01

    The circumstellar ring of supernova 1987A first became visible a few months after the explosion due to photoionisation by the supernova flash. From 1995 hotspots appeared in the ring and their brightness increased nearly exponentially as a result of interaction with the supernova blast wave. Imaging and spectroscopic observations with the Hubble Space Telescope and the Very Large Telescope now show that both the shocked and the unshocked emission components from the ring have been decreasing since ~ 2009. In addition, the most recent images reveal the brightening of new spots outside the ring. These observations indicate that the hotspots are being dissolved by the shocks and that the blast wave is now expanding and interacting with dense clumps beyond the ring. Based on the currently observed decay we predict that the ring will be destroyed by ~ 2025, while the blast wave will reveal the distribution of gas as it expands outside the ring, thus tracing the mass-loss history of the supernova progenitor.

  1. LSND, SN1987A, and CPT violation

    SciTech Connect

    Murayama, Hitoshi; Yanagida, T.

    2000-10-17

    We point out that neutrino events observed at Kamiokande andIMB from SN1987A disfavor the neutrino oscillation parameters preferredby the LSND experiment. For Delta m2>0 (the light side), theelectron neutrinos from the neutronization burst would be lost, while thefirst event at Kamiokande is quite likely to be due to an electronneutrino. For Delta m2<0 (the dark side), the average energy of thedominantly bar nu e events is already lower than the theoreticalexpectations, which would get aggravated by a complete conversion frombar nu mu to bar nu e. If taken seriously, the LSND data are disfavoredindependent of the existence of a sterile neutrino. A possible remedy isCPT violation, which allows different mass spectra for neutrinos andanti-neutrinos and hence can accommodate atmospheric, solar and LSND datawithout a sterile neutrino. If this is the case, Mini-BooNE must run inbar nu rather than the planned nu mode to test the LSND signal. Wespeculate on a possible origin of CPT violation.

  2. Increases in the right dorsolateral prefrontal cortex and decreases the rostral prefrontal cortex activation after-8 weeks of focused attention based mindfulness meditation.

    PubMed

    Tomasino, Barbara; Fabbro, Franco

    2016-02-01

    Mindfulness meditation is a form of attention control training. The training exercises the ability to repeatedly focus attention. We addressed the activation changes related to an 8-weeks mindfulness-oriented focused attention meditation training on an initially naïve subject cohort. Before and after training participants underwent an fMRI experiment, thus, although not strictly a cross over design, they served as their internal own control. During fMRI they exercised focused attention on breathing and body scan as compared to resting. We found increased and decreased activation in different parts of the prefrontal cortex (PFC) by comparing pre- vs. post-mindfulness training (MT) during breathing and body scan meditation exercises that were compared against their own resting state. In the post-MT (vs. pre-MT) meditation increased activation in the right dorsolateral PFC and in the left caudate/anterior insula and decreased activation in the rostral PFC and right parietal area 3b. Thus a brief mindfulness training caused increased activation in areas involved in sustaining and monitoring the focus of attention (dorsolateral PFC), consistent with the aim of mindfulness that is exercising focused attention mechanisms, and in the left caudate/anterior insula involved in attention and corporeal awareness and decreased activation in areas part of the "default mode" network and is involved in mentalizing (rostral PFC), consistent with the ability trained by mindfulness of reducing spontaneous mind wandering.

  3. The Remnant of Supernova 1987A

    NASA Astrophysics Data System (ADS)

    McCray, Richard; Fransson, Claes

    2016-09-01

    Although it has faded by a factor of ˜107, SN 1987A is still bright enough to be observed in almost every band of the electromagnetic spectrum. Today, the bolometric luminosity of the debris is dominated by a far-infrared (˜200μm) continuum from ˜0.5 M⊙ of dust grains in the interior debris. The dust is heated by UV, optical, and near-infrared (NIR) emission resulting from radioactive energy deposition by 44Ti. The optical light of the supernova debris is now dominated by illumination of the debris by X-rays resulting from the impact of the outer supernova envelope with an equatorial ring (ER) of gas that was expelled some 20,000 years before the supernova explosion. X-ray and optical observations trace a complex system of shocks resulting from this impact, whereas radio observations trace synchrotron radiation from relativistic electrons accelerated by these shocks. The luminosity of the remnant is dominated by an NIR (˜20μm) continuum from dust grains in the ER heated by collisions with ions in the X-ray emitting gas. With the Atacama Large Millimeter Array (ALMA), we can observe the interior debris at millimeter/submillimeter wavelengths, which are not absorbed by the interior dust. The ALMA observations reveal bright emission lines from rotational transitions of CO and SiO lines that provide a new window into the interior structure of the supernova debris. Optical, NIR, and ALMA observations all indicate strongly asymmetric ejecta. Intensive searches have failed to yield any evidence for the compact object expected to reside at the center of the remnant. The current upper limit to the luminosity of such an object is a few tens of solar luminosities.

  4. Dust and Other Recent Discoveries in SN 1987A

    NASA Technical Reports Server (NTRS)

    Sonneborn, George

    2011-01-01

    Supernova 1987 A in the Large Magellanic Cloud is one of the most intensively studied objects in the universe and a Rosetta Stone for understanding the explosions of massive stars. Now almost 25 years old, SN 1987 A is a very young supernova remnant, a phase previously unobserved in any other supernova. In this talk I will discuss recent observations from the far ultraviolet to the far-infrared with HST, the VLT, and the Herschel Space Observatory. These data reveal new insights into the composition, geometry, and heating of the explosion debris, the shock interaction with circumstellar material, and dust in the SN 1987 A system.

  5. Hubble Observations of Supernova 1987A, 1994-2006

    NASA Video Gallery

    A time-lapse sequence of 12 years of Hubble observing SN 1987A shows the onrushing stellar shock wave from the stellar explosion as it is slamming into, heating up, and illuminating the inner regio...

  6. Simulating the Outer Nebula of SN 1987A

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, Ben; Morris, Thomas; Podsiadlowski, Philipp

    2014-01-01

    As has been shown previously, the triple-ring nebula around SN 1987A can be understood as a direct consequence of the merger of two stars, some 20,000 yr before the explosion. Here we present new SPH simulations that also include the pre-merger mass loss and show that this may be able to explain other structures observed around SN 1987A, such as Napoleon's hat and various light echoes.

  7. Signatures of neutrino cooling in the SN1987A scenario

    NASA Astrophysics Data System (ADS)

    Fraija, N.; Bernal, C. G.; Hidalgo-Gaméz, A. M.

    2014-07-01

    The neutrino signal from SN1987A confirmed the core-collapse scenario and the possible formation of a neutron star. Although this compact object has eluded all observations, theoretical and numerical developments have allowed a glimpse of the fate of it. In particular, a hypercritical accretion model has been proposed to forecast the accretion of ˜0.15 M⊙ in two hours and the subsequent submergence of the magnetic field in the newborn neutron star. In this paper, we revisit Chevalier's model in a numerical framework, focusing on the neutrino cooling effect on the supernova fall-back dynamics. For that, using a customized version of the FLASH code, we carry out numerical simulations of the accretion of matter on to the newborn neutron star in order to estimate the size of the neutrino-sphere, the emissivity and luminosity of neutrinos. As a signature of this phase, we estimate the neutrinos expected on SK neutrino experiment and their flavour ratios. This is academically important because, although currently it was very difficult to detect 1.46 thermal neutrinos and their oscillations, these fingerprints are the only viable and reliable way to confirm the hypercritical phase. Perhaps new techniques for detecting neutrino oscillations will arise in the near future allowing us to confirm our estimates.

  8. A working memory workout: how to expand the focus of serial attention from one to four items in 10 hours or less.

    PubMed

    Verhaeghen, Paul; Cerella, John; Basak, Chandramallika

    2004-11-01

    Five individuals participated in an extensive practice study (10 1-hr sessions, 11,000 trials total) on a self-paced identity-judgment (1)n-back task (n ranging from 1 to 5). Within Session 1, response time increased abruptly by about 300 ms in passing from n = 1 to n > 1, suggesting that the focus of attention can accommodate only a single item (H. Caravan, 1998; B. McElree, 2001). Within Session 10, response time was dramatically reduced and increased linearly with n for n < or = 4, with a slope of about 30 ms. The data suggest that working memory consists of a focus of attention governed by a limited-capacity search, expandable through practice, and a content-addressable region outside the focus of attention.

  9. Using the Representation in a Neural Network’s Hidden Layer for Task-Specific Focus of Attention.

    DTIC Science & Technology

    1995-05-22

    m Avail and/or Special Artificial Neural Networks , Selective Attention, Autonomous Road Following, Saliency Map, Visual Processing 3/10 1...of artificial neural networks [Mozer, 1988][Koch & Ullman, 1985]. Mozer makes the dis- tinction between "data-driven" and "conceptually-driven...Attention in Visual Perception. TR, University of Toronto, CRG-TR-88-4. Pomerleau, D.A. (1991) "Efficient Training of Artificial Neural Networks for

  10. Effect of training focused on executive functions (attention, inhibition, and working memory) in preschoolers exhibiting ADHD symptoms

    PubMed Central

    Re, Anna M.; Capodieci, Agnese; Cornoldi, Cesare

    2015-01-01

    The development of early intervention strategies for children with symptoms of Attention Deficit Hyperactivity Disorder (ADHD) is important because it provides an opportunity to prevent severe problems in the future. The main purpose of this investigation was to determine the efficacy of a group training for the control of attention, working memory and impulsive behaviors, involving 5-year-old children with ADHD symptoms. Twenty-six children with ADHD symptoms and 26 with typical development were randomly divided in two conditions. Thirteen children in each group were assigned to the training condition and the other to the business as usual condition (normal class activity). Children who participated in the intervention showed an improvement in the tasks measuring their control of attention, impulsive behavior, and working memory. Moreover, children with typical development who attended the training also improved their competencies. The results confirm the importance of an early intervention for preschool-age children with ADHD symptoms. PMID:26300836

  11. Letter to the editor concerning the article "Performance of gymnastics skill benefits from an external focus of attention" by Abdollahipour, Wulf, Psotta & Nieto (2015).

    PubMed

    Collins, Dave; Carson, Howie J; Toner, John

    2016-01-01

    Abdollahipour, Wulf, Psotta, and Nieto (2015) recently published data in the Journal of Sports Sciences to show that an external focus of attention promotes superior performance effects (gymnastics jump height and judged movement form score) when compared to internal or control foci during skill execution without an implement involved. While we do not contest the veracity of findings reported, nor others that have been used to support beneficial effects of an external focus of attention, in this Letter to the Editor we comment on considerable methodological limitations associated with this and previous studies that, we suggest, have resulted in serious theoretical oversights regarding the control of movement and, most crucially from our practitioner perspective, suboptimal recommendations for applied coaching practice. Specifically, we discuss the lack of consideration towards translational research in this area, the problematic nature of attentional focus cues employed, interpretation of findings in relation to other applied recommendations and coherence with mechanistic underpinning and, finally, the representative nature of task involved. In summary, while (laboratory) research evidence may appear to be conclusive, we suggest that the focus of attention effects are in need of more ecologically valid and rigorous testing as well as consideration of current coaching practices if it is to optimally serve the applied sporting domain that it purportedly aims to.

  12. Self-Esteem, Self-Focused Attention, and the Mediating Role of Fear of Negative Evaluation in College Students with and without Asthma

    ERIC Educational Resources Information Center

    Junghans-Rutelonis, Ashley N.; Suorsa, Kristina I.; Tackett, Alayna P.; Burkley, Edward; Chaney, John M.; Mullins, Larry L.

    2015-01-01

    Objective: The current study investigated the mediating role of fear of negative evaluation on the relationship between self-focused attention and self-esteem among college students with and without asthma. Participants: Young adults with (n = 148) and without (n = 530) childhood-onset asthma were recruited from a college student population.…

  13. Not self-focused attention but negative beliefs affect poor social performance in social anxiety: an investigation of pathways in the social anxiety-social rejection relationship.

    PubMed

    Voncken, Marisol J; Dijk, Corine; de Jong, Peter J; Roelofs, Jeffrey

    2010-10-01

    Patients with social anxiety disorder (SAD) not only fear negative evaluation but are indeed less likeable than people without SAD. Previous research shows social performance to mediate this social anxiety-social rejection relationship. This study studied two pathways hypothesized to lead to poor social performance in social anxiety: increased self-focused attention and negative beliefs. State social anxiety was experimentally manipulated in high and low-blushing-fearful individuals by letting half of the participants believe that they blushed intensely during a 5 min getting-acquainted interaction with two confederates. Participants rated their state social anxiety, self-focused attention, and level of negative beliefs. Two confederates and two video-observers rated subsequently likeability (i.e., social rejection) and social performance of the participants. In both groups, the social anxiety-social rejection relationship was present. Although state social anxiety was related to heightened self-focused attention and negative beliefs, only negative beliefs were associated with relatively poor social performance. In contrast to current SAD models, self-focused attention did not play a key-role in poor social performance but seemed to function as a by-product of state social anxiety. Beliefs of being negatively evaluated seem to elicit changes in behavioral repertoire resulting in a poor social performance and subsequent rejection.

  14. SN 1987A: The Supernova of the Century

    NASA Technical Reports Server (NTRS)

    Sonneborne, George

    2012-01-01

    Supernova 1987 A in the Large Magellanic Cloud is one of the most intensively studied objects in the universe and a Rosetta Stone for understanding the explosions of massive stars. Approaching its 25th anniversary, SN 1987 A is a very young supernova remnant, a phase previously unobserved in any other supernova. The supernova of the 20th Century is now the supernova remnant of the 21st Century. In this talk I will discuss recent observations from the far-ultraviolet to the far-infrared with HST, the VLT, Spitzer, and the Herschel Space Observatory. These data reveal new insights into the composition, geometry, and heating of the explosion debris, the shock interaction with circumstellar material, and dust in the SN 1987 A system.

  15. Disability and Sunshine: Can Hedonic Predictions Be Improved by Drawing Attention to Focusing Illusions or Emotional Adaptation?

    ERIC Educational Resources Information Center

    Ubel, Peter A.; Loewenstein, George; Jepson, Christopher

    2005-01-01

    People frequently mispredict the long-term emotional impact of circumstances. The authors examine 2 causes of such mispredictions--a focusing illusion and underappreciation of adaptation. In Experiment 1, the authors found, in 852 adults, that quality of life estimates (for living with disability) were not increased by reducing focusing illusions.…

  16. What does SN1987A say about extra dimensions?

    NASA Astrophysics Data System (ADS)

    Veerahanumak, Satheeshkumar

    2010-02-01

    There has been a tremendous progress in the last decade in our efforts to confront the String-inspired ideas with experiments or observations. There are two approaches to this problem. One is to use the LHC data and other is to use astronomical data. Among the latter, using SN1987A data for placing the constraints on the models of extra dimensions is very popular. In this poster, we consider all the possible energy loss mechanisms of SN1987A and study the constraints they place on the number and size of extra dimensions and the higher dimensional Planck scale in the ADD scenario. )

  17. The Allocation of Attention to Learning of Goal-Directed Actions: A Cognitive Neuroscience Framework Focusing on the Basal Ganglia

    PubMed Central

    Franz, E. A.

    2012-01-01

    The present paper builds on the idea that attention is largely in service of our actions. A framework and model which captures the allocation of attention for learning of goal-directed actions is proposed and developed. This framework highlights an evolutionary model based on the notion that rudimentary functions of the basal ganglia have become embedded into increasingly higher levels of networks which all contribute to adaptive learning. Supporting the proposed model, background literature is presented alongside key evidence based on experimental studies in the so-called “split-brain” (surgically divided cerebral hemispheres), and selected evidence from related areas of research. Although overlap with other existing findings and models is acknowledged, the proposed framework is an original synthesis of cognitive experimental findings with supporting evidence of a neural system and a carefully formulated model of attention. It is the hope that this new synthesis will be informative in fields of cognition and other fields of brain sciences and will lead to new avenues for experimentation across domains. PMID:23267335

  18. Shifting Attention

    ERIC Educational Resources Information Center

    Ingram, Jenni

    2014-01-01

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

  19. OSSE Observations of 57Co In SN1987A

    DTIC Science & Technology

    1992-01-01

    ray--observations; nucleosynthesis ; X-rays: general 1E.O. Hulburt Center for Space Research, Naval Research Laboratory, Washington DC 20375 2Dept...gamma-ray thickness of the ejecta. Nucleosynthetic models for SN1987A and general nucleosynthesis constraints suggest that the production ratio of 57Ni

  20. IAUS 331: Supernova 1987A thirty years later

    NASA Astrophysics Data System (ADS)

    Ray, Alak

    2017-04-01

    First the neutrinos arrived, then the burst of light: messengers of a cataclysmic event in the galaxy next door. Alak Ray recounts IAUS 331, a conference that celebrated the thirtieth anniversary of the supernova of a lifetime, SN1987A, and explored the critical role of asymmetry in the explosions, surroundings and initial conditions.

  1. Neurofeedback training aimed to improve focused attention and alertness in children with ADHD: a study of relative power of EEG rhythms using custom-made software application.

    PubMed

    Hillard, Brent; El-Baz, Ayman S; Sears, Lonnie; Tasman, Allan; Sokhadze, Estate M

    2013-07-01

    Neurofeedback is a nonpharmacological treatment for attention-deficit hyperactivity disorder (ADHD). We propose that operant conditioning of electroencephalogram (EEG) in neurofeedback training aimed to mitigate inattention and low arousal in ADHD, will be accompanied by changes in EEG bands' relative power. Patients were 18 children diagnosed with ADHD. The neurofeedback protocol ("Focus/Alertness" by Peak Achievement Trainer) has a focused attention and alertness training mode. The neurofeedback protocol provides one for Focus and one for Alertness. This does not allow for collecting information regarding changes in specific EEG bands (delta, theta, alpha, low and high beta, and gamma) power within the 2 to 45 Hz range. Quantitative EEG analysis was completed on each of twelve 25-minute-long sessions using a custom-made MatLab application to determine the relative power of each of the aforementioned EEG bands throughout each session, and from the first session to the last session. Additional statistical analysis determined significant changes in relative power within sessions (from minute 1 to minute 25) and between sessions (from session 1 to session 12). Analysis was of relative power of theta, alpha, low and high beta, theta/alpha, theta/beta, and theta/low beta and theta/high beta ratios. Additional secondary measures of patients' post-neurofeedback outcomes were assessed, using an audiovisual selective attention test (IVA + Plus) and behavioral evaluation scores from the Aberrant Behavior Checklist. Analysis of data computed in the MatLab application, determined that theta/low beta and theta/alpha ratios decreased significantly from session 1 to session 12, and from minute 1 to minute 25 within sessions. The findings regarding EEG changes resulting from brain wave self-regulation training, along with behavioral evaluations, will help elucidate neural mechanisms of neurofeedback aimed to improve focused attention and alertness in ADHD.

  2. A Working Memory Workout: How to Expand the Focus of Serial Attention From One to Four Items in 10 Hours or Less

    ERIC Educational Resources Information Center

    Verhaeghen, Paul; Cerella, John; Basak, Chandramallika

    2004-01-01

    Five individuals participated in an extensive practice study (10 1-hr sessions, 11,000 trials total) on a self-paced identity-judgment ?n-back task (n ranging from 1 to 5). Within Session 1, response time increased abruptly by about 300 ms in passing from n = 1 to n > 1, suggesting that the focus of attention can accommodate only a single item (H.…

  3. Back Translating: An Integrated Approach to Focus Learners' Attention on Their L2 Knowledge Gaps

    ERIC Educational Resources Information Center

    Zhang, Yun; Gao, Cun

    2014-01-01

    Integration of the four language skills can be enhanced by focusing on back translating--translating an English text into the students' first language and then back into English. This article describes a three-step process for using back translation in reading classes as a way to help students identify gaps in their English competence.

  4. The role of shyness and self-focused attention for attribution of reactions in social situations to internal and external causes.

    PubMed

    Alm, Charlotte

    2007-12-01

    The hypothesis that shyness would be associated with attribution of emotional reactions to stable internal causes rather than to less stable internal and external causes was tested in Study 1 (N = 60). In Study 2 (N= 112) the hypothesis that the explanatory power of shyness would decrease once the effect of self-focused attention on attribution to stable internal causes had been controlled for was tested. The results confirmed both hypotheses. Shyness correlated positively with attribution to stable internal causes, but non-significant with attribution to less stable internal and external causes. Shyness explained a lesser portion of the variance in attribution to both of the internal causes when controlling for self-focus. Even though the findings indicate that self-focus is central to the social cognitive processes of shy individuals, they also suggest that self-focus cannot fully explain attribution to internal causes in general and shy individuals' attributional pattern in particular.

  5. What's the Technology For? Teacher Attention and Pedagogical Goals in a Modeling-Focused Professional Development Workshop

    NASA Astrophysics Data System (ADS)

    Wilkerson, Michelle Hoda; Andrews, Chelsea; Shaban, Yara; Laina, Vasiliki; Gravel, Brian E.

    2016-02-01

    This paper explores the role that technology can play in engaging pre-service teachers with the iterative, "messy" nature of model-based inquiry. Over the course of 5 weeks, 11 pre-service teachers worked in groups to construct models of diffusion using a computational animation and simulation toolkit, and designed lesson plans for the toolkit. Content analyses of group discussions and lesson plans document attention to content, representation, revision, and evaluation as interwoven aspects of modeling over the course of the workshop. When animating, only content and representation were heavily represented in group discussions. When simulating, all four aspects were represented to different extents across groups. Those differences corresponded with different planned uses for the technology during lessons: to teach modeling, to engage learners with one another's ideas, or to reveal student ideas. We identify specific ways in which technology served an important role in eliciting teachers' knowledge and goals related to scientific modeling in the classroom.

  6. Attention focusing in a sit-and-wait forager: a spider controls its prey-detection ability in different web sectors by adjusting thread tension.

    PubMed

    Nakata, Kensuke

    2010-01-07

    Focusing attention is a way for animals to search for and to obtain food efficiently. This study examines whether a sit-and-wait forager, the orb-web spider Cyclosa octotuberculata, focuses its attention on limited foraging areas. Video records of foraging activity revealed that the spiders detected prey trapped in the west and east sectors of their web less frequently than prey trapped in the north and south sectors. Comparison of photos of the web hub area with and without spiders present revealed that the spiders pulled radii towards the centre when waiting for prey. Radius pulling is stronger in the north and south web sectors than in the west and east sectors, possibly causing more tension in radii running vertically. Experimental manipulation indicated that the spiders responded to prey quicker when thread tension was increased. The results suggest that C. octotuberculata focus their attention on the web areas above and below the spider by adjusting the tension in web threads; and this causes higher prey detection rates in these areas.

  7. An external focus of attention is a conditio sine qua non for athletes: a response to Carson, Collins, and Toner (2015).

    PubMed

    Wulf, Gabriele

    2016-01-01

    In this invited response to a Letter to the Editor by Carson, Collins, and Toner (2015), I comment on various issues raised by the authors. I highlight the broad range of tasks and dependent measures used in studies comparing the effectiveness of external versus internal foci of attention. These studies--many of which involved sport skills--have consistently found performance or learning benefits when an external focus was adopted. There is no convincing evidence that performers' preferences, or their familiarity with a certain focus, have a moderating effect. Anecdotal evidence reported by coaches who have compared the two types of foci is consistent with research findings. An external focus presumably promotes functional connectivity and contributes to goal-action coupling.

  8. Supernova 1987 A - The nebular loops and 'Napoleon's Hat'

    NASA Astrophysics Data System (ADS)

    Wang, L.; Wampler, E. J.

    1992-08-01

    We discuss observations of the circumstellar environment of SN 1987A that were obtained between August 1989 and January 1992 at ESO's New Technology Telescope. We find that the angular dimensions of the two nebular loops (Wampler et al., 1990) have not changed during this period. Therefore these loops are confined to a small region. The expansion velocity of the loops is less than about 40 km/s if the loops expanded with a uniform velocity from a common origin. This structure and velocity is hard to reproduce with existing wind interaction models. Our observations further suggest that the Napoleon's Hat nebula does not originate from the general background LMC dust, but from a bow shock dust whose origins are closely related to the stellar winds from the progenitor star of SN 1987A.

  9. Light echoes and transient luminescence near SN 1987A

    NASA Technical Reports Server (NTRS)

    Crotts, Arlin P. S.; Kunkel, William E.; Mccarthy, Patrick J.

    1989-01-01

    The discovery of two new light echoes from sheets of material behind supernova 1987A and present images of the progenitor's circumstellar shell are reported, indicating diffuse echoes from the star's red giant wind. The echo sheets' geometry explains well the behavior of SN 1987's 10-micron flux, but the circumstellar shell appears to be 70 percent larger than the prediction from the analysis of narrow UV emission lines. The sheets' recombination time show them relatively thin and dense. The data also constrain the existence of any fourth star in the Sanduleak -69 deg 202 system and show that the feature reported 8 arcsecs from the supernova is probably not an echo from a thin sheet in SN 1987A's foreground.

  10. Radio evolution of the remnant of Supernova 1987A

    NASA Astrophysics Data System (ADS)

    Zanardo, Giovanna

    Radio supernovae result from the collision between a supernova (SN) shock and the progenitor's circumstellar medium (CSM). Supernova 1987A in the Large Magellanic Cloud, as the only nearby core-collapse supernova observed with a telescope since its early stages, has allowed unique studies of the SN-CSM interaction and the complex structure of the resulting emission. This thesis investigates the evolution of the remnant of SN 1987A, as the shock wave impacts the dense CSM in the equatorial ring, and the possible presence of a compact object in the remnant interior, using new data from the Australia Telescope Compact Array, the Atacama Large Millimeter/submillimeter Array, the Australian Long Baseline Array, and the Parkes telescope.

  11. Similarity Analysis of Experiments on SN 1987A Hydrodynamics

    NASA Astrophysics Data System (ADS)

    Ryutov, D.; Kane, J.; Remington, B.

    1997-11-01

    Similarity criteria for experimentally studying hydrodynamic aspects of the SN 1987A explosion are considered. Particular emphasis is made on the study of Richtmyer-Meshkov and Rayleigh-Taylor instabilities. At the early stage of the explosion (t ~a few hours), for the power-law adiabat equations and high pressure in the pusher, there exist a universal similarity that allows one to establish direct links between the SN event and laboratory experiments of the type described in [1]. For the late stage (t ~20 yr) the plasma becomes weakly collisional and transparent to radiation. Radiation losses are insignificant at this stage. We predict an important role of the fire-hose instability in the plasma flow past the SN 1987A ring. We discuss experimental setting where these phenomena could be simulated in a correct way. [1] B. Remington et al. "Phys. Plasmas", v. 4, 1994 (1997); J. Kane et al., ApJ. 478, L75 (1997)

  12. Observing SN 1987A with the International Ultraviolet Explorer

    NASA Technical Reports Server (NTRS)

    Kirshner, Robert P.

    1991-01-01

    The International Ultraviolet Explorer (IUE) satellite played a leading role in elucidating the nature of SN 1987A, providing a unique ultraviolet perspective on the brightest supernova since 1604. IUE observations of SN 1987A began promptly after discovery and were frequent through 1988 and 1989, using the FES (Fine Error Sensor) for photometry, low dispersion spectra for the supernova spectrum, high dispersion observations for the interstellar medium when the supernova was bright, and for circumstellar gas surrounding the supernova as the initial event faded. The UV data were especially useful in determining which star exploded, assessing the ionizing pulse produced as the shock hit the surface of the star, and in constraining the stellar evolution that preceded the explosion through observation of a circumstellar shell.

  13. First results from the Faint Object Camera - SN 1987A

    NASA Technical Reports Server (NTRS)

    Jakobsen, P.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.

    1991-01-01

    The first images of SN 1987A taken on day 1278 after outburst with the Faint Object Camera on board the Hubble Space Telescope are presented. The supernova is well detected and resolved spatially in three broadband ultraviolet exposures spanning the 1500-3800 A range and in a narrow-band image centered on the forbidden O III 5007 line. Simple uniform disk fits to the profiles of SN 1987A yield an average angular diameter of 170 + or - 30 mas, corresponding to an average expansion velocity of 6000 km/s. The derived broadband ultraviolet fluxes, when corrected for interstellar absorption, indicate a blue ultraviolet spectrum corresponding to a color temperature near 13,000 K.

  14. Regularly pulsed neutrinos from supernova SN1987A?

    NASA Technical Reports Server (NTRS)

    Harwit, Martin; Wasserman, Ira M.; Biermann, Peter L.; Meyer, Hinrich

    1987-01-01

    Some consequences of the 8.9 millisecond periodicity observed in neutrino events from SN1987A with the Kamiokonde and IMB experiments are discussed. Interpreting the apparent period as a rotation of a compact object would imply that the neutrino emission is anisotropic and that the neutrino mass, averaged over all observed flavors, is less than 0.2 eV/c-squared. It is also noted that P = 8.9 ms is a reasonable period for very young pulsars.

  15. The Mont Blanc detection of neutrinos from SN 1987A.

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Badino, G.; Bologna, G.; Castagnoli, C.; Castellina, A.; Dadykin, V. L.; Fulgione, W.; Galeotti, P.; Kalchukov, F. F.; Kortchaguin, V. B.; Kortchaguin, P. V.; Malguin, A. S.; Ryassny, V. G.; Ryazhkaya, O. G.; Saavedra, O.; Talochkin, V. P.; Trinchero, G.; Vernetto, S.; Zatsepin, G. T.; Yakushev, V. F.

    The authors discuss the event detected in the Mont Blanc Underground Neutrino Observatory on February 23, 1987, during the occurrence of supernova SN 1987A. The pulse amplitudes, the background imitation probability, and the energetics connected with the event are reported. It is also shown that some interactions recorded at the same time in other underground experiments, with a lower detection efficiency, are consistent with the Mont Blanc event.

  16. The Origin of the Rings Around SN1987A

    NASA Astrophysics Data System (ADS)

    Martin, Crystal L.; Arnett, David

    1994-12-01

    Hubble Space Telescope (HST) images show three elliptical rings of fluorescing gas around SN1987A. The progenitor's mass loss history is encoded in this circumstellar structure, and the spatial and temporal variations in the winds' velocity, density, and chemical composition can be derived if the formation of the nebula is understood. Hence, SN1987A's nebula provides a unique opportunity to learn how the outer layers of a massive star were changing during the relatively short, late evolutionary stages preceeding core collapse. A successful model may have applications in a much broader context as well, since the morphology of SN1987A's nebula is not unique. The Crab Nebula, Eta Carina, and a class of planetary nebulae share the same basic geometry -- a double-lobed bubble constricted at the waist by higher density gas in a disk or torus. We present a direct comparison of the interacting-winds model for the formation of SN1987A's nebula and HST images. New two-dimensional hydrodynamic calculations of the interaction of the fast wind from the blue supergiant progenitor with a slower wind expelled during an earlier red supergiant phase are used to construct emission-measure images. The similarity of the overall morphology of these images and the HST images suggests the interacting-winds model is the likely solution for the origin of the nebula. We demonstrate the remarkable agreement between the time scales in this model and a series of stellar evolution calculations. Further work with the interacting-winds model is needed to establish the physical processes responsible for the extreme flattening inferred for the red supergiant wind and the subtle differences between the images.

  17. Assessing the molecular genetics of the development of executive attention in children: focus on genetic pathways related to the anterior cingulate cortex and dopamine.

    PubMed

    Brocki, K; Clerkin, S M; Guise, K G; Fan, Jin; Fossella, J A

    2009-11-24

    It is well known that children show gradual and protracted improvement in an array of behaviors involved in the conscious control of thought and emotion. Non-invasive neuroimaging in developing populations has revealed many neural correlates of behavior, particularly in the developing cingulate cortex and frontostriatal circuits. These brain regions, themselves, undergo protracted molecular and cellular change in the first two decades of human development and, as such, are ideal regions of interest for cognitive- and imaging-genetic studies that seek to link processes at the biochemical and synaptic levels to brain activity and behavior. We review our research to date that employs both adult and child-friendly versions of the attention network task (ANT) in an effort to begin to describe the role of specific genes in the assembly of a functional attention system. Presently, we constrain our predictions for genetic association studies by focusing on the role of the anterior cingulate cortex (ACC) and of dopamine in the development of executive attention.

  18. How to Make the Ghosts in my Bedroom Disappear? Focused-Attention Meditation Combined with Muscle Relaxation (MR Therapy)—A Direct Treatment Intervention for Sleep Paralysis

    PubMed Central

    Jalal, Baland

    2016-01-01

    Sleep paralysis (SP) is a common state of involuntary immobility occurring at sleep onset or offset. It can include terrifying hypnogogic or hypnopompic hallucinations of menacing bedroom intruders. Unsurprisingly, the experience is associated with great fear and horror worldwide. To date, there exist no direct treatment intervention for SP. In this article, I propose for the first time a type of focused inward-attention meditation combined with muscle relaxation as a direct intervention to be applied during the attack, to ameliorate and possibly eliminate it (what could be called, meditation-relaxation or MR therapy for SP). The intervention includes four steps: (1) reappraisal of the meaning of the attack; (2) psychological and emotional distancing; (3) inward focused-attention meditation; (4) muscle relaxation. The intervention promotes attentional shift away from unpleasant external and internal stimuli (i.e., terrifying hallucinations and bodily paralysis sensations) unto an emotionally pleasant internal object (e.g., a positive memory). It may facilitate a relaxed meditative state characterized by a shift from sympathetic to parasympathetic dominance, associated with greater levels of alpha activity (which may lead to drowsiness and potentially sleep). The procedure may also reduce the initial panic and arousal that occur when realizing one is paralyzed. In addition, I present a novel Panic-Hallucination (PH) Model of Sleep Paralysis; describing how through escalating cycles of fear and panic-like autonomic arousal, a positive feedback loop is created that worsens the attack (e.g., leading to longer and more fearful episodes), drives content of hallucinations, and causes future episodes of SP. Case examples are presented to illustrate the feasibility of MR therapy for SP. PMID:26858675

  19. How to Make the Ghosts in my Bedroom Disappear? Focused-Attention Meditation Combined with Muscle Relaxation (MR Therapy)-A Direct Treatment Intervention for Sleep Paralysis.

    PubMed

    Jalal, Baland

    2016-01-01

    Sleep paralysis (SP) is a common state of involuntary immobility occurring at sleep onset or offset. It can include terrifying hypnogogic or hypnopompic hallucinations of menacing bedroom intruders. Unsurprisingly, the experience is associated with great fear and horror worldwide. To date, there exist no direct treatment intervention for SP. In this article, I propose for the first time a type of focused inward-attention meditation combined with muscle relaxation as a direct intervention to be applied during the attack, to ameliorate and possibly eliminate it (what could be called, meditation-relaxation or MR therapy for SP). The intervention includes four steps: (1) reappraisal of the meaning of the attack; (2) psychological and emotional distancing; (3) inward focused-attention meditation; (4) muscle relaxation. The intervention promotes attentional shift away from unpleasant external and internal stimuli (i.e., terrifying hallucinations and bodily paralysis sensations) unto an emotionally pleasant internal object (e.g., a positive memory). It may facilitate a relaxed meditative state characterized by a shift from sympathetic to parasympathetic dominance, associated with greater levels of alpha activity (which may lead to drowsiness and potentially sleep). The procedure may also reduce the initial panic and arousal that occur when realizing one is paralyzed. In addition, I present a novel Panic-Hallucination (PH) Model of Sleep Paralysis; describing how through escalating cycles of fear and panic-like autonomic arousal, a positive feedback loop is created that worsens the attack (e.g., leading to longer and more fearful episodes), drives content of hallucinations, and causes future episodes of SP. Case examples are presented to illustrate the feasibility of MR therapy for SP.

  20. Observing Supernova 1987A with the Refurbished Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    France, Kevin; McCray, Richard; Heng, Kevin; Kirshner, Robert P.; Challis, Peter; Bouchet, Patrice; Crotts, Arlin; Dwek, Eli; Fransson, Claes; Garnavich, Peter M.; Larsson, Josefin; Lundqvist, Peter; Panagia, Nino; Pun, Chun S. J.; Smith, Nathan; Sollerman, Jesper; Sonneborn, George; Stocke, John T.; Wheeler, J. Craig

    2010-01-01

    The young remnant of supernova 1987A (SN 1987A) offers an unprecedented glimpse into the hydrodynamics and kinetics of fast astrophysical shocks. We have been monitoring SN 1987A with the Hubble Space Telescope (HST) since it was launched. The recent repair of the Space Telescope Imaging Spectrograph (STIS) allows us to compare observations in 2004, just before its demise, with those in 2010, shortly after its resuscitation by NASA astronauts. We find that the Ly-alpha and H-alpha lines from shock emission continue to brighten, while their maximum velocities continue to decrease. We report evidence for nearly coherent, resonant scattering of Lya photons (to blueshifts approximately -12,000 km /s) from hotspots on the equatorial ring. We also report emission to the red of Ly-alpha that we attribute to N v lambda lambda 1239,1243 Angstrom line emission. These lines are detectable because, unlike hydrogen atoms, N4+ ions emit hundreds of photons before they are ionized. The profiles of the N v lines differ markedly from that of H-alpha. We attribute this to scattering of N4+ ions by magnetic fields in the ionized plasma. Thus, N v emission provides a unique probe of the isotropization zone of the collisionless shock. Observations with the recently installed Cosmic Origins Spectrograph (COS) will enable us to observe the N v lambda lambda 1239,1243 Angstrom line profiles with much higher signal-to-noise ratios than possible with STIS and may reveal lines of other highly ionized species (such as C IVlambda lambda 1548,1551 Angstrom) that will test our explanation for the N v emission

  1. The Continuing Infrared Evolution of SN1987A

    NASA Astrophysics Data System (ADS)

    Dwek, Eli; Arendt, Richard; Bouchet, Patrice; Burrows, David; Challis, Peter; Danziger, John; De Buizer, James; Gehrz, Robert; Kirshner, Robert; McCray, Richard; Park, Sangwook; Polomski, Elisha; Woodward, Charles

    2008-03-01

    We will use the SPITZER to continue the ongoing monitoring of SN1987A, the youngest supernova remnant that is undergoing noticable evolutionary changes during the lifetime of the Great Observatories. At infrared wavelengths SN1987A provides a unique complimentary view of the interaction of the SN blast wave with the equatorial ring (ER). Dust in the ER is being swept up by the expanding shock and collisionally heated by the X-ray emitting gas observed with CHANDRA, giving rise to IR emission that reveals the composition and amount of dust that formed in the outflow of the presupernova star. The IR observations also provide a unique tool for studying physical processes - the collisional heating and destruction of dust - in dusty X-ray emitting plasmas. Parts of the blast wave has penetrated the denser regions of the ER, creating the 'hotspots' observed with HUBBLE. IR line emission from these regions provide important information on the physical conditions and the elemental and dust composition in these cooling shocks. Additionally, the ejecta of the SN explosion contains dust that was observed to have formed about 530 days after the explosion. Its imminent interaction with the ring will heat up this dust, which will be observable with SPITZER. In addition to providing useful information on SN1987A and its environment, the proposed observations will address key global issues regarding the origin and evolution of dust in the universe: how much dust is formed in SN ejecta and in quiescent stellar outflows, and how efficiently grains are destroyed by interstellar shock waves.

  2. The Continuing Infrared Evolution of SN1987A

    NASA Astrophysics Data System (ADS)

    Dwek, Eli; Arendt, Richard; Bouchet, Patrice; Burrows, David; Challis, Peter; Danziger, John; De Buizer, James; Gehrz, Robert; Kirshner, Robert; McCray, Richard; Park, Sangwook; Polomski, Elisha; Woodward, Charles

    2007-05-01

    We will use the SPITZER to continue the ongoing monitoring of SN1987A, the youngest supernova remnant that is undergoing noticable evolutionary changes during the lifetime of the Great Observatories. At infrared wavelengths SN1987A provides a unique complimentary view of the interaction of the SN blast wave with the equatorial ring (ER). Dust in theÊ ERÊ is being swept up by the expanding shock and collisionally heated by the X-ray emitting gas observed with CHANDRA, giving rise to IR emission that reveals the composition and amount of dust that formed in the outflow of the presupernova star. The IR observations also provide a unique tool for studying physical processes - the collisional heating and destruction of dust -Ê in dusty X-ray emitting plasmas. Parts of the blast wave has penetrated the denser regions of the ER, creating the 'hotspots' observed with HUBBLE. IR line emission from these regions provide important information on the physical conditions and theÊelemental and dust composition in these cooling shocks. Additionally, the ejecta of the SN explosion contains dust that was observed to have formed about 530 days after the explosion. Its imminent interaction with the ring will heat up this dust, which will be observable with SPITZER. In addition to providing useful information on SN1987A and its environment, the proposed observations will address key global issues regarding the origin and evolution of dust in the universe: how much dust is formed in SN ejecta and in quiescent stellar outflows, and how efficiently grains are destroyed by interstellar shock waves.

  3. Hubble Reveals Structure Of Supernova 1987a Explosion Debris

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Hubble Space Telescope picture shows Supernova 1987A and its neighborhood. The series of four panels shows the evolution of the SN 1987A debris from February 1994 to February 1996. Material from the stellar interior was ejected into space during the supernova explosion in February 1987. The explosion debris is expanding at nearly 6 million miles per hour. Ten years now after the explosion, this cosmic fireball is large enough --- about one-sixth of a light-year in diameter --- to be resolved from the Earth's orbit with the Hubble Space Telescope. The debris is resolved into two opposing blobs and is dim in the center. The apparent direction of ejection is the same as the short axis of the bright inner ring that surrounds the supernova. This suggests that the explosion is directed out of the plane of the ring. The ring is probably composed of materials lost by the pre-supernova star in the last stages of its evolution. Supernova 1987A is located 167,000 light-years away from Earth in the Large Magellanic Cloud. The telescope captured the images with the Wide Field and Planetary Camera 2. The central image of the supernova and the ring system was taken in light emitted by nitrogen gas (658 nanometers) on Sept. 24, 1994. The series of debris images were taken using a visible light filter of wavelength around 550 nanometers taken (from left to right) on Feb. 4, 1994, Sept. 24, 1994, March 5, 1995, and Feb. 6, 1996. Credit: Chun Shing Jason Pun (NASA/GSFC), Robert P. Kirshner (Harvard-Smithsonian Center for Astrophysics), and NASA

  4. Supernova 1987A: The Supernova of a Lifetime

    NASA Astrophysics Data System (ADS)

    Kirshner, Robert

    2017-01-01

    Supernova 1987A, the brightest supernova since Kepler's in 1604, was detected 30 years ago at a distance of 160 000 light years in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. Visible with the naked eye and detected with the full range of technology constructed since Kepler's time, SN 1987A has continued to be a rich source of empirical information to help understand supernova explosions and their evolution into supernova remnants. While the light output has faded by a factor of 10 000 000 over those 30 years, instrumentation, like the Hubble Space Telescope, the Chandra X-ray Observatory, and the Atacama Large Millimeter Array has continued to improve so that this supernova continues to be visible in X-rays, ultraviolet light, visible light, infrared light and in radio emission. In this review, I will sketch what has been learned from these observations about the pre-supernova star and its final stages of evolution, the explosion physics, the energy sources for emission, and the shock physics as the expanding debris encounters the circumstellar ring that was created about 20 000 years before the explosion. Today, SN 1987A is making the transition to a supernova remnant- the energetics are no longer dominated by the radioactive elements produced in the explosion, but by the interaction of the expanding debris with the surrounding gas. While we are confident that the supernova explosion had its origin in gravitational collapse, careful searches for a compact object at the center of the remnant place upper limits of a few solar luminosities on that relic. Support for HST GO programs 13401 and 13405 was provided by NASA through grants from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  5. NASA plans for observations of SN1987A

    NASA Technical Reports Server (NTRS)

    Riegler, Guenter R.

    1987-01-01

    The scientific aims and technological implementation of NASA observations of SN 1987A are outlined in a status report. Key questions to be answered involve nucleosynthesis and the light curves of type II SN; the multilayer structure of the progenitor and the SNR; circumstellar gas, shock-wave, and dust formation; and the evolution of the core remnant. Consideration is given to continued SMM, IUE, Voyager UVS, and DSN observations; future space missions such as GRO, AXAF, and Rosat; balloon-borne gamma-ray, rocket-borne X-ray, and airborne IR observations; and the Science Communications Network and Data Archive.

  6. Axions, SN 1987A, and one pion exchange

    NASA Technical Reports Server (NTRS)

    Turner, Michael S.; Kang, Ho-Shik; Steigman, Gary

    1988-01-01

    Nucleon-nucleon, axion bremsstrahlung is the primary mechanism for axion emission from the nascent neutron star associated with SN 1987A, and the rate for this process has been calculated in the one pion exchange approximation (OPE). The axion mass limit which follows from SN 1987A, m sub a less than or approx equal to 10 to the -3 eV, is the most stringent astrophysical bound, and has received much scrutiny. It has been suggested that by using OPE to calculate the cross section for the analog process, pp yields pp + pi sup o, and comparing the result of the experimental data one can test the validity of this approximation, and further, that such a comparison indicates that OPE leads to a value for this cross section which is a factor of 30 to 40 too large. If true, this would suggest that the axion mass limit should be revised upward by a factor of approximately 6. The cross section for pp yields pp + pi sup o using OPE is carefully evaluated, and excellent agreement found (to better than a factor of 2) with the experimental data.

  7. Rapid ionization of the environment of SN 1987A

    NASA Technical Reports Server (NTRS)

    Raga, A. C.

    1987-01-01

    It has been suggested by some authors that IUE observations of the supernova SN 1987A show the presence of a strong component of the interstellar C IV 1550 and Si IV 1393 absorption lines at a velocity that approximately corresponds to the velocity of the LMC. It is possible that this component might come from originally neutral (or at least not very highly ionized) gas which has been photoionized by the initially very strong ionizing radiation field of the supernova. Theoretical considerations of this scenario lead to the study of fast (with velocities of about c) ionization fronts. It is shown that for reasonable model parameters it is possible to obtain considerably large C IV column densities, in agreement with the IUE observations. On the other hand, the models do not so easily predict the large Si IV column densities that are also obtained from the IUE observations. It is found that only models in which the interstellar medium surrounding SN 1987A is initially composed of already ionized hydrogen and helium predict substantial Si IV column densities. This result provides an interesting prediction of the ionization state of the environment of the presupernova star.

  8. Revisiting Supernova 1987A constraints on dark photons

    NASA Astrophysics Data System (ADS)

    Chang, Jae Hyeok; Essig, Rouven; McDermott, Samuel D.

    2017-01-01

    We revisit constraints on dark photons with masses below ˜ 100 MeV from the observations of Supernova 1987A. If dark photons are produced in sufficient quantity, they reduce the amount of energy emitted in the form of neutrinos, in conflict with observations. For the first time, we include the effects of finite temperature and density on the kinetic-mixing parameter, ɛ, in this environment. This causes the constraints on ɛ to weaken with the dark-photon mass below ˜ 15 MeV. For large-enough values of ɛ, it is well known that dark photons can be reabsorbed within the supernova. Since the rates of reabsorption processes decrease as the dark-photon energy increases, we point out that dark photons with energies above the Wien peak can escape without scattering, contributing more to energy loss than is possible assuming a blackbody spectrum. Furthermore, we estimate the systematic uncertainties on the cooling bounds by deriving constraints assuming one analytic and four different simulated temperature and density profiles of the proto-neutron star. Finally, we estimate also the systematic uncertainty on the bound by varying the distance across which dark photons must propagate from their point of production to be able to affect the star. This work clarifies the bounds from SN1987A on the dark-photon parameter space.

  9. SN 1987A: A Unique Laboratory for Shock Physics

    NASA Technical Reports Server (NTRS)

    Sonneborn, George

    2012-01-01

    Supernova 1987 A is the brightest and nearest supernova observed since Kepler's SN1604, and is the only one close enough to resolve and directly observe the temporal growth of the ejecta. Over the past 25 years, intensive observations across the electromagnetic spectrum with observatories on the ground (Australia Telescope Compact Array, Gemini-S, Magellan, VLT) and in space (IUE, KAO, CGRO, Hubble, Chandra, Spitzer, Herschel) have given us an unprecedented view of the evolution of the debris of the supernova and of its shock interaction with circumstellar matter. The outer supernova debris, now expanding with velocities -8000 km/s, encountered the relatively dense circumstellar ring formed by presupernova mass loss starting in 1994. The resulting shock interaction has been manifested by: rapidly brightening UV-optical "hotspots", an expanding X-ray ring. an expanding ring of knotty non-thermal radio emission, and a ring of thermal IR emission from silicate dust. The recent evolution of these emissions reveal new details about the shock interaction, circumstellar material, and the star that exploded. Certain critical problems about SN 1987 A, such as the still undiscovered compact object formed in the explosion and the structure of the central debris, require the capabilities of JWST.

  10. ALMA resolves SN 1987A's dust factory and particle accelerator

    NASA Astrophysics Data System (ADS)

    Indebetouw, Remy; SN1987A ALMA Cycle 0 Team

    2014-01-01

    SN1987A in the Large Magellanic Cloud is the closest supernova to earth to be observed since 1604, making it a unique laboratory to study supernova physics in real time. Among SN87A's remarkable properties are a very large mass of new dust forming in the supernova ejecta. This dust was inferred from Herschel data, but its location not proven since Herschel could not resolve the 1.8" diameter remnant. Another mystery is whether the explosion left behind a neutron star - neither pulsar nor pulsar wind nebula has been detected so far. Excess emission from a PWN should be easiest to detect at millimeter wavelengths, if it can be spatially resolved from the synchrotron-emitting supernova shock. We present the first spatially resolved images of SN1987A at 450um, 870um, and 1.4mm, observed with the Atacama Large Millimeter/Submillimeter Array (ALMA). ALMA resolves emission from the newly formed dust, unambiguously locating it within the ejecta, interior to the reverse shock. The shocked ring is also well-resolved, and separated spatially from the ejecta. The ring shows no spectral break compared to centimeter wavelengths, and no free-free or PWN emission is required to explain the data. We discuss physical properties of the components of the remnant determined from these high resolution ALMA images.

  11. SN 1987A: Chandra Witnesses the End of an Era

    NASA Astrophysics Data System (ADS)

    Frank, Kari A.; Burrows, David N.

    2016-04-01

    Due to its age and close proximity, the remnant of SN 1987A is the only supernova remnant in which we can study the early developmental stages in detail, providing insight into stellar evolution, the mechanisms of the supernova explosion, and the transition from supernova to supernova remnant as the debris begins to interact with the surrounding circumstellar medium (CSM). We present the latest results from 16 years of Chandra ACIS observations of SN 1987A, now covering 4600 - 10500 days after the supernova. At approximately day 7500, the east-west asymmetry of the ring began to reverse, while the spectra and soft X-ray light curve revealed that the increase in soft X-ray emission slowed dramatically. This suggests the average CSM density encountered by the blast wave decreased at this time, likely due to lack of new emission from the densest clumps in the equatorial ring. Since day 9700 the soft X-ray light curve has flattened and remained approximately constant, evidence that the blast wave has now left the dense material of the known equatorial ring and is beginning to probe the unknown territory beyond.

  12. The X-ray evolution of SNR 1987A

    NASA Astrophysics Data System (ADS)

    Burrows, David N.; Frank, Kari A.; Park, Sangwook; McCray, Richard; Zhekov, Svetozar

    2016-06-01

    Due to its age and close proximity, the remnant of SN 1987A is the only supernova remnant in which we can study the early developmental stages in detail, providing insight into stellar evolution, the mechanisms of the supernova explosion, and the transition from supernova to supernova remnant as the debris begins to interact with the surrounding circumstellar medium (CSM). We present the latest results from 16 years of Chandra ACIS observations of SN 1987A, now covering 4600-10600 days after the supernova. At approximately day 7500, the east-west asymmetry of the ring began to reverse, while the soft X-ray light curve switched from an exponential increase to a linear brightening. Since day 9700 the soft X-ray light curve has flattened and remained approximately constant at about 8×10^(12) ergs/cm^2/s, evidence that the blast wave has now left the dense material of the known equatorial ring and is beginning to probe the unknown territory beyond.

  13. SN1987A: The Birth of a Supernova Remnant

    NASA Technical Reports Server (NTRS)

    McCray, Richard

    2003-01-01

    This grant was intended to support the development of theoretical models needed to interpret and understand the observations by the Hubble Space Telescope and the Chandra X-ray telescope of the rapidly developing remnant of Supernova 1987A. In addition, we carried out a few investigations of related topics. The project was spectacularly successful. The models that we developed provide the definitive framework for predicting and interpreting this phenomenon. Following is a list of publications based on our work. Some of these papers include results of both theoretical modeling supported by this project and also analysis of data supported by the Space Telescope Science Institute and the Chandra X-ray Observatory. We first list papers published in refereed journals, then conference proceedings and book chapters, and also an educational web site.

  14. Herschel Detects a Massive Dust Reservoir in Supernova 1987A

    NASA Technical Reports Server (NTRS)

    Matsuura, M.; Dwek, E.; Meixner, M.; Otsuka, M.; Babler, B.; Barlow, M. J.; Roman-Duval, J.; Engelbracht, C.; Sandstrom K.; Lakicevic, M.; vanLoon, J. Th.; Sonneborn, G.; Clayton, G. C.; Long, K. S.; Lundqvist, P.; Nozawa, T.; Gordon, K. D.; Hony, S.; Okumura, K.; Misselt, K. A.; Montiel, E.; Sauvage, M.

    2011-01-01

    We report far-infrared and submillimeter observations of Supernova 1987A, the star that exploded on February 23, 1987 in the Large Magellanic Cloud, a galaxy located 160,000 light years away. The observations reveal the presence of a population of cold dust grains radiating with a temperature of approx.17-23 K at a rate of about 220 stellar luminosity. The intensity and spectral energy distribution of the emission suggests a dust mass of approx.0.4-0.7 stellar mass. The radiation must originate from the SN ejecta and requires the efficient precipitation of all refractory material into dust. Our observations imply that supernovae can produce the large dust masses detected in young galaxies at very high red shifts.

  15. When will a pulsar in supernova 1987a be seen?

    PubMed

    Michel, F C; Kennel, C F; Fowler, W A

    1987-11-13

    The means by which a pulsar might be detected in the remnant of supernova 1987a in the Large Magelanic Cloud is examined. One possibility is that the slower-than-radioactive decay typically seen in the type II light curves is itself the sign of powering by the underlying pulsar, with the decline representing not the spinning down of the pulsar but rather the declining nebular opacity that would allow increasing amounts of the energy to escape as gamma rays. The test of this hypothesis (if the supernova conforms to type II expectations) would be to look for the "missing" energy in the form of those gamma rays that escape from the remnant instead of powering it.

  16. When will a pulsar in supernova 1987a be seen?

    NASA Technical Reports Server (NTRS)

    Michel, F. Curtis; Kennel, C. F.; Fowler, William A.

    1987-01-01

    The means by which a pulsar might be detected in the remnant of supernova 1987a in the Large Magellanic Cloud is examined. One possibility is that the slower-than-radioactive decay typically seen in the type II light curves is itself the sign of powering by the underlying pulsar, with the decline representing not the spinning down of the pulsar but rather the declining nebular opacity that would allow increasing amounts of the energy to escape as gamma rays. The test of this hypothesis (if the supernova conforms to type II expectations) would be to look for the 'missing' energy in the form of those gamma rays that escape from the remnant instead of powering it.

  17. Observing supernova 1987A with the refurbished Hubble Space Telescope.

    PubMed

    France, Kevin; McCray, Richard; Heng, Kevin; Kirshner, Robert P; Challis, Peter; Bouchet, Patrice; Crotts, Arlin; Dwek, Eli; Fransson, Claes; Garnavich, Peter M; Larsson, Josefin; Lawrence, Stephen S; Lundqvist, Peter; Panagia, Nino; Pun, Chun S J; Smith, Nathan; Sollerman, Jesper; Sonneborn, George; Stocke, John T; Wang, Lifan; Wheeler, J Craig

    2010-09-24

    Observations with the Hubble Space Telescope (HST), conducted since 1990, now offer an unprecedented glimpse into fast astrophysical shocks in the young remnant of supernova 1987A. Comparing observations taken in 2010 with the use of the refurbished instruments on HST with data taken in 2004, just before the Space Telescope Imaging Spectrograph failed, we find that the Lyα and Hα lines from shock emission continue to brighten, whereas their maximum velocities continue to decrease. We observe broad, blueshifted Lyα, which we attribute to resonant scattering of photons emitted from hot spots on the equatorial ring. We also detect N v λλ1239, 1243 angstrom line emission, but only to the red of Lyα. The profiles of the N v lines differ markedly from that of Hα, suggesting that the N4+ ions are scattered and accelerated by turbulent electromagnetic fields that isotropize the ions in the collisionless shock.

  18. Herschel detects a massive dust reservoir in supernova 1987A.

    PubMed

    Matsuura, M; Dwek, E; Meixner, M; Otsuka, M; Babler, B; Barlow, M J; Roman-Duval, J; Engelbracht, C; Sandstrom, K; Lakićević, M; van Loon, J Th; Sonneborn, G; Clayton, G C; Long, K S; Lundqvist, P; Nozawa, T; Gordon, K D; Hony, S; Panuzzo, P; Okumura, K; Misselt, K A; Montiel, E; Sauvage, M

    2011-09-02

    We report far-infrared and submillimeter observations of supernova 1987A, the star whose explosion was observed on 23 February 1987 in the Large Magellanic Cloud, a galaxy located 160,000 light years away. The observations reveal the presence of a population of cold dust grains radiating with a temperature of about 17 to 23 kelvin at a rate of about 220 times the luminosity of the Sun. The intensity and spectral energy distribution of the emission suggest a dust mass of about 0.4 to 0.7 times the mass of the Sun. The radiation must originate from the supernova ejecta and requires the efficient precipitation of all refractory material into dust. Our observations imply that supernovae can produce the large dust masses detected in young galaxies at very high redshifts.

  19. Line fluorescence from the ring around supernova 1987A

    NASA Technical Reports Server (NTRS)

    Dwek, Eli; Felten, James E.

    1992-01-01

    Observations in lambda 5007 which reveal an ellipse of line emission around SN 1987A are reviewed. A simple expression for the rate at which the kinematically accessible paraboloid sweeps over the length of a thin uniform circular ring is derived, and a simple integral expression for the light curve F(t) of a fluorescent line in terms of epsilon(t), the local line emissivity, is presented. Many simple examples of the relationship between epsilon(t) and F(t) are graphed, and the results are used to deduce the characteristics of the local emissivity functions which produce the best fit to the observed semiforbidden N III 1750 and N V 1240 light curves. The N III and N V light curves are inverted to find the functions epsilon(t) which give best fits to the observations.

  20. THE DESTRUCTION OF THE CIRCUMSTELLAR RING OF SN 1987A

    SciTech Connect

    Fransson, Claes; Migotto, Katia; Lundqvist, Peter; Taddia, Francesco; Sollerman, Jesper; Larsson, Josefin; Pesce, Dominic; Chevalier, Roger A.; Challis, Peter; Kirshner, Robert P.; France, Kevin; Leibundgut, Bruno; Spyromilio, Jason; McCray, Richard; Jerkstrand, Anders; Mattila, Seppo; Smith, Nathan; Wheeler, J. Craig; Crotts, Arlin; Garnavich, Peter; and others

    2015-06-10

    We present imaging and spectroscopic observations with Hubble Space Telescope and Very Large Telescope of the ring of SN 1987A from 1994 to 2014. After an almost exponential increase of the shocked emission from the hotspots up to day ∼8000 (∼2009), both this and the unshocked emission are now fading. From the radial positions of the hotspots we see an acceleration of these up to 500–1000 km s{sup −1}, consistent with the highest spectroscopic shock velocities from the radiative shocks. In the most recent observations (2013 and 2014), we find several new hotspots outside the inner ring, excited by either X-rays from the shocks or by direct shock interaction. All of these observations indicate that the interaction with the supernova ejecta is now gradually dissolving the hotspots. We predict, based on the observed decay, that the inner ring will be destroyed by ∼2025.

  1. Light echoes - supernovae 1987A and 1986G

    SciTech Connect

    Schaefer, B.E.

    1987-12-01

    The sudden brilliance of a supernova (SN) eruption will be reflected on surrounding dust grains to create a phantom nebula. The paper presents a series of calculations in which the apparent brightness of this light echo is predicted for a variety of situations where the dust is part of the interstellar medium (ISM). It is found that the supernova 1987 A will have a very bright echo off the ISM that may perhaps be visible with binoculars for many years. At a time of 400 days past maximum, the SN 1986G is found to be 2.7 mag brighter than would be predicted by an extrapolation of its light curve. This unique property has an easy explanation as a light echo off the dust in the dust lane of Cen A. 24 references.

  2. The Emission Line Spectrum of SN 1987A

    NASA Astrophysics Data System (ADS)

    Li, Hongwei

    With Supernova 1987A (SN 1987A) we have an unprecedented view of the optical and infrared spectrum of a supernova. Here, we develop the basic theory to describe the emission line spectrum of a supernova in the nebular phase and we apply this theory to three of the most prominent important emission line systems: the (OI) lambda lambda 6300, 6364 doublet; the (Ca II) lambda lambda 7300 and Ca II lambda lambda 8600 system, and the optical and infrared lines of Fe, Co and Ni. As a first example, we analyze the evolution of the (OI) lambda lambda 6300, 6364 doublet. We find that the ratio of the mass of OI to its filling factor, M_{rm O}/f_{rm O} , must be about 11, so that for a reasonable value of M_{rm O} = 1.3 Modot, f _{rm O} ~ 0.12. Second, we analyze the near-infrared emission lines of Ca II. We find that UV pumping is required for t _sp{~}> 350 days to fit the (Ca II) lambda lambda 7300 and Ca II lambda lambda 8600 lines. Moreover, we find that the Ca II lines came from the primordial gas rather than the freshly nucleosynthesised products. Iron, cobalt and nickel lines are extremely important in understanding the physical processes in the envelope of SN 1987A. Radioactive decays of ^{56 }Co, 57Co, 44Ti and ^ {22}Na are the dominant energy sources of radiation of SN 1987A in the nebular phase. We find that the nickel-cobalt-iron clumps must have expanded by a factor ~30 or more during a few weeks after outburst as a result of heating by 56Ni and ^{56 }Co decay. This expansion leads to a large filling factor of iron clumps, f_{ rm Fe}~ 0.5, and a small filling factor, f_{rm H,He}~ 0.1-0.2, for primordial gas, such as H, He, etc. From the conditions of thermal equilibrium and ionization equilibrium we determine the evolution of temperature and ionization of the iron clumps. We can account for the light curves (for 150 days_sp ~> t_sp ~> 2 yr) of almost all the observed emission lines of Fe I, Fe II, Co I, Co II, Ni I and Ni II within the uncertainties in

  3. Supernova 1987A Interpreted through the SLIP Pulsar Model

    NASA Astrophysics Data System (ADS)

    Middleditch, John

    2010-01-01

    The model of pulsar emission through superluminally induced polarization currents (SLIP) predicts that pulsations produced by such currents, induced by a rotating, magnetized body at many light cylinder radii, as would be the case for a neutron star born within any star of >1.5 solar masses, will drive pulsations close to the axis of rotation. Such highly collimated pulsations (<= 1 in 10,000), and the similarly collimated jets of particles which it drove, including 1e-6 solar masses with velocities of up to 0.95 c, were responsible for the features of its very early light curve (days 3 - 20), the "Mystery Spot," observed slightly later (days 30 - 50 and >), and later, in less collimated form, the bipolarity of SN 1987A itself. The pulsations and jet interacted with circumstellar material (CM), to produce features observed in the very early light curve which correspond to: 1) the entry of the pulsed beam into the CM; 2) the entry of the 0.95 c particles into the CM; 3) the exit of the pulsed beam from the CM (with contributions in the B and I bands -- the same as later inferred/observed for its 2.14 ms pulsations); and 4) the exit of the fastest particles from the CM. Because of the energy requirements of the jet in these early stages, the spindown required of its pulsar could exceed 1e-5 Hz/s at a rotation rate of 500 Hz. There is no reason to suggest that this mechanism is not universally applicable to all SNe with gaseous remnants remaining, and thus SN 1987A is the Rosetta Stone for 99% of SNe, gamma-ray bursts, and millisecond pulsars. This work was supported in part by the Department of Energy through the Los Alamos Directed Research Grant DR20080085.

  4. Prefrontal Function Engaging in External-Focused Attention in 5- to 6-Month-Old Infants: A Suggestion for Default Mode Network

    PubMed Central

    Xu, Mingdi; Hoshino, Eiichi; Yatabe, Kiyomi; Matsuda, Soichiro; Sato, Hiroki; Maki, Atsushi; Yoshimura, Mina; Minagawa, Yasuyo

    2017-01-01

    The present study used functional near-infrared spectroscopy (fNIRS) to measure 5- to 6-month-old infants’ hemodynamic response in the prefrontal cortex (PFC) to visual stimuli differing in saliency and social value. Nineteen Japanese 5- to 6-month-old infants watched video clips of Peek-a-Boo (social signal) performed by an anime character (AC) or a human, and hand movements without social signal performed by an AC. The PFC activity of infants was measured by 22-channel fNIRS, while behaviors including looking time were recorded simultaneously. NIRS data showed that infants’ hemodynamic responses in the PFC generally decreased due to these stimuli, and the decrease was most prominent in the frontopolar (FP), covering medial PFC (MPFC), when infants were viewing Peek-a-Boo performed by an AC. Moreover, the decrease was more pronounced in the dorsolateral PFC (DLPFC) when infants were viewing Peek-a-Boo performed by an AC than by a human. Accordingly, behavioral data revealed significantly longer looking times when Peek-a-Boo was performed by an AC than by a human. No significant difference between Peek-a-Boo and non-Peek-a-Boo conditions was observed in either measure. These findings indicate that infants at this age may prefer stimuli with more salient features, which may be more effective in attracting their attentions. In conjunction with our previous findings on responses to self-name calling in infants of similar age, we hypothesize that the dynamic function of the MPFC and its vicinity (as part of default mode network (DMN): enhanced by self-focused stimuli, attenuated by externally focused stimuli), which is consistently observed in adults, may have already emerged in 5- to 6-month-old infants. PMID:28119586

  5. CARBON MONOXIDE IN THE COLD DEBRIS OF SUPERNOVA 1987A

    SciTech Connect

    Kamenetzky, J.; McCray, R.; Glenn, J.; Indebetouw, R.; Barlow, M. J.; Matsuura, M.; Baes, M.; Blommaert, J. A. D. L.; Decin, L.; Bolatto, A.; Dunne, L.; Fransson, C.; Gomez, H. L.; Groenewegen, M. A. T.; Hopwood, R.; Kirshner, R. P.; Lakicevic, M.; Marcaide, J.; Meixner, M.; and others

    2013-08-20

    We report spectroscopic and imaging observations of rotational transitions of cold CO and SiO in the ejecta of SN1987A, the first such emission detected in a supernova remnant. In addition to line luminosities for the CO J = 1-0, 2-1, 6-5, and 7-6 transitions, we present upper limits for all other transitions up to J = 13-12, collectively measured from the Atacama Large Millimeter Array, the Atacama Pathfinder EXperiment, and the Herschel Spectral and Photometric Imaging REceiver. Simple models show the lines are emitted from at least 0.01 M{sub Sun} of CO at a temperature >14 K, confined within at most 35% of a spherical volume expanding at {approx}2000 km s{sup -1}. Moreover, we locate the emission within 1'' of the central debris. These observations, along with a partial observation of SiO, confirm the presence of cold molecular gas within supernova remnants and provide insight into the physical conditions and chemical processes in the ejecta. Furthermore, we demonstrate the powerful new window into supernova ejecta offered by submillimeter observations.

  6. SN 1987 A: A Unique Laboratory for Shock Physics

    NASA Technical Reports Server (NTRS)

    Sonneborn, George

    2012-01-01

    Supernova 1987 A has given us an unprecedented view of the evolution of the explosion debris and its interaction with circumstellar matter. The outer supernova debris, now expanding with velocities approx.8000 km/s, encountered the relatively dense circumstellar ring formed by presupernova mass loss in the early 1990s. The shock interaction is manifested by UV-optical "hotspots", an expanding X-ray ring, an expanding ring of knotty non-thermal radio emission, and a ring of thermal IR emission from silicate dust Recent ultraviolet observations of the emissions from the reverse shock and the ring with the HST/COS reveal new details about the shock interaction. Lyman alpha emission from the reverse shock is much stronger than H alpha and they have different emission morphologies, pointing to different emission mechanisms. The reverse shock was detected for the first time in C IV 1550. The N V to C IV brightness ratio indicates the N/C abundance ratio in the expanding debris is about 100X solar, about 3X N/C in the inner ring.

  7. Iron, Cobalt, and Nickel in SN 1987A

    NASA Technical Reports Server (NTRS)

    Li, Hongwei; McCray, Richard; Sunyaev, Rashid A.

    1993-01-01

    During the first several weeks after the explosion of SN 1987A, Fe/Co/Ni clumps, containing approx. 1% of the mass of the supernova envelope, absorbed most of the energy release by Ni-56 and Co-56 decay. As a result, the clumps expanded relative to the substrate, forming a 'nickel bubble' of low-density Fe/Co/Ni. Later the clumps captured approx. 10% of the radioactive luminosity of gamma rays and positrons. Assuming that these elements are not mixed microscopically with other elements, we find that the clumps must occupy approx. greater than 30% of the volume of the emitting region (radial velocity approx. less than 2500 km/s). The result indicates that the emission at late times is dominated by an extra source of heating and ionization, most likely photoionization by two-photon continuum from metastable helium in the gas surrounding the clumps. The resulting 'frothy' structure, consisting of bubbles of low-density Fe surrounded by higher-density filaments of H, He, and other elements, will persist and may be seen in the spectra and structure of supernova remnants.

  8. Co-57 and Ti-44 production in SN 1987A

    NASA Technical Reports Server (NTRS)

    Woosley, S. E.; Hoffman, Robert D.

    1991-01-01

    A survey of parameterized explosive silicon burning is carried out in order to limit the range of allowed masses of Co-57 produced by SN 1987A. The most likely value is between 0.5 and 2.5 times that implied by a solar ratio for Fe-57/Fe-56. Values more than four and less than one-third times the solar ratio would pose very severe problems for the theory of stellar nucleosynthesis, implying, for example, that Fe-56 was not the dominant iron group isotope or that no electron capture occurred during oxygen burning. Though dependent somewhat on the neutron excess, the Fe-57 yield is most sensitive to the occurrence of an alpha-rich freeze-out. An accurate measurement of the Fe-57 yield, as reflected observationally by the current abundance of radioactive Co-57, is thus an important constraint upon the supernova explosion mechanism. The abundance of Ti-44, another nucleus produced exclusively in the alpha-rich freeze-out, cannot be much greater than that implied by the solar ratio of Ca-44/Fe-56.

  9. Supernova SN1987A in the Large Magellanic Cloud

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Glittering stars and wisps of gas create a breathtaking backdrop for the self-destruction of a massive star, called supernova 1987A, in the Large Magellanic Cloud, a nearby galaxy. Astronomers in the Southern hemisphere witnessed the brilliant explosion of this star on Feb. 23, 1987. Shown in this NASA Hubble Space Telescope image, the supernova remnant, surrounded by inner and outer rings of material, is set in a forest of ethereal, diffuse clouds of gas. This three-color image is composed of several pictures of the supernova and its neighboring region taken with the Wide Field and Planetary Camera 2 in Sept. 1994, Feb. 1996 and July 1997. The many bright blue stars nearby the supernova are massive stars, each more than six times heftier than our Sun. They are members of the same generation of stars as the star that went supernova about 12 million years ago. The presence of bright gas clouds is another sign of the youth of this region, which still appears to be a fertile breeding ground for new stars. In a few years the supernova's fast moving material will sweep the inner ring with full force, heating and exciting its gas, and will produce a new series of cosmic fireworks that will offer a striking view for more than a decade.

  10. SN 1987A - The evolution from red to blue

    SciTech Connect

    Tuchman, Y.; Wheeler, J.C. )

    1989-11-01

    Envelope models in thermal and dynamic equilibrium are used to explore the nature of the transition of SK -69 deg 202, the progenitor of SN 1987A, from the Hayashi track to its final blue position in the H-R diagram. Loci of possible thermal equilibrium solutions are presented as a function of Teff and M(C/O), the mass of the carbon/oxygen core interior to the helium burning shell. It is found that uniform helium enrichment of the envelope results in red-blue evolution but that the resulting blue solution is much hotter than SK -69 deg 202. Solutions in which the only change is to redistribute the portion of the envelope enriched in helium during main-sequence convective core contraction into a step function with Y of about 0.5 at a mass cut of about 10 solar masses give a natural transition from red to blue and a final value of Teff in agreement with observations. It is argued that SK -69 deg 202 probably fell on a post-Hayashi track sequence at moderate Teff. The possible connection of this sequence to the step distribution in the H-R diagram of the LMC. 19 refs.

  11. SN1987A IN THE LARGE MAGELLANIC CLOUD

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Glittering stars and wisps of gas create a breathtaking backdrop for the self-destruction of a massive star, called supernova 1987A, in the Large Magellanic Cloud, a nearby galaxy. Astronomers in the Southern hemisphere witnessed the brilliant explosion of this star on Feb. 23, 1987. Shown in this NASA Hubble Space Telescope image, the supernova remnant, surrounded by inner and outer rings of material, is set in a forest of ethereal, diffuse clouds of gas. This three-color image is composed of several pictures of the supernova and its neighboring region taken with the Wide Field and Planetary Camera 2 in Sept. 1994, Feb. 1996 and July 1997. The many bright blue stars nearby the supernova are massive stars, each more than six times heftier than our Sun. With ages of about 12 million years old, they are members of the same generation of stars as the star that went supernova. The presence of bright gas clouds is another sign of the youth of this region, which still appears to be a fertile breeding ground for new stars. In a few years the supernova's fast moving material will sweep the inner ring with full force, heating and exciting its gas, and will produce a new series of cosmic fireworks that will offer a striking view for more than a decade. Credit: Hubble Heritage Team (AURA/STScI/NASA)

  12. The impact of SN 1987A with its circumstellar ring

    NASA Technical Reports Server (NTRS)

    Luo, Ding; Mccray, Richard; Slavin, Johnathan

    1994-01-01

    The envleope of SN 1987A will strike its circumstellar ring in 12 +/- 3 yr after explosion (A.D. 1999+/-3), the exact time depending weakly on the uncertain density of diffuse gas between the supernova and the ring. The impact will drive a radiative shock into the ring with velocity approximatley 200-400 km s(exp -1). The shocked ring will become a bright optical and ultraviolet emsiison-line source. A bright arc will suddenly appear at the near side of the ring and grow into an entire ring about 11 months later. The luminosities of the brightest lines, H-alpha H-alpha, N v lambda lambda 1238, 1242, and O VI lambda lambda 1032, 1038 will rise rapidly to approxminately 10(exp 36)-10(exp 37) ergs s(exp -1) and remain bright for several years after impact. The emission lines from the shocked ring will have FWHM approximatley 300-600 km s(exp -1) and complex profiles that will depend on position and will be sensitive to the details of the density distribution of gas in the ring. Strong EUV radiation from the shock will photoionize the unshocked ring, causing emission of narrow FWHM equivalent to 15 km s(exp -1) H-alpha, H-beta and (O III) lambda lambda 4959, 5007 lines with luminosities approximatley 10(exp 35) ergs s(exp -1).The EUV radiation will probably cause the nebulosity beyond the ring to become visable again. The EUV radiation may also illuminate the unshocked outer supernova envelope, causing visible emission of broad FWHM equivalent to 10(exp 4) km s(exp -1) H-alpha and H-beta lines.

  13. The Three-dimensional Circumstellar Environment of SN 1987A

    NASA Astrophysics Data System (ADS)

    Sugerman, Ben E. K.; Crotts, Arlin P. S.; Kunkel, William E.; Heathcote, Stephen R.; Lawrence, Stephen S.

    2005-07-01

    Surrounding SN 1987A is a three-ring nebula attributed to interacting stellar winds, yet no model has successfully reproduced this system. Fortunately, the progenitor's mass-loss history can be reconstructed using light echoes, in which scattered light from the supernova traces the three-dimensional morphology of its circumstellar dust. In this paper, we construct and analyze the most complete map to date of the progenitor's circumstellar environment, using ground- and space-based imaging from the past 16 years. PSF-matched difference-imaging analyses of data from 1988 through 1997 reveal material between 1 and 28 lt-yr from the SN. Previously known structures, such as an inner hourglass, Napoleon's Hat, and a contact discontinuity, are probed in greater spatial detail than before. Previously unknown features are also discovered, such as a southern counterpart to Napoleon's Hat. Careful analyses of these echoes allows the reconstruction of the probable circumstellar environment, revealing a richly structured bipolar nebula. An outer, double-lobed ``Peanut,'' which is believed to be the contact discontinuity between red supergiant and main-sequence winds, is a prolate shell extending 28 lt-yr along the poles and 11 lt-yr near the equator. Napoleon's Hat, previously believed to be an independent structure, is the waist of this Peanut, which is pinched to a radius of 6 lt-yr. Interior to this is a cylindrical hourglass, 1 lt-yr in radius and 4 lt-yr long, which connects to the Peanut by a thick equatorial disk. The nebulae are inclined 41° south and 8° east of the line of sight, slightly elliptical in cross section, and marginally offset west of the SN. From the hourglass to the large, bipolar lobes, echo fluxes suggest that the gas density drops from 1-3 to >~0.03 cm-3, while the maximum dust-grain size increases from ~0.2 to 2 μm, and the silicate:carbonaceous dust ratio decreases. The nebulae have a total mass of ~1.7 Msolar. The geometry of the three rings is

  14. The Type II supernovae 2006V and 2006au: two SN 1987A-like events

    NASA Astrophysics Data System (ADS)

    Taddia, F.; Stritzinger, M. D.; Sollerman, J.; Phillips, M. M.; Anderson, J. P.; Ergon, M.; Folatelli, G.; Fransson, C.; Freedman, W.; Hamuy, M.; Morrell, N.; Pastorello, A.; Persson, S. E.; Gonzalez, S.

    2012-01-01

    Context. Supernova 1987A revealed that a blue supergiant (BSG) star can end its life as a core-collapse supernova (SN). SN 1987A and other similar objects exhibit properties that distinguish them from ordinary Type II Plateau (IIP) SNe, whose progenitors are believed to be red supergiants (RSGs). Similarities among 1987A-like events include a long rise to maximum, early luminosity fainter than that of normal Type IIP SNe, and radioactivity acting as the primary source powering the light curves. Aims: We present and analyze two SNe monitored by the Carnegie Supernova Project that are reminiscent of SN 1987A. Methods: Optical and near-infrared (NIR) light curves, and optical spectroscopy of SNe 2006V and 2006au are presented. These observations are compared to those of SN 1987A, and are used to estimate properties of their progenitors. Results: Both objects exhibit a slow rise to maximum and light curve evolution similar to that of SN 1987A. At the earliest epochs, SN 2006au also displays an initial dip which we interpret as the signature of the adiabatic cooling phase that ensues shock break-out. SNe 2006V and 2006au are both found to be bluer, hotter and brighter than SN 1987A. Spectra of SNe 2006V and 2006au are similar to those of SN 1987A and other normal Type II objects, although both consistently exhibit expansion velocities higher than SN 1987A. Semi-analytic models are fit to the UVOIR light curve of each object from which physical properties of the progenitors are estimated. This yields ejecta mass estimates of Mej ≈ 20 M⊙, explosion energies of E ≈ 2-3 × 1051 erg s-1, and progenitor radii of R ≈ 75-100 R⊙ for both SNe. Conclusions: The progenitors of SNe 2006V and 2006au were most likely BSGs with a larger explosion energy as compared to that of SN 1987A. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (ESO Programme 076.A-0156). This paper includes data gathered with the 6

  15. Mechanisms of attention

    PubMed Central

    Lu, Zhong-Lin

    2009-01-01

    Sensory physiologists and psychologists have recognized the importance of attention on human performance for more than 100 years. Since the 1970s, controlled and extensive experiments have examined effects of selective attention to a location in space or to an object. In addition to behavioral studies, cognitive neuroscientists have investigated the neural bases of attention. In this paper, I briefly review some classical attention paradigms, recent advances on the theory of attention, and some new insights from psychophysics and cognitive neuroscience. The focus is on the mechanisms of attention, that is, how attention improves human performance. Situations in which the perception of objects is unchanged, but performance may differ due to different decision structures, are distinguished from those in which attention changes the perceptual processes. The perceptual template model is introduced as a theoretical framework for analyzing mechanisms of attention. I also present empirical evidence for two attention mechanisms, stimulus enhancement and external noise exclusion, from psychophysics, neurophysiology and brain imaging. PMID:20523762

  16. Facilitating Transition from High School and Special Education to Adult Life: Focus on Youth with Learning Disorders, Attention-Deficit/Hyperactivity Disorder, and Speech/Language Impairments.

    PubMed

    Ascherman, Lee I; Shaftel, Julia

    2017-04-01

    Youth with learning disorders, speech/language disorders, and/or attention-deficit/hyperactivity disorder may experience significant struggles during the transition from high school to postsecondary education and employment. These disorders often occur in combination or concurrently with behavioral and emotional difficulties. Incomplete evaluation may not fully identify the factors underlying academic and personal challenges. This article reviews these disorders, the role of special education law for transitional age youth in public schools, and the Americans with Disabilities Act in postsecondary educational and employment settings. The role of the child and adolescent psychiatrist and the importance of advocacy for these youth are presented.

  17. Sustained treatment effect in attention-deficit/hyperactivity disorder: focus on long-term placebo-controlled randomized maintenance withdrawal and open-label studies.

    PubMed

    Goodman, David W

    2013-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that often persists throughout life. Approximately two-thirds of patients with a childhood diagnosis of ADHD continue to experience clinically significant symptoms into adulthood. Nevertheless, most of these individuals consider themselves "well," and a vast majority discontinue medication treatment during adolescence. As evidence concerning the adult presentation of ADHD becomes more widely accepted, increasing numbers of physicians and patients will face decisions about the benefits and risks of continuing ADHD treatment. The risks associated with psychostimulant pharmacotherapy, including abuse, dependence, and cardiovascular events, are well understood. Multiple clinical trials demonstrate the efficacy of psychostimulants in controlling ADHD symptoms in the short term. Recent investigations using randomized withdrawal designs now provide evidence of a clinically significant benefit with continued long-term ADHD pharmacotherapy and provide insight into the negative consequences associated with discontinuation. Because many patients lack insight regarding their ADHD symptoms and impairments, they may place a low value on maintaining treatment. Nevertheless, for patients who choose to discontinue treatment, physicians can remain a source of support and schedule follow-up appointments to reassess patient status. Medication discontinuation can be used as an opportunity to help patients recognize their most impairing symptoms, learn and implement behavioral strategies to cope with ADHD symptoms, and understand when additional supportive resources and the resumption of medication management may be necessary.

  18. Ti-44 Gamma-Ray Emission Lines from SN1987A Reveal an Asymmetric Explosion

    NASA Technical Reports Server (NTRS)

    Boggs, S. E.; Harrison, F. A.; Miyasaka, H.; Grefenstette, B. W.; Zoglauer, A.; Fryer, C. L.; Reynolds, S. P.; Alexander, D. M.; An, H.; Barret, D.; Christensen, F. E.; Craig, W. W.; Forster, K.; Giommi, P.; Hailey, C. J.; Hornstrup, A.; Kitaguchi, T.; Koglin, J. E.; Madsen, K. K.; Zhang, W. W.

    2015-01-01

    In core-collapse supernovae, titanium-44 (Ti-44) is produced in the innermost ejecta, in the layer of material directly on top of the newly formed compact object. As such, it provides a direct probe of the supernova engine. Observations of supernova 1987A (SN1987A) have resolved the 67.87- and 78.32-kilo-electron volt emission lines from decay of Ti-44 produced in the supernova explosion. These lines are narrow and redshifted with a Doppler velocity of 700 kilometers per second, direct evidence of large-scale asymmetry in the explosion.

  19. Experimental limits on the radiative decay of SN 1987A neutrinos

    NASA Technical Reports Server (NTRS)

    Chupp, Edward L.; Vestrand, W. Thomas; Reppin, Claus

    1989-01-01

    SMM gamma-ray spectrometer data are examined to look for gamma-ray emission coincident with the about-10-s neutrino burst from SN 1987A. The absence of a detectable signal suggests that the energy radiated into MeV gamma rays by neutrino decay (or any other process) is less than 10 to the -10th of that in supernova neutrinos above 9 MeV. The results are used to set a direct limit on the lifetime of any massive neutrino type generated in the core collapse leading to SN 1987A.

  20. The Structure of the Relationship between Attention and Intelligence

    ERIC Educational Resources Information Center

    Schweizer, Karl; Moosbrugger, Helfried; Goldhammer, Frank

    2005-01-01

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

  1. Plant intelligence and attention

    PubMed Central

    Marder, Michael

    2013-01-01

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

  2. Plant intelligence and attention.

    PubMed

    Marder, Michael

    2013-05-01

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

  3. Neutrinos from SN 1987A and cooling of the nascent neutron star

    NASA Technical Reports Server (NTRS)

    Lamb, D. Q.; Loredo, Thomas J.; Melia, Fulvio

    1988-01-01

    The implications of the detection of neutrinos from SN 1987A for the cooling of the nascent neutron star are considered. The nu-bar(e) number N, the apparent temperature, the cooling time scale measured by the Kamioka and IMB detectors, and the inferred neutron star apparent radius and binding energy are all found to provide striking verification of current supernova theory.

  4. ASYMMETRY IN THE OUTBURST OF SN 1987A DETECTED USING LIGHT ECHO SPECTROSCOPY

    SciTech Connect

    Sinnott, B.; Welch, D. L.; Sutherland, P. G.; Rest, A.; Bergmann, M.

    2013-04-10

    We report direct evidence for asymmetry in the early phases of SN 1987A via optical spectroscopy of five fields of its light echo system. The light echoes allow the first few hundred days of the explosion to be reobserved, with different position angles providing different viewing angles to the supernova. Light echo spectroscopy therefore allows a direct spectroscopic comparison of light originating from different regions of the photosphere during the early phases of SN 1987A. Gemini multi-object spectroscopy of the light echo fields shows fine structure in the H{alpha} line as a smooth function of position angle on the near-circular light echo rings. H{alpha} profiles originating from the northern hemisphere of SN 1987A show an excess in redshifted emission and a blue knee, while southern hemisphere profiles show an excess of blueshifted H{alpha} emission and a red knee. This fine structure is reminiscent of the 'Bochum event' originally observed for SN 1987A, but in an exaggerated form. Maximum deviation from symmetry in the H{alpha} line is observed at position angles 16 Degree-Sign and 186 Degree-Sign , consistent with the major axis of the expanding elongated ejecta. The asymmetry signature observed in the H{alpha} line smoothly diminishes as a function of viewing angle away from the poles of the elongated ejecta. We propose an asymmetric two-sided distribution of {sup 56}Ni most dominant in the southern far quadrant of SN 1987A as the most probable explanation of the observed light echo spectra. This is evidence that the asymmetry of high-velocity {sup 56}Ni in the first few hundred days after explosion is correlated to the geometry of the ejecta some 25 years later.

  5. Origin of pulsed emission from the young supernova remnant SN 1987A

    NASA Technical Reports Server (NTRS)

    Ruderman, M.; Kluzniak, W.; Shaham, Jacob

    1989-01-01

    To overcome difficulties in understanding the origin of the submillisecond optical pulses from SN 1987A a model similar to that of Kundt and Krotscheck for pulsed synchrotron emission from the Crab was applied. The interaction of the expected ultrarelativistic e(sup + or -) pulsar wind with the pulsar dipole electromagnetic wave reflected from the walls of a pulsar cavity within the SN 1987A nubula can generate pulsed optical emission with efficiency at most eta(sub max) is approximately equal to 10(exp -3). The maximum luminosity of the source is reproduced and other observational constraints can be satisfied for an average wind energy flow is approximately equal to 10(exp 38) erg/(s steradian) and for electron Lorentz factor gamma is approximately equal to 10(exp 5). This model applied to the Crab yields pulsations of much lower luminosity and frequency.

  6. Origin of the Napoleon's hat nebula around SN1987A and implications for the progenitor

    NASA Astrophysics Data System (ADS)

    Podsiadlowski, Ph.; Fabian, A. C.; Stevens, I. R.

    1991-11-01

    A simple geometrical model for the emission nebula around SN1987A, whose morphology has been likened to Napoleon's hat, is presented. The model consists of a ring and a truncated double cone. When the effects of light travel time are included, the model reproduces the important topological structures of the nebula and makes detailed quantitative predictions for its future appearance. In particular, the hat-shaped northern rim is simply explained as the interaction of the light front with the northern cone. To explain the origin of the double cone, it is argued that the progenitor of SN1987A was in a binary system: its strong wind, colliding with a weaker wind from the companion star, created an asymptotic shock surface that was spread out into the required geometry by the rotation of the binary.

  7. Chandra Observations of SN 1987A: The Soft X-Ray Light Curve Revisited

    NASA Technical Reports Server (NTRS)

    Helder, E. A.; Broos, P. S.; Dewey, D.; Dwek, E.; McCray, R.; Park, S.; Racusin, J. L.; Zhekov, S. A.; Burrows, D. N.

    2013-01-01

    We report on the present stage of SN 1987A as observed by the Chandra X-Ray Observatory. We reanalyze published Chandra observations and add three more epochs of Chandra data to get a consistent picture of the evolution of the X-ray fluxes in several energy bands. We discuss the implications of several calibration issues for Chandra data. Using the most recent Chandra calibration files, we find that the 0.5-2.0 keV band fluxes of SN 1987A have increased by approximately 6 x 10(exp-13) erg s(exp-1)cm(exp-2) per year since 2009. This is in contrast with our previous result that the 0.5-2.0 keV light curve showed a sudden flattening in 2009. Based on our new analysis, we conclude that the forward shock is still in full interaction with the equatorial ring.

  8. SUPERNOVA 1987A: A TEMPLATE TO LINK SUPERNOVAE TO THEIR REMNANTS

    SciTech Connect

    Orlando, S.; Miceli, M.; Pumo, M. L.; Bocchino, F.

    2015-09-10

    The emission of supernova remnants (SNRs) reflects the properties of both the progenitor supernovae (SNe) and the surrounding environment. The complex morphology of the remnants, however, hampers the disentanglement of the two contributions. Here, we aim at identifying the imprint of SN 1987A on the X-ray emission of its remnant and at constraining the structure of the environment surrounding the SN. We performed high-resolution hydrodynamic simulations describing SN 1987A soon after the core-collapse and the following three-dimensional expansion of its remnant between days 1 and 15,000 after the SN. We demonstrated that the physical model reproducing the main observables of SN 1987A during the first 250 days of evolution also reproduces the X-ray emission of the subsequent expanding remnant, thus bridging the gap between SNe and SNRs. By comparing model results with observations, we constrained the explosion energy in the range 1.2–1.4 × 10{sup 51} erg and the envelope mass in the range 15–17 M{sub ⊙}. We found that the shape of X-ray lightcurves and spectra at early epochs (<15 years) reflects the structure of outer ejecta: our model reproduces the observations if the outermost ejecta have a post-explosion radial profile of density approximated by a power law with index α = −8. At later epochs, the shapes of X-ray lightcurves and spectra reflect the density structure of the nebula around SN 1987A. This enabled us to ascertain the origin of the multi-thermal X-ray emission, disentangle the imprint of the SN on the remnant emission from the effects of the remnant interaction with the environment, and constrain the pre-supernova structure of the nebula.

  9. Supernova 1987A: a Template to Link Supernovae to Their Remnants

    NASA Astrophysics Data System (ADS)

    Orlando, S.; Miceli, M.; Pumo, M. L.; Bocchino, F.

    2015-09-01

    The emission of supernova remnants (SNRs) reflects the properties of both the progenitor supernovae (SNe) and the surrounding environment. The complex morphology of the remnants, however, hampers the disentanglement of the two contributions. Here, we aim at identifying the imprint of SN 1987A on the X-ray emission of its remnant and at constraining the structure of the environment surrounding the SN. We performed high-resolution hydrodynamic simulations describing SN 1987A soon after the core-collapse and the following three-dimensional expansion of its remnant between days 1 and 15,000 after the SN. We demonstrated that the physical model reproducing the main observables of SN 1987A during the first 250 days of evolution also reproduces the X-ray emission of the subsequent expanding remnant, thus bridging the gap between SNe and SNRs. By comparing model results with observations, we constrained the explosion energy in the range 1.2-1.4 × 1051 erg and the envelope mass in the range 15-17 M ⊙. We found that the shape of X-ray lightcurves and spectra at early epochs (<15 years) reflects the structure of outer ejecta: our model reproduces the observations if the outermost ejecta have a post-explosion radial profile of density approximated by a power law with index α = -8. At later epochs, the shapes of X-ray lightcurves and spectra reflect the density structure of the nebula around SN 1987A. This enabled us to ascertain the origin of the multi-thermal X-ray emission, disentangle the imprint of the SN on the remnant emission from the effects of the remnant interaction with the environment, and constrain the pre-supernova structure of the nebula.

  10. SN Refsdal: Classification as a Luminous and Blue SN 1987A-like Type II Supernova

    NASA Astrophysics Data System (ADS)

    Kelly, P. L.; Brammer, G.; Selsing, J.; Foley, R. J.; Hjorth, J.; Rodney, S. A.; Christensen, L.; Strolger, L.-G.; Filippenko, A. V.; Treu, T.; Steidel, C. C.; Strom, A.; Riess, A. G.; Zitrin, A.; Schmidt, K. B.; Bradač, M.; Jha, S. W.; Graham, M. L.; McCully, C.; Graur, O.; Weiner, B. J.; Silverman, J. M.; Taddia, F.

    2016-11-01

    We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in fall 2014. The HST light curve of SN Refsdal has a shape consistent with the distinctive, slowly rising light curves of SN 1987A-like SNe, and we find strong evidence for a broad Hα P-Cygni profile and Na I D absorption in the HST grism spectrum at the redshift (z = 1.49) of the spiral host galaxy. SNe IIn, largely powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show broad and strong Hα and Na I D absorption. From the grism spectrum, we measure an Hα expansion velocity consistent with those of SN 1987A-like SNe at a similar phase. The luminosity, evolution, and Gaussian profile of the Hα emission of the WFC3 and X-shooter spectra, separated by ˜2.5 months in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other examples of SN 1987A-like SNe, photometry of SN Refsdal favors bluer B - V and V - R colors and one of the largest luminosities for the assumed range of potential magnifications. The evolution of the light curve at late times will provide additional evidence about the potential existence of any substantial circumstellar material. Using MOSFIRE and X-shooter spectra, we estimate a subsolar host-galaxy metallicity (8.3 ± 0.1 dex and <8.4 dex, respectively) near the explosion site.

  11. The neutrino burst from SN 1987A detected in the Mont Blanc LSD experiment.

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Badino, G.; Bologna, G.; Castagnoli, C.; Castellina, A.; Dadykin, V. L.; Fulgione, W.; Galeotti, P.; Kalchukov, F. F.; Khalchukov, F. F.; Kortchaguin, V. B.; Korchagin, V. B.; Kortchaguin, P. V.; Korchagin, P. V.; Malguin, A. S.; Mal'Gin, A. S.; Ryassny, V. G.; Ryasnyj, V. G.; Ryazhkaya, O. G.; Saavedra, O.; Talochkin, V. P.; Trinchero, G.; Vernetto, S.; Zatsepin, G. T.; Yakushev, V. F.

    The authors discuss the event, (5 interactions recorded during 7 seconds) detected in the Mont Blanc Underground Neutrino Observatory on February 23, 1987, during the occurrence of supernova SN 1987A. The pulse amplitudes, the background imitation probability, and the energetics connected with the event are reported. It is also shown that some interactions recorded at the same time in other underground experiments, with a lower detection efficiency, are consistent with the Mont Blanc event.

  12. High-Velocity Ly(Alpha) Emission from SMR 1987A

    NASA Technical Reports Server (NTRS)

    Michael, Eli; McCray, Richard; Borkowski, Kazimierz J.; Pun, Chu S. J.; Sonneborn, George

    1998-01-01

    The high-velocity Ly(Alpha) emission from SN 1987A observed with the Space Telescope Imaging Spectrograph (STIS) evidently comes from a reverse shock formed where the outer envelope of SN 1987A strikes ionized gas inside the inner circumstellar ring. The observations can be explained by a simple kinematic model, in which the Ly(Alpha) emission comes from hydrogen atoms with radial velocity approximately 15,000 km s(exp -1) crossing a reverse shock in the shape of a slightly prolate ellipsoid with equatorial radius 4.8 x 10(exp 17) cm or approximately 80% of the distance to the inner surface of the inner ring. N v double Lambda 1239, 1243 emission, if present, has a net luminosity approximately less than 30% times that of the Ly(Alpha) emission. Future STIS observations should enable us to predict the time of impact with the inner ring and to determine unambiguously whether or not N v emission is present. These observations will offer a unique opportunity to probe the structure of SN 1987A's circumstellar environment and the hydrodynamics and kinetics of very fast shocks.

  13. Confirmation of Dust Condensation in the Ejecta of Supernova 1987a

    NASA Astrophysics Data System (ADS)

    Gehrz, R. D.; Ney, E. P.

    1990-06-01

    Shortly after its outburst, we suggested that supernova 1987a might condense a dust shell of substantial visual optical thickness as many classical novae do and predicted that dust might form within a year after the explosion. A critical examination of recent optical and infrared observations reported by others confirms that dust grains had begun to grow at a temperature of 1000 K after 300 days and that the dust shell had become optically thick by day 600. After day 600, the infrared luminosity closely followed the intrinsic luminosity expected for thermalized 56Co γ rays, demonstrating that the luminosity is powered by radioactivity and that the dust is outside the radioactivity zone. The infrared luminosity sets an upper limit to the soft intrinsic bolometric luminosity of a pulsar central engine. This upper limit for the pulsar in supernova 1987a is the same luminosity as the Crab pulsar has today 936 years after its formation. It is unlikely that the rotation rate for a pulsar in supernova 1987a can be much higher than ≈ 30 revolutions per sec. The relatively long time required for the shell to grow to maximum optical depth as compared with the dust in nova shells may be related to the relatively low outflow velocity of the condensible ejecta.

  14. Thirteen years of pummeling the circumstellar ring around SN 1987A

    NASA Astrophysics Data System (ADS)

    Dwek, Eli; Arendt, Richard G.; Bouchet, Patrice; Danziger, John

    2016-06-01

    Since 2003, about 6000 days after the explosion, the radiative energy output from SN 1987A has shifted from being dominated by the release of radioactive energy from the ejecta, to the release of mechanical energy caused by the interaction of the SN blast wave with the circumstellar ring. The energy from the interaction is released at X-ray, UV-optical, and infrared (IR) wavelengths. The 5-35 micron IR spectrum from the ring is dominated by the emission from collisionally-heated silicate dust. The circumstellar ring around SN 1987A therefore provides astronomers with a unique laboratory for studying the physical conditions and gas-dust interaction in dusty astrophysical plasmas. In particular, the X-ray and IR observations can be used to determine the erosion efficiency of dust grains in such hostile astrophysical environment. In this talk I will summarize what we have learned from 12 years of Gemini and Spitzer observations of the ring around SN 1987A.

  15. Confirmation of dust condensation in the ejecta of supernova 1987a.

    PubMed Central

    Gehrz, R D; Ney, E P

    1990-01-01

    Shortly after its outburst, we suggested that supernova 1987a might condense a dust shell of substantial visual optical thickness as many classical novae do and predicted that dust might form within a year after the explosion. A critical examination of recent optical and infrared observations reported by others confirms that dust grains had begun to grow at a temperature of 1000 K after 300 days and that the dust shell had become optically thick by day 600. After day 600, the infrared luminosity closely followed the intrinsic luminosity expected for thermalized 56Co gamma rays, demonstrating that the luminosity is powered by radioactivity and that the dust is outside the radioactivity zone. The infrared luminosity sets an upper limit to the soft intrinsic bolometric luminosity of a pulsar central engine. This upper limit for the pulsar in supernova 1987a is the same luminosity as the Crab pulsar has today 936 years after its formation. It is unlikely that the rotation rate for a pulsar in supernova 1987a can be much higher than approximately 30 revolutions per sec. The relatively long time required for the shell to grow to maximum optical depth as compared with the dust in nova shells may be related to the relatively low outflow velocity of the condensible ejecta. PMID:11607082

  16. Oriented Scintillation Spectrometer Experiment observations of Co-57 in SN 1987A

    NASA Technical Reports Server (NTRS)

    Kurfess, J. D.; Johnson, W. N.; Kinzer, R. L.; Kroeger, R. A.; Strickman, M. S.; Grove, J. E.; Leising, M. D.; Clayton, D. D.; Grabelsky, D. A.; Purcell, W. R.

    1992-01-01

    The Oriented Scintillation Spectrometer Experiment (OSSE) on the Compton Gamma Ray Observatory has observed SN 1987A for two 2 week periods during the first 9 months of the mission. Evidence for gamma-ray line and continuum emission from Co-57 is observed with an intensity of about 10 exp -4 gamma/sq cm/s. This photon flux between 50 and 136 keV is demonstrated by Monte Carlo calculations to be independent of the radial distribution of Co-57 for models of low optical depth, viz., models having photoelectric absorption losses of 122 keV photons no greater than several percent. For such models the observed Co-57 flux indicates that the ratio Ni-57/Ni-56 produced in the explosion was about 1.5 times the solar system ratio of Fe-57/Fe-56. When compared with nearly contemporaneous bolometric estimates of the luminosity for SN 1987A, our observations imply that Co-57 radioactivity does not account for most of the current luminosity of the supernova remnant in low optical depth models. We suggest alternatives, including a large optical depth model that is able to provide the SN 1987A luminosity and is consistent with the OSSE flux. It requires a 57/56 production ratio about twice solar.

  17. Brief report: cognitive flexibility and focused attention in children and adolescents with Asperger syndrome or high-functioning autism as measured on the computerized version of the Wisconsin Card Sorting Test.

    PubMed

    Kaland, Nils; Smith, Lars; Mortensen, Erik Lykke

    2008-07-01

    The aim of the present study was to assess mental flexibility and set maintenance of a group of individuals with Asperger syndrome (AS) or high-functioning autism (HFA) (N = 13; mean age 16,4), as compared with a matched group of typically developing children and adolescents (N = 13; mean age 15,6) on the computerized version of the Wisconsin Card Sorting Test (WCST). The participants in the AS/HFA group performed less well than the controls on all categories of the WCST, but the differences did not reach conventional statistical significance on most categories of the WCST. On the category failure to maintain set, however, the AS/HFA participants performed significantly less well than the controls, suggesting a deficit of focused attention.

  18. Reading Aloud and Solving Simple Arithmetic Calculation Intervention (Learning Therapy) Improves Inhibition, Verbal Episodic Memory, Focus Attention and Processing Speed in Healthy Elderly People: Evidence from a Randomized Controlled Trial

    PubMed Central

    Nouchi, Rui; Taki, Yasuyuki; Takeuchi, Hikaru; Nozawa, Takayuki; Sekiguchi, Atsushi; Kawashima, Ryuta

    2016-01-01

    Background: Previous reports have described that simple cognitive training using reading aloud and solving simple arithmetic calculations, so-called “learning therapy”, can improve executive functions and processing speed in the older adults. Nevertheless, it is not well-known whether learning therapy improve a wide range of cognitive functions or not. We investigated the beneficial effects of learning therapy on various cognitive functions in healthy older adults. Methods: We used a single-blinded intervention with two groups (learning therapy group: LT and waiting list control group: WL). Sixty-four elderly were randomly assigned to LT or WL. In LT, participants performed reading Japanese aloud and solving simple calculations training tasks for 6 months. WL did not participate in the intervention. We measured several cognitive functions before and after 6 months intervention periods. Results: Compared to WL, results revealed that LT improved inhibition performance in executive functions (Stroop: LT (Mean = 3.88) vs. WL (Mean = 1.22), adjusted p = 0.013 and reverse Stroop LT (Mean = 3.22) vs. WL (Mean = 1.59), adjusted p = 0.015), verbal episodic memory (Logical Memory (LM): LT (Mean = 4.59) vs. WL (Mean = 2.47), adjusted p = 0.015), focus attention (D-CAT: LT (Mean = 2.09) vs. WL (Mean = −0.59), adjusted p = 0.010) and processing speed compared to the WL control group (digit symbol coding: LT (Mean = 5.00) vs. WL (Mean = 1.13), adjusted p = 0.015 and Symbol Search (SS): LT (Mean = 3.47) vs. WL (Mean = 1.81), adjusted p = 0.014). Discussion: This randomized controlled trial (RCT) can be showed the benefit of LT on inhibition of executive functions, verbal episodic memory, focus attention and processing speed in healthy elderly people. Our results were discussed under overlapping hypothesis. PMID:27242481

  19. Core collapse supernovae from blue supergiant progenitors : The evolutionary history of SN 1987A

    NASA Astrophysics Data System (ADS)

    Menon, Athira

    2015-08-01

    SN 1987A is historically one of the most remarkable supernova explosions to be seen from Earth. Due to the proximity of its location in the LMC, it remains the most well-studied object outside the solar system. It was also the only supernova whose progenitor was observed prior to its explosion.SN 1987A however, was a unique and enigmatic core collapse supernova. It was the first Type II supernova to have been observed to have exploded while its progenitor was a blue supergiant (BSG). Until then Type II supernovae were expected to originate from explosions of red supergiants (RSGs). A spectacular triple-ring nebula structure, rich in helium and nitrogen, was observed around the remnant, indicating a recent RSG phase before becoming a BSG. Even today it is not entirely understood what the evolutionary history may have been to cause a BSG to explode. The most commonly accepted hypothesis for its origin is the merger of a massive binary star system.An evolutionary scenario for such a binary system, was proposed by Podsiadlowski (1992) (P92). Through SPH simulations of the merger and the stellar evolution of the post-merger remnant, Ivanova & Podsiadlowski (2002) and (2003) (I&M) could successfully obtain the RSG to BSG transition of the progenitor.The aim of the present work is to produce the evolutionary history of the progenitor of SN 1987A and its explosion. We construct our models based on the results of P92 and I&M. Here, the secondary (less massive) star is accreted on the primary, while being simultaneously mixed in its envelope over a period of 100 years. The merged star is evolved until the onset of core collapse. For this work we use the 1-dimensional, implicit, hydrodynamical stellar evolution code, KEPLER. A large parameter space is explored, consisting of primary (16-20 Ms) and secondary masses (5-8 Ms), mixing boundaries, and accreting timescales. Those models whose end states match the observed properties of the progenitor of SN 1987A are exploded. The

  20. The quest for blue supergiants : The evolution of the progenitor of SN 1987A

    NASA Astrophysics Data System (ADS)

    Menon, Athira; Heger, Alexander

    2015-08-01

    SN 1987A is historically one of the most remarkable supernova explosions to be seen from Earth. Due to the proximity of its location in the LMC, it remains the most well-studied object outside the solar system. It was also the only supernova whose progenitor was observed prior to its explosion.SN 1987A however, was a unique and enigmatic core collapse supernova. It was the first Type II supernova to have been observed to have exploded while its progenitor was a blue supergiant (BSG). Until then Type II supernovae were expected to originate from explosions of red supergiants (RSGs). A spectacular triple-ring nebula structure, rich in helium and nitrogen, was observed around the remnant, indicating a recent RSG phase before becoming a BSG. Even today it is not entirely understood what the evolutionary history may have been to cause a BSG to explode. The most commonly accepted hypothesis for its origin is the merger of a massive binary star system.An evolutionary scenario for such a binary system, was proposed by Podsiadlowski (1992) (P92). Through SPH simulations of the merger and the stellar evolution of the post-merger remnant, Ivanova & Podsiadlowski (2002) and (2003) (I&M) could successfully obtain the RSG to BSG transition of the progenitor.The aim of the present work is to produce the evolutionary history of the progenitor of SN 1987A and its explosion. We construct our models based on the results of P92 and I&M. Here, the secondary (less massive) star is accreted on the primary, while being simultaneously mixed in its envelope over a period of 100 years. The merged star is evolved until the onset of core collapse. For this work we use the 1-dimensional, implicit, hydrodynamical stellar evolution code, KEPLER. A large parameter space is explored, consisting of primary (16-20 Ms) and secondary masses (5-8 Ms), mixing boundaries, and accreting timescales. Those models whose end states match the observed properties of the progenitor of SN 1987A are exploded. The

  1. Supernova 1987A: neutrino-driven explosions in three dimensions and light curves

    NASA Astrophysics Data System (ADS)

    Utrobin, V. P.; Wongwathanarat, A.; Janka, H.-Th.; Müller, E.

    2015-09-01

    Context. The well-observed and well-studied type IIP Supernova 1987A (SN 1987A), produced by the explosion of a blue supergiant in the Large Magellanic Cloud, is a touchstone for the evolution of massive stars, the simulation of neutrino-driven explosions, and the modeling of light curves and spectra. Aims: In the framework of the neutrino-driven explosion mechanism, we study the dependence of explosion properties on the structure of different blue supergiant progenitors and compare the corresponding light curves with observations of SN 1987A. Methods: Three-dimensional (3D) simulations of neutrino-driven explosions are performed with the explicit, finite-volume, Eulerian, multifluid hydrodynamics code Prometheus, using of four available presupernova models as initial data. At a stage of almost homologous expansion, the hydrodynamical and composition variables of the 3D models are mapped to a spherically symmetric configuration, and the simulations are continued with the implicit, Lagrangian radiation-hydrodynamics code Crab to follow the blast-wave evolution into the SN outburst. Results: All of our 3D neutrino-driven explosion models, with explosion energies compatible with SN 1987A, produce 56Ni in rough agreement with the amount deduced from fitting the radioactively powered light-curve tail. Two of our models (based on the same progenitor) yield maximum velocities of around 3000 km s-1 for the bulk of ejected 56Ni, consistent with observational data. In all of our models inward mixing of hydrogen during the 3D evolution leads to minimum velocities of hydrogen-rich matter below 100 km s-1, which is in good agreement with spectral observations. However, the explosion of only one of the considered progenitors reproduces the shape of the broad light curve maximum of SN 1987A fairly well. Conclusions: The considered presupernova models, 3D explosion simulations, and light-curve calculations can explain the basic observational features of SN 1987A, except for those

  2. Shared Attention.

    PubMed

    Shteynberg, Garriy

    2015-09-01

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

  3. Search for O VI Emission from the Shocked Circurmstellar Gas of SN 1987A

    NASA Technical Reports Server (NTRS)

    Sonneborn, G.; Iping, R. C.; Lundqvist, P.; Fransson, C.

    2008-01-01

    The Far Ultraviolet Spectroscopic Explorer (FUSE) was used to search for broad O VI emission from the shock interaction zones produced by the collision of high-velocity supernova ejecta with the dense inner circumstellar ring of SN 1987A. Since the shock interaction with the inner ring began in 1997, broad (FWHM = 300 km/sec) emission from optical coronal lines (e.g. [Fe X], [Fe XI], and [Fe XIV]) has emerged and increased exponentially in strength. O VI 1032-1038 Angstrom emission is expected to track the coronal lines. O VI is also expected to be the primary cooling transition for the million-degree shocked gas. An accurate measurement of the O VI line strength would significantly improve current models of the shock interaction. FUSE observations of SN 1987A in 2000 and 2001 did not detect broad O VI due to spectral contamination fiom two earlytype stars within a few arc seconds of the SN. However, O VI emission was detected with narrow line widths (FWHM less than 35 km/sec) and a heliocentric radial velocity of +280 km/sec. This places the emitting gas at rest relative to the supernova and is interpreted as emission from unshocked circumstellar gas. A new FUSE observation of SN 1987A obtained in May 2007 used a narrow slit (1.25 x 20 arcsec) to significantly reduce the spectral contamination from the two early-type stars. Yet the 2007 spectrum does not reveal any significant O VI emission. The implications of these results are discussed.

  4. Low radio frequency observations and spectral modelling of the remnant of Supernova 1987A

    NASA Astrophysics Data System (ADS)

    Callingham, J. R.; Gaensler, B. M.; Zanardo, G.; Staveley-Smith, L.; Hancock, P. J.; Hurley-Walker, N.; Bell, M. E.; Dwarakanath, K. S.; Franzen, T. M. O.; Hindson, L.; Johnston-Hollitt, M.; Kapińska, A.; For, B.-Q.; Lenc, E.; McKinley, B.; Morgan, J.; Offringa, A. R.; Procopio, P.; Wayth, R. B.; Wu, C.; Zheng, Q.

    2016-10-01

    We present Murchison Widefield Array observations of the supernova remnant (SNR) 1987A between 72 and 230 MHz, representing the lowest frequency observations of the source to date. This large lever arm in frequency space constrains the properties of the circumstellar medium created by the progenitor of SNR 1987A when it was in its red supergiant phase. As of late 2013, the radio spectrum of SNR 1987A between 72 MHz and 8.64 GHz does not show any deviation from a non-thermal power law with a spectral index of -0.74 ± 0.02. This spectral index is consistent with that derived at higher frequencies, beneath 100 GHz, and with a shock in its adiabatic phase. A spectral turnover due to free-free absorption by the circumstellar medium has to occur below 72 MHz, which places upper limits on the optical depth of ≤0.1 at a reference frequency of 72 MHz, emission measure of ≲13 000 cm-6 pc, and an electron density of ≲110 cm-3. This upper limit on the electron density is consistent with the detection of prompt radio emission and models of the X-ray emission from the supernova. The electron density upper limit implies that some hydrodynamic simulations derived a red supergiant mass-loss rate that is too high, or a wind velocity that is too low. The mass-loss rate of ˜5 × 10-6 M⊙ yr-1 and wind velocity of 10 km s-1 obtained from optical observations are consistent with our upper limits, predicting a current turnover frequency due to free-free absorption between 5 and 60 MHz.

  5. The structure of SN 1987A's outer circumstellar envelope as probed by light echoes

    NASA Astrophysics Data System (ADS)

    Crotts, Arlin; Sugerman, Ben; Lawrence, Stephen; Kunkel, William

    2001-05-01

    We present ground-based and HST images processed by image subtraction to highlight transient reflection nebulae or ``light echoes'' of the maximum light pulse of the explosion of SN 1987A from surrounding material. Along with numerous structures already discussed elsewhere, we have found (in multiple epochs of data) a new feature opposite the SN from the mysterious ``Napoleon's Hat'' which indicates a symmetric structure due to shocks internal to the SN's red supergiant wind and probably caused by the pile-up of gas due to differential velocities within the outflow. We also show how echoes betray the ram pressure distribution of the progenitor mass loss flow. .

  6. The triple-ring nebula around SN 1987A: fingerprint of a binary merger.

    PubMed

    Morris, Thomas; Podsiadlowski, Philipp

    2007-02-23

    Supernova 1987A, the first naked-eye supernova observed since Kepler's supernova in 1604, defies a number of theoretical expectations. Its anomalies have long been attributed to a merger between two massive stars that occurred some 20,000 years before the explosion, but so far there has been no conclusive proof that this merger took place. Here, we present three-dimensional hydrodynamical simulations of the mass ejection associated with such a merger and the subsequent evolution of the ejecta, and we show that this accurately reproduces the properties of the triple-ring nebula surrounding the supernova.

  7. Hydrodynamic study of Supernova 1987A: The phase of a wave of cooling and recombination

    NASA Technical Reports Server (NTRS)

    Utrobin, V. P.

    1991-01-01

    The dependence of the bolometric light curve and of the effective temperature on the density distribution in a progenitor, its chemical composition, mass, radius, and explosion energy is studied. It is shown that, just before the supernova 1987 A outburst, the outside layers of the blue supergiant Sk-69.202 deg had a density distribution similar to that of the polytropic model with an index of n equals 3, a chemical composition with a mass fraction of hydrogen of the order of 0.1, and a relative helium abundance of about 0.9.

  8. Neutrino out-blow from supernova 1987A detected in the Mont Blanc observatory

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Badino, G.; Bologna, G.; Castagnoli, C.; Castellina, A.

    The authors discuss the neutrino outflow connected with the event detected in the Mont Blanc Underground Neutrino Observatory on February 23, 1987, and consisting of 5 interactions recorded during 7 seconds. The measured energies of the 5 pulses, the duration of the burst, and the advance of the detection time in comparison with the first optical observations give evidence that the event can be explained in terms of detection of neutrinos emitted during the stellar collapse in the Large Magellanic Cloud, which originated supernova SN 1987A.

  9. SN 2009mw: a member of the tiny group of 1987A-like supernovae

    NASA Astrophysics Data System (ADS)

    Takats, Katalin; Pignata, Giuliano

    2015-08-01

    SN 1987A was an event that have had a great role in forming our understanding of supernovae (SNe). It was an unusal object, different from type II-P SNe, with a broad light curve that reached the peak about 3 months after the explosion. Even today, there have been only a handful of similar objects studied.We present an event belonging to this elite group. SN 2009mw was discovered by the Chilean Supernova Search project soon after its explosion. We present our observational data of the SN, analyse its nature and compare it to the other similar objects.

  10. New analysis for the correlation between gravitational wave and neutrino detectors during SN1987A

    NASA Astrophysics Data System (ADS)

    Galeotti, P.; Pizzella, G.

    2016-08-01

    Two major problems, still associated with the SN1987A, are: (a) the signals observed with the gravitational waves detectors, (b) the duration of the collapse. Indeed, (a) the sensitivity of the gravitational wave detectors seems to be small for detecting gravitational waves and, (b) while some experimental data indicate a duration of order of hours, most theories assume that the collapse develops in a few seconds. Since recent data of the X-ray NuSTAR satellite show a clear evidence of an asymmetric collapse, we have revisited the experimental data recorded by the underground and gravitational wave detectors running during the SN1987A. New evidence is shown that confirms previous results, namely that the data recorded by the gravitational wave detectors running in Rome and in Maryland are strongly correlated with the data of both the Mont Blanc and the Kamiokande detectors, and that the correlation extends over a long period of time (1 or 2 h) centered at the Mont Blanc time. This result indicates that also Kamiokande detected neutrinos at the Mont Blanc time, and these interactions were not identified because not grouped in a burst.

  11. The nature of the Napoleon's Hat nebula of SN 1987A

    NASA Astrophysics Data System (ADS)

    Wang, L.; Dyson, J. E.; Kahn, F. D.

    1993-03-01

    The interstellar and circumstellar environment of SN 1987A is modeled. The geometries of Napoleon's Hat nebula and the dark bay suggest that there is relative motion between the SN progenitor and the surrounding ISM. Most of the dark bay can be identified with the bubble produced by the fast blue supergiant (BSG) wind before the red supergiant (RSG) stage. The relative motion between the star and the ISM is the primary reason for the star being at the edge of this bubble. After the first BSG stage, the star evolves to the RSG stage; the wind velocity is now typically 10 km/s and the mass loss rate is around 10 exp -5 solar mass/yr. The star eventually breaks through the bubble produced in the early BSG stage and starts to interact directly with the ISM outside, thus producing Napoleon's Hat. The success of this model is convincing proof of the BSG-RSG-BSG evolutionary model for the SN 1987A progenitors, and shows that is has moved from the site where it was formed.

  12. HIGH RESOLUTION 36 GHz IMAGING OF THE SUPERNOVA REMNANT OF SN 1987A

    SciTech Connect

    Potter, T. M.; Staveley-Smith, L.; Zanardo, G.; Ng, C.-Y.; Gaensler, B. M.; Ball, Lewis; Kesteven, M. J.; Manchester, R. N.; Tzioumis, A. K.

    2009-11-01

    The aftermath of supernova (SN) 1987A continues to provide spectacular insights into the interaction between an SN blastwave and its circumstellar environment. We here present 36 GHz observations from the Australia Telescope Compact Array of the radio remnant of SN 1987A. These new images, taken in 2008 April and 2008 October, substantially extend the frequency range of an ongoing monitoring and imaging program conducted between 1.4 and 20 GHz. Our 36.2 GHz images have a diffraction-limited angular resolution of 0.''3-0.''4, which covers the gap between high resolution, low dynamic range VLBI images of the remnant and low resolution, high dynamic range images at frequencies between 1 and 20 GHz. The radio morphology of the remnant at 36 GHz is an elliptical ring with enhanced emission on the eastern and western sides, similar to that seen previously at lower frequencies. Model fits to the data in the Fourier domain show that the emitting region is consistent with a thick inclined torus of mean radius 0.''85, and a 2008 October flux density of 27 +- 6 mJy at 36.2 GHz. The spectral index for the remnant at this epoch, determined between 1.4 GHz and 36.2 GHz, is alpha = -0.83. There is tentative evidence for an unresolved central source with flatter spectral index.

  13. Dust Production and Particle Acceleration in Supernova 1987A Revealed with ALMA

    NASA Technical Reports Server (NTRS)

    Indebetouw, R.; Matsuura, M.; Dwek, E.; Zanardo, G.; Barlow, M. J.; Baes, M.; Bouchet, P.; Burrows, D. N.; Chevalier, R.; Clayton, G. C.; Fransson, C.; Gaensler, B.; Kirshner, R.; Lakicevic, M.; Long, K. S.; Lundqvist, P.; Marti-Vidal, I.; Marcaide, J.; McCray, R.; Meixner, M.; Ng, C.-Y.; Park, S.; Sonneborn, G.; Staveley-Smith, L.; vanLoon, J.

    2014-01-01

    Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/ Submillimeter Array to observe SN1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450 µm, 870 µm, 1.4 mm, and 2.8 mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (>0.2 Solar Mass). For the first time we show unambiguously that this dust has formed in the inner ejecta (the cold remnants of the exploded star's core). The dust emission is concentrated at the center of the remnant, so the dust has not yet been affected by the shocks. If a significant fraction survives, and if SN 1987A is typical, supernovae are important cosmological dust producers.

  14. Dust Production and Particle Acceleration in Supernova 1987A Revealed with ALMA

    NASA Astrophysics Data System (ADS)

    Indebetouw, R.; Matsuura, M.; Dwek, E.; Zanardo, G.; Barlow, M. J.; Baes, M.; Bouchet, P.; Burrows, D. N.; Chevalier, R.; Clayton, G. C.; Fransson, C.; Gaensler, B.; Kirshner, R.; Lakićević, M.; Long, K. S.; Lundqvist, P.; Martí-Vidal, I.; Marcaide, J.; McCray, R.; Meixner, M.; Ng, C.-Y.; Park, S.; Sonneborn, G.; Staveley-Smith, L.; Vlahakis, C.; van Loon, J.

    2014-02-01

    Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/Submillimeter Array to observe SN 1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450 μm, 870 μm, 1.4 mm, and 2.8 mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (>0.2 M ⊙). For the first time we show unambiguously that this dust has formed in the inner ejecta (the cold remnants of the exploded star's core). The dust emission is concentrated at the center of the remnant, so the dust has not yet been affected by the shocks. If a significant fraction survives, and if SN 1987A is typical, supernovae are important cosmological dust producers.

  15. Revisiting the SN1987A gamma-ray limit on ultralight axion-like particles

    SciTech Connect

    Payez, Alexandre; Ringwald, Andreas; Evoli, Carmelo; Mirizzi, Alessandro; Fischer, Tobias; Giannotti, Maurizio E-mail: carmelo.evoli@desy.de E-mail: mgiannotti@barry.edu E-mail: andreas.ringwald@desy.de

    2015-02-01

    We revise the bound from the supernova SN1987A on the coupling of ultralight axion-like particles (ALPs) to photons. In a core-collapse supernova, ALPs would be emitted via the Primakoff process, and eventually convert into gamma rays in the magnetic field of the Milky Way. The lack of a gamma-ray signal in the GRS instrument of the SMM satellite in coincidence with the observation of the neutrinos emitted from SN1987A therefore provides a strong bound on their coupling to photons. Due to the large uncertainty associated with the current bound, we revise this argument, based on state-of-the-art physical inputs both for the supernova models and for the Milky-Way magnetic field. Furthermore, we provide major amendments, such as the consistent treatment of nucleon-degeneracy effects and of the reduction of the nuclear masses in the hot and dense nuclear medium of the supernova. With these improvements, we obtain a new upper limit on the photon-ALP coupling: g{sub aγ} ∼< 5.3 × 10{sup -12} GeV{sup -1}, for m{sub a} ∼< 4.4 × 10{sup -10} eV, and we also give its dependence at larger ALP masses m{sub a}. Moreover, we discuss how much the Fermi-LAT satellite experiment could improve this bound, should a close-enough supernova explode in the near future.

  16. EXITE/IPC observations of SN1987A and southern targets

    NASA Technical Reports Server (NTRS)

    Grindlay, Jonathan E.

    1991-01-01

    The Energetic X-ray Imaging Telescope Experiment (EXITE) was developed to a flight-ready status and conducted two flights (May 18, 1988, and May 8-10, 1989) from Alice Springs, Australia, as part of the campaigns to observe the supernova SN1987A. The basic operation of the detector and gondola systems in the laboratory was tested on the first flight and found to meet expected performance values. A bizarre 'balloon tape' insulation problem, however, prevented normal telescope pointing on the first flight so no data on SN1987A or other targets were obtained. Following a successful second EXITE flight from Ft. Sumner, NM, in October 1988, the experiment was flown again on a successful 30 hour flight as part of the final 1989 supernova campaign. A second x-ray imaging experiment from MSFC was also flown (piggy-back) for this third flight. Good data were obtained on the supernova and a variety of high priority galactic targets, and final analysis is still in progress. Preliminary results from this flight are presented.

  17. 9500 Nights of Mid-Infrared Observations of SN 1987A: the birth of the remnant

    NASA Astrophysics Data System (ADS)

    Bouchet, Patrice; Danziger, John

    2014-01-01

    The one-in-a-life-time event Supernova SN 1987A, the brightest supernova seen since Kepler's in 1604, has given us a unique opportunity to study the mechanics of a supernova explosion and now to witness the birth of a supernova remnant. A violent encounter is underway between the fastest-moving debris and the circumstellar ring: shocks excite ``hotspots''. ATCA/ANTF, Gemini, VLT, HST, Spitzer, Chandra, and recently ALMA observations have been so far organized to help understanding the several emission mechanisms at work. In the mid-infrared SN 1987A has transformed from a SN with the bulk of its radiation from the ejecta to a SNR whose emission is dominated by the interaction of the blast wave with the surrounding interstellar medium, a process in which kinetic energy is converted into radiative energy. Currently this remnant emission is dominated by material in or near the inner equatorial ring (ER). We give here a brief history of our mid-infrared observations, and present our last data obtained with the SPITZER infrared satellite and the ESO VLT and Gemini telescopes: we show how together with Chandra observations, they contribute to the understanding of this fascinating object. We argue also that our imaging observations suggest that warm dust is still present in the ejecta, and we dispute the presence of huge amount of very cold dust in it, as it has been claimed on the basis of data obtained with the HERSCHELl satellite.

  18. Extra dimensions, SN1987a, and nucleon-nucleon scattering data

    SciTech Connect

    Christoph Hanhart; Daniel R. Phillips; Sanjay Reddy; Martin J. Savage

    2001-02-01

    One of the strongest constraints on the existence of large, compact, ''gravity-only'' dimensions comes from SN1987a. If the rate of energy loss into these putative extra dimensions is too high, then the neutrino pulse from the supernova will differ from that actually seen. The dominant mechanism for the production of Kaluza-Klein gravitons and dilatons in the supernova is via gravistrahlung and dilastrahlung from the nucleon-nucleon system. In this paper we compute the rates for these processes in a model-independent way using low-energy theorems which relate the emissivities to the measured nucleon-nucleon cross section. This is possible because for soft gravitons and dilatons the leading contribution to the energy-loss rate is from graphs in which the gravitational radiation is produced from external nucleon legs. Previous calculations neglected these mechanisms. We re-evaluate the bounds on toroidally-compactified ''gravity-only'' dimensions (GODs), and find that consistency with the observed SN1987a neutrino signal requires that if there are two such dimensions then their radius must be less than 1 micron.

  19. Non-LTE model calculations for SN 1987A and the extragalactic distance scale

    NASA Technical Reports Server (NTRS)

    Schmutz, W.; Abbott, D. C.; Russell, R. S.; Hamann, W.-R.; Wessolowski, U.

    1990-01-01

    This paper presents model atmospheres for the first week of SN 1987A, based on the luminosity and density/velocity structure from hydrodynamic models of Woosley (1988). The models account for line blanketing, expansion, sphericity, and departures from LTE in hydrogen and helium and differ from previously published efforts because they represent ab initio calculations, i.e., they contain essentially no free parameters. The formation of the UV spectrum is dominated by the effects of line blanketing. In the absorption troughs, the Balmer line profiles were fit well by these models, but the observed emissions are significantly stronger than predicted, perhaps due to clumping. The generally good agreement between the present synthetic spectra and observations provides independent support for the overall accuracy of the hydrodynamic models of Woosley. The question of the accuracy of the Baade-Wesselink method is addressed in a detailed discussion of its approximations. While the application of the standard method produces a distance within an uncertainty of 20 percent in the case of SN 1987A, systematic errors up to a factor of 2 are possible, particularly if the precursor was a red supergiant.

  20. Revisiting the SN1987A gamma-ray limit on ultralight axion-like particles

    NASA Astrophysics Data System (ADS)

    Payez, Alexandre; Evoli, Carmelo; Fischer, Tobias; Giannotti, Maurizio; Mirizzi, Alessandro; Ringwald, Andreas

    2015-02-01

    We revise the bound from the supernova SN1987A on the coupling of ultralight axion-like particles (ALPs) to photons. In a core-collapse supernova, ALPs would be emitted via the Primakoff process, and eventually convert into gamma rays in the magnetic field of the Milky Way. The lack of a gamma-ray signal in the GRS instrument of the SMM satellite in coincidence with the observation of the neutrinos emitted from SN1987A therefore provides a strong bound on their coupling to photons. Due to the large uncertainty associated with the current bound, we revise this argument, based on state-of-the-art physical inputs both for the supernova models and for the Milky-Way magnetic field. Furthermore, we provide major amendments, such as the consistent treatment of nucleon-degeneracy effects and of the reduction of the nuclear masses in the hot and dense nuclear medium of the supernova. With these improvements, we obtain a new upper limit on the photon-ALP coupling: gaγ lesssim 5.3 × 10-12 GeV-1, for ma lesssim 4.4 × 10-10 eV, and we also give its dependence at larger ALP masses ma. Moreover, we discuss how much the Fermi-LAT satellite experiment could improve this bound, should a close-enough supernova explode in the near future.

  1. DUST PRODUCTION AND PARTICLE ACCELERATION IN SUPERNOVA 1987A REVEALED WITH ALMA

    SciTech Connect

    Indebetouw, R.; Chevalier, R.; Matsuura, M.; Barlow, M. J.; Dwek, E.; Zanardo, G.; Baes, M.; Bouchet, P.; Burrows, D. N.; Clayton, G. C.; Fransson, C.; Lundqvist, P.; Gaensler, B.; Kirshner, R.; Lakićević, M.; Long, K. S.; Meixner, M.; Martí-Vidal, I.; Marcaide, J.; and others

    2014-02-10

    Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/Submillimeter Array to observe SN 1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450 μm, 870 μm, 1.4 mm, and 2.8 mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (>0.2 M {sub ☉}). For the first time we show unambiguously that this dust has formed in the inner ejecta (the cold remnants of the exploded star's core). The dust emission is concentrated at the center of the remnant, so the dust has not yet been affected by the shocks. If a significant fraction survives, and if SN 1987A is typical, supernovae are important cosmological dust producers.

  2. STIS DISCOVERS HIGH-SPEED GAS FROM COLLISION AROUND SUPERNOVA 1987A

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image from the Hubble's Space Telescope Imaging Spectrograph (STIS) shows a new and unprecedented look at the light-year wide ring of glowing gas around supernova 1987A, the nearest stellar explosion in 400 years, which occurred in February 1987. The STIS long-slit spectrograph viewed the entire ring system, dissecting its light and producing a detailed image of the ring in each of its component colors. This image shows the ring in the optical light of hydrogen (center) flanked by images in nitrogen emission. The arrow points to a streak produced by gas rushing toward us at 200 miles per sec. This is the same place where the bright knot is seen in Hubble's WFPC-2 images. This is the first hint that the collision between the high-speed supernova debris and gases in the glowing ring has begun. Supernova 1987A is located 167,000 light years away from Earth in the Large Magellanic Cloud. Credit: George Sonneborn and Jason Pun (NASA

  3. A STUBBORNLY LARGE MASS OF COLD DUST IN THE EJECTA OF SUPERNOVA 1987A

    SciTech Connect

    Matsuura, M.; Barlow, M. J.; Dwek, E.; Babler, B.; Baes, M.; Fritz, Jacopo; Meixner, M.; Cernicharo, José; Clayton, Geoff C.; Dunne, L.; Fransson, C.; Lundqvist, P.; Gear, Walter; Gomez, H. L.; Groenewegen, M. A. T.; Indebetouw, R.; Ivison, R. J.; Jerkstrand, A.; Lebouteiller, V.; and others

    2015-02-10

    We present new Herschel photometric and spectroscopic observations of Supernova 1987A, carried out in 2012. Our dedicated photometric measurements provide new 70 μm data and improved imaging quality at 100 and 160 μm compared to previous observations in 2010. Our Herschel spectra show only weak CO line emission, and provide an upper limit for the 63 μm [O I] line flux, eliminating the possibility that line contaminations distort the previously estimated dust mass. The far-infrared spectral energy distribution (SED) is well fitted by thermal emission from cold dust. The newly measured 70 μm flux constrains the dust temperature, limiting it to nearly a single temperature. The far-infrared emission can be fitted by 0.5 ± 0.1 M {sub ☉} of amorphous carbon, about a factor of two larger than the current nucleosynthetic mass prediction for carbon. The observation of SiO molecules at early and late phases suggests that silicates may also have formed and we could fit the SED with a combination of 0.3 M {sub ☉} of amorphous carbon and 0.5 M {sub ☉} of silicates, totalling 0.8 M {sub ☉} of dust. Our analysis thus supports the presence of a large dust reservoir in the ejecta of SN 1987A. The inferred dust mass suggests that supernovae can be an important source of dust in the interstellar medium, from local to high-redshift galaxies.

  4. Attention Genes

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  5. [Thalamus and Attention].

    PubMed

    Tokoro, Kazuhiko; Sato, Hironobu; Yamamoto, Mayumi; Nagai, Yoshiko

    2015-12-01

    Attention is the process by which information and selection occurs, the thalamus plays an important role in the selective attention of visual and auditory information. Selective attention is a conscious effort; however, it occurs subconsciously, as well. The lateral geniculate body (LGB) filters visual information before it reaches the cortex (bottom-up attention). The thalamic reticular nucleus (TRN) provides a strong inhibitory input to both the LGB and pulvinar. This regulation involves focusing a spotlight on important information, as well as inhibiting unnecessary background information. Behavioral contexts more strongly modulate activity of the TRN and pulvinar influencing feedforward and feedback information transmission between the frontal, temporal, parietal and occipital cortical areas (top-down attention). The medial geniculate body (MGB) filters auditory information the TRN inhibits the MGB. Attentional modulation occurring in the auditory pathway among the cochlea, cochlear nucleus, superior olivary complex, and inferior colliculus is more important than that of the MGB and TRN. We also discuss the attentional consequence of thalamic hemorrhage.

  6. Modelling auditory attention.

    PubMed

    Kaya, Emine Merve; Elhilali, Mounya

    2017-02-19

    Sounds in everyday life seldom appear in isolation. Both humans and machines are constantly flooded with a cacophony of sounds that need to be sorted through and scoured for relevant information-a phenomenon referred to as the 'cocktail party problem'. A key component in parsing acoustic scenes is the role of attention, which mediates perception and behaviour by focusing both sensory and cognitive resources on pertinent information in the stimulus space. The current article provides a review of modelling studies of auditory attention. The review highlights how the term attention refers to a multitude of behavioural and cognitive processes that can shape sensory processing. Attention can be modulated by 'bottom-up' sensory-driven factors, as well as 'top-down' task-specific goals, expectations and learned schemas. Essentially, it acts as a selection process or processes that focus both sensory and cognitive resources on the most relevant events in the soundscape; with relevance being dictated by the stimulus itself (e.g. a loud explosion) or by a task at hand (e.g. listen to announcements in a busy airport). Recent computational models of auditory attention provide key insights into its role in facilitating perception in cluttered auditory scenes.This article is part of the themed issue 'Auditory and visual scene analysis'.

  7. Modelling auditory attention

    PubMed Central

    Kaya, Emine Merve

    2017-01-01

    Sounds in everyday life seldom appear in isolation. Both humans and machines are constantly flooded with a cacophony of sounds that need to be sorted through and scoured for relevant information—a phenomenon referred to as the ‘cocktail party problem’. A key component in parsing acoustic scenes is the role of attention, which mediates perception and behaviour by focusing both sensory and cognitive resources on pertinent information in the stimulus space. The current article provides a review of modelling studies of auditory attention. The review highlights how the term attention refers to a multitude of behavioural and cognitive processes that can shape sensory processing. Attention can be modulated by ‘bottom-up’ sensory-driven factors, as well as ‘top-down’ task-specific goals, expectations and learned schemas. Essentially, it acts as a selection process or processes that focus both sensory and cognitive resources on the most relevant events in the soundscape; with relevance being dictated by the stimulus itself (e.g. a loud explosion) or by a task at hand (e.g. listen to announcements in a busy airport). Recent computational models of auditory attention provide key insights into its role in facilitating perception in cluttered auditory scenes. This article is part of the themed issue ‘Auditory and visual scene analysis’. PMID:28044012

  8. Nickel, argon and cobalt in the infrared spectrum of SN1987A - The core becomes visible

    NASA Technical Reports Server (NTRS)

    Rank, D. M.; Pinto, P. A.; Woosley, S. E.; Bregman, J. D.; Witteborn, F. C.

    1988-01-01

    Infrared spectra of supernova 1987A taken in April and November 1987 are presented, showing two distinctly different stages in the evolution of the expanding gas shell. The optical and infrared spectrum in April originated from the hydrogen envelope and show weak hydrogen lines rising above a 5,000-K photospheric continuum. The November spectrum was dominated by strong emission lines from heavy elements as well as many lines from highly excited levels of hydrogen, with peak flux levels in the lines at or slightly above the level of the continuum in April. It is concluded that the inner regions of the supernova were just becoming visible in early 1988. It is expected that these regions contain heavy elements produced by advanced nuclear burning stages in the progenitor star and in the shock wave that ejected all material external to the iron core.

  9. X-Ray Heating of the Ejecta of Supernova 1987A

    NASA Technical Reports Server (NTRS)

    Sonneborn, George; Larsson, Josefin; Fransson, Claes; Kirshner, Robert; Challis, Peter; McCray, Richard

    2012-01-01

    Analysis of Hubble Space Telescope Band R band images from 1994 to 2009 show that the optical luminosity of SN 1987A has transitioned from being powered by radioactive decay of Ti-44 to energy deposited by X-rays produced as the ejecta interacts with the surrounding material (Larsson et al. 2011, Nature, 474, 484). The B and R band flux from the densest, central parts of the ejecta followed the expected exponential decline until 2001 (about day 5000) when the flux in these bands started increasing, more than doubling by the end of 2009. This increase is the result of heat deposited by X-rays from the shock interaction of the fast-moving outer ejecta with the inner circumstellar ring. In time, the X-rays will penetrate farther into the ejecta, enabling us to analyze the structure and chemistry of the vanished star.

  10. Hydrogen recombination at high optical depth and the spectrum of SN 1987A

    NASA Technical Reports Server (NTRS)

    Xu, Yueming; Mccray, Richard; Oliva, Ernesto; Randich, Sofia

    1992-01-01

    A general theory is presented for hydrogen recombination line formation in an expanding medium in which some of the lines are optically thick. This theory is used to calculate the time evolution of the hydrogen lines of SN 1987A at t equal to or greater than 150 days, assuming that the supernova envelope is a homologously expanding uniform sphere. The theoretical luminosities and ratios of the recombination lines agree remarkably well with the observations. For the first 2 yr, the supernova envelope is optically thick to Balmer continuum. For t equal to or less than 400 days, hydrogen is ionized primarily from the n = 2 level by Balmer continuum photons, which are provided partly by the two-photon decay of the 2s state and partly by emission lines of heavy elements.

  11. The emergence of X-rays and gamma-rays from supernova 1987A

    NASA Technical Reports Server (NTRS)

    Shull, J. Michael; Xu, Yueming

    1988-01-01

    Attempts to arrive at a unified scenario for the optical, X-ray, and gamma-ray emission of SN 1987A are discussed. Theoretical spectra are in reasonable agreement with recent observations of hard X-rays by the Ginga and Mir satellites, but the early turn-on of X-rays suggests that the mantle and envelope may be 'leaky', perhaps as a result of Rayleigh-Taylor instabilities and clumping. The soft X-ray spectrum should be dominated by a 6.4 keV Fe K-alpha fluorescence line. The reported Ginga detection of 4-10 keV X-ray emission is also discussed.

  12. The theory of gamma-ray emergence in supernova 1987A

    NASA Technical Reports Server (NTRS)

    Pinto, Philip A.; Woosley, S. E.

    1988-01-01

    It was anticipated that the decay of Co-56 to Fe-56 in SN1987A would give rise to detectable gamma-ray emission at 847 and 1238 keV with a peak flux of 0.001 photon/sq cm/s about one year after the explosion. Both these lines were detected in August, with a strength within a factor of two of 0.001 photon/sq cm/s, but about six months earlier than predicted. It is shown here that the early emergence of gamma-rays can be accounted for in a 'mixed' model in which an approximately isotropic process destroys chemical segregation with respect to radial mass coordinate and velocity.

  13. Formation of the three-ring structure around supernova 1987A.

    PubMed

    Tanaka, T; Washimi, H

    2002-04-12

    From a magnetohydrodynamic simulation, we reproduce a three-ring structure in the circumstellar space of the supernova (SN) 1987A observed by the Hubble Space Telescope. When a star develops from a red supergiant (RSG) to a blue supergiant (BSG) just before the SN explosion, a wind-wind interaction occurs between the slow stellar wind from the RSG and the subsequent fast stellar wind from the BSG. This process is simulated numerically under an assumption that the density and velocity distributions around the RSG are anisotropic owing to the existence of toroidal magnetic field and coronal holes. The three rings with observed size and position are reproduced by the magnetic pinch effect and amplification of initial density asymmetry through the dynamical interaction.

  14. Far-infrared observations of thermal dust emission from supernova 1987A

    NASA Technical Reports Server (NTRS)

    Moseley, S. H.; Dwek, E.; Glaccum, W.; Graham, J. R.; Loewenstein, R. F.

    1989-01-01

    Observations of SN1987A in the spectral range 18-35 microns taken on November 16 and 23, 1988, 632 and 639 days after core collapse, are reported. A strong and rather flat continuum underlies weak fine-structure lines from heavy elements and declines slowly between 24 and 30 microns. The spectral shape indicates thermal emission from an almost featureless dust component, probably graphite, with silicates contributing less than 20 percent of the emitting dust mass. Some of the emission may be an 'echo' of supernova light reflected from a preexisting dust cloud, but a better explanation which can account for the entirety of emission from infrared to gamma wavelengths, is that dust is being formed in the supernova ejecta. This also accounts more naturally for the inferred dust composition.

  15. Correlation mass method for analysis of neutrinos from supernova 1987A

    NASA Technical Reports Server (NTRS)

    Chiu, Hong-Yee; Chan, Kwing L.; Kondo, Yoji

    1988-01-01

    Application of a time-energy correlation method to the Kamiokande II (KII) observations of neutrinos apparently emitted from supernova 1987A has yielded a neutrino rest mass of 3.6 eV. A Monte Carlo analysis shows a reconfirming probabilty distribution for the neutrino rest mass peaked at 2.8, and dropping to 50 percent of the peak at 1.4 and 4.8 eV. Although the KII data indicate a very short time scale of emission, over an extended period on the order of 10 sec, both data from the Irvine-Michigan-Brookhaven experiment and the KII data show a tendency for the more energetic neutrinos to be emitted earlier at the source, suggesting the possibility of cooling.

  16. Constraints to the decays of Dirac neutrinos from SN 1987A

    NASA Technical Reports Server (NTRS)

    Dodelson, Scott; Frieman, Joshua A.; Turner, Michael S.

    1992-01-01

    The decay mode of a keV-mass Dirac neutrino is addressed with reference to the nineteen neutrino events associated with SN 1987A that were detected by the Kamiokande II and Irvine-Brookhaven-Michigan detectors. A complementary constraint is presented which is based upon a distinctive signal associated with the decay of wrong-helicity neutrinos that was not seen: high-energy (50 MeV and higher) neutrino events. The absence of such events excludes the decay of wrong-helicity neutrinos into proper-helicity neutrinos for a Dirac neutrino of mass between 1 and 300 keV. The constraint also rules out models of the 17-keV neutrino.

  17. An optical and near infrared search for a pulsar in Supernova 1987A

    SciTech Connect

    Sasseen, T.P.

    1990-12-01

    We describe a search for an optical pulsar in the remnant of Supernova 1987A. We have performed over one hundred separate observations of the supernova, covering wavelengths from 3500 angstroms to 1.8 microns, with sensitivity to pulsations as faint as magnitude 22.7. As of September 26, 1990, we have not seen evidence for pulsations due to a pulsar in the supernova. We discuss the implications of this result on predictions of pulsar optical luminosity. We have constructed for the search two photodiode detectors and a data system. We describe their design, calibration and performance. These detectors have allowed us to increase our sensitivity as much as a factor of 5 over standard photomultiplier tubes, and extend this search to near infrared wavelengths. 59 refs., 10 figs., 1 tab.

  18. Balloon-borne measurements of the SN 1987A hard X-ray continuum

    NASA Technical Reports Server (NTRS)

    Pendleton, Geoffrey N.; Paciesas, William S.; Fishman, Gerald J.; Meegan, Charles A.; Wilson, Robert B.

    1995-01-01

    SN 1987A hard X-ray continuum spectra obtained on 1987 October 29, 1988 April 9-10, and 1988 November 11 from balloon-flight measurments are presented. The spectra, spanning the energy range from 25 keV to 300 keV, have been analyzed using a detector response matrix inversion technique that converts the spectra form counts/s/sq cm keV to photons/s/sq cm keV allowing direct comparison with theoretical models. The results indicate that the bulk of the (56)Co is mixed moderately through the inner regions of the supernova envelope but they do not preclude the mixing of a small amount of the (56)Co farther out into the envelope necessary to account for the observed (56)Co line fluxes. The effect of the ratio (57)Co to (56)Co on the 1988 November 11 continuum spectrum is discussed.

  19. Balloon-borne measurements of the SN1987A hard x ray continuum

    NASA Technical Reports Server (NTRS)

    Pendleton, Geoffrey N.; Paciesas, William S.; Fishman, Gerald J.; Meegan, Charles A.; Wilson, Robert B.

    1994-01-01

    SN1987A hard x ray continuum spectra obtained on 29 Oct. 1987, 9-10 Apr. 1988, and 11 Nov. 1988, from balloon flight measurements are presented. The spectra, spanning the energy range from 25 keV to 300 keV, were analyzed using a detector response matrix inversion technique that converts the spectra from counts/sec-sq cm-kev to photons/sec-sq cm-kev allowing direct comparison with theoretical models. The results indicate that the bulk of the Co-56 is mixed moderately through the inner regions of the SN envelope but they do not preclude the mixing of a small amount of the Co-56 further out into the envelope necessary to account for the observed Co-56 line fluxes. The effect of the ratio of Co-57 to Co-56 on the 11 Nov. 1988, continuum spectrum is discussed.

  20. Mapping High-Velocity H-alpha and Lyman-alpha Emission from Supernova 1987A

    NASA Technical Reports Server (NTRS)

    France, Kevin; McCray, Richard; Fransson, Claes; Larsson, Josefin; Frank, Kari A.; Burrows, David N.; Challis, Peter; Kirshner, Robert P.; Chevalier, Roger A.; Garnavich, Peter; Heng, Kevin; Lawrence, Stephen S.; Lundqvist, Peter; Smith, Nathan; Sonneborn, George

    2015-01-01

    We present new Hubble Space Telescope images of high-velocity H-alpha and Lyman-alpha emission in the outer debris of SN 1987A. The H-alpha images are dominated by emission from hydrogen atoms crossing the reverse shock. For the first time we observe emission from the reverse shock surface well above and below the equatorial ring, suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H-alpha imaging, we measure the mass flux of hydrogen atoms crossing the reverse shock front, in the velocity intervals (-7,500 < V(sub obs) < -2,800 km/s) and (1,000 < V(sub obs) < 7,500 km/s), ?M(sub H) = 1.2 × 10(exp -3) M/ y. We also present the first Lyman-alpha imaging of the whole remnant and new Chandra X-ray observations. Comparing the spatial distribution of the Lyman-alpha and X-ray emission, we observe that the majority of the high-velocity Lyman-alpha emission originates interior to the equatorial ring. The observed Lyman-alpha/H-alpha photon ratio, R(L-alpha/H-alpha) approx. = 17, is significantly higher than the theoretically predicted ratio of approx. = 5 for neutral atoms crossing the reverse shock front. We attribute this excess to Lyman-alpha emission produced by X-ray heating of the outer debris. The spatial orientation of the Lyman-alpha and X-ray emission suggests that X-ray heating of the outer debris is the dominant Lyman-alpha production mechanism in SN 1987A at this phase in its evolution.

  1. SN1987A-Neutrino emission from Supernova': in Dynamic universe model of cosmology

    NASA Astrophysics Data System (ADS)

    Naga Parameswara Gupta, Satyavarapu

    SN1987A-Neutrino emission from supernova before the star bursts' is an important discovery, when viewed from `Dynamic universe model of cosmology' point of view. In OMEG05, we have successfully presented the reasons for calculation error called `missing mass' in an inhomoge-neous, anisotropic and multi-body Dynamic universe Model, where this error is not occurring. But there are some new voices that say about generation of some flavors of neutrinos during Bigbang. We find from SN1987A Neutrino generation covers all flavors. Remaining flavors of Neutrinos are generated from sun and stars. This covers the whole spectrum. This paper covers all these aspects. And other earlier results by Dynamic Universe Model 1. Offers Singularity free solutions 2. Non-collapsing Galaxy structures 3. Solving Missing mass in Galaxies, and it finds reason for Galaxy circular velocity curves. . . . 4. Blue shifted and red shifted Galaxies co-existence. . . 5. Explains the force behind expansion of universe. 6. Explains the large voids and non-uniform matter densities. 7. Explains the Pioneer anomaly 8. Predicts the trajectory of New Horizons satellite. 9 Jeans swindle test 10. Existence of large number of blue shifted Galaxies `SITA Simulations' software was developed about 18 years back for Dynamic Universe Model of Cosmology. It is based on Newtonian physics. It is Classical singularity free N-body tensor solution to the old problem announced by King Oscar II and tried by Poincare in year AD1888 for 133 masses, tested extensively for so many years. This was developed on 486 based PC of those days; the same software was used repeatedly for so many years for solving different Physical problems on Different PCs and Laptops. It is based on Dynamic Universe Model's mathematical back ground.

  2. Three-dimensional Distribution of Ejecta in Supernova 1987A at 10,000 Days

    NASA Astrophysics Data System (ADS)

    Larsson, J.; Fransson, C.; Spyromilio, J.; Leibundgut, B.; Challis, P.; Chevalier, R. A.; France, K.; Jerkstrand, A.; Kirshner, R. P.; Lundqvist, P.; Matsuura, M.; McCray, R.; Smith, N.; Sollerman, J.; Garnavich, P.; Heng, K.; Lawrence, S.; Mattila, S.; Migotto, K.; Sonneborn, G.; Taddia, F.; Wheeler, J. C.

    2016-12-01

    Due to its proximity, SN 1987A offers a unique opportunity to directly observe the geometry of a stellar explosion as it unfolds. Here we present spectral and imaging observations of SN 1987A obtained ˜10,000 days after the explosion with HST/STIS and VLT/SINFONI at optical and near-infrared wavelengths. These observations allow us to produce the most detailed 3D map of Hα to date, the first 3D maps for [Ca ii] λ λ 7292,7324, [O i] λ λ 6300,6364, and Mg ii λ λ 9218,9244, as well as new maps for [Si i]+[Fe ii] 1.644 μ {{m}} and He i 2.058 μm. A comparison with previous observations shows that the [Si i]+[Fe ii] flux and morphology have not changed significantly during the past ten years, providing evidence that this line is powered by 44Ti. The time evolution of Hα shows that it is predominantly powered by X-rays from the ring, in agreement with previous findings. All lines that have sufficient signal show a similar large-scale 3D structure, with a north-south asymmetry that resembles a broken dipole. This structure correlates with early observations of asymmetries, showing that there is a global asymmetry that extends from the inner core to the outer envelope. On smaller scales, the two brightest lines, Hα and [Si i]+[Fe ii] 1.644 μm, show substructures at the level of ˜200-1000 km s-1and clear differences in their 3D geometries. We discuss these results in the context of explosion models and the properties of dust in the ejecta.

  3. The Shape of SN 1987A's Circumstellar Nebula (and The Distance to the LMC)

    NASA Astrophysics Data System (ADS)

    Crotts, A. P. S.; Kunkel, W. E.; Heathcote, S. R.; Blanton, E. L.

    1993-12-01

    The circumstellar continuum nebula around SN 1987A, discovered in 1989, disappeared in early 1992 after evolving during the intervening period. We interpret this continuum nebulosity as the light echo from the SN maximum light pulse propagating through reflecting material. In this case the nebula appears consistent with a squat, double-lobed structure with a rotational axis inclined about 45(deg) to the line of sight (and oriented nearly north-south). A least-squares fit, in spherical coordinates, yields R(phi ) = [1 - 0.29phi (2) ](2.47 ly), for -0.45pi < phi < 0.45pi , where phi = 0 along the rotational axis. The equatorial pinch corresponds closely to the position inferred for the small elliptical ring centered on SN 1987A, assuming that it is expanding, and assuming that it is roughly circular. We investigate, by examining the morphology of the diffuse wind beyond this double-lobed nebula, how this non-spherical geometry was created. Presumably this nebula is created at the interface of the inner, blue-supergiant (BSG) wind, and the earlier, denser and slower red-giant (RG) wind. The distribution of this RG wind suggests that the anisotropy of this interface is due both to anisotropic RG wind density and velocity fields. Panagia et al. 1991 suggested that the angular diameter of the inner ring compared to the light-propagation time from its front to back can be used to establish the distance to the SN, therefore the Large Magellanic Cloud (LMC). This idea was further refined by Dwek & Felten 1992 and Gould 1993. A major uncertainty in this determination is the ring's angle of inclination. The double-lobed nebula we have mapped suggests this is close to 45(deg) , indicating a distance to the LMC of about 52 kpc. (We will give a more detailed determination of D_{LMC} in our poster!)

  4. Supernovae. ⁴⁴Ti gamma-ray emission lines from SN1987A reveal an asymmetric explosion.

    PubMed

    Boggs, S E; Harrison, F A; Miyasaka, H; Grefenstette, B W; Zoglauer, A; Fryer, C L; Reynolds, S P; Alexander, D M; An, H; Barret, D; Christensen, F E; Craig, W W; Forster, K; Giommi, P; Hailey, C J; Hornstrup, A; Kitaguchi, T; Koglin, J E; Madsen, K K; Mao, P H; Mori, K; Perri, M; Pivovaroff, M J; Puccetti, S; Rana, V; Stern, D; Westergaard, N J; Zhang, W W

    2015-05-08

    In core-collapse supernovae, titanium-44 ((44)Ti) is produced in the innermost ejecta, in the layer of material directly on top of the newly formed compact object. As such, it provides a direct probe of the supernova engine. Observations of supernova 1987A (SN1987A) have resolved the 67.87- and 78.32-kilo-electron volt emission lines from decay of (44)Ti produced in the supernova explosion. These lines are narrow and redshifted with a Doppler velocity of ~700 kilometers per second, direct evidence of large-scale asymmetry in the explosion.

  5. Attention: an evolving construct.

    PubMed

    Joyce, Arthur; Hrin, Skip

    2015-01-01

    We review the implications of large-scale brain systems on the construct of attention by first focusing on significant theories and discoveries during the previous 150 years and then considering how the comparatively recent discovery of large-scale brain systems may render previous conceptualizations of attention outdated. Seven functional brain networks are briefly reviewed and the implications of emerging principles of brain functioning for test construction and neuropsychological evaluation are considered. To remain a relevant discipline moving into the 21st century, the field of neuropsychology needs to apply the principles that have been discovered about brain networks to better inform our understanding of attention as well as our ever-refining evaluation of this construct.

  6. Possible explanation of the correlations between events recorded by underground detectors during the Supernova 1987A explosion

    SciTech Connect

    Alexeyev, E. N.

    2010-02-15

    A possible explanation of the time correlations between the data from underground detectors (Baksan telescope, LSD, IMB, Kamiokande II) and from the Rome and Maryland gravitational-wave antennas obtained during the Supernova 1987A explosion is proposed. It is shown that the synchronization of the events recorded by various underground facilities could be produced by gravitational radiation from the Supernova.

  7. The Death of a Star: Supernova 1987a. NASA Educational Briefs for the Upper Elementary-Level Classroom.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    This material discusses supernova, the violent death of a massive star, at a level appropriate for upper elementary students. Background information on Supernova 1987a is presented. Observation techniques using visible light, ultraviolet waves, radio waves, neutrinos, X-rays, and gamma-rays are described. A vocabulary list, 11 questions, and 6…

  8. Three-dimensional hydrodynamic modeling of SN 1987A from the supernova explosion till the Athena era

    NASA Astrophysics Data System (ADS)

    Orlando, Salvatore

    2016-06-01

    The proximity of SN 1987A and the wealth of observations collected at all wavelenght bands since its outburst allow us to study in details the evolution of a supernova remnant (SNR) from the immediate aftermath of the SN explosion till its expansion through the highly inhomogeneous circumstellar medium (CSM). We investigate the interaction between SN 1987A and the surrounding CSM through three-dimensional hydrodynamic modeling. The aim is to determine the contribution of shocked ejecta and shocked CSM to the detected X-ray flux and to derive the density structure of the inhomogeneous CSM and clues on the early structure of ejecta. We show that the physical model reproducing the main observables of SN 1987A reproduces also the X-ray emission of the subsequent expanding remnant, thus bridging the gap between supernovae and supernova remnants. By comparing model results with observations, we constrain the explosion energy in the range 1.2 - 1.4 × 10^(51) erg and the envelope mass in the range 15 - 17 M_{⊙}) . We find that the shape of X-ray lightcurves and spectra at early epochs (< 15 years) reflect the structure of outer ejecta. At later epochs, the shape of X-ray lightcurves and spectra reflect the density structure of the nebula around SN 1987A. This enabled us to ascertain the origin of the multi-thermal X-ray emission, to disentangle the imprint of the supernova on the remnant emission from the effects of the remnant interaction with the environment, and to constrain the pre-supernova structure of the nebula. Finally the remnant evolution is followed for 40 years, providing predictions on the future of SN 1987A until the adventof Athena.

  9. Brain activity associated with selective attention, divided attention and distraction.

    PubMed

    Salo, Emma; Salmela, Viljami; Salmi, Juha; Numminen, Jussi; Alho, Kimmo

    2017-03-28

    Top-down controlled selective or divided attention to sounds and visual objects, as well as bottom-up triggered attention to auditory and visual distractors, has been widely investigated. However, no study has systematically compared brain activations related to all these types of attention. To this end, we used functional magnetic resonance imaging (fMRI) to measure brain activity in participants performing a tone pitch or a foveal grating orientation discrimination task, or both, distracted by novel sounds not sharing frequencies with the tones or by extrafoveal visual textures. To force focusing of attention to tones or gratings, or both, task difficulty was kept constantly high with an adaptive staircase method. A whole brain analysis of variance (ANOVA) revealed fronto-parietal attention networks for both selective auditory and visual attention. A subsequent conjunction analysis indicated partial overlaps of these networks. However, like some previous studies, the present results also suggest segregation of prefrontal areas involved in the control of auditory and visual attention. The ANOVA also suggested, and another conjunction analysis confirmed, an additional activity enhancement in the left middle frontal gyrus related to divided attention supporting the role of this area in top-down integration of dual task performance. Distractors expectedly disrupted task performance. However, contrary to our expectations, activations specifically related to the distractors were found only in the auditory and visual cortices. This suggests gating of the distractors from further processing perhaps due to strictly focused attention in the current demanding discrimination tasks.

  10. Assessment of Attention in Preschoolers

    PubMed Central

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

    2012-01-01

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

  11. X-Ray Illumination of the Ejecta of Supernova 1987A

    NASA Technical Reports Server (NTRS)

    Larsson, J.; Fransson, C.; Oestlin, G.; Groeningsson, P.; Jerkstrand, A.; Kozma, C.; Sollerman, J.; Challis, P.; Kirshner, R. P.; Chevalier, R. A.; Heng, K.; McCray, R.; Suntzeff, N. B.; Bouchet, P.; Crotts, A.; Danziger, J.; Dwek, E.; France, K.; Garnavich, P. M.; Lawrence, S. S.; Leibundgut, B.; Lundqvist, P.; Panagia, N.; Pun, C. S. J.; Sonneborn, G.

    2011-01-01

    When a massive star explodes as a supernova, substantial amounts of radioactive elements-primarily Ni-56, Ni-57 and Ti-44 are produced. After the initial from shock heating, the light emitted by the supernova is due to the decay of these elements. However, after decades, the energy powering a supernova remnant comes from the shock interaction between the ejecta and the surrounding medium. The transition to this phase has hitherto not been observed: supernovae occur too infrequently in the Milky Way to provide a young example, and extragalactic supernovae are generally too faint and too small. Here we report observations that show this transition in the supernova SN 1987A in the Large Magellan Cloud. From 1994 to 200l, the ejecta faded owing to radioactive decay of Ti-44 as predicted. Then the flux started to increase, more than doubling by the end of 2009. We show that this increase is the result of heat deposited by X-rays produced as the ejecta interacts with the surrounding material. In time, the X-rays will penetrate farther into the ejects, enabling us to analyse the structure and chemistry of the vanished star.

  12. X-ray illumination of the ejecta of supernova 1987A.

    PubMed

    Larsson, J; Fransson, C; Ostlin, G; Gröningsson, P; Jerkstrand, A; Kozma, C; Sollerman, J; Challis, P; Kirshner, R P; Chevalier, R A; Heng, K; McCray, R; Suntzeff, N B; Bouchet, P; Crotts, A; Danziger, J; Dwek, E; France, K; Garnavich, P M; Lawrence, S S; Leibundgut, B; Lundqvist, P; Panagia, N; Pun, C S J; Smith, N; Sonneborn, G; Wang, L; Wheeler, J C

    2011-06-08

    When a massive star explodes as a supernova, substantial amounts of radioactive elements--primarily (56)Ni, (57)Ni and (44)Ti--are produced. After the initial flash of light from shock heating, the fading light emitted by the supernova is due to the decay of these elements. However, after decades, the energy powering a supernova remnant comes from the shock interaction between the ejecta and the surrounding medium. The transition to this phase has hitherto not been observed: supernovae occur too infrequently in the Milky Way to provide a young example, and extragalactic supernovae are generally too faint and too small. Here we report observations that show this transition in the supernova SN 1987A in the Large Magellanic Cloud. From 1994 to 2001, the ejecta faded owing to radioactive decay of (44)Ti as predicted. Then the flux started to increase, more than doubling by the end of 2009. We show that this increase is the result of heat deposited by X-rays produced as the ejecta interacts with the surrounding material. In time, the X-rays will penetrate farther into the ejecta, enabling us to analyse the structure and chemistry of the vanished star.

  13. Mystery spot in supernova 1987A - Reflection or fluorescence by an interstellar cloud?

    NASA Technical Reports Server (NTRS)

    Felten, James E.; Dwek, Eli; Viegas-Aldrovandi, Sueli M.

    1989-01-01

    This paper explores fluorescence and reflection models of the companion to SN 1987A obseved by speckle interferometry, recalling a 1901 precedent. The apparent small angular size of the companion is a severe constraint. A fluorescence model cannot reach the observed brightness unless the ultraviolet burst from the supernova contained as many as 2 x 10 to the 58th ionizing photons. This is about 25 times stronger than generous current models. Even then, the expected line ratios and widths do not fit the observations. The absence of narrow H-alpha and H-beta lines in the supernova spectrum, the ratio of fluxes of the companion in H-alpha and forbidden N II line filters, the invisibility of the companion at 4861 (H-beta), and its detection at 5330 fail to agree with theory. A dust-reflection model is more promising, and the color can be reddened by the evaporation of small grains, but the model still falls more than about 1 mag short in brightness. Furthermore, a dust reflection should have increased in relative brightness in May-June 1987, rather than disappearing as the mystery spot did. If all the observations are correct, neither model is likely to work.

  14. Production and Collimation of Astrophysical Jets or Accretion: M87 and SN 1987A Scenarios

    NASA Astrophysics Data System (ADS)

    Bernal, C. G.; Page, D.

    2006-06-01

    Jets and outflows of various degrees of collimation and energetics are an ubiquitous phenomenon in astrophysics. They are present at all length scales, ranging from those found in young stellar objects (YSOs, Reipurth & Bally1991) and the galactic microquasars (Mirabel & Rodriguez 1994, Fender & Belloni 2004), to kpc-scale relativistic jets in AGNs. In many cases these appear to be symmetrical, with two oppositely directed lines of flow, and almost always they seem to be directly connected with accretion onto a central object at the base of the collimated outflow. The energy in the outflow itself ultimately comes from the gravitational potential well created by the central object. The structure and evolution of jet-like structures under a variety of physical conditions is a problem that generally requires numerical modelling. However, in certain cases valuable insight can be gained from purely hydrodynamical analytical solutions which exhibit outflows (or accretion) of varying characteristics. We show here several solutions of this type, applicable to various accretion scenarios. Assuming that our solutions are Jets, we applied the model to M87 scenario and to SN1987A scenario, assuming that our solutions are like accretion.

  15. Analysis of the SN 1987A neutrinos with a flexible spectral shape

    SciTech Connect

    Mirizzi, Alessandro; Raffelt, Georg G.

    2005-09-15

    We analyze the neutrino events from the supernova (SN) 1987A detected by the Kamiokande-II (KII) and Irvine-Michigan-Brookhaven (IMB) experiments. For the time-integrated flux we assume a quasithermal spectrum of the form (E/E{sub 0}){sup {alpha}}e{sup -({alpha}{sup +1})E/E{sub 0}} where {alpha} plays the role of a spectral index. This simple representation not only allows one to fit the total energy E{sub tot} emitted in {nu}{sub e} and the average energy , but also accommodates a wide range of shapes, notably antipinched spectra that are broader than a thermal distribution. We find that the pile-up of low-energy events near threshold in KII forces the best-fit value for {alpha} to the lowest value of any assumed prior range. This applies to the KII events alone as well as to a common analysis of the two data sets. The preference of the data for an 'unphysical' spectral shape implies that one can extract meaningful values for and E{sub tot} only if one fixes a prior value for {alpha}. The tension between the KII and IMB data sets and theoretical expectations for is not resolved by an antipinched spectrum.

  16. On the Possibility of Dust Condensation in the Ejecta of Supernova 1987a

    NASA Astrophysics Data System (ADS)

    Gehrz, R. D.; Ney, E. P.

    1987-10-01

    We suggest that supernova 1987a may condense dust of substantial visual optical thickness as do many novae. The dust will act as a calorimeter of the photon luminosity of any central engine that is dominant at the time of dust formation. Observations of novae suggest that dust formation may occur when the expanding ejecta reach a temperature of 1000 K. The early luminosity of the supernova may be dominated by radioactivity that is unrelated to the central engine that determines the energy balance for the long-term development of the supernova. We discuss the possibility that a constant luminosity central power source such as a pulsar dominates the luminosity of the supernova ejecta by the time that dust can condense and argue that, if a shell mass of more than a few tenths of one solar mass was ejected, emission from dust may be observable in the thermal infrared spectral region. Maximum dust optical depth should occur by late 1987 or early 1988. If the dust becomes optically thick, the visual light from the supernova may drop precipitously. The characteristics of an optically thick dust shell as a calorimeter of the luminosity of the central engine are discussed and are related to previous observations of dust formation in type II supernovae. It is suggested that dust of several chemical compositions may form at different epochs.

  17. Explosive nucleosynthesis in SN 1987A. II - Composition, radioactivities, and the neutron star mass

    NASA Technical Reports Server (NTRS)

    Thielemann, Friedrich-Karl; Hashimoto, Masa-Aki; Nomoto, Ken'ichi

    1990-01-01

    The 20 solar mass model of Nomoto and Hashimoto (1988) is utilized with a 6 solar mass. He core is used to perform explosive nucleosynthesis calculations. The employed explosion energy of 10 to the 51st ergs lies within the uncertainty range inferred from the bolometric light curve. The nucleosynthesis processes and their burning products are discussed in detail. The results are compared with abundances from IR observations of SN 1987A and the average nucleosynthesis expected for Type II supernovae in Galactic chemical evolution. The abundances of long-lived radioactive nuclei and their importance for the late light curve and gamma-ray observations are predicted. The position of the mass cut between the neutron star and the ejecta is deduced from the total amount of ejected Ni-56. This requires a neutron star with a baryonic mass of 1.6 + or - 0.045 solar mass, which corresponds to a gravitational mass of 1.43 + or - 0.05 solar mass after subtracting the binding energy of a nonrotating neutron star.

  18. INFRARED CONTINUUM AND LINE EVOLUTION OF THE EQUATORIAL RING AROUND SN 1987A

    SciTech Connect

    Arendt, Richard G.; Frank, Kari A.; Gehrz, Robert D.; Woodward, Charles E.; Park, Sangwook

    2016-03-15

    Spitzer observations of SN 1987A have now spanned more than a decade. Since day ∼4000, mid-infrared (mid-IR) emission has been dominated by that from shock-heated dust in the equatorial ring (ER). From 6000 to 8000 days after the explosion, Spitzer observations included broadband photometry at 3.6–24 μm, and low and moderate resolution spectroscopy at 5–35 μm. Here we present later Spitzer observations, through day 10,377, which include only the broadband measurements at 3.6 and 4.5 μm. These data show that the 3.6 and 4.5 μm brightness has clearly begun to fade after day ∼8500, and no longer tracks the X-ray emission as well as it did at earlier epochs. This can be explained by the destruction of the dust in the ER on timescales shorter than the cooling time for the shocked gas. We find that the evolution of the late time IR emission is also similar to the now fading optical emission. We provide the complete record of the IR emission lines, as seen by Spitzer prior to day 8000. The past evolution of the gas as seen by the IR emission lines seems largely consistent with the optical emission, although the IR [Fe ii] and [Si ii] lines show different, peculiar velocity structures.

  19. RE-EXAMINATION OF THE EXPECTED GAMMA-RAY EMISSION OF SUPERNOVA REMNANT SN 1987A

    SciTech Connect

    Berezhko, E. G.; Ksenofontov, L. T.; Völk, H. J.

    2015-09-01

    A nonlinear kinetic theory, combining cosmic-ray (CR) acceleration in supernova remnants (SNRs) with their gas dynamics, is used to re-examine the nonthermal properties of the remnant of SN 1987A for an extended evolutionary period of 5–50 year. This spherically symmetric model is approximately applied to the different features of the SNR, consisting of (i) a blue supergiant wind and bubble, and (ii) of the swept-up red supergiant (RSG) wind structures in the form of an H ii region, an equatorial ring (ER), and an hourglass region. The RSG wind involves a mass loss rate that decreases significantly with elevation above and below the equatorial plane. The model adapts recent three-dimensional hydrodynamical simulations by Potter et al. in 2014 that use a significantlysmaller ionized mass of the ER than assumed in the earlier studies by the present authors. The SNR shock recently swept up the ER, which is the densest region in the immediate circumstellar environment. Therefore, the expected gamma-ray energy flux density at TeV energies in the current epoch has already reached its maximal value of ∼10{sup −13} erg cm{sup −2} s{sup −1}. This flux should decrease by a factor of about two over the next 10 years.

  20. Infrared Continuum and Line Evolution of the Equatorial Ring around SN 1987A

    NASA Astrophysics Data System (ADS)

    Arendt, Richard G.; Dwek, Eli; Bouchet, Patrice; Danziger, I. John; Frank, Kari A.; Gehrz, Robert D.; Park, Sangwook; Woodward, Charles E.

    2016-03-01

    Spitzer observations of SN 1987A have now spanned more than a decade. Since day ˜4000, mid-infrared (mid-IR) emission has been dominated by that from shock-heated dust in the equatorial ring (ER). From 6000 to 8000 days after the explosion, Spitzer observations included broadband photometry at 3.6-24 μm, and low and moderate resolution spectroscopy at 5-35 μm. Here we present later Spitzer observations, through day 10,377, which include only the broadband measurements at 3.6 and 4.5 μm. These data show that the 3.6 and 4.5 μm brightness has clearly begun to fade after day ˜8500, and no longer tracks the X-ray emission as well as it did at earlier epochs. This can be explained by the destruction of the dust in the ER on timescales shorter than the cooling time for the shocked gas. We find that the evolution of the late time IR emission is also similar to the now fading optical emission. We provide the complete record of the IR emission lines, as seen by Spitzer prior to day 8000. The past evolution of the gas as seen by the IR emission lines seems largely consistent with the optical emission, although the IR [Fe ii] and [Si ii] lines show different, peculiar velocity structures.

  1. Infrared Continuum and Line Evolution of the Equatorial Ring Around SN 1987A

    NASA Technical Reports Server (NTRS)

    Arendt, Richard G.; Dwek, Eli; Bouchet, Patrice; Danziger, I. John; Frank, Kari A.; Gehrz, Robert D.; Park, Sangwook; Woodward, Charles E.

    2017-01-01

    Spitzer observations of SN 1987A have now spanned more than a decade. Since day approximately 4000, mid-infrared (mid-IR) emission has been dominated by that from shock-heated dust in the equatorial ring (ER). From 6000 to 8000 days after the explosion, Spitzer observations included broadband photometry at 3.6-24 micrometer, and low and moderate resolution spectroscopy at 5-35 micrometer. Here we present later Spitzer observations, through day 10,377, which include only the broadband measurements at 3.6 and 4.5 micrometer. These data show that the 3.6 and 4.5 micrometer brightness has clearly begun to fade after day approximately 8500, and no longer tracks the X-ray emission as well as it did at earlier epochs. This can be explained by the destruction of the dust in the ER on timescales shorter than the cooling time for the shocked gas. We find that the evolution of the late time IR emission is also similar to the now fading optical emission. We provide the complete record of the IR emission lines, as seen by Spitzer prior to day 8000. The past evolution of the gas as seen by the IR emission lines seems largely consistent with the optical emission, although the IR [Fe(II)]and [Si(II)]lines show different, peculiar velocity structures.

  2. A 2.14 ms candidate optical pulsar in SN1987A: Ten years after

    SciTech Connect

    Middleditch, J.; Kristian, J.A.; Kunkel, W.E.; Hill, K.M.; Watson, R.D.

    1997-09-01

    We have monitored Supernova 1987A in optical/near-infrared bands from a few weeks following its birth until the present time in order to search for a pulsar remnant. We have found an apparent pattern of emission near the frequency of 467.5 Hz - a 2.14 ms pulsar candidate, first detected in data taken on the remnant at the Las Campanas Observatory (LCO) 2.5-m Dupont telescope during 14-16 Feb. 1992 UT. We detected further signals near the 2.14 ms period on numerous occasions over the next four years in data taken with a variety of telescopes, data systems and detectors, at a number of ground- and space-based observatories. The sequence of detections of this signal from Feb. `92 through August `93, prior to its apparent subsequent fading, is highly improbable (< 10{sup -10} for any noise source). We also find evidence for modulation of the 2.14 ms period with a {approx}1,000 s period which, when taken with the high spindown of the source (2-3 x 10{sup -10} Hz/s), is consistent with precession and spindown via gravitational radiation of a neutron star with a non- axisymmetric oblateness of {approx}10{sup -6}, and an implied gravitational luminosity exceeding that of the Crab Nebula pulsar by an order of magnitude.

  3. Re-examination of the Expected Gamma-Ray Emission of Supernova Remnant SN 1987A

    NASA Astrophysics Data System (ADS)

    Berezhko, E. G.; Ksenofontov, L. T.; Völk, H. J.

    2015-09-01

    A nonlinear kinetic theory, combining cosmic-ray (CR) acceleration in supernova remnants (SNRs) with their gas dynamics, is used to re-examine the nonthermal properties of the remnant of SN 1987A for an extended evolutionary period of 5-50 year. This spherically symmetric model is approximately applied to the different features of the SNR, consisting of (i) a blue supergiant wind and bubble, and (ii) of the swept-up red supergiant (RSG) wind structures in the form of an H ii region, an equatorial ring (ER), and an hourglass region. The RSG wind involves a mass loss rate that decreases significantly with elevation above and below the equatorial plane. The model adapts recent three-dimensional hydrodynamical simulations by Potter et al. in 2014 that use a significantlysmaller ionized mass of the ER than assumed in the earlier studies by the present authors. The SNR shock recently swept up the ER, which is the densest region in the immediate circumstellar environment. Therefore, the expected gamma-ray energy flux density at TeV energies in the current epoch has already reached its maximal value of ˜10-13 erg cm-2 s-1. This flux should decrease by a factor of about two over the next 10 years.

  4. Far-infrared spectrophotometry of SN 1987A - Days 265 and 267

    NASA Technical Reports Server (NTRS)

    Moseley, S. H.; Dwek, E.; Silverberg, R. F.; Glaccum, W.; Graham, J. R.; Loewenstein, R. F.

    1989-01-01

    The paper presents 16-66-micron spectra of SN 1987A taken on days 266 and 268 after core collapse. The spectrum consists of a nearly flat continuum, strong emission lines of hydrogen, and fine-structure lines of Fe II, Fe III, Co II, S I, and possibly Fe I, Ni II, and S III. From the relative strength of three lines which arise from transitions within the ground and excited states of Fe II, the temperature and a lower limit on the density of the line-emitting region are derived. From the line strengths, the abundances of Fe and S I, the end products of explosive nucleosynthesis in the supernova are estimated. An upper limit is also set to the amount of Co II remaining in the mantle. The low measured mass of Fe suggests that the ejecta are clumpy. The flat continuum is most likely free-free emission from the expanding supernova ejecta. About 35 percent of this emission arises from the ionized metals in the mantle; the rest arises from ionized hydrogen. At the time of these observations, there is no evidence for any emission from dust that may have formed in the supernova ejecta or from preexisting dust in the surrounding medium.

  5. On the possibility of dust condensation in the ejecta of supernova 1987a

    PubMed Central

    Gehrz, R. D.; Ney, E. P.

    1987-01-01

    We suggest that supernova 1987a may condense dust of substantial visual optical thickness as do many novae. The dust will act as a calorimeter of the photon luminosity of any central engine that is dominant at the time of dust formation. Observations of novae suggest that dust formation may occur when the expanding ejecta reach a temperature of 1000 K. The early luminosity of the supernova may be dominated by radioactivity that is unrelated to the central engine that determines the energy balance for the long-term development of the supernova. We discuss the possibility that a constant luminosity central power source such as a pulsar dominates the luminosity of the supernova ejecta by the time that dust can condense and argue that, if a shell mass of more than a few tenths of one solar mass was ejected, emission from dust may be observable in the thermal infrared spectral region. Maximum dust optical depth should occur by late 1987 or early 1988. If the dust becomes optically thick, the visual light from the supernova may drop precipitously. The characteristics of an optically thick dust shell as a calorimeter of the luminosity of the central engine are discussed and are related to previous observations of dust formation in type II supernovae. It is suggested that dust of several chemical compositions may form at different epochs. PMID:16593876

  6. Far-infrared spectrophotometry of SN 1987A - Days 265 and 267

    SciTech Connect

    Moseley, S.H.; Dwek, E.; Silverberg, R.F.; Glaccum, W.; Graham, J.R.; Loewenstein, R.F. Applied Research Corp., Landover, MD California Institute of Technology, Pasadena Yerkes Observatory, Williams Bay, WI )

    1989-12-01

    The paper presents 16-66-micron spectra of SN 1987A taken on days 266 and 268 after core collapse. The spectrum consists of a nearly flat continuum, strong emission lines of hydrogen, and fine-structure lines of Fe II, Fe III, Co II, S I, and possibly Fe I, Ni II, and S III. From the relative strength of three lines which arise from transitions within the ground and excited states of Fe II, the temperature and a lower limit on the density of the line-emitting region are derived. From the line strengths, the abundances of Fe and S I, the end products of explosive nucleosynthesis in the supernova are estimated. An upper limit is also set to the amount of Co II remaining in the mantle. The low measured mass of Fe suggests that the ejecta are clumpy. The flat continuum is most likely free-free emission from the expanding supernova ejecta. About 35 percent of this emission arises from the ionized metals in the mantle; the rest arises from ionized hydrogen. At the time of these observations, there is no evidence for any emission from dust that may have formed in the supernova ejecta or from preexisting dust in the surrounding medium. 53 refs.

  7. Neutrino properties from SN 1987A and from future observations of GSC.

    NASA Astrophysics Data System (ADS)

    Dar, A.

    The early neutrino signal reported by the Mont Blanc group on Feb 23, 1987 was not produced by a neutrino burst from SN 1987A. The second neutrino burst that was reported by the KAMIOKANDE II, the IMB and the Baksan groups is consistent with the general theoretical picture of supernovae explosions, but it also has unexpected features. Analysis of the neutrino burst yields new limits on the lifetime, mass, mixing, and electric charge of the νe, and new limits on the magnetic moment and the radiative lifetime of light neutrinos. These limits imply that neither decay, nor mixing, nor electric charge, nor magnetic moment of the νe are responsible for the solar neutrino problem. Similar limits on the properties of the νμ and the ντ require the observation of a gravitational stellar collapse in the Galaxy with more advanced neutrino telescopes which are under construction. Such limits, when obtained, will resolve the question whether relic neutrinos from the big bang can close the universe.

  8. SN 1987A after 18 Years: Mid-Infrared GEMINI and SPITZER Observations of the Remnant

    NASA Technical Reports Server (NTRS)

    Bouchet, Patrice; Dwek, Eli; Danziger, John; Arendt, Richard G.; DeBuizer, James M.; Park, Sangwook; Suntzeff, Nicholas B.; Kirshner, Robert P.; Challis, Peter

    2007-01-01

    We present high resolution 11.7 and 18.3 micron mid-IR images of SN 1987A obtained on day 6526 since the explosion with the Thermal-Region Camera and Spectrograph (T-ReCS) attached to the Gemini South 8m telescope. The 11.7 micron flux has increased significantly since our last observations on day 6067. The images clearly show that all the emission arises from the equatorial ring (ER). Nearly contemporaneous spectra obtained on day 6184 with the MIPS at 24 micron, on day 6130 with the IRAC in 3.6- 8 micron region, and on day 6190 with the IRS in the 12-37 micron instruments on board the Spitzer Space Telescope's show that the emission consists of thermal emission from silicate dust that condensed out in the red giant wind of the progenitor star. The dust temperature is 1662(sup +18) (sub -12) K, and the emitting dust mass is (2.6(sup +2.0 (sub -1.4)) x 10 (exp -6) M(solar). Lines of [Ne II] 12.82 micron and [Ne III] 15.56 pm are clearly present in the Spitzer spectrum, as well as a weak [Si II] 3 34.8 micron line. We also detect two lines near 26 micron which we tentatively ascribe to [Fe II] 25.99 pm and [0 IV] 25.91 micron. Comparison of the mid-IR Gemini 11.7 micron image with X-ray images obtained by Chandra, UV-optical images obtained by HST, and radio synchrotron images obtained by the ATCA show generally good correlation of the images across all wavelengths. Because of the limited resolution of the mid-IR images we cannot uniquely determine the location. or heating mechanism of the dust giving rise to the emission. The dust could be collisionally heated by the X-ray emitting plasma, providing a unique diagnostic of plasma conditions. Alternatively, the dust could be radiatively heated in the dense UV-optical knots that are overrun by the advancing supernova blast wave. In either case the dust-to-gas mass ratio in the circumstellar medium around the supernova is significantly lower than that in the general interstellar medium of the LMC, suggesting either a

  9. Visual attention: The past 25 years

    PubMed Central

    Carrasco, Marisa

    2012-01-01

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

  10. q -deformed statistics and the role of light fermionic dark matter in SN1987A cooling

    NASA Astrophysics Data System (ADS)

    Guha, Atanu; J, Selvaganapathy; Das, Prasanta Kumar

    2017-01-01

    The light dark matter (≃1 - 30 MeV ) particles pair produced in electron-positron annihilation e-e+→ γ χ χ ¯ inside the supernova core can take away the energy released in the supernova SN1987A explosion. Working within the formalism of q -deformed statistics [with the average value of the supernovae core temperature (fluctuating) being TS N=30 MeV ] and using the Raffelt's criterion on the emissivity for any new channel ɛ ˙ (e+e-→χ χ ¯ )≤1 019 erg g-1 s-1 , we find that as the deformation parameter q changes from 1.0 (undeformed scenario) to 1.1 (deformed scenario), the lower bound on the scale Λ of the dark matter effective theory varies from 3.3 ×1 06 TeV to 3.2 ×1 07 TeV for a dark matter fermion of mass mχ=30 MeV . Using the optical depth criteria on the free streaming of the dark matter fermion, we find the lower bound on Λ ˜1 08 TeV for mχ=30 MeV . In a scenario, where the dark matter fermions are pair produced in the outermost sector of the supernova core [with radius 0.9 Rc≤r ≤Rc , Rc(=10 km ) being the supernova core radius or the radius of protoneutron star], we find that the bound on Λ (˜3 ×1 07 TeV ) obtained from SN cooling criteria (Raffelt's criteria) is comparable with the bound obtained from free streaming (optical depth criterion) for light fermion dark matter of mass mχ=10 - 30 MeV .

  11. Tsallis Statistics and the Role of a Stabilized Radion in the Supernovae SN1987A Cooling

    NASA Astrophysics Data System (ADS)

    Das, Prasanta Kumar; Selvaganapathy, J.; Sharma, Chandradew; Jha, Tarun Kumar; Kumar, V. Sunil

    2013-11-01

    The radion in the two-brane Randall-Sundrum model is required to stabilize the size of the fifth (extra) spatial dimension. It can be copiously produced inside the supernova core due to electron-positron annihilation (e+e-→ϕ), plasmon-plasmon annihilation (γP+γP→ϕ) and nucleon-nucleon bremsstrahlung and can take away the energy released in SN1987A explosion. Working within the q-deformed statistics (Tsallis statistics) and using the "Raffelt criterion" on the supernovae cooling rate ˙ {ǎrepsilon}<= 1019 ergs g-1 s-1, we find that in Case I (cooling due to e+e-→ϕ channel): for q = 1.22, as the radion mass mϕ changes from 20 GeV to 150 GeV, the lower bound <ϕ> changes from 7 TeV to 1.5 TeV and in Case II (cooling due to γP+γP→ϕ channel): for q = 1.11, as mϕ ranges from 20 GeV to 150 GeV, the lower bound <ϕ> changes from 201 TeV to 3.3 TeV. We investigate the dependence of <ϕ> on q and found that in Case I: mϕ = 50(100) GeV, <ϕ> changes from 0.5(0.2) TeV (for q = 1.18) to 5.5(4.8) TeV (for q = 1.30) and in Case II: for mϕ = 50(100) GeV, <ϕ> changes from 0.8( 0.1) TeV (for q = 1.09) to 569(216) TeV (for q = 1.13). We also verified that the normal Fermi-Dirac and Bose-Einstein statistics get recovered from the Tsallis statistics in the q→1 limit.

  12. Multi-dimensional simulations of the expanding supernova remnant of SN 1987A

    SciTech Connect

    Potter, T. M.; Staveley-Smith, L.; Reville, B.; Ng, C.-Y.; Bicknell, G. V.; Sutherland, R. S.; Wagner, A. Y.

    2014-10-20

    The expanding remnant from SN 1987A is an excellent laboratory for investigating the physics of supernovae explosions. There is still a large number of outstanding questions, such as the reason for the asymmetric radio morphology, the structure of the pre-supernova environment, and the efficiency of particle acceleration at the supernova shock. We explore these questions using three-dimensional simulations of the expanding remnant between days 820 and 10,000 after the supernova. We combine a hydrodynamical simulation with semi-analytic treatments of diffusive shock acceleration and magnetic field amplification to derive radio emission as part of an inverse problem. Simulations show that an asymmetric explosion, combined with magnetic field amplification at the expanding shock, is able to replicate the persistent one-sided radio morphology of the remnant. We use an asymmetric Truelove and McKee progenitor with an envelope mass of 10 M {sub ☉} and an energy of 1.5 × 10{sup 44} J. A termination shock in the progenitor's stellar wind at a distance of 0.''43-0.''51 provides a good fit to the turn on of radio emission around day 1200. For the H II region, a minimum distance of 0.''63 ± 0.''01 and maximum particle number density of (7.11 ± 1.78) × 10{sup 7} m{sup –3} produces a good fit to the evolving average radius and velocity of the expanding shocks from day 2000 to day 7000 after explosion. The model predicts a noticeable reduction, and possibly a temporary reversal, in the asymmetric radio morphology of the remnant after day 7000, when the forward shock left the eastern lobe of the equatorial ring.

  13. Spectral and morphological analysis of the remnant of supernova 1987A with ALMA and ATCA

    SciTech Connect

    Zanardo, Giovanna; Staveley-Smith, Lister; Indebetouw, Remy; Chevalier, Roger A.; Matsuura, Mikako; Barlow, Michael J.; Gaensler, Bryan M.; Fransson, Claes; Lundqvist, Peter; Manchester, Richard N.; Baes, Maarten; Kamenetzky, Julia R.; Lakićević, Maša; Marcaide, Jon M.; Meixner, Margaret; Ng, C.-Y.; Park, Sangwook; and others

    2014-12-01

    We present a comprehensive spectral and morphological analysis of the remnant of supernova (SN) 1987A with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA). The non-thermal and thermal components of the radio emission are investigated in images from 94 to 672 GHz (λ 3.2 mm to 450 μm), with the assistance of a high-resolution 44 GHz synchrotron template from the ATCA, and a dust template from ALMA observations at 672 GHz. An analysis of the emission distribution over the equatorial ring in images from 44 to 345 GHz highlights a gradual decrease of the east-to-west asymmetry ratio with frequency. We attribute this to the shorter synchrotron lifetime at high frequencies. Across the transition from radio to far infrared, both the synchrotron/dust-subtracted images and the spectral energy distribution (SED) suggest additional emission beside the main synchrotron component (S {sub ν}∝ν{sup –0.73}) and the thermal component originating from dust grains at T ∼ 22 K. This excess could be due to free-free flux or emission from grains of colder dust. However, a second flat-spectrum synchrotron component appears to better fit the SED, implying that the emission could be attributed to a pulsar wind nebula (PWN). The residual emission is mainly localized west of the SN site, as the spectral analysis yields –0.4 ≲ α ≲ –0.1 across the western regions, with α ∼ 0 around the central region. If there is a PWN in the remnant interior, these data suggest that the pulsar may be offset westward from the SN position.

  14. Multi-dimensional Simulations of the Expanding Supernova Remnant of SN 1987A

    NASA Astrophysics Data System (ADS)

    Potter, T. M.; Staveley-Smith, L.; Reville, B.; Ng, C.-Y.; Bicknell, G. V.; Sutherland, R. S.; Wagner, A. Y.

    2014-10-01

    The expanding remnant from SN 1987A is an excellent laboratory for investigating the physics of supernovae explosions. There is still a large number of outstanding questions, such as the reason for the asymmetric radio morphology, the structure of the pre-supernova environment, and the efficiency of particle acceleration at the supernova shock. We explore these questions using three-dimensional simulations of the expanding remnant between days 820 and 10,000 after the supernova. We combine a hydrodynamical simulation with semi-analytic treatments of diffusive shock acceleration and magnetic field amplification to derive radio emission as part of an inverse problem. Simulations show that an asymmetric explosion, combined with magnetic field amplification at the expanding shock, is able to replicate the persistent one-sided radio morphology of the remnant. We use an asymmetric Truelove & McKee progenitor with an envelope mass of 10 M ⊙ and an energy of 1.5 × 1044 J. A termination shock in the progenitor's stellar wind at a distance of 0.''43-0.''51 provides a good fit to the turn on of radio emission around day 1200. For the H II region, a minimum distance of 0.''63 ± 0.''01 and maximum particle number density of (7.11 ± 1.78) × 107 m-3 produces a good fit to the evolving average radius and velocity of the expanding shocks from day 2000 to day 7000 after explosion. The model predicts a noticeable reduction, and possibly a temporary reversal, in the asymmetric radio morphology of the remnant after day 7000, when the forward shock left the eastern lobe of the equatorial ring.

  15. The Evolution of Dust Mass in the Ejecta of SN1987A

    NASA Astrophysics Data System (ADS)

    Dwek, Eli; Arendt, Richard G.

    2015-09-01

    We present a new analysis of the infrared (IR) emission from the ejecta of SN 1987A covering days 615, 775, 1144, 8515, and 9090 after the explosion. We show that the observations are consistent with the rapid formation of about 0.4 {M}⊙ of dust, consisting of mostly silicates (MgSiO3), near day 615, and evolving to about 0.45 {M}⊙ of composite dust grains consisting of ˜0.4 {M}⊙ of silicates and ˜0.05 {M}⊙ of amorphous carbon after day ˜8500. The proposed scenario challenges previous claims that dust in supernova (SN) ejecta is predominantly carbon, and that it grew from an initial mass of ˜10-3 {M}⊙ , to over 0.5 {M}⊙ by cold accretion. It alleviates several problems with previous interpretations of the data: (1) it reconciles the abundances of silicon, magnesium, and carbon with the upper limits imposed by nucleosynthesis calculations, (2) it eliminates the requirement that most of the dust observed around day 9000 grew by cold accretion onto the ˜10-3 {M}⊙ of dust previously inferred for days 615 and 775 after the explosion, and (3) establishes the dominance of silicate over carbon dust in the SN ejecta. At early epochs, the IR luminosity of the dust is powered by the radioactive decay of 56Co, and at late times by at least (1.3-1.6) × 10-4 {M}⊙ of 44Ti.

  16. EVOLUTION OF THE RADIO REMNANT OF SUPERNOVA 1987A: MORPHOLOGICAL CHANGES FROM DAY 7000

    SciTech Connect

    Ng, C.-Y.; Zanardo, G.; Potter, T. M.; Staveley-Smith, L.; Gaensler, B. M.; Manchester, R. N.; Tzioumis, A. K.

    2013-11-10

    We present radio imaging observations of supernova remnant 1987A at 9 GHz, taken with the Australia Telescope Compact Array over 21 years from 1992 to 2013. By employing a Fourier modeling technique to fit the visibility data, we show that the remnant structure has evolved significantly since day 7000 (mid-2006): the emission latitude has gradually decreased such that the overall geometry has become more similar to a ring structure. Around the same time, we find a decreasing trend in the east-west asymmetry of the surface emissivity. These results could reflect the increasing interaction of the forward shock with material around the circumstellar ring, and the relative weakening of the interaction with the lower-density material at higher latitudes. The morphological evolution caused an apparent break in the remnant expansion measured with a torus model, from a velocity of 4600{sup +150}{sub -}200 km s{sup –1} between day 4000 and 7000 to 2400{sup +100}{sub -200} km s{sup –1} after day 7000. However, we emphasize that there is no conclusive evidence for a physical slowing of the shock at any given latitude in the expanding remnant, and that a change of radio morphology alone appears to dominate the evolution. This is supported by our ring-only fits which show a constant expansion of 3890 ± 50 km s{sup –1} without deceleration between days 4000 and 9000. We suggest that once the emission latitude no longer decreases, the expansion velocity obtained from the torus model should return to the same value as that measured with the ring model.

  17. The late behavior of supernova 1987A. I - The light curve. II - Gamma-ray transparency of the ejecta

    NASA Technical Reports Server (NTRS)

    Arnett, W. David; Fu, Albert

    1989-01-01

    Observations of the late (t = 20-1500 days) bolometric light curve and the gamma-lines and X-rays from supernova 1987A are compared to theoretical models. It is found that 0.073 + or - 0.015 solar masses of freshly synthesized Ni-56 must be present to fit the bolometric light curve. The results place limits on the luminosity and presumed period of the newly formed pulsar/neutron star. In the second half of the paper, the problem of computing the luminosities in gamma-ray lines and in X-rays from supernova 1987A is addressed. High-energy observations suggest the development of large-scale clumping and bubbling of radioactive material in the ejecta. A model is proposed with a hydrogen envelope mass of about 7 solar masses, homologous scale expansion velocities of about 3000 km/s, and an approximately uniform mass distribution.

  18. Coincidences among Mont Blanc, Kamiokande, Baksan, IMB, Frejus, Homestake and Plateau Rosa detectors during SN1987A.

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Badino, G.; Bologna, G.; Castagnoli, C.; Castellina, A.; Fulgione, W.; Galeotti, P.; Saavedra, O.; Trinchero, G.; Vernetto, S.

    Correlation analysis has been performed among the events recorded during the occurrence of SN1987A by the underground detectors of Mont Blanc, Kamiokande, Baksan, IMB, Frejus, Homestake and the EAS array of Plateau Rosa. A significative excess of coincidence exists between low energy events of Mont Blanc and IMB muons, in the time interval from 1:45 to 3:45 UT on Feb. 23, 1987.

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

    PubMed Central

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

    2014-01-01

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

  20. A New View of the Circumstellar Environment of SN 1987A

    NASA Astrophysics Data System (ADS)

    Sugerman, Ben E. K.; Crotts, Arlin P. S.; Kunkel, William E.; Heathcote, Stephen R.; Lawrence, Stephen S.

    2005-07-01

    We summarize the analysis of a uniform set of both previously known and newly discovered scattered-light echoes, detected within 30" of SN 1987A in 10 years of optical imaging, and with which we have constructed the most complete three-dimensional model of the progenitor's circumstellar environment. Surrounding the SN is a richly structured bipolar nebula. An outer, double-lobed ``peanut,'' which we believe is the contact discontinuity between the red supergiant and main-sequence winds, is a prolate shell extending 28 lt-yr along the poles and 11 lt-yr near the equator. Napoleon's Hat, previously believed to be an independent structure, is the waist of this peanut, which is pinched to a radius of 6 lt-yr. Interior, the innermost circumstellar material lies along a cylindrical hourglass, 1 lt-yr in radius and 4 lt-yr long, which connects to the peanut by a thick equatorial disk. The nebulae are inclined 41° south and 8° east of the line of sight, slightly elliptical in cross section, and marginally offset west of the SN. The three-dimensional geometry of the three circumstellar rings is studied, suggesting the northern and southern rings are located 1.3 and 1.0 lt-yr from the SN, while the equatorial ring is elliptical (b/a<~0.98) and spatially offset in the same direction as the hourglass. Dust-scattering models of the observed echo fluxes suggest that between the hourglass and bipolar lobes: the gas density drops from 1 to 3 cm-3 to >~0.03 cm-3 the maximum dust-grain size increases from ~0.2 to 2 μm and the silicate:carbonaceous dust ratio decreases. The nebulae have a total mass of ~1.7 Msolar, yielding a red-supergiant mass loss around 5×10-6 Msolar yr-1. We compare these results to current formation models and find that no model has successfully reproduced this system. However, our results suggest a heuristic evolutionary sequence in which the progenitor evolves through two ``blue loops,'' perhaps accompanied by a close binary companion.

  1. The light curve of SN 1987A revisited: constraining production masses of radioactive nuclides

    SciTech Connect

    Seitenzahl, Ivo R.; Timmes, F. X.; Magkotsios, Georgios

    2014-09-01

    We revisit the evidence for the contribution of the long-lived radioactive nuclides {sup 44}Ti, {sup 55}Fe, {sup 56}Co, {sup 57}Co, and {sup 60}Co to the UVOIR light curve of SN 1987A. We show that the V-band luminosity constitutes a roughly constant fraction of the bolometric luminosity between 900 and 1900 days, and we obtain an approximate bolometric light curve out to 4334 days by scaling the late time V-band data by a constant factor where no bolometric light curve data is available. Considering the five most relevant decay chains starting at {sup 44}Ti, {sup 55}Co, {sup 56}Ni, {sup 57}Ni, and {sup 60}Co, we perform a least squares fit to the constructed composite bolometric light curve. For the nickel isotopes, we obtain best fit values of M({sup 56}Ni) = (7.1 ± 0.3) × 10{sup –2} M {sub ☉} and M({sup 57}Ni) = (4.1 ± 1.8) × 10{sup –3} M {sub ☉}. Our best fit {sup 44}Ti mass is M({sup 44}Ti) = (0.55 ± 0.17) × 10{sup –4} M {sub ☉}, which is in disagreement with the much higher (3.1 ± 0.8) × 10{sup –4} M {sub ☉} recently derived from INTEGRAL observations. The associated uncertainties far exceed the best fit values for {sup 55}Co and {sup 60}Co and, as a result, we only give upper limits on the production masses of M({sup 55}Co) < 7.2 × 10{sup –3} M {sub ☉} and M({sup 60}Co) < 1.7 × 10{sup –4} M {sub ☉}. Furthermore, we find that the leptonic channels in the decay of {sup 57}Co (internal conversion and Auger electrons) are a significant contribution and constitute up to 15.5% of the total luminosity. Consideration of the kinetic energy of these electrons is essential in lowering our best fit nickel isotope production ratio to [{sup 57}Ni/{sup 56}Ni] = 2.5 ± 1.1, which is still somewhat high but is in agreement with gamma-ray observations and model predictions.

  2. The Light Curve of SN 1987A Revisited: Constraining Production Masses of Radioactive Nuclides

    NASA Astrophysics Data System (ADS)

    Seitenzahl, Ivo R.; Timmes, F. X.; Magkotsios, Georgios

    2014-09-01

    We revisit the evidence for the contribution of the long-lived radioactive nuclides 44Ti, 55Fe, 56Co, 57Co, and 60Co to the UVOIR light curve of SN 1987A. We show that the V-band luminosity constitutes a roughly constant fraction of the bolometric luminosity between 900 and 1900 days, and we obtain an approximate bolometric light curve out to 4334 days by scaling the late time V-band data by a constant factor where no bolometric light curve data is available. Considering the five most relevant decay chains starting at 44Ti, 55Co, 56Ni, 57Ni, and 60Co, we perform a least squares fit to the constructed composite bolometric light curve. For the nickel isotopes, we obtain best fit values of M(56Ni) = (7.1 ± 0.3) × 10-2 M ⊙ and M(57Ni) = (4.1 ± 1.8) × 10-3 M ⊙. Our best fit 44Ti mass is M(44Ti) = (0.55 ± 0.17) × 10-4 M ⊙, which is in disagreement with the much higher (3.1 ± 0.8) × 10-4 M ⊙ recently derived from INTEGRAL observations. The associated uncertainties far exceed the best fit values for 55Co and 60Co and, as a result, we only give upper limits on the production masses of M(55Co) < 7.2 × 10-3 M ⊙ and M(60Co) < 1.7 × 10-4 M ⊙. Furthermore, we find that the leptonic channels in the decay of 57Co (internal conversion and Auger electrons) are a significant contribution and constitute up to 15.5% of the total luminosity. Consideration of the kinetic energy of these electrons is essential in lowering our best fit nickel isotope production ratio to [57Ni/56Ni] = 2.5 ± 1.1, which is still somewhat high but is in agreement with gamma-ray observations and model predictions.

  3. An Operant Analysis of Joint Attention Skills

    ERIC Educational Resources Information Center

    Holth, Per

    2005-01-01

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

  4. Attention and other constructs: evolution or revolution?

    PubMed

    Koziol, Leonard F; Barker, Lauren A; Jansons, Laura

    2015-01-01

    This article provides a review of the construct of attention from a non-traditional standpoint. Attention is conceptualized by focusing on the categorical concept of the diagnosis of attention-deficit hyperactivity disorder, large-scale brain network models of functional neuroanatomy, and implications for understanding lateralized hemispheric brain organization. Cortical systems are multifunctional, with certain degrees of specialization, but no cortical region or network supports only one, specific, isolated cognitive process, such as attention. Future implications for clinical practice must focus on connectivity patterns rather than the idea of "domains" or "constructs" when considering attention and other cognitive processes. This has significant implications for the future of neuropsychological assessment and intervention.

  5. Effects of Psychological Attention on Pronoun Comprehension

    PubMed Central

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

    2015-01-01

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

  6. The Attention Cascade Model and Attentional Blink

    ERIC Educational Resources Information Center

    Shih, Shui-I

    2008-01-01

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

  7. Attention in a Bayesian Framework

    PubMed Central

    Whiteley, Louise; Sahani, Maneesh

    2012-01-01

    The behavioral phenomena of sensory attention are thought to reflect the allocation of a limited processing resource, but there is little consensus on the nature of the resource or why it should be limited. Here we argue that a fundamental bottleneck emerges naturally within Bayesian models of perception, and use this observation to frame a new computational account of the need for, and action of, attention – unifying diverse attentional phenomena in a way that goes beyond previous inferential, probabilistic and Bayesian models. Attentional effects are most evident in cluttered environments, and include both selective phenomena, where attention is invoked by cues that point to particular stimuli, and integrative phenomena, where attention is invoked dynamically by endogenous processing. However, most previous Bayesian accounts of attention have focused on describing relatively simple experimental settings, where cues shape expectations about a small number of upcoming stimuli and thus convey “prior” information about clearly defined objects. While operationally consistent with the experiments it seeks to describe, this view of attention as prior seems to miss many essential elements of both its selective and integrative roles, and thus cannot be easily extended to complex environments. We suggest that the resource bottleneck stems from the computational intractability of exact perceptual inference in complex settings, and that attention reflects an evolved mechanism for approximate inference which can be shaped to refine the local accuracy of perception. We show that this approach extends the simple picture of attention as prior, so as to provide a unified and computationally driven account of both selective and integrative attentional phenomena. PMID:22712010

  8. Dissociations between developmental dyslexias and attention deficits

    PubMed Central

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

    2014-01-01

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

  9. Dissociations between developmental dyslexias and attention deficits.

    PubMed

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

    2014-01-01

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

  10. Long-acting stimulants for treatment of attention-deficit/hyperactivity disorder: a focus on extended-release formulations and the prodrug lisdexamfetamine dimesylate to address continuing clinical challenges.

    PubMed

    López, Frank A; Leroux, Jacques R

    2013-09-01

    Individuals with attention-deficit/hyperactivity disorder (ADHD) show pervasive impairments across family, peer, and school or work functioning that may extend throughout the day. Psychostimulants are highly effective medications for the treatment of ADHD, and the development of long-acting stimulant formulations has greatly expanded the treatment options for individuals with ADHD. Strategies for the formulation of long-acting stimulants include the combination of immediate-release and delayed-release beads, and an osmotic-release oral system. A recent development is the availability of the first prodrug stimulant, lisdexamfetamine dimesylate (LDX). LDX itself is inactive but is cleaved enzymatically, primarily in the bloodstream, to release d-amphetamine (d-AMP). Several clinical trials have demonstrated that long-acting stimulants are effective in reducing ADHD symptoms compared with placebo. Analog classroom and simulated adult workplace environment studies have shown that long-acting stimulants produce symptom reduction for at least 12 h. Long-acting stimulants exhibit similar tolerability and safety profiles to short-acting equivalents. While variations in gastric pH and motility can alter the availability and absorption of stimulants released from long-acting formulations, the systemic exposure to d-AMP following LDX administration is unlikely to be affected by gastrointestinal conditions. Long-acting formulations may also improve adherence and lower abuse potential compared with their short-acting counterparts. The development of long-acting stimulants provides physicians with an increased range of medication options to help tailor treatment for individuals with ADHD.

  11. Modelling supernova line profile asymmetries to determine ejecta dust masses: SN 1987A from days 714 to 3604

    NASA Astrophysics Data System (ADS)

    Bevan, Antonia; Barlow, M. J.

    2016-02-01

    The late-time optical and near-IR line profiles of many core-collapse supernovae exhibit a red-blue asymmetry as a result of greater extinction by internal dust of radiation emitted from the receding parts of the supernova ejecta. We present here a new code, DAMOCLES, that models the effects of dust on the line profiles of core-collapse supernovae in order to determine newly formed dust masses. We find that late-time dust-affected line profiles may exhibit an extended red scattering wing (as noted by Lucy et al. 1989) and that they need not be flux-biased towards the blue, although the profile peak will always be blueshifted. We have collated optical spectra of SN 1987A from a variety of archival sources and have modelled the Hα line from days 714 to 3604 and the [O I] 6300,6363 Å doublet between days 714 and 1478. Our line profile fits rule out day 714 dust masses >3 × 10-3 M⊙ for all grain types apart from pure magnesium silicates, for which no more than 0.07 M⊙ can be accommodated. Large grain radii ( ≥ 0.6 μm) are generally required to fit the line profiles even at the earlier epochs. We find that a large dust mass (≥0.1 M⊙) had formed by day 3604 and infer that the majority of the present dust mass must have formed after this epoch. Our findings agree with recent estimates from spectral energy distribution fits for the dust mass evolution of SN 1987A and support the inference that the majority of SN 1987A's dust formed many years after the initial explosion.

  12. Neutrino Signal of Collapse-induced Thermonuclear Supernovae: The Case for Prompt Black Hole Formation in SN 1987A

    NASA Astrophysics Data System (ADS)

    Blum, Kfir; Kushnir, Doron

    2016-09-01

    Collapse-induced thermonuclear explosion (CITE) may explain core-collapse supernovae (CCSNe). We analyze the neutrino signal in CITE and compare it to the neutrino burst of SN 1987A. For strong (≳ {10}51 erg) CCSNe, such as SN 1987A, CITE predicts a proto-neutron star (PNS) accretion phase lasting up to a few seconds that is cut off by black hole (BH) formation. The neutrino luminosity can later be revived by accretion disk emission after a dead time of a few to a few tens of seconds. In contrast, the neutrino mechanism for CCSNe predicts a short (≲s) PNS accretion phase, followed by slowly declining PNS cooling luminosity. We repeat statistical analyses used in the literature to interpret the neutrino mechanism, and apply them to CITE. The first 1-2 s of the neutrino burst are equally compatible with CITE and with the neutrino mechanism. However, the data points toward a luminosity drop at t = 2-3 s, which is in some tension with the neutrino mechanism but can be naturally attributed to BH formation in CITE. The occurrence of neutrino signal events at 5 s suggests that, within CITE, the accretion disk formed by that time. We perform two-dimensional numerical simulations showing that CITE may be able to accommodate this disk formation time while reproducing the ejected 56Ni mass and ejecta kinetic energy within factors of 2-3 of observations. We estimate the accretion disk neutrino luminosity, finding it to be on the low side but compatible with the data to a factor of 10. Given comparable uncertainties in the disk luminosity simulation, we conclude that direct BH formation may have occurred in SN 1987A.

  13. X ray radiation from Supernova 1987A. The results of the Kvant module in 1987-1989

    NASA Technical Reports Server (NTRS)

    Sunyaev, Rashid A.; Kaniovsky, A. S.; Efremov, V. V.; Grebenev, S. A.; Kuznetsov, A. V.; Churasov, E.; Gilfanov, M.; Yamburenko, N.; Englhauser, J.; Doebereiner, S.

    1991-01-01

    The results of two years of SN1987A hard X-ray observations by the HEXE instrument aboard the Kvant module are summarized. By May to June 1989, the hard x-ray flux had declined more than 8.5 times in comparison with the maximum of the x-ray light curve. The upper limit of the ratio of Co-57/Co-56 abundances at the level of ratio of Fe-57/Fe-56 abundances at the Earth is a factor of 1.5.

  14. Limits to the radiative decays of neutrinos and axions from gamma-ray observations of SN 1987A

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.; Turner, Michael S.

    1989-01-01

    Gamma-ray observations obtained by the SMM gamma-ray spectrometer in the energy range 4.1-6.4 MeV are used to provide limits on the possible radiative decay of neutrinos and axions emitted by SN 1987A. For branching ratio values for the radiative decay modes of less than about 0.0001, the present limits are more stringent than those based upon the photon flux from decaying relic neutrinos. The data are also used to set an axion mass limit.

  15. The search for gamma radiation from supernova 1987A in an experiment aboard the Salut-7/Cosmos-1686 complex

    NASA Astrophysics Data System (ADS)

    Bachilova, R. N.; Bloch, G. M.; Pankov, V. M.; Prohin, V. L.; Rutkovsky, A. I.; Rumin, S. P.

    1988-07-01

    Gamma-quanta flux measurements were carried out during February-October 1987 in a search for radiation from SN 1987A. The time dependence of the mean monthly gamma-quanta flux measured with the Nega telescope at an altitude of 500 km in the equatorial region is analyzed. The upper limit of the gamma-quanta flux is determined to be 1.5 x 10 to the -6th/sq cm s keV on the 3-sigma level for the 1.5-4.4 MeV energy interval.

  16. Toddlers' Spontaneous Attention to Number

    ERIC Educational Resources Information Center

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

    2008-01-01

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

  17. Attention deficit hyperactivity disorder.

    PubMed

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

    2014-01-01

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

  18. Sustained Attention at Age 5 Predicts Attention-Related Problems at Age 9

    ERIC Educational Resources Information Center

    Martin, Anne; Razza, Rachel A.; Brooks-Gunn, Jeanne

    2012-01-01

    This study tested whether two aspects of sustained attention (focused attention and lack of impulsivity) measured at child age 5 predicted attention problems reported by mothers and teachers at age 9. Because lack of impulsivity reflects the executive control network, and ADHD is commonly characterized as a deficit in executive function, it was…

  19. Attentional Spreading in Object-Based Attention

    ERIC Educational Resources Information Center

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

    2008-01-01

    The authors investigated 2 effects of object-based attention: the spread of attention within an attended object and the prioritization of search across possible target locations within an attended object. Participants performed a flanker task in which the location of the task-relevant target was fixed and known to participants. A spreading…

  20. Ion focusing

    DOEpatents

    Cooks, Robert Graham; Baird, Zane; Peng, Wen-Ping

    2017-01-17

    The invention generally relates to apparatuses for focusing ions at or above ambient pressure and methods of use thereof. In certain embodiments, the invention provides an apparatus for focusing ions that includes an electrode having a cavity, at least one inlet within the electrode configured to operatively couple with an ionization source, such that discharge generated by the ionization source is injected into the cavity of the electrode, and an outlet. The cavity in the electrode is shaped such that upon application of voltage to the electrode, ions within the cavity are focused and directed to the outlet, which is positioned such that a proximal end of the outlet receives the focused ions and a distal end of the outlet is open to ambient pressure.

  1. Ion focusing

    SciTech Connect

    Cooks, Robert Graham; Baird, Zane; Peng, Wen-Ping

    2015-11-10

    The invention generally relates to apparatuses for focusing ions at or above ambient pressure and methods of use thereof. In certain embodiments, the invention provides an apparatus for focusing ions that includes an electrode having a cavity, at least one inlet within the electrode configured to operatively couple with an ionization source, such that discharge generated by the ionization source is injected into the cavity of the electrode, and an outlet. The cavity in the electrode is shaped such that upon application of voltage to the electrode, ions within the cavity are focused and directed to the outlet, which is positioned such that a proximal end of the outlet receives the focused ions and a distal end of the outlet is open to ambient pressure.

  2. Attention to natural auditory signals.

    PubMed

    Caporello Bluvas, Emily; Gentner, Timothy Q

    2013-11-01

    The challenge of understanding how the brain processes natural signals is compounded by the fact that such signals are often tied closely to specific natural behaviors and natural environments. This added complexity is especially true for auditory communication signals that can carry information at multiple hierarchical levels, and often occur in the context of other competing communication signals. Selective attention provides a mechanism to focus processing resources on specific components of auditory signals, and simultaneously suppress responses to unwanted signals or noise. Although selective auditory attention has been well-studied behaviorally, very little is known about how selective auditory attention shapes the processing on natural auditory signals, and how the mechanisms of auditory attention are implemented in single neurons or neural circuits. Here we review the role of selective attention in modulating auditory responses to complex natural stimuli in humans. We then suggest how the current understanding can be applied to the study of selective auditory attention in the context natural signal processing at the level of single neurons and populations in animal models amenable to invasive neuroscience techniques. This article is part of a Special Issue entitled "Communication Sounds and the Brain: New Directions and Perspectives".

  3. Timing divided attention.

    PubMed

    Hogendoorn, Hinze; Carlson, Thomas A; VanRullen, Rufin; Verstraten, Frans A J

    2010-11-01

    Visual attention can be divided over multiple objects or locations. However, there is no single theoretical framework within which the effects of dividing attention can be interpreted. In order to develop such a model, here we manipulated the stage of visual processing at which attention was divided, while simultaneously probing the costs of dividing attention on two dimensions. We show that dividing attention incurs dissociable time and precision costs, which depend on whether attention is divided during monitoring or during access. Dividing attention during monitoring resulted in progressively delayed access to attended locations as additional locations were monitored, as well as a one-off precision cost. When dividing attention during access, time costs were systematically lower at one of the accessed locations than at the other, indicating that divided attention during access, in fact, involves rapid sequential allocation of undivided attention. We propose a model in which divided attention is understood as the simultaneous parallel preparation and subsequent sequential execution of multiple shifts of undivided attention. This interpretation has the potential to bring together diverse findings from both the divided-attention and saccade preparation literature and provides a framework within which to integrate the broad spectrum of divided-attention methodologies.

  4. How to keep attention from straying: get engaged!

    PubMed

    Folk, Charles L; Ester, Edward F; Troemel, Kristof

    2009-02-01

    Previous research has suggested that the involuntary allocation of spatial attention to salient, irrelevant stimuli (i.e., attentional capture) is prevented when attention is in a focused state (e.g., Yantis & Jonides, 1990). Recent work has suggested that although focused attention may be necessary to prevent attentional capture by irrelevant stimuli, it is not sufficient (e.g., Folk, Leber, & Egeth, 2002). The present experiments provide evidence that attentional engagement, rather than attentional focusing, prevents capture. Observers performed a rapid serial visual presentation task in which they were asked to identify a target letter defined by color. Peripheral distractors that shared the color of the target produced evidence of attentional capture. This effect was completely eliminated, however, when the peripheral distractor was preceded by a central distractor designed to engage attention on the stream. It is concluded that attentional engagement serves to lock out capture by irrelevant, salient stimuli.

  5. A search for gamma-ray lines from the decay of Fe-59 in Supernova 1987A

    NASA Technical Reports Server (NTRS)

    Harris, M. J.; Leising, M. D.

    1994-01-01

    We have searched spectra of Supernova (SN) 1987A, accumulated during several 35-day intervals after the explosion by the Solar Maximum Mission (SMM) Gamma Ray Spectrometer (GRS), for gamma-ray lines at 1.099 and 1.292 MeV from the decay of Fe-59 which may have been produced in the progenitor's helium shell. We find no evidence for these lines, down to 3-sigma upper limits approximately = 7 x 10(exp -4) gamma/sq cm/s for the 1.099 MeV line, or approximately = 4.5 x 10(exp -4) gamma/sq cm/s for the 1.292 MeV line, in any 35-day interval. We derive a conservative 3-sigma upper limit on the mass fraction of Fe-59 in the helium shell of 2.9 x 10(exp -3).

  6. The bolometric light curve of SN 1987A. I - Results from ESO and CTIO U to Q0 photometry

    NASA Astrophysics Data System (ADS)

    Suntzeff, Nicholas B.; Bouchet, Patrice

    1990-02-01

    The UV, optical, and IR (UVOIR) bolometric luminosity curve of SN 1987A was derived from ESO, CTIO, and NASA Kuiper Airborne Observatory spectrophotometry for days 1-903 since outburst. It is found that the sum of this UVOIR flux and the high-energy flux predicted by models is consistent with the energy liberated by 0.071 solar mass of Co-56, with no need for additional energy sources for days 126-903 since outburst. By day 400, the flux at wavelegths larger than 5 microns was found to increase rapidly, and by day 650, the UVOIR flux shifted from the optical to a thermal IR source with a temperature of 200-300 K. The optical colors began to fade more rapidly at the time the FIR flux increased, consistent with dust formation local to the supernova.

  7. New Hubble Space Telescope Observations of High-Velocity Ly(alpha) and H(alpha) in SNR 1987A

    NASA Technical Reports Server (NTRS)

    Michael, Eli; McCray, Richard; Pun, C. S. J.; Borkowski, Kazimierz; Garnavich, Peter; Challis, Peter; Kirshner, Robert P.; Chevalier, Roger; Filippenko, Alexei V.; Fransson, Claes; Panagia, Nino; Phillips, Mark; Schmidt, Brian; Suntzef, Nicholas

    1998-01-01

    We describe and model high-velocity (approximately 15,000 km S(exp -1)) Ly Alpha and H Alpha emission from the supernova remnant SNR 1987A seen in 1997 September and October with the Space Telescope Imaging Spectrograph. Part of this emission comes from a reverse shock located at approximately 75% of the radius of the inner boundary ofthe innercircumstellar ring and confined within + or - 30 degrees of the equatorial plane. Departure from axisymmetry in the Ly Alpha and H Alpha emission correlates with that seen in nonthermal radio emission and reveals an asymmetry in the circumstellar gas distribution. We also see diffuse high-velocity Ly-Alpha emission from supernova debris inside the reverse shock that may be due to excitation by nonthermal particles accelerated by the shock.

  8. Neutrinos from SN 1987A - Implications for cooling of the nascent neutron star and the mass of the electron antineutrino

    NASA Technical Reports Server (NTRS)

    Loredo, Thomas J.; Lamb, Don Q.

    1989-01-01

    Data on neutrinos from SN 1987A are compared here with parameterized models of the neutrino emission using a consistent and straightforward statistical methodology. The empirically measured detector background spectra are included in the analysis, and the data are compared with a much wider variety of neutrino emission models than was explored previously. It is shown that the inferred neutrino emission model parameters are strongly correlated. The analysis confirms that simple models of the neutrino cooling of the nascent neutron star formed by the SN adequately explain the data. The inferred radius and binding energy of the neutron star are in excellent agreement with model calculations based on a wide range of equations of state. The results also raise the upper limit of the electron antineutrino rest mass to roughly 25 eV at the 95 percent confidence level, roughly 1.5-5 times higher than found previously.

  9. Correlation analysis of the data recorded by the Baksan, Kamioka, and Mont Blanc detectors during SN 1987A

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Badino, G.; Bologna, G.; Castagnoli, C.; Castellina, A.

    1989-12-01

    Results are presented on the correlation analysis of data recorded by the Baksan, Kamioka, and Mont Blanc underground detectors during the explosion of the SN 1987. The analysis was performed in order to reinvestigate the observations of two burst of several pulses each occurring several hours before first optical observations. The Mont Blanc computer detected a burst of five pulses about 8 hrs before the first optical observation, followed by a second burst of three pulses about 2 hrs later; Kamioka and Baksan reported observations of a burst made by eleven and five pulses, respectively, delayed by 4.7 hrs in comparison with the Mont Blanc burst. The results of the analysis strongly suggest that the event was real, occurring a few hours before the first optical observation of SN 1987A.

  10. Airborne spectrophotometry of SN 1987A from 1.7 to 12.6 microns - Time history of the dust continuum and line emission

    NASA Technical Reports Server (NTRS)

    Wooden, Diane H.; Rank, David M.; Bregman, Jesse D.; Witteborn, Fred C.; Tielens, A. G. G. M.; Cohen, Martin; Pinto, Philip A.; Axelrod, Timothy S.

    1993-01-01

    Spectrophotometric observations of SN 1987A from the Kuiper Airborne Observatory are presented for five epochs at 60, 260, 415, 615, and 775 days after the explosion. The low-resolution (lambda/Delta lambda = 50-100) spectra of SN 1987A are combined with data from other wavelengths to model the continuum, subtract the continuum from the spectra to determine line strengths and reveal molecular bands, separate the atomic continuum radiation from the dust continuum, and derive constraints on the grain temperatures and optical depths. A scenario for the evolution of SN 1987A and that of the ejecta from which it arises is obtained on the basis of the analysis of the continuum emission.

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

    PubMed

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

    2012-02-01

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

  12. Hard-X-ray emission lines from the decay of 44Ti in the remnant of supernova 1987A.

    PubMed

    Grebenev, S A; Lutovinov, A A; Tsygankov, S S; Winkler, C

    2012-10-18

    It is assumed that the radioactive decay of (44)Ti powers the infrared, optical and ultraviolet emission of supernova remnants after the complete decay of (56)Co and (57)Co (the isotopes that dominated the energy balance during the first three to four years after the explosion) until the beginning of active interaction of the ejecta with the surrounding matter. Simulations show that the initial mass of (44)Ti synthesized in core-collapse supernovae is (0.02-2.5) × 10(-4) solar masses (M circled dot). Hard X-rays and γ-rays from the decay of this (44)Ti have been unambiguously observed from Cassiopeia A only, leading to the suggestion that values of the initial mass of (44)Ti near the upper bound of the predictions occur only in exceptional cases. For the remnant of supernova 1987A, an upper limit to the initial mass of (44)Ti of <10(-3) M circled dot has been obtained from direct X-ray observations, and an estimate of (1-2) × 10(-4) M circled dot has been made from infrared light curves and ultraviolet spectra by complex and model-dependent computations. Here we report observations of hard X-rays from the remnant of supernova 1987A in the narrow band containing two direct-escape lines of (44)Ti at 67.9 and 78.4 keV. The measured line fluxes imply that this decay provided sufficient energy to power the remnant at late times. We estimate that the initial mass of (44)Ti was (3.1 ± 0.8) × 10(-4), which is near the upper bound of theoretical predictions.

  13. Interventions Targeting Attention in Young Children with Autism

    ERIC Educational Resources Information Center

    Patten, Elena; Watson, Linda R.

    2011-01-01

    Purpose: The ability to focus and sustain one's attention is critical for learning. Children with autism demonstrate unusual characteristics of attention from infancy. It is reasonable to assume that early anomalies in attention influence a child's developmental trajectories. Therapeutic interventions for autism often focus on core features of…

  14. Training Visual Attention

    ERIC Educational Resources Information Center

    Mulholland, Thomas B.

    1974-01-01

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

  15. Involuntary attentional capture by abrupt onsets

    NASA Technical Reports Server (NTRS)

    Remington, Roger W.; Johnston, James C.; Yantis, Steven

    1992-01-01

    Five experiments were carried out to examine the extent to which brief abrupt-onset visual stimuli involuntarily capture spatial attention. A fundumantal limitation on the conscious control of spatial attention is demonstrated. Data obtained reveal conditions under which the control of spatial attention is completely involuntary: attention is captured by an irrelevant event despite subjects' intentions to ignore the event. The paradigm used provided strong incentives to ignore the distracting abrupt onset, but these were insufficient to prevent capture. Results suggest that voluntary control of attention is limited to focusing attention in advance on locations, objects, or properties of interest. Under appropriate conditions, spatial attention can be involantarily drawn to abrupt-onset events despite the intention of subjects' to ignore them.

  16. The role of attention in subitizing.

    PubMed

    Railo, Henry; Koivisto, Mika; Revonsuo, Antti; Hannula, Minna M

    2008-04-01

    The process of rapidly and accurately enumerating small numbers of items without counting, i.e. subitizing, is often believed to rest on parallel preattentive processes. However, the possibility that enumeration of small numbers of items would also require attentional processes has remained an open question. The present study is the first that directly contrasts the preattentive and attentive models of subitizing. We used an inattentional blindness paradigm to manipulate the availability of attentional resources during enumeration. In the inattention condition, the items to be enumerated were presented unexpectedly while participants focused on a line length comparison task. Divided- and full-attention conditions were also included. The results showed that only numbers one and two could be enumerated when the effects of attention were minimized. Freeing attentional resources increased the enumeration accuracies considerably, including for number two. The results suggest that even for enumerating small numbers, the attentional demands increase as the number of objects increases.

  17. Enacting Attention: Concentration and Shared Focus in Montessori Classrooms

    ERIC Educational Resources Information Center

    Epstein, Paul

    2012-01-01

    Concentration is a "sine qua non," a hallmark, of a Montessori Casa program. Yet, it happens that some children do not concentrate. They do not engage with the materials in the classic pattern of normalization. They are not challenged by ADD, ADHD, or a variant of sensory integration spectrum disorder. Instead of working alone, they prefer the…

  18. Researchers focus attention on coastal response to climate change

    NASA Astrophysics Data System (ADS)

    Anderson, John; Rodriguez, Antonio; Fletcher, Charles; Fitzgerald, Duncan

    The world's population has been steadily migrating toward coastal cities, resulting in severe stress on coastal environments. But the most severe human impact on coastal regions may lie ahead as the rate of global sea-level rise accelerates and the impacts of global warming on coastal climates and oceanographic dynamics increase [Varekamp and Thomas, 1998; Hinrichsen, 1999; Goodwin et al., 2000]. Little is currently being done to forecast the impact of global climate change on coasts during the next century and beyond. Indeed, there are still many politicians, and even some scientists, who doubt that global change is a real threat to society.

  19. Overcoming Content-Associated Challenges Using Attention-Focused Methods

    ERIC Educational Resources Information Center

    Lebec, Michael T.; Kesteloot, Lauren

    2015-01-01

    A common challenge in higher education is teaching required content for which students traditionally have lower levels of interest. Physical therapist education programs experience this challenge when training entry-level students to document in the medical record. The authors compared learning outcomes among physical therapy students taught…

  20. A taxonomy of external and internal attention.

    PubMed

    Chun, Marvin M; Golomb, Julie D; Turk-Browne, Nicholas B

    2011-01-01

    Attention is a core property of all perceptual and cognitive operations. Given limited capacity to process competing options, attentional mechanisms select, modulate, and sustain focus on information most relevant for behavior. A significant problem, however, is that attention is so ubiquitous that it is unwieldy to study. We propose a taxonomy based on the types of information that attention operates over--the targets of attention. At the broadest level, the taxonomy distinguishes between external attention and internal attention. External attention refers to the selection and modulation of sensory information. External attention selects locations in space, points in time, or modality-specific input. Such perceptual attention can also select features defined across any of these dimensions, or object representations that integrate over space, time, and modality. Internal attention refers to the selection, modulation, and maintenance of internally generated information, such as task rules, responses, long-term memory, or working memory. Working memory, in particular, lies closest to the intersection between external and internal attention. The taxonomy provides an organizing framework that recasts classic debates, raises new issues, and frames understanding of neural mechanisms.

  1. Attentional Processes in Autism.

    ERIC Educational Resources Information Center

    Goldstein, Gerald; Johnson, Cynthia R.; Minshew, Nancy J.

    2001-01-01

    Attention processes in 103 children and adults with high functioning autism were compared with a matched control group using a battery of attention measures. Differences were found only on tasks which placed demands on cognitive flexibility or psychomotor speed, suggesting that purported attention deficits in autism may actually be primary…

  2. Children's Attention to Television.

    ERIC Educational Resources Information Center

    Anderson, Daniel R.

    This paper summarizes a series of studies investigating the nature of children's attention to television. In a study of distraction, children's visual attention was found to be affected by distractions in the environment, by the nature of the program and by the viewer's own patterns of attending. A study of the general patterns of attention to…

  3. Attention competition with advertisement

    NASA Astrophysics Data System (ADS)

    Cetin, Uzay; Bingol, Haluk O.

    2014-09-01

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

  4. Attention competition with advertisement.

    PubMed

    Cetin, Uzay; Bingol, Haluk O

    2014-09-01

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

  5. Electrophoretic Focusing

    NASA Technical Reports Server (NTRS)

    Snyder, Robert S.

    2001-01-01

    Electrophoretic focusing is a new method of continuous flow electrophoresis that introduces precision flow control to achieve high resolution separations. The electric field is applied perpendicular to an incoming sample lamina and buffer but also perpendicular to the broad faces of the thin rectangular chamber. A uniform fluid cross-flow then enters and exits the separation chamber through the same broad faces which are porous. A balance is achieved by adjusting either the electric field or the cross-flow so the desired sample fraction with its specific migration velocity encounters an opposing flow of the same velocity. Applying an electric field transverse to the incoming sample lamina and opposing this field with a carefully configured buffer flow, a sample constituent can be selected and focused into a narrow stream for subsequent analysis. Monotonically changing either electric field or buffer cross-flow will yield a scan of all constituents of the sample. Stopping the scan increases the collection time for minor constituents to improve their analysis. Using the high voltage gradients and/or cross-flow to rapidly deflect extraneous sample through the porous screens and into either of the side (purge) chambers, the selected sample is focused in the center plane of the separation chamber and collected without contact or interaction with the separation chamber walls. Results will be presented on the separation of a range of materials including dyes, proteins, and monodisperse polystyrene latexes. Sources of sample dispersion inherent in other electrokinetic techniques will be shown to be negligible for a variety of sample concentrations, buffer properties and operating conditions.

  6. Attention Alters Perceived Attractiveness.

    PubMed

    Störmer, Viola S; Alvarez, George A

    2016-04-01

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

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

    PubMed Central

    Viviani, Roberto

    2013-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  9. Neural Mechanisms of Attention

    DTIC Science & Technology

    1993-05-21

    315-335). : Elsevier Science Publishers BV. Andrew, R.J. (1991). Testosterone, attention and memory. In P. Bateson (Ed.),The development and...reflects global stimulus properties. Nature, M,334-337. Gregory , S. D., Heath, J. A., & Rosenberg, M. E. (1989). Does selective attention influence...properties. Nature, 338,334-337. Gregory , S. D., Heath, J. A., & Rosenberg, M. E. (1989). Does selective attention influence the brain-stem auditory evoked

  10. Personality and Selective Attention.

    DTIC Science & Technology

    1980-03-28

    hyperactivity in children (Rosenthal & Allen, 1978) to impotence (Geer & Fuhr, 1976). Deficits in attention have been shown to be important in the...PERSONALITY AND SELECTIVE ATTENTION .(U) MAR 80 S L NIELSEN. 1 G SARASON N000lN-75-C-0905 UNCLASSIFIED SCS-LS-010 NL Llhhhhhhhhhlm 11111 . , L28...selective attentio . However, the theorizing of some cognitive psychologists as well as r ent research in selective attention , though particularly

  11. Internal and external attention and the default mode network.

    PubMed

    Scheibner, Hannah J; Bogler, Carsten; Gleich, Tobias; Haynes, John-Dylan; Bermpohl, Felix

    2017-03-01

    Focused attention meditations have been shown to improve psychological health and wellbeing and are nowadays an integral part of many psychotherapies. While research on the neural correlates of focused attention meditation is increasing, findings vary on whether meditations are associated with high or low activity in the default mode network (DMN). To clarify the relationship between focused attention meditation and the activity in DMN regions, it may be helpful to distinguish internal and external attention as well as different phases within one meditation: During focused attention meditation, the practitioner switches between mindful attention, mind-wandering and refocusing. Here, we employed a thought-probe paradigm to study the neural correlates of these different phases. Twenty healthy, meditation naïve participants were introduced to external (mindfulness of sound) and internal (mindfulness of breathing) attention meditation and then practiced the meditation at home for four consecutive days. They then performed the same focused attention meditations during fMRI scanning, in four runs alternating between internal and external attention. At pseudorandom intervals, participants were asked whether they had just been focused on the task (mindful attention) or had been distracted (mind-wandering). During mindful attention, brain regions typically associated with the DMN, such as the medial prefrontal cortex, posterior cingulate cortex and left temporoparietal junction showed significantly less neural activation compared to mind-wandering phases. Reduced activity of the DMN was found during both external and internal attention, with stronger deactivation in the posterior cingulate cortex during internal attention compared to external attention. Moreover, refocusing after mind-wandering was associated with activity in the left inferior frontal gyrus. Our results support the theory that mindful attention is associated with reduced DMN activity compared to mind

  12. Active suppression after involuntary capture of attention.

    PubMed

    Sawaki, Risa; Luck, Steven J

    2013-04-01

    After attention has been involuntarily captured by a distractor, how is it reoriented toward a target? One possibility is that attention to the distractor passively fades over time, allowing the target to become attended. Another possibility is that the captured location is actively suppressed so that attention can be directed toward the target location. The present study investigated this issue with event-related potentials (ERPs), focusing on the N2pc component (a neural measure of attentional deployment) and the Pd component (a neural measure of attentional suppression). Observers identified a color-defined target in a search array, which was preceded by a task-irrelevant cue array. When the cue array contained an item that matched the target color, this item captured attention (as measured both behaviorally and with the N2pc component). This capture of attention was followed by active suppression (indexed by the Pd component), and this was then followed by a reorienting of attention toward the target in the search array (indexed by the N2pc component). These findings indicate that the involuntary capture of attention by a distractor is followed by an active suppression process that presumably facilitates the subsequent voluntary orienting of attention to the target.

  13. Gamma rays, X-rays, and optical light from the cobalt and the neutron star in SN 1987A

    NASA Technical Reports Server (NTRS)

    Kumagai, Shiomi; Shigeyama, Toshikazu; Nomoto, Ken'ichi; Itoh, Masayuki; Nishimura, Jun

    1989-01-01

    Recent developments in modeling the X-ray and gamma-ray emission from SN 1987A are discussed by taking into account both the decaying cobalt and the buried neutron star. The light curve and the spectra evolution of X-rays and gamma-rays are well modeled up to day of about 300 if mixing of Co-56 into hydrogen-rich envelope is assumed. However, the 16-28 keV flux observed by Ginga declines very slowly, whereas the spherical mixing model predicts that the flux should have decreased by a large factor at t greater than 300d. It is shown that this problem can be solved if the photoelectric absorption of X-rays is effectively reduced as a result of the formation of chemically inhomogeneous clumps. Based on the adopted hydrodynamical model and the abundance distribution, predictions are offered for future optical, X-ray, and gamma-ray light curves by taking into account other radioactive sources and various types of the central source, e.g., a buried neutron star accreting the reinfalling material or an isolated pulsar.

  14. Reduced upper limits on the equivalent width of interstellar Li I 670.8 towards SN 1987 A

    NASA Astrophysics Data System (ADS)

    Baade, D.; Cristiani, S.; Lanz, T.; Malaney, R. A.; Sahu, K. S.; Vladilo, G.

    1991-11-01

    A new search for interstellar Li I 670.8 along the line of sight to SN 1987 A has been carried out using all 34 known high-resolution Reticon spectra obtained at the European Southern Observatory. The most probably 3-sigma detection limit in equivalent width is 7.3 x 10 exp -6 nm. For the cloud at radial velocity +286 km/s, standard relations then imply a maximum abundance, Li/H, of 1.7 x 10 exp -11 in the gaseous interstellar medium of the LMC. If depletion to dust grains is the same for both lithium and potassium, this figure has to be increased by 1.1 dex. Accordingly, conventional present-day reasoning suggests that the elemental abundance of lithium does not exceed 2.7 x 10 exp -10. However, the cumulative uncertainties are such that a primordial abundance which is an order of magnitude higher is not firmly ruled out. Constraints on primordial nucleosynthesis models are, therefore, only weak.

  15. High-resolution mid-infrared spectra of Co II, Ni I, and Fe II in SN 1987A

    NASA Technical Reports Server (NTRS)

    Jennings, D. E.; Boyle, R. J.; Wiedemann, G. R.; Moseley, S. H.

    1993-01-01

    Ground-based infrared observations of SN 1987A on day 612 after the explosion have yielded resolved line profiles of Co II, Ni I, Fe II at 10.52, 11.31, and 17.94 micron, respectively. The spectra were taken at a resolving power of about 1000 with an array grating spectrometer on the 4 m telescope of Cerro Tololo Inter-American Observatory. Based on the observed line intensities we have estimated the minimum mass of each ion: M(Co II) = (6.0 +/- 1.8) x 10 exp -5 solar mass; M(Ni I) = (1.1 +/- 0.1) x 10 exp -3 solar mass; and M(Fe II) = (8.0 +/- 1.5) x 10 exp -3 solar mass. From these we infer total masses for cobalt, nickel, and iron in the ejecta. The nickel and iron line profiles are markedly asymmetric. We interpret these as arising from two components, one centered on the stellar rest velocity with an approximately 3250 km/s full width, and the second at about +1200 km/s with an approximately 1100 km/s full width. The asymmetry may represent a large-scale fracturing of the ejecta by Rayleigh-Taylor instabilities.

  16. High-resolution mid-infrared spectra of Co II, Ni I, and Fe II in SN 1987A

    NASA Astrophysics Data System (ADS)

    Jennings, D. E.; Boyle, R. J.; Wiedemann, G. R.; Moseley, S. H.

    1993-05-01

    Ground-based infrared observations of SN 1987A on day 612 after the explosion have yielded resolved line profiles of Co II, Ni I, Fe II at 10.52, 11.31, and 17.94 micron, respectively. The spectra were taken at a resolving power of about 1000 with an array grating spectrometer on the 4 m telescope of Cerro Tololo Inter-American Observatory. Based on the observed line intensities we have estimated the minimum mass of each ion: M(Co II) = (6.0 +/- 1.8) x 10 exp -5 solar mass; M(Ni I) = (1.1 +/- 0.1) x 10 exp -3 solar mass; and M(Fe II) = (8.0 +/- 1.5) x 10 exp -3 solar mass. From these we infer total masses for cobalt, nickel, and iron in the ejecta. The nickel and iron line profiles are markedly asymmetric. We interpret these as arising from two components, one centered on the stellar rest velocity with an approximately 3250 km/s full width, and the second at about +1200 km/s with an approximately 1100 km/s full width. The asymmetry may represent a large-scale fracturing of the ejecta by Rayleigh-Taylor instabilities.

  17. Spectral line profiles of nickel and argon in supernova 1987A - Expansion velocity and electron scattering effects

    NASA Technical Reports Server (NTRS)

    Witteborn, F. C.; Bregman, J. D.; Wooden, D. H.; Pinto, P. A.; Rank, D. M.

    1989-01-01

    Spectra of SN 1987A showing the Ni II 6.634-micron and Ar II 6.983-micron fine-structure lines were obtained from the Kuiper Airborne Observatory in April 1988. The signal-to-noise ratio of 100 near the peaks and resolving power of 200 are sufficient to show the average velocity of expansion from the core of about 1400 km/s and to indicate the range of velocities. An asymmetry in the profiles of both lines and a redshift of the line centroids of about 440 km/s above the 280-km/s recessional velocity of the LMC can be explained in terms of scattering of the photons by electrons in the expanding hydrogen envelope of the supernova. A mass of 0.0030 solar masses of Ni II can be deduced from the line strength of the Ni II line and a mass of 0.0009 solar masses of Ar II from the Ar II line strength.

  18. Attention and Intelligence.

    ERIC Educational Resources Information Center

    Lewis, Michael; Brooks-Gunn, Jeanne

    1981-01-01

    The authors discuss methodological and theoretical issues in psychological investigations of infant attention, fixation times, habituation, and intelligence. A consensus on how to measure individual differences in habituation has not been reached. The relation between IQ and attention is discussed. (RD)

  19. Attention Deficit Hyperactivity Disorder.

    ERIC Educational Resources Information Center

    Durbin, Karen

    1993-01-01

    This brief paper summarizes information on attention deficit hyperactivity disorder (ADHD). First it identifies eight common characteristics of this disorder: (1) inattentiveness and distractibility, (2) impulsiveness, (3) hyperactivity, (4) attention-demanding behavior, (5) learning difficulties, (6) coordination difficulties, (7) unacceptable…

  20. Embodied Infant Attention

    ERIC Educational Resources Information Center

    Robertson, Steven S.; Johnson, Sarah L.

    2009-01-01

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

  1. Special attention network

    NASA Astrophysics Data System (ADS)

    Indekeu, J. O.

    2004-02-01

    In this Note a social network model for opinion formation is proposed in which a person connected to q partners pays an attention 1/ q to each partner. The mutual attention between two connected persons i and j is taken equal to the geometric mean 1/ q iq j. Opinion is represented as usual by an Ising spin s=±1 and mutual attention is given through a two-spin coupling J ij=JQ/ q iq j, Q being the average connectivity in the network. Connectivity diminishes attention and only persons with low connectivity can pay special attention to each other leading to a durable common (or opposing) opinion. The model is solved in “mean-field” approximation and a critical “temperature” Tc proportional to JQ is found, which is independent of the number of persons N, for large N.

  2. Contingent Attentional Capture

    NASA Technical Reports Server (NTRS)

    Remington, Roger; Folk, Charles L.

    1994-01-01

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

  3. Interaction of attention and graphomotor functions in children with attention deficit hyperactivity disorder.

    PubMed

    Lange, K W; Tucha, L; Walitza, S; Gerlach, M; Linder, M; Tucha, O

    2007-01-01

    The present article provides a review of a series of studies in children with attention deficit hyperactivity disorder (ADHD) concerning (1) the effects of methylphenidate on various attentional functions, (2) the stimulant-induced changes of both qualitative and quantitative (i.e. kinematic) aspects of handwriting, (3) the interaction between conscious control of handwriting and fluency of handwriting movements, and (4) possible therapeutic approaches to graphomotor disturbances. Children with ADHD showed impairments in various aspects of attentional functioning. Pharmacological treatment of ADHD children with methylphenidate resulted in marked improvements of various components of attentional functioning. In comparison to the performance following the withdrawal of methylphenidate, children with ADHD on methylphenidate displayed a significant improvement in task accuracy in the areas of vigilance, divided attention, selective attention (inhibition, focused attention and integration of sensory information) and flexibility. However, the comparison with healthy children revealed considerable deficits regarding vigilance, divided attention, flexibility and selective attention (focused attention and integration of sensory information) in children with ADHD on methylphenidate. The comparison of writing movements of children on and off methylphenidate revealed that medication resulted in a better handwriting, but a deterioration in handwriting fluency as assessed by kinematic analysis. Children with ADHD may use their increased attentional capacities to focus on skills (e.g. handwriting) that are independent of conscious control or may even be disturbed by attention. The findings summarized in this paper indicate, therefore, that administration of methylphenidate alone is insufficient in the treatment of children with ADHD. Children with ADHD may benefit from instructions on how to best use their improved attentional capacities.

  4. Supernova 1987A!

    PubMed

    Woosley, S E; Phillips, M M

    1988-05-06

    Light from the brightest supernova in almost 400 years arrived at Earth on 23 February 1987. Although located 160,000 light years away in a satellite galaxy of our own known as the Large Magellanic Cloud, this supernova's relative proximity compared to all others that have been observed in modern times has allowed observations, which were never possible before, to be made from space, from detectors on the ground and carried by balloons and airplanes, and from neutrino detectors deep underground. What emerges is a greater understanding of one of the most violent events in the universe, the death of a massive star. For the most part, theoretical expectations have been borne out, but some major surprises have made the event all the more fascinating.

  5. Minds "at attention": mindfulness training curbs attentional lapses in military cohorts.

    PubMed

    Jha, Amishi P; Morrison, Alexandra B; Dainer-Best, Justin; Parker, Suzanne; Rostrup, Nina; Stanley, Elizabeth A

    2015-01-01

    We investigated the impact of mindfulness training (MT) on attentional performance lapses associated with task-unrelated thought (i.e., mind wandering). Periods of persistent and intensive demands may compromise attention and increase off-task thinking. Here, we investigated if MT may mitigate these deleterious effects and promote cognitive resilience in military cohorts enduring a high-demand interval of predeployment training. To better understand which aspects of MT programs are most beneficial, three military cohorts were examined. Two of the three groups were provided MT. One group received an 8-hour, 8-week variant of Mindfulness-based Mind Fitness Training (MMFT) emphasizing engagement in training exercises (training-focused MT, n = 40), a second group received a didactic-focused variant emphasizing content regarding stress and resilience (didactic-focused MT, n = 40), and the third group served as a no-training control (NTC, n = 24). Sustained Attention to Response Task (SART) performance was indexed in all military groups and a no-training civilian group (CIV, n = 45) before (T1) and after (T2) the MT course period. Attentional performance (measured by A', a sensitivity index) was lower in NTC vs. CIV at T2, suggesting that performance suffers after enduring a high-demand predeployment interval relative to a similar time period of civilian life. Yet, there were significantly fewer performance lapses in the military cohorts receiving MT relative to NTC, with training-focused MT outperforming didactic-focused MT at T2. From T1 to T2, A' degraded in NTC and didactic-focused MT but remained stable in training-focused MT and CIV. In sum, while protracted periods of high-demand military training may increase attentional performance lapses, practice-focused MT programs akin to training-focused MT may bolster attentional performance more than didactic-focused programs. As such, training-focused MT programs should be further examined in cohorts experiencing

  6. Using frequency tagging to quantify attentional deployment in a visual divided attention task.

    PubMed

    Toffanin, Paolo; de Jong, Ritske; Johnson, Addie; Martens, Sander

    2009-06-01

    Frequency tagging is an EEG method based on the quantification of the steady state visual evoked potential (SSVEP) elicited from stimuli which flicker with a distinctive frequency. Because the amplitude of the SSVEP is modulated by attention such that attended stimuli elicit higher SSVEP amplitudes than do ignored stimuli, the method has been used to investigate the neural mechanisms of spatial attention. However, up to now it has not been shown whether the amplitude of the SSVEP is sensitive to gradations of attention and there has been debate about whether attention effects on the SSVEP are dependent on the tagging frequency used. We thus compared attention effects on SSVEP across three attention conditions-focused, divided, and ignored-with six different tagging frequencies. Participants performed a visual detection task (respond to the digit 5 embedded in a stream of characters). Two stimulus streams, one to the left and one to the right of fixation, were displayed simultaneously, each with a background grey square whose hue was sine-modulated with one of the six tagging frequencies. At the beginning of each trial a cue indicated whether targets on the left, right, or both sides should be responded to. Accuracy was higher in the focused- than in the divided-attention condition. SSVEP amplitudes were greatest in the focused-attention condition, intermediate in the divided-attention condition, and smallest in the ignored-attention condition. The effect of attention on SSVEP amplitude did not depend on the tagging frequency used. Frequency tagging appears to be a flexible technique for studying attention.

  7. HST-COS OBSERVATIONS OF HYDROGEN, HELIUM, CARBON, AND NITROGEN EMISSION FROM THE SN 1987A REVERSE SHOCK

    SciTech Connect

    France, Kevin; Penton, Steven V.; McCray, Richard; Kirshner, Robert P.; Challis, Peter; Laming, Martin J.; Bouchet, Patrice; Garnavich, Peter M.; Fransson, Claes; Larsson, Josefin; Lundqvist, Peter; Sollerman, Jesper; Heng, Kevin; Lawrence, Stephen; Panagia, Nino; Pun, Chun S. J.; Smith, Nathan; Sonneborn, George; Sugerman, Ben; and others

    2011-12-20

    We present the most sensitive ultraviolet observations of Supernova 1987A to date. Imaging spectroscopy from the Hubble Space Telescope-Cosmic Origins Spectrograph shows many narrow ({Delta}v {approx} 300 km s{sup -1}) emission lines from the circumstellar ring, broad ({Delta}v {approx} 10-20 Multiplication-Sign 10{sup 3} km s{sup -1}) emission lines from the reverse shock, and ultraviolet continuum emission. The high signal-to-noise ratio (>40 per resolution element) broad Ly{alpha} emission is excited by soft X-ray and EUV heating of mostly neutral gas in the circumstellar ring and outer supernova debris. The ultraviolet continuum at {lambda} > 1350 A can be explained by H I two-photon (2s {sup 2} S{sub 1/2}-1s {sup 2} S{sub 1/2}) emission from the same region. We confirm our earlier, tentative detection of N V {lambda}1240 emission from the reverse shock and present the first detections of broad He II {lambda}1640, C IV {lambda}1550, and N IV] {lambda}1486 emission lines from the reverse shock. The helium abundance in the high-velocity material is He/H = 0.14 {+-} 0.06. The N V/H{alpha} line ratio requires partial ion-electron equilibration (T{sub e} /T{sub p} Almost-Equal-To 0.14-0.35). We find that the N/C abundance ratio in the gas crossing the reverse shock is significantly higher than that in the circumstellar ring, a result that may be attributed to chemical stratification in the outer envelope of the supernova progenitor. The N/C abundance may have been stratified prior to the ring expulsion, or this result may indicate continued CNO processing in the progenitor subsequent to the expulsion of the circumstellar ring.

  8. Infrared and X-Ray Evidence for Circumstellar Grain Destruction by the Blast Wave of Supernova 1987A

    NASA Technical Reports Server (NTRS)

    Dwek, Eliahu; Arendt, Richard G.; Bouchet, Patrice; Burrows, David N.; Challis, Peter; Danziger, John; DeBuizer James M.; Gehrz, Robert D.; Kirshner, Robert P.; McCray, Richard; Park, Sangwok; Polomski, Elisha; Woodward, Charles

    2007-01-01

    Multiwavelength observations of supernova remnant (SNR) 1987A show that its morphology and luminosity are rapidly changing at X-ray, optical, infrared, and radio wavelengths as the blast wave from the explosion expands into the circumstellar equatorial ring, produced by mass loss from the progenitor star. The observed infrared (IR) radiation arises from the interaction of dust grains that formed in mass outflow with the soft X-ray emitting plasma component of the shocked gas. Spitzer IRS spectra at 5 - 30 microns taken on day 6190 since the explosion show that the emission arises from approx. 1.1 x 10(exp -6) solar mass of silicate grains radiating at a temperature of approx. 180+/-(15-20) K. Subsequent observations on day 7137 show that the IR flux had increased by a factor of 2 while maintaining an almost identical spectral shape. The observed IR-to-X-ray flux ratio (IRX) is consistent with that of a dusty plasma with standard LMC dust abundances. This flux ratio has decreased by a factor of approx. 2 between days 6190 and 7137, providing the first direct observation of the ongoing destruction of dust in an expanding SN blast wave on dynamic time scales. Detailed models consistent with the observed dust temperature, the ionization fluence of the soft X-ray emission component, and the evolution of IRX suggest that the radiating si1icate grains are immersed in a 3.5 x 10(exp 6) K plasma with a density of (0.3 - 1) x 10(exp 4)/cu cm, and have a size distribution that is confined to a narrow range of radii between 0.02 and 0.2 microns. Smaller grains may have been evaporated by the initial UV flash from the supernova.

  9. HST-COS Observations on Hydrogen, Helium, Carbon, and Nitrogen Emission from the SN 1987A Reverse Shock

    NASA Technical Reports Server (NTRS)

    France, Kevin; McCray, Richard; Penton, Steven V.; Kirshner, Robert P.; Challis, Peter; Laming, J. Martin; Bouchet, Patrice; Chevalier, Roger; Garnavich, Peter M.; Fransson, Claes; Heng, Kevin; Larsson, Josefin; Lawrence, Stephen; Lundqvist, Peter; Panagia, Nino; Pun, Chun S. J.; Smith, Nathan; Sollerman, Jesper; Sonneborn, George; Sugerman, Ben; Wheeler, J. Craig

    2011-01-01

    We present the most sensitive ultraviolet observations of Supernova 1987 A to date. Imaging spectroscopy from the Hubble Space Telescope-Cosmic Origins Spectrograph shows many narrow (Delta v approximates 300 km/s) emission lines from the circumstellar ring, broad Delta v approximates 10-20 x 10(exp 3) km/s) emission lines from the reverse shock, and ultraviolet continuum emission. The high signal-to-noise ratio (>40 per resolution element) broad Ly-alpha emission is excited by soft X-ray and EUV heating of mostly neutral gas in the circumstellar ring and outer supernova debris. The ultraviolet continuum at lambda > 1350 A can be explained by H-I two-photon (2s(exp 2)S(sub 1/2)-l(exp 2)S(sub 1/2)) emission from the same region. We confirm our earlier, tentative detection of N V lambda 1240 emission from the reverse shock and present the first detections of broad He II lambda1640, C IV lambda 1550, and N IV ] lambda1486 emission lines from the reverse shock. The helium abundance in the high-velocity material is He/H = 0.14 +/- 0.06. The N V /H alpha line ratio requires partial ion-electron equilibration (T(sub e)/T(sub p) approximately equal to 0.14-0.35). We find that the N/C abundance ratio in the gas crossing the reverse shock is significantly higher than that in the circumstellar ring, a result that may be attributed to chemical stratification in the outer envelope of the supernova progenitor. The N/C abundance may have been stratified prior to the ring expUlsion, or this result may indicate continued CNO processing in the progenitor subsequent to the expUlsion of the circumstellar ring.

  10. Attention in dichoptic and binocular vision

    NASA Technical Reports Server (NTRS)

    Kimchi, Ruth; Rubin, Yifat; Gopher, Daniel; Raij, David

    1989-01-01

    The ability of human subjected to mobilize attention and cope with task requirements under dichoptic and binocular viewing was investigated in an experiment employing a target search task. Subjects were required to search for a target at either the global level, the local level, or at both levels of a compound stimulus. The tasks were performed in a focused attention condition in which subjects had to attend to the stimulus presented to one eye/field (under dichoptic and binocular viewings, respectively) and to ignore the stimulus presented to the irrelevant eye/field, and in a divided attention condition in which subjects had to attend to the stimuli presented to both eyes/fields. Subjects' performance was affected mainly by attention conditions which interacted with task requirements, rather than by viewing situation. An interesting effect of viewing was found for the local-directed search task in which the cost of dividing attention was higher under binocular than under dichoptic viewing.

  11. Visual Attention and Applications in Multimedia Technologies

    PubMed Central

    Le Callet, Patrick; Niebur, Ernst

    2013-01-01

    Making technological advances in the field of human-machine interactions requires that the capabilities and limitations of the human perceptual system are taken into account. The focus of this report is an important mechanism of perception, visual selective attention, which is becoming more and more important for multimedia applications. We introduce the concept of visual attention and describe its underlying mechanisms. In particular, we introduce the concepts of overt and covert visual attention, and of bottom-up and top-down processing. Challenges related to modeling visual attention and their validation using ad hoc ground truth are also discussed. Examples of the usage of visual attention models in image and video processing are presented. We emphasize multimedia delivery, retargeting and quality assessment of image and video, medical imaging, and the field of stereoscopic 3D images applications. PMID:24489403

  12. Attention Deficit Hyperactivity Disorder

    MedlinePlus

    ... If so, your child may have attention deficit hyperactivity disorder (ADHD). Nearly everyone shows some of these ... children. The main features of ADHD are Inattention Hyperactivity Impulsivity No one knows exactly what causes ADHD. ...

  13. Unmasking the Attentional Blink

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  14. Understanding and Working with Attention Deficit Disorder Students

    ERIC Educational Resources Information Center

    Buttery, Thomas J.

    2009-01-01

    From a holistic perspective the term attention refers to a student's capacity to focus, direct and sustain their attention on a particular stimulus within their environment for a significant period of time. The development of students' attention spans develops progressively from the time they enter school. From the beginning some students have…

  15. Attention-like processes in insects

    PubMed Central

    2016-01-01

    Attention is fundamentally important for sensory systems to focus on behaviourally relevant stimuli. It has therefore been an important field of study in human psychology and neuroscience. Primates, however, are not the only animals that might benefit from attention-like processes. Other animals, including insects, also have to use their senses and select one among many stimuli to forage, avoid predators and find mates. They have evolved different mechanisms to reduce the information processed by their brains to focus on only relevant stimuli. What are the mechanisms used by insects to selectively attend to visual and auditory stimuli? Do these attention-like mechanisms achieve the same functions as they do in primates? To investigate these questions, I use an established framework for investigating attention in non-human animals that proposes four fundamental components of attention: salience filters, competitive selection, top-down sensitivity control and working memory. I discuss evidence for each of these component processes in insects and compare the characteristics of these processes in insects to what we know from primates. Finally, I highlight important outstanding questions about insect attention that need to be addressed for us to understand the differences and similarities between vertebrate and insect attention. PMID:27852803

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

    ERIC Educational Resources Information Center

    Hanania, Rima; Smith, Linda B.

    2010-01-01

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

  17. A Longitudinal Analysis of Joint Attention and Language Development in Young Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Tek, Saime

    2010-01-01

    Joint attention (JA), which occurs when two individuals focus on the same object or event, plays a critical role in social and language development. Two major kinds of joint attention have been observed: response to joint attention (RJA), in which children follow the attentional focus of their social partners, and initiation of joint attention…

  18. Exogenous spatial attention decreases audiovisual integration.

    PubMed

    Van der Stoep, N; Van der Stigchel, S; Nijboer, T C W

    2015-02-01

    Multisensory integration (MSI) and spatial attention are both mechanisms through which the processing of sensory information can be facilitated. Studies on the interaction between spatial attention and MSI have mainly focused on the interaction between endogenous spatial attention and MSI. Most of these studies have shown that endogenously attending a multisensory target enhances MSI. It is currently unclear, however, whether and how exogenous spatial attention and MSI interact. In the current study, we investigated the interaction between these two important bottom-up processes in two experiments. In Experiment 1 the target location was task-relevant, and in Experiment 2 the target location was task-irrelevant. Valid or invalid exogenous auditory cues were presented before the onset of unimodal auditory, unimodal visual, and audiovisual targets. We observed reliable cueing effects and multisensory response enhancement in both experiments. To examine whether audiovisual integration was influenced by exogenous spatial attention, the amount of race model violation was compared between exogenously attended and unattended targets. In both Experiment 1 and Experiment 2, a decrease in MSI was observed when audiovisual targets were exogenously attended, compared to when they were not. The interaction between exogenous attention and MSI was less pronounced in Experiment 2. Therefore, our results indicate that exogenous attention diminishes MSI when spatial orienting is relevant. The results are discussed in terms of models of multisensory integration and attention.

  19. IMAGING ATTENTION NETWORKS1

    PubMed Central

    Posner, Michael I.

    2012-01-01

    The study of attention has largely been about how to select among the various sensory events but also involves the selection among conflicting actions. Prior to the late 1980s, locating bottlenecks between sensory input and response dominated these studies, a different view was that attentional limits involved the importance of maintaining behavioral coherence rather than resulting from a bottleneck. In both cases ideas of resource limits taken over from economics were important. Early evidence relating to the anatomy of attention came from neurological investigations of lesioned patients, but the major impetus for the anatomical approach came from neuroimaging studies that provided evidence of brain networks related to orienting to sensory events and control of response tendencies. The presence of a functional anatomy has supported studies of the development of attention networks and the role of neuromodulators and genetic poymorphisms in their construction. Together these developments have enhanced our understanding of attention and paved the way for significant applications to education, pathology and prevention of mental illness. PMID:22227132

  20. The confirmation of the 2.1 ms candidate for PSR1987A and the 1000-hour Arecibo Piggyback ms Pulsar Survey. Final report

    SciTech Connect

    Middleditch, J.; Kulkarni, S.

    1995-06-01

    The authors objectives included (1) The confirmation of the 2.1 ms candidate for the pulsar (PSR1987A) in Supernova 1987A (SN1987A), and, provided the candidate is real (and if it is real, the authors have successfully tracked its frequency for two years), (2) to determine the nature of its spindown, including whether it is a result of gravitational radiation (GR), inertia transfer associated with differential rotation, changes in the moment of inertia, or the affects of a wide binary system. The authors have decent results to support the supposition that the spindown of this candidate for PSR1987A is indeed due almost entirely to gravitational radiation. The observations with the University of Tasmania 1-m telescope were successful in detecting the 2.1 ms candidate pulsar on at least three occasions. They can conclude that there is now little doubt that SN1987A was the result of a merger of two giant stars which resulted in: (1) The ejection of the three rings during a common-envelope/Roche lobe overflow phase which may have lasted only 300 to 1,000 years some 30,000 years ago, (2) The extreme mixing of the elements during the spiraling in phase of the two {approximately}0.7 solar mass white dwarf cores, (3) The blue supergiant nature of the progenitor star, Sk-69 202, and (4) the formation of a weak-field ms pulsar spinning every 2.1 ms. The importance of this finding is nearly inestimable. The authors now know that neutron stars can sustain or grow oblatenesses of 5 parts in ten million some 5-7 years after their explosive birth, and that pulsars born in such a way can outshine all other compact solar mass type objects by an order of magnitude in nearly pure gravitational radiation. They know now that most weak field ms, pulsars are born in such core mergers, which explains their drastic overabundance in the globular clusters relative to the low mass X-ray binaries, which were previously, and erroneously thought of as their progenitors.

  1. Cognitive Penetration and Attention

    PubMed Central

    Gross, Steven

    2017-01-01

    Zenon Pylyshyn argues that cognitively driven attentional effects do not amount to cognitive penetration of early vision because such effects occur either before or after early vision. Critics object that in fact such effects occur at all levels of perceptual processing. We argue that Pylyshyn’s claim is correct—but not for the reason he emphasizes. Even if his critics are correct that attentional effects are not external to early vision, these effects do not satisfy Pylyshyn’s requirements that the effects be direct and exhibit semantic coherence. In addition, we distinguish our defense from those found in recent work by Raftopoulos and by Firestone and Scholl, argue that attention should not be assimilated to expectation, and discuss alternative characterizations of cognitive penetrability, advocating a kind of pluralism. PMID:28275358

  2. Dynamic Interaction between Reinforcement Learning and Attention in Multidimensional Environments.

    PubMed

    Leong, Yuan Chang; Radulescu, Angela; Daniel, Reka; DeWoskin, Vivian; Niv, Yael

    2017-01-18

    Little is known about the relationship between attention and learning during decision making. Using eye tracking and multivariate pattern analysis of fMRI data, we measured participants' dimensional attention as they performed a trial-and-error learning task in which only one of three stimulus dimensions was relevant for reward at any given time. Analysis of participants' choices revealed that attention biased both value computation during choice and value update during learning. Value signals in the ventromedial prefrontal cortex and prediction errors in the striatum were similarly biased by attention. In turn, participants' focus of attention was dynamically modulated by ongoing learning. Attentional switches across dimensions correlated with activity in a frontoparietal attention network, which showed enhanced connectivity with the ventromedial prefrontal cortex between switches. Our results suggest a bidirectional interaction between attention and learning: attention constrains learning to relevant dimensions of the environment, while we learn what to attend to via trial and error.

  3. Attention Capture by Faces

    ERIC Educational Resources Information Center

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

    2008-01-01

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

  4. Expectancy, Attention, and Time.

    ERIC Educational Resources Information Center

    Barnes, Ralph; Jones, Mari Riess

    2000-01-01

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

  5. Attentional Bias and Training in Social Anxiety Disorder

    PubMed Central

    FISTIKCI, Nurhan; SAATCİOĞLU, Ömer; KEYVAN, Ali; KALKAN, Murat; TOPÇUOĞLU, Volkan

    2015-01-01

    Cognitive behavioral therapy (CBT) is one of the most effective treatment modalities for social anxiety disorder (SAD), showing a high level of clinical evidence supporting its effectiveness. On the other hand, lack of the desired benefit from this treatment in some patients causes continuation of the search for new techniques. Recent research studies have focused on attentional bias and attention training in SAD. Attention processes in SAD have been a major target of interest and investigation since the introduction of the first cognitive models explaining SAD. In the first model, it was highlighted that attention was self-focused. The relationship between threatening stimuli and attention was considered in the subsequent models. Attentional bias towards threat may take place in several ways, such as facilitated processing of threat, difficulty in disengaging attention from the threat and avoidance of attention from the threat. After these descriptions regarding the phenomenology of the disorder, treatments to modify attention, processes were developed. In spite of conflicting results, investigations on attentional training are promising. Attention processes, attentional bias and attentional training in SAD are discussed in this review.

  6. Attention Deficit Hyperactivity Disorder (ADHD)

    MedlinePlus

    ... Education Visitor Information RePORT NIH Fact Sheets Home > Attention Deficit Hyperactivity Disorder (ADHD) Small Text Medium Text Large Text Attention Deficit Hyperactivity Disorder (ADHD) Attention deficit/hyperactivity disorder (ADHD) is one ...

  7. Attention: Moral-Cognitive Geography.

    ERIC Educational Resources Information Center

    Tuan, Yi-Fu

    1987-01-01

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

  8. Humorous Relations: Attentiveness, Pleasure and Risk

    ERIC Educational Resources Information Center

    Mayo, Cris

    2014-01-01

    This article focuses on the structures of humor and joke telling that require particular kinds of attentiveness and particular relationships between speaker and audience, or more specifically, between classmates. First, I will analyze the pedagogical and relational preconditions that are necessary for humor to work. If humor is to work well, the…

  9. Joint Attention Enhances Visual Working Memory

    ERIC Educational Resources Information Center

    Gregory, Samantha E. A.; Jackson, Margaret C.

    2017-01-01

    Joint attention--the mutual focus of 2 individuals on an item--speeds detection and discrimination of target information. However, what happens to that information beyond the initial perceptual episode? To fully comprehend and engage with our immediate environment also requires working memory (WM), which integrates information from second to…

  10. Learned States of Preparatory Attentional Control

    ERIC Educational Resources Information Center

    Sali, Anthony W.; Anderson, Brian A.; Yantis, Steven

    2015-01-01

    Individuals regularly experience fluctuations in the ability to perform cognitive operations. Although previous research has focused on predicting cognitive flexibility from persistent individual traits, as well as from spontaneous fluctuations in neural activity, the role of learning in shaping preparatory attentional control remains poorly…

  11. Laterality, Implicit Memory, and Attention Disorder.

    ERIC Educational Resources Information Center

    Shaw, Geraldine A.; Brown, Geoffrey

    1991-01-01

    Presents study showing children with behaviors characteristic of attention disorder/hyperactivity deficit and high intelligence have more mixed laterality and allergies. Finds these children gather and use more diverse nonverbal and poorly focused information. Concludes such children use uncommon information when exhibiting novelty in nonverbal…

  12. Capturing Students' Attention: An Empirical Study

    ERIC Educational Resources Information Center

    Rosegard, Erik; Wilson, Jackson

    2013-01-01

    College students ("n" = 846) enrolled in a general education course were randomly assigned to either an arousal (experimental) or no-arousal (control) group. The experimental group was exposed to a topic-relevant, 90-second external stimulus (a technique used to elevate arousal and focus attention). The control group listened to the…

  13. Vision in Flies: Measuring the Attention Span

    PubMed Central

    Koenig, Sebastian; Wolf, Reinhard; Heisenberg, Martin

    2016-01-01

    A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA). The animal is said to have a focus of attention (FoA) which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s. PMID:26848852

  14. Socially guided attention influences infants' communicative behavior.

    PubMed

    Miller, Jennifer L; Gros-Louis, Julie

    2013-12-01

    For effective prelinguistic communication, infants must be able to direct their attention, vocalizations, and nonverbal gestures in social interactions. The purpose of our study was to examine how different styles of caregiver responses influenced infant attentional and communicative behavior in social interactions, based on prior studies that have shown influences of responsiveness on attention, language and cognitive outcomes. Infants were exposed to redirective and sensitive behavior systematically using an ABA design to examine real-time changes in infants' behavior as a function of caregiver responses. During the two baseline "A" periods, caregivers were instructed to play as they would at home. During the social response "B" period, caregivers were instructed to respond sensitively to infants' behavior on one visit and redirectively on the other visit. Results demonstrated that when caregivers behaved redirectively, infants shifted their attention more frequently and decreased the duration of their visual attention. Caregiver responses also resulted in changes in vocal and gesture production. Infants decreased their production of caregiver-directed vocalizations, gestures, and gesture-vocal combinations during in the redirective condition. Results suggest that caregiver sensitive responding to infants' attentional focus may be one influence on infants' attentional and prelinguistic communicative behavior.

  15. Hierarchical nonlinear dynamics of human attention.

    PubMed

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

    2015-08-01

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

  16. Attention Moderates the Processing of Inhibitory Information in Primary Psychopathy

    PubMed Central

    Zeier, Joshua D.; Maxwell, Jeffrey S.; Newman, Joseph P.

    2009-01-01

    Primary psychopathic individuals are less apt to re-evaluate or change their behavior in response to stimuli outside of their current focus of attention. According to the response modulation hypothesis, this tendency reflects a lack of responsivity to important peripheral information and undermines adaptive self-regulation. To evaluate this hypothesis, we administered a response competition (flanker-type) task and manipulated focus of visual attention. We predicted that psychopathic individuals would display significantly less interference to response incongruent information than non-psychopathic participants when attention was cued to the target location but display normal interference when there was no pre-potent focus of attention. The results confirmed this hypothesis and are consistent with the contention that attention moderates psychopathic individuals’ responsivity to inhibitory cues. Finally, we discuss the implications of this attentional anomaly for psychopathic traits and behavior. PMID:19685952

  17. Attention distributed across sensory modalities enhances perceptual performance

    PubMed Central

    Mishra, Jyoti; Gazzaley, Adam

    2012-01-01

    This study investigated the interaction between top-down attentional control and multisensory processing in humans. Using semantically congruent and incongruent audiovisual stimulus streams, we found target detection to be consistently improved in the setting of distributed audiovisual attention versus focused visual attention. This performance benefit was manifested as faster reaction times for congruent audiovisual stimuli, and as accuracy improvements for incongruent stimuli, resulting in a resolution of stimulus interference. Electrophysiological recordings revealed that these behavioral enhancements were associated with reduced neural processing of both auditory and visual components of the audiovisual stimuli under distributed vs. focused visual attention. These neural changes were observed at early processing latencies, within 100–300 ms post-stimulus onset, and localized to auditory, visual, and polysensory temporal cortices. These results highlight a novel neural mechanism for top-down driven performance benefits via enhanced efficacy of sensory neural processing during distributed audiovisual attention relative to focused visual attention. PMID:22933811

  18. Emotion-attention interactions in recognition memory for distractor faces.

    PubMed

    Srinivasan, Narayanan; Gupta, Rashmi

    2010-04-01

    Effective filtering of distractor information has been shown to be dependent on perceptual load. Given the salience of emotional information and the presence of emotion-attention interactions, we wanted to explore the recognition memory for emotional distractors especially as a function of focused attention and distributed attention by manipulating load and the spatial spread of attention. We performed two experiments to study emotion-attention interactions by measuring recognition memory performance for distractor neutral and emotional faces. Participants performed a color discrimination task (low-load) or letter identification task (high-load) with a letter string display in Experiment 1 and a high-load letter identification task with letters presented in a circular array in Experiment 2. The stimuli were presented against a distractor face background. The recognition memory results show that happy faces were recognized better than sad faces under conditions of less focused or distributed attention. When attention is more spatially focused, sad faces were recognized better than happy faces. The study provides evidence for emotion-attention interactions in which specific emotional information like sad or happy is associated with focused or distributed attention respectively. Distractor processing with emotional information also has implications for theories of attention.

  19. Attentional consequences of pregoal and postgoal positive affects.

    PubMed

    Gable, Philip A; Harmon-Jones, Eddie

    2011-12-01

    Decades of research have suggested that all positive affective states broaden attention. Recent studies have found that positive affects high in approach motivation narrow attention, whereas positive affects low in approach motivation broaden attention. However, these studies were limited because they used only affective pictures to manipulate positive affect. The pictures, rather than the affective states created by them, may have caused individuals to focus on the emotional details of the picture, and this attentional focus may have caused the narrowing of attentional scope. Moreover, no experiment has yet to examine both low and high approach-motivated positive affect within the same individuals in the same study. The current experiments manipulated pregoal (high approach) and postgoal (low approach) positive states by giving participants the opportunity to win money on a game. Results revealed that pregoal positive affect caused a narrowing of attention, whereas postgoal positive affect caused a broadening of attention.

  20. Attention-Seeking Displays

    PubMed Central

    Számadó, Szabolcs

    2015-01-01

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

  1. A relational structure of voluntary visual-attention abilities.

    PubMed

    Skogsberg, KatieAnn; Grabowecky, Marcia; Wilt, Joshua; Revelle, William; Iordanescu, Lucica; Suzuki, Satoru

    2015-06-01

    Many studies have examined attention mechanisms involved in specific behavioral tasks (e.g., search, tracking, distractor inhibition). However, relatively little is known about the relationships among those attention mechanisms. Is there a fundamental attention faculty that makes a person superior or inferior at most types of attention tasks, or do relatively independent processes mediate different attention skills? We focused on individual differences in voluntary visual-attention abilities using a battery of 11 representative tasks. An application of parallel analysis, hierarchical-cluster analysis, and multidimensional scaling to the intertask correlation matrix revealed 4 functional clusters, representing spatiotemporal attention, global attention, transient attention, and sustained attention, organized along 2 dimensions, one contrasting spatiotemporal and global attention and the other contrasting transient and sustained attention. Comparison with the neuroscience literature suggests that the spatiotemporal-global dimension corresponds to the dorsal frontoparietal circuit and the transient-sustained dimension corresponds to the ventral frontoparietal circuit, with distinct subregions mediating the separate clusters within each dimension. We also obtained highly specific patterns of gender difference and of deficits for college students with elevated attention-deficit/hyperactivity disorder traits. These group differences suggest that different mechanisms of voluntary visual attention can be selectively strengthened or weakened based on genetic, experiential, and/or pathological factors.

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

    PubMed

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

    2013-01-01

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

  3. SN1987A: correlation between the data recorded by the Mont Blanc neutrino detector and by the Maryland and Rome gravitational wave antennas.

    NASA Astrophysics Data System (ADS)

    Pallottino, G. V.

    The author reports the analysis of gravitational wave and neutrino detectors over a period of 18 hours that includes the Mont Blanc 5 neutrino burst time. There is statistical evidence for correlations during a period of about two hours, centered on the 5 neutrino burst: the effect is mainly due to a dozen of large amplitude Maryland and Rome events. The interpretation of these events as due to gravitational radiation from SN1987A should be rejected, according to the standard theory of the cross-section of g.w. detectors, since it would imply an emission of energy too large by a factor of about 104.

  4. Visual attention: Linking prefrontal sources to neuronal and behavioral correlates.

    PubMed

    Clark, Kelsey; Squire, Ryan Fox; Merrikhi, Yaser; Noudoost, Behrad

    2015-09-01

    Attention is a means of flexibly selecting and enhancing a subset of sensory input based on the current behavioral goals. Numerous signatures of attention have been identified throughout the brain, and now experimenters are seeking to determine which of these signatures are causally related to the behavioral benefits of attention, and the source of these modulations within the brain. Here, we review the neural signatures of attention throughout the brain, their theoretical benefits for visual processing, and their experimental correlations with behavioral performance. We discuss the importance of measuring cue benefits as a way to distinguish between impairments on an attention task, which may instead be visual or motor impairments, and true attentional deficits. We examine evidence for various areas proposed as sources of attentional modulation within the brain, with a focus on the prefrontal cortex. Lastly, we look at studies that aim to link sources of attention to its neuronal signatures elsewhere in the brain.

  5. The interplay of attention and emotion: top-down attention modulates amygdala activation in psychopathy.

    PubMed

    Larson, Christine L; Baskin-Sommers, Arielle R; Stout, Daniel M; Balderston, Nicholas L; Curtin, John J; Schultz, Douglas H; Kiehl, Kent A; Newman, Joseph P

    2013-12-01

    Psychopathic behavior has long been attributed to a fundamental deficit in fear that arises from impaired amygdala function. Growing evidence has demonstrated that fear-potentiated startle (FPS) and other psychopathy-related deficits are moderated by focus of attention, but to date, no work on adult psychopathy has examined attentional modulation of the amygdala or concomitant recruitment of relevant attention-related circuitry. Consistent with previous FPS findings, here we report that psychopathy-related differences in amygdala activation appear and disappear as a function of goal-directed attention. Specifically, decreased amygdala activity was observed in psychopathic offenders only when attention was engaged in an alternative goal-relevant task prior to presenting threat-relevant information. Under this condition, psychopaths also exhibited greater activation in selective-attention regions of the lateral prefrontal cortex (LPFC) than did nonpsychopaths, and this increased LPFC activation mediated psychopathy's association with decreased amygdala activation. In contrast, when explicitly attending to threat, amygdala activation did not differ in psychopaths and nonpsychopaths. This pattern of amygdala activation highlights the potential role of LPFC in mediating the failure of psychopathic individuals to process fear and other important information when it is peripheral to the primary focus of goal-directed attention.

  6. Focus on Form: A Critical Review

    ERIC Educational Resources Information Center

    Ellis, Rod

    2016-01-01

    "Focus on form" (FonF) is a central construct in task-based language teaching. The term was first introduced by Michael Long to refer to an approach where learners' attention is attracted to linguistic forms as they engage in the performance of tasks. It contrasts with a structure-based approach--"focus on forms" (FonFs)--where…

  7. Attention to detail

    SciTech Connect

    Niccolai, G.C.

    1994-11-01

    Insurance is an increasingly important part of international projects. Understanding various coverages can make the difference between success and failure. With more than $50 billion of investment capital per year slated for development of power projects in Asia alone, international development has gained the attention of many developers eager to participate. Coordinating an international insurance program for power projects is much different than a developer may be accustomed to in the United States. With insurance taking on an extremely important role in the success of project development it is imperative the unique international exposures inherent be identified and addressed.

  8. A relational structure of voluntary visual-attention abilities

    PubMed Central

    Skogsberg, KatieAnn; Grabowecky, Marcia; Wilt, Joshua; Revelle, William; Iordanescu, Lucica; Suzuki, Satoru

    2015-01-01

    Many studies have examined attention mechanisms involved in specific behavioral tasks (e.g., search, tracking, distractor inhibition). However, relatively little is known about the relationships among those attention mechanisms. Is there a fundamental attention faculty that makes a person superior or inferior at most types of attention tasks, or do relatively independent processes mediate different attention skills? We focused on individual differences in voluntary visual-attention abilities using a battery of eleven representative tasks. An application of parallel analysis, hierarchical-cluster analysis, and multidimensional scaling to the inter-task correlation matrix revealed four functional clusters, representing spatiotemporal attention, global attention, transient attention, and sustained attention, organized along two dimensions, one contrasting spatiotemporal and global attention and the other contrasting transient and sustained attention. Comparison with the neuroscience literature suggests that the spatiotemporal-global dimension corresponds to the dorsal frontoparietal circuit and the transient-sustained dimension corresponds to the ventral frontoparietal circuit, with distinct sub-regions mediating the separate clusters within each dimension. We also obtained highly specific patterns of gender difference, and of deficits for college students with elevated ADHD traits. These group differences suggest that different mechanisms of voluntary visual attention can be selectively strengthened or weakened based on genetic, experiential, and/or pathological factors. PMID:25867505

  9. Attention and memory protection: Interactions between retrospective attention cueing and interference.

    PubMed

    Makovski, Tal; Pertzov, Yoni

    2015-01-01

    Visual working memory (VWM) and attention have a number of features in common, but despite extensive research it is still unclear how the two interact. Can focused attention improve VWM precision? Can it protect VWM from interference? Here we used a partial-report, continuous-response orientation memory task to examine how attention and interference affect different aspects of VWM and how they interact with one another. Both attention and interference were orthogonally manipulated during the retention interval. Attention was manipulated by presenting informative retro-cues, whereas interference was manipulated by introducing a secondary interfering task. Mixture-model analyses revealed that retro-cues, compared to uninformative cues, improved all aspects of performance: Attention increased recall precision and decreased guessing rate and swap-errors (reporting a wrong item in memory). Similarly, performing a secondary task impaired all aspects of the VWM task. In particular, an interaction between retro-cue and secondary task interference was found primarily for swap-errors. Together these results suggest that both the quantity and quality of VWM representations are sensitive to attention cueing and interference modulations, and they highlight the role of attention in protecting the feature-location associations needed to access the correct items in memory.

  10. Feature-based attentional modulation increases with stimulus separation in divided-attention tasks.

    PubMed

    Sally, Sharon L; Vidnyánsky, Zoltán; Papathomas, Thomas V

    2009-01-01

    Attention modifies our visual experience by selecting certain aspects of a scene for further processing. It is therefore important to understand factors that govern the deployment of selective attention over the visual field. Both location and feature-specific mechanisms of attention have been identified and their modulatory effects can interact at a neural level (Treue and Martinez-Trujillo, 1999). The effects of spatial parameters on feature-based attentional modulation were examined for the feature dimensions of orientation, motion and color using three divided-attention tasks. Subjects performed concurrent discriminations of two briefly presented targets (Gabor patches) to the left and right of a central fixation point at eccentricities of +/-2.5 degrees , 5 degrees , 10 degrees and 15 degrees in the horizontal plane. Gabors were size-scaled to maintain consistent single-task performance across eccentricities. For all feature dimensions, the data show a linear increase in the attentional effects with target separation. In a control experiment, Gabors were presented on an isoeccentric viewing arc at 10 degrees and 15 degrees at the closest spatial separation (+/-2.5 degrees ) of the main experiment. Under these conditions, the effects of feature-based attentional effects were largely eliminated. Our results are consistent with the hypothesis that feature-based attention prioritizes the processing of attended features. Feature-based attentional mechanisms may have helped direct the attentional focus to the appropriate target locations at greater separations, whereas similar assistance may not have been necessary at closer target spacings. The results of the present study specify conditions under which dual-task performance benefits from sharing similar target features and may therefore help elucidate the processes by which feature-based attention operates.

  11. Attentional networks and consciousness.

    PubMed

    Posner, Michael I

    2012-01-01

    The term consciousness is an important one in the vernacular of the western literature in many fields. It is no wonder that scientists have assumed that consciousness will be found as a component of the human brain and that we will come to understand its neural basis. However, there is rather little in common between consciousness as the neurologist would use it to diagnose the vegetative state, how the feminist would use it to support raising male consciousness of the economic plight of women and as the philosopher would use it when defining the really hard question of the subjective state of awareness induced by sensory qualities. When faced with this kind of problem it is usual to subdivide the term into more manageable perhaps partly operational definitions. Three meanings that capture aspects of consciousness are: (1) the neurology of the state of mind allowing coherent orientation to time and place (2) the selection of sensory or memorial information for awareness and (3) the voluntary control over overt responses. In each of these cases the mechanisms of consciousness overlap with one or more of the attentional networks that have been studied with the methods of cognitive neuroscience. In this paper we explore the overlap and discuss how to exploit the growing knowledge of attentional networks to constrain ideas of consciousness.

  12. Joint attention and language evolution

    NASA Astrophysics Data System (ADS)

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

    2008-06-01

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

  13. Attention deficit hyperactivity disorder.

    PubMed

    Thapar, Anita; Cooper, Miriam

    2016-03-19

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

  14. Attention deficit hyperactivity disorder.

    PubMed

    Kulkarni, Madhuri

    2015-03-01

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

  15. The role of somatic threat feature detectors in the attentional bias toward pain: effects of spatial attention.

    PubMed

    Dowman, Robert

    2011-03-01

    Our previous work suggests that somatic threat feature detectors indexed by a pain-evoked midlatency negative scalp potential play an important role in the attentional bias toward pain. In these studies the somatic threat feature detectors facilitated the shift in attention to a somatic threat when attention was focused on another stimulus modality but not when it was focused on another spatial location. This experiment used the Posner cuing paradigm to investigate possible explanations for this discrepancy. The results demonstrate that the different somatic threat effects observed in previous modal and spatial cuing studies are not due to attentional set. Rather, this discrepancy may be related to differences in contingent attention capture. This study also verifies earlier findings suggesting that some of the pain-related P2 component generators are involved in stimulus-driven shifts in spatial attention toward task-relevant stimuli.

  16. Developmental attentional dyslexia.

    PubMed

    Friedmann, Naama; Kerbel, Noa; Shvimer, Lilach

    2010-01-01

    Attentional dyslexia is a reading deficit in which letters migrate between neighboring words, but are correctly identified and keep their correct relative position within the word. Thus, for example, fig tree can be read as fig free or even tie free. This study reports on 10 Hebrew-speaking individuals with developmental attentional dyslexia and explores in detail the characteristics of their between-word errors. Each participant read 2290 words, presented in word pairs: 845 horizontally presented word pairs, 240 vertically presented word pairs, and 60 nonword pairs. The main results are that almost all migrations preserve the relative position of the migrating letter within the word, indicating that the between-word position can be impaired while the within-word position encoding remains intact. This result is also supported by the finding that the participants did not make many letter position errors within words. Further analyses indicated that more errors occur in longer words, that most migrations occur in final letters (which are the leftmost letters in Hebrew), and that letters migrate both horizontally and vertically, and more frequently from the first to the second word in horizontal presentation. More migrations occurred when the result of migration was an existing word. Similarity between words in a pair did not increase error rates, and more migrations occurred when the words shared fewer letters. The between-word errors included the classic errors of migration of a letter between words, but also omission of one instance of a letter that appeared in the same position in the two words, an error that constituted a considerable percentage of the between-word errors, and intrusion of a letter from one word to the corresponding position in the neighboring word without erasing the original letter in the same position.

  17. Attention Style and Performance in a Coincident Anticipation Task.

    ERIC Educational Resources Information Center

    Nettleton, Brian

    1982-01-01

    Students were ranked in ability to anticipate the arrival of a relatively fast moving stimulus at a certain point along a trackway and compared with "narrow attentional focus," a measure of attentional style. An association between an individual's field independence and performance on an anticipation task was shown. (Author/CM)

  18. Coincidence of Homophone Spelling Errors and Attention Problems in Schoolchildren: A Survey Study

    ERIC Educational Resources Information Center

    Tsai, Li-Hui; Meng, Ling-Fu; Hung, Li-Yu; Chen, Hsin-Yu; Lu, Chiu-Ping

    2011-01-01

    This article examines the relationship between writing and attention problems and hypothesizes that homophone spelling errors coincide with attention deficits. We analyze specific types of attention deficits, which may contribute to Attention Deficits Hyperactivity Disorder (ADHD); rather than studying ADHD, however, we focus on the inattention…

  19. Across the Continuum of Attention Skills: A Twin Study of the SWAN ADHD Rating Scale

    ERIC Educational Resources Information Center

    Polderman, Tinca J. C.; Derks, Eske M.; Hudziak, Jim J.; Verhulst, Frank C.; Posthuma, Danielle; Boomsma, Dorret I.

    2007-01-01

    Introduction: Most behavior checklists for attention problems or attention deficit/hyperactivity disorder (ADHD) such as the Child Behavior Checklist (CBCL) have a narrow range of scores, focusing on the extent to which problems are present. It has been proposed that measuring attention on a continuum, from positive attention skills to attention…

  20. Attention engagement in early infancy.

    PubMed

    Perra, Oliver; Gattis, Merideth

    2012-12-01

    We report a longitudinal study investigating developmental changes in the structure of attention engagement during early infancy. Forty-three infants were observed monthly from 2 to 4 months. Attention engagement was assessed from play interactions with parents, using a coding system developed by Bakeman and Adamson (1984). The results indicated a developmental transition in attention engagement at 3 months: after this age infants engaged for longer periods and in a wider variety of states. Most infants displayed person engagement at 2 months, passive joint engagement at 3 months, and object engagement at 4 months. To address whether emerging abilities of attention engagement allow infants to follow the attention of social partners, we compared attention engagement to performance on an experimental measure of attention control (reported by Perra & Gattis, 2010). Analyses revealed a positive relation between passive joint engagement and checking back, suggesting that changes in passive joint engagement reflect the development in attention control.

  1. Attention deficit hyperactivity disorder (ADHD)

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/001551.htm Attention deficit hyperactivity disorder To use the sharing features on this page, please enable JavaScript. Attention deficit hyperactivity disorder (ADHD) is a problem caused by the presence ...

  2. Intensive meditation training improves perceptual discrimination and sustained attention.

    PubMed

    MacLean, Katherine A; Ferrer, Emilio; Aichele, Stephen R; Bridwell, David A; Zanesco, Anthony P; Jacobs, Tonya L; King, Brandon G; Rosenberg, Erika L; Sahdra, Baljinder K; Shaver, Phillip R; Wallace, B Alan; Mangun, George R; Saron, Clifford D

    2010-06-01

    The ability to focus one's attention underlies success in many everyday tasks, but voluntary attention cannot be sustained for extended periods of time. In the laboratory, sustained-attention failure is manifest as a decline in perceptual sensitivity with increasing time on task, known as the vigilance decrement. We investigated improvements in sustained attention with training (approximately 5 hr/day for 3 months), which consisted of meditation practice that involved sustained selective attention on a chosen stimulus (e.g., the participant's breath). Participants were randomly assigned either to receive training first (n = 30) or to serve as waiting-list controls and receive training second (n = 30). Training produced improvements in visual discrimination that were linked to increases in perceptual sensitivity and improved vigilance during sustained visual attention. Consistent with the resource model of vigilance, these results suggest that perceptual improvements can reduce the resource demand imposed by target discrimination and thus make it easier to sustain voluntary attention.

  3. Visual attention spreads broadly but selects information locally

    PubMed Central

    Shioiri, Satoshi; Honjyo, Hajime; Kashiwase, Yoshiyuki; Matsumiya, Kazumichi; Kuriki, Ichiro

    2016-01-01

    Visual attention spreads over a range around the focus as the spotlight metaphor describes. Spatial spread of attentional enhancement and local selection/inhibition are crucial factors determining the profile of the spatial attention. Enhancement and ignorance/suppression are opposite effects of attention, and appeared to be mutually exclusive. Yet, no unified view of the factors has been provided despite their necessity for understanding the functions of spatial attention. This report provides electroencephalographic and behavioral evidence for the attentional spread at an early stage and selection/inhibition at a later stage of visual processing. Steady state visual evoked potential showed broad spatial tuning whereas the P3 component of the event related potential showed local selection or inhibition of the adjacent areas. Based on these results, we propose a two-stage model of spatial attention with broad spread at an early stage and local selection at a later stage. PMID:27759056

  4. Dopamine supports coupling of attention-related networks.

    PubMed

    Dang, Linh C; O'Neil, James P; Jagust, William J

    2012-07-11

    Attentional processing has been associated with the dorsal attention, default mode, and frontoparietal control networks. The dorsal attention network is involved in externally focused attention whereas the default mode network is involved in internally directed attention. The frontoparietal control network has been proposed to mediate the transition between external and internal attention by coupling its activity to either the dorsal attention network or the default mode network, depending on the attentional demand. Dopamine is hypothesized to modulate attention and has been linked to the integrity of these three attention-related networks. We used PET with 6-[(18)F]fluoro-L-m-tyrosine to quantify dopamine synthesis capacity in vivo and fMRI to acquire stimulus-independent brain activity in cognitively healthy human subjects. We found that in the resting state where internal cognition dominates, dopamine enhances the coupling between the frontoparietal control network and the default mode network while reducing the coupling between the frontoparietal control network and the dorsal attention network. These results add a neurochemical perspective to the role of network interaction in modulating attention.

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

    PubMed

    Wöllner, Clemens; Halpern, Andrea R

    2016-01-01

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

  6. Recent theoretical, neural, and clinical advances in sustained attention research.

    PubMed

    Fortenbaugh, Francesca C; DeGutis, Joseph; Esterman, Michael

    2017-03-05

    Models of attention often distinguish among attention subtypes, with classic models separating orienting, switching, and sustaining functions. Compared with other forms of attention, the neurophysiological basis of sustaining attention has received far less notice, yet it is known that momentary failures of sustained attention can have far-ranging negative effects in healthy individuals, and lasting sustained attention deficits are pervasive in clinical populations. In recent years, however, there has been increased interest in characterizing moment-to-moment fluctuations in sustained attention, in addition to the overall vigilance decrement, and understanding how these neurocognitive systems change over the life span and across various clinical populations. The use of novel neuroimaging paradigms and statistical approaches has allowed for better characterization of the neural networks supporting sustained attention and has highlighted dynamic interactions within and across multiple distributed networks that predict behavioral performance. These advances have also provided potential biomarkers to identify individuals with sustained attention deficits. These findings have led to new theoretical models explaining why sustaining focused attention is a challenge for individuals and form the basis for the next generation of sustained attention research, which seeks to accurately diagnose and develop theoretically driven treatments for sustained attention deficits that affect a variety of clinical populations.

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

    PubMed

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

    2015-01-01

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

  8. Is Object-Based Attention Mandatory? Strategic Control over Mode of Attention

    ERIC Educational Resources Information Center

    Yeari, Menahem; Goldsmith, Morris

    2010-01-01

    Is object-based attention mandatory or under strategic control? In an adapted spatial cuing paradigm, participants focused initially on a central arrow cue that was part of a perceptual group (Experiment 1) or a uniformly connected object (Experiment 2), encompassing one of the potential target locations. The cue always pointed to an opposite,…

  9. Anxiety and attention to threat: Cognitive mechanisms and treatment with attention bias modification.

    PubMed

    Mogg, Karin; Bradley, Brendan P

    2016-12-01

    Anxiety disorders are common and difficult to treat. Some cognitive models of anxiety propose that attention bias to threat causes and maintains anxiety. This view led to the development of a computer-delivered treatment: attention bias modification (ABM) which predominantly trains attention avoidance of threat. However, meta-analyses indicate disappointing effectiveness of ABM-threat-avoidance training in reducing anxiety. This article considers how ABM may be improved, based on a review of key ideas from models of anxiety, attention and cognitive control. These are combined into an integrative framework of cognitive functions which support automatic threat evaluation/detection and goal-directed thought and action, which reciprocally influence each other. It considers roles of bottom-up and top-down processes involved in threat-evaluation, orienting and inhibitory control in different manifestations of attention bias (initial orienting, attention maintenance, threat avoidance, threat-distractor interference) and different ABM methods (e.g., ABM-threat-avoidance, ABM-positive-search). The framework has implications for computer-delivered treatments for anxiety. ABM methods which encourage active goal-focused attention-search for positive/nonthreat information and flexible cognitive control across multiple processes (particularly inhibitory control, which supports a positive goal-engagement mode over processing of minor threat cues) may prove more effective in reducing anxiety than ABM-threat-avoidance training which targets a specific bias in spatial orienting to threat.

  10. Attention and Implicit Memory: Priming-Induced Benefits and Costs Have Distinct Attentional Requirements

    PubMed Central

    Keane, Margaret M.; Cruz, Matt E.; Verfaellie, Mieke

    2014-01-01

    Attention at encoding plays a critical and ubiquitous role in explicit memory performance, but its role in implicit memory performance (i.e., priming) is more variable: Some, but not all, priming effects are reduced by division of attention at encoding. A wealth of empirical and theoretical work has aimed to define the critical features of priming effects that do or do not require attention at encoding. This work, however, has focused exclusively on priming effects that are beneficial in nature (wherein performance is enhanced by prior exposure to task stimuli), and has overlooked priming effects that are costly in nature (wherein performance is harmed by prior exposure to task stimuli). The present study takes up this question by examining the effect of divided attention on priming-induced costs and benefits in a speeded picture-naming task. Experiment 1 shows that the costs, but not the benefits, are eliminated by division of attention at encoding. Experiment 2 shows that the costs (as well as the benefits) in this task are intact in amnesic participants, demonstrating that the elimination of the cost in the divided attention condition in Experiment 1 was not an artifact of the reduced availability of explicit memory in that condition. We suggest that the differential role of attention in priming-induced performance costs and benefits is linked to differences in response competition associated with these effects. This interpretation situates the present findings within a theoretical framework that has been applied to a broad range of facilitatory priming effects. PMID:25257650

  11. "Only" and Focus.

    ERIC Educational Resources Information Center

    Vallduvi, Enric

    The relationship of the word "only," one of a class of words known as scalar particles, focus adverbs, focus inducers, or focus-sensitive particles, with the "focus" of the sentence is examined. It is suggested, based on analysis of discourse structure, that this "association with focus" is not an inherent property of…

  12. [Attention deficit hyperactivity disorder].

    PubMed

    Cunill, Ruth; Castells, Xavier

    2015-04-20

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

  13. Exogenous attention to unseen objects?

    PubMed

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

    2015-09-01

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

  14. Instructions to Adopt an External Focus Enhance Muscular Endurance

    ERIC Educational Resources Information Center

    Marchant, David C.; Greig, Matt; Bullough, Jonathan; Hitchen, Daniel

    2011-01-01

    The influence of internal (movement focus) and external (outcome focus) attentional-focusing instructions on muscular endurance were investigated using three exercise protocols with experienced exercisers. Twenty-three participants completed a maximal repetition, assisted bench-press test on a Smith's machine. An external focus of attention…

  15. Toward Connecting Core-Collapse Supernova Theory with Observations: Nucleosynthetic Yields and Distribution of Elements in a 15 M⊙ Blue Supergiant Progenitor with SN 1987A Energetics

    NASA Astrophysics Data System (ADS)

    Plewa, Tomasz; Handy, Timothy; Odrzywolek, Andrzej

    2014-03-01

    We compute and discuss the process of nucleosynthesis in a series of core-collapse explosion models of a 15 solar mass, blue supergiant progenitor. We obtain nucleosynthetic yields and study the evolution of the chemical element distribution from the moment of core bounce until young supernova remnant phase. Our models show how the process of energy deposition due to radioactive decay modifies the dynamics and the core ejecta structure on small and intermediate scales. The results are compared against observations of young supernova remnants including Cas A and the recent data obtained for SN 1987A. The work has been supported by the NSF grant AST-1109113 and DOE grant DE-FG52-09NA29548. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the U.S. DoE under Contract No. DE-AC02-05CH11231.

  16. SN 1987 A - Correlations between the Maryland and Rome gravitational wave detector data and the Mont Blanc and KAMIOKANDE neutrino detector data

    NASA Astrophysics Data System (ADS)

    Pallottino, G. V.

    1990-02-01

    The paper describes the analysis of data obtained in the period 12 h of February 22, 1987 to 6 h of February 23, 1987, that includes the time of neutrino observation with the Mont Blanc detector during SN 1987 A. A very significant correlation has been observed among the data of the above detectors in a period of one or two hours which includes the time of the Mont Blanc 5-neutrino observation. The correlation between the gravitational wave detector data and the Kamiokande data is found if a time of 7.8 s is added to the Kamioka recorded time; this is very close to the time difference, 6.2 s, between the IMB and Kamioka large neutrino bursts observed at about 7 h 35 min.

  17. What Research Says: Teaching Children Science Concepts: The Role of Attention.

    ERIC Educational Resources Information Center

    Koran, John J., Jr.; Lehman, Jeffrey R.

    1981-01-01

    Summarizes representative research relating to the critical role of attention in concept formation in science. Topics discussed include curing, manipulation of symbols, and directions for focusing attention on particular aspects of concepts. (Author/DS)

  18. Attention-Modulating Effects of Cognitive Enhancers

    EPA Science Inventory

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

  19. Cross-training in hemispatial neglect: auditory sustained attention training ameliorates visual attention deficits.

    PubMed

    Van Vleet, Thomas M; DeGutis, Joseph M

    2013-03-01

    Prominent deficits in spatial attention evident in patients with hemispatial neglect are often accompanied by equally prominent deficits in non-spatial attention (e.g., poor sustained and selective attention, pronounced vigilance decrement). A number of studies now show that deficits in non-spatial attention influence spatial attention. Treatment strategies focused on improving vigilance or sustained attention may effectively remediate neglect. For example, a recent study employing Tonic and Phasic Alertness Training (TAPAT), a task that requires monitoring a constant stream of hundreds of novel scenes, demonstrated group-level (n=12) improvements after training compared to a test-retest control group or active treatment control condition on measures of visual search, midpoint estimation and working memory (DeGutis and Van Vleet, 2010). To determine whether the modality of treatment or stimulus novelty are key factors to improving hemispatial neglect, we designed a similar continuous performance training task in which eight patients with chronic and moderate to severe neglect were challenged to rapidly and continuously discriminate a limited set of centrally presented auditory tones once a day for 9 days (36-min/day). All patients demonstrated significant improvement in several, untrained measures of spatial and non-spatial visual attention, and as a group failed to demonstrate a lateralized attention deficit 24-h post-training compared to a control group of chronic neglect patients who simply waited during the training period. The results indicate that TAPAT-related improvements in hemispatial neglect are likely due to improvements in the intrinsic regulation of supramodal, non-spatial attentional resources.

  20. Elastic Attention: Enhanced, then Sharpened Response to Auditory Input as Attentional Load Increases

    PubMed Central

    Neelon, Michael F.; Williams, Justin; Garell, P. Charles

    2011-01-01

    A long debate in selective attention research is whether attention enhances sensory response or sharpens neural tuning by suppressing response to non-target input. In fact, both processes may occur as a function of load: an uncertain listener might use a broad attentional filter to enhance responses to all inputs (i.e., vigilance), yet employ sharpened tuning to focus on hard to discriminate targets. The present work used the greater signal gain, anatomical precision, and laterality separation of intracranial electrophysiological recordings (electrocorticograms) to investigate these competing effects. Data were recorded from acoustically-responsive cortex in the perisylvian region of a single hemisphere in five neurosurgery patients. Patients performed a dichotic listening task in which they alternately attended toward, away from, or completely ignored (silent reading) tones presented to designated ears at varying presentation rates. Comparisons between the grand-averaged event-related potential (ERP) waveforms show a striking change in the effect of selective auditory attention with attentional load. At slower presentation rates (low-load), ERPs were overall enhanced in response to both input channels and regardless of attended ear, including a significant enhancement of ipsilateral input. This result supports a broadly enhancing model of attention under low perceptual load conditions. At the fastest rate, however, only responses to attended inputs contralateral to grid location remained enhanced. This result supports an increasing suppression, or “sharpening,” of neural responses to non-targets with increasing attentional load. These data provide support for an elastic model of attention in which attentional scope narrows with increasing load. PMID:21559348