A Normalization Framework for Emotional Attention.

PubMed

Zhang, Xilin; Japee, Shruti; Safiullah, Zaid; Mlynaryk, Nicole; Ungerleider, Leslie G

2016-11-01

The normalization model of attention proposes that attention can affect performance by response- or contrast-gain changes, depending on the size of the stimulus and attention field. Here, we manipulated the attention field by emotional valence, negative faces versus positive faces, while holding stimulus size constant in a spatial cueing task. We observed changes in the cueing effect consonant with changes in response gain for negative faces and contrast gain for positive faces. Neuroimaging experiments confirmed that subjects' attention fields were narrowed for negative faces and broadened for positive faces. Importantly, across subjects, the self-reported emotional strength of negative faces and positive faces correlated, respectively, both with response- and contrast-gain changes and with primary visual cortex (V1) narrowed and broadened attention fields. Effective connectivity analysis showed that the emotional valence-dependent attention field was closely associated with feedback from the dorsolateral prefrontal cortex (DLPFC) to V1. These findings indicate a crucial involvement of DLPFC in the normalization processes of emotional attention.

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

ERIC Educational Resources Information Center

Huang, Liqiang

2010-01-01

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

Practice of Environmentally Significant Behaviours in Rural China: From Being Motivated by Economic Gains to Being Motivated by Environmental Considerations.

PubMed

Chen, Yanyan

2017-08-22

A continuous and increasing crisis that present-day China is facing is environmental degradation. The cultivation of citizens who have environmentally friendly behaviours has been deemed as a fundamental way to solve environmental crises. However, the main focus of environmentalism studies has been urban residents, whereas rare research attention was put on rural Chinese. This paper focuses on environmentally significant behaviours in rural China and aims to clarify the practice of five environmentally significant behaviours and two motivations underlying these behaviours. In total, 508 rural residents in 51 villages of Ningyang county were interviewed. Analytical results derived from survey data showed that environmentally significant behaviours are widely conducted in rural areas. However, these behaviours are mainly motivated by economic gains rather than environmental considerations. In addition, based on the norm-activation theory and considering the influences of demographic factors, the formation of environmentally motivated behaviours were quantitatively analysed. Analytical results indicated that the more people worried about environmental deterioration, the more likely they were to form environmentally motivated behaviours, and people who ascribe the most important environmental responsibility to the government are less likely to form environmentally motivated behaviours. Increasing people's anxiety towards the environment, decreasing people's dependency on the government in protecting the environment, and using females, the elderly, and people with low income and education levels as the main targets of environmental education are suggested to promote environmentally motivated behaviours in rural China.

Practice of Environmentally Significant Behaviours in Rural China: From Being Motivated by Economic Gains to Being Motivated by Environmental Considerations

PubMed Central

Chen, Yanyan

2017-01-01

A continuous and increasing crisis that present-day China is facing is environmental degradation. The cultivation of citizens who have environmentally friendly behaviours has been deemed as a fundamental way to solve environmental crises. However, the main focus of environmentalism studies has been urban residents, whereas rare research attention was put on rural Chinese. This paper focuses on environmentally significant behaviours in rural China and aims to clarify the practice of five environmentally significant behaviours and two motivations underlying these behaviours. In total, 508 rural residents in 51 villages of Ningyang county were interviewed. Analytical results derived from survey data showed that environmentally significant behaviours are widely conducted in rural areas. However, these behaviours are mainly motivated by economic gains rather than environmental considerations. In addition, based on the norm-activation theory and considering the influences of demographic factors, the formation of environmentally motivated behaviours were quantitatively analysed. Analytical results indicated that the more people worried about environmental deterioration, the more likely they were to form environmentally motivated behaviours, and people who ascribe the most important environmental responsibility to the government are less likely to form environmentally motivated behaviours. Increasing people’s anxiety towards the environment, decreasing people’s dependency on the government in protecting the environment, and using females, the elderly, and people with low income and education levels as the main targets of environmental education are suggested to promote environmentally motivated behaviours in rural China. PMID:28829395

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

PubMed

Papera, Massimiliano; Richards, Anne

2016-05-01

Exogenous allocation of attentional resources allows the visual system to encode and maintain representations of stimuli in visual working memory (VWM). However, limits in the processing capacity to allocate resources can prevent unexpected visual stimuli from gaining access to VWM and thereby to consciousness. Using a novel approach to create unbiased stimuli of increasing saliency, we investigated visual processing during a visual search task in individuals who show a high or low propensity to neglect unexpected stimuli. When propensity to inattention is high, ERP recordings show a diminished amplification concomitantly with a decrease in theta band power during the N1 latency, followed by a poor target enhancement during the N2 latency. Furthermore, a later modulation in the P3 latency was also found in individuals showing propensity to visual neglect, suggesting that more effort is required for conscious maintenance of visual information in VWM. Effects during early stages of processing (N80 and P1) were also observed suggesting that sensitivity to contrasts and medium-to-high spatial frequencies may be modulated by low-level saliency (albeit no statistical group differences were found). In accordance with the Global Workplace Model, our data indicate that a lack of resources in low-level processors and visual attention may be responsible for the failure to "ignite" a state of high-level activity spread across several brain areas that is necessary for stimuli to access awareness. These findings may aid in the development of diagnostic tests and intervention to detect/reduce inattention propensity to visual neglect of unexpected stimuli. © 2016 Society for Psychophysiological Research.

Different Signal Enhancement Pathways of Attention and Consciousness Underlie Perception in Humans.

PubMed

van Boxtel, Jeroen J A

2017-06-14

It is not yet known whether attention and consciousness operate through similar or largely different mechanisms. Visual processing mechanisms are routinely characterized by measuring contrast response functions (CRFs). In this report, behavioral CRFs were obtained in humans (both males and females) by measuring afterimage durations over the entire range of inducer stimulus contrasts to reveal visual mechanisms behind attention and consciousness. Deviations relative to the standard CRF, i.e., gain functions, describe the strength of signal enhancement, which were assessed for both changes due to attentional task and conscious perception. It was found that attention displayed a response-gain function, whereas consciousness displayed a contrast-gain function. Through model comparisons, which only included contrast-gain modulations, both contrast-gain and response-gain effects can be explained with a two-level normalization model, in which consciousness affects only the first level and attention affects only the second level. These results demonstrate that attention and consciousness can effectively show different gain functions because they operate through different signal enhancement mechanisms. SIGNIFICANCE STATEMENT The relationship between attention and consciousness is still debated. Mapping contrast response functions (CRFs) has allowed (neuro)scientists to gain important insights into the mechanistic underpinnings of visual processing. Here, the influence of both attention and consciousness on these functions were measured and they displayed a strong dissociation. First, attention lowered CRFs, whereas consciousness raised them. Second, attention manifests itself as a response-gain function, whereas consciousness manifests itself as a contrast-gain function. Extensive model comparisons show that these results are best explained in a two-level normalization model in which consciousness affects only the first level, whereas attention affects only the second level

On the Structure of Neuronal Population Activity under Fluctuations in Attentional State

PubMed Central

Denfield, George H.; Bethge, Matthias; Tolias, Andreas S.

2016-01-01

Attention is commonly thought to improve behavioral performance by increasing response gain and suppressing shared variability in neuronal populations. However, both the focus and the strength of attention are likely to vary from one experimental trial to the next, thereby inducing response variability unknown to the experimenter. Here we study analytically how fluctuations in attentional state affect the structure of population responses in a simple model of spatial and feature attention. In our model, attention acts on the neural response exclusively by modulating each neuron's gain. Neurons are conditionally independent given the stimulus and the attentional gain, and correlated activity arises only from trial-to-trial fluctuations of the attentional state, which are unknown to the experimenter. We find that this simple model can readily explain many aspects of neural response modulation under attention, such as increased response gain, reduced individual and shared variability, increased correlations with firing rates, limited range correlations, and differential correlations. We therefore suggest that attention may act primarily by increasing response gain of individual neurons without affecting their correlation structure. The experimentally observed reduction in correlations may instead result from reduced variability of the attentional gain when a stimulus is attended. Moreover, we show that attentional gain fluctuations, even if unknown to a downstream readout, do not impair the readout accuracy despite inducing limited-range correlations, whereas fluctuations of the attended feature can in principle limit behavioral performance. SIGNIFICANCE STATEMENT Covert attention is one of the most widely studied examples of top-down modulation of neural activity in the visual system. Recent studies argue that attention improves behavioral performance by shaping of the noise distribution to suppress shared variability rather than by increasing response gain. Our work

Individual differences in attentional modulation of cortical responses correlate with selective attention performance

PubMed Central

Choi, Inyong; Wang, Le; Bharadwaj, Hari; Shinn-Cunningham, Barbara

2014-01-01

Many studies have shown that attention modulates the cortical representation of an auditory scene, emphasizing an attended source while suppressing competing sources. Yet, individual differences in the strength of this attentional modulation and their relationship with selective attention ability are poorly understood. Here, we ask whether differences in how strongly attention modulates cortical responses reflect differences in normal-hearing listeners’ selective auditory attention ability. We asked listeners to attend to one of three competing melodies and identify its pitch contour while we measured cortical electroencephalographic responses. The three melodies were either from widely separated pitch ranges (“easy trials”), or from a narrow, overlapping pitch range (“hard trials”). The melodies started at slightly different times; listeners attended either the leading or lagging melody. Because of the timing of the onsets, the leading melody drew attention exogenously. In contrast, attending the lagging melody required listeners to direct top-down attention volitionally. We quantified how attention amplified auditory N1 response to the attended melody and found large individual differences in the N1 amplification, even though only correctly answered trials were used to quantify the ERP gain. Importantly, listeners with the strongest amplification of N1 response to the lagging melody in the easy trials were the best performers across other types of trials. Our results raise the possibility that individual differences in the strength of top-down gain control reflect inherent differences in the ability to control top-down attention. PMID:24821552

Everyday attention.

PubMed

Risko, Evan F; Kingstone, Alan

2017-06-01

Understanding the basic mechanisms underlying attentional function using naturalistic stimuli, tasks, and/or settings is the focus of everyday attention research. Interest in everyday approaches to attention research has increased recently-arguably riding a more general wave of support for such considerations in experimental psychology. This special issue of the Canadian Journal of Experimental Psychology attempts to capture the emerging enthusiasm for studying everyday attention by bringing together work from a wide array of attentional domains (e.g., visual attention, dual tasking, search, mind wandering, social attention) that are representative of this general approach. The 14 contributions to the special issue highlight the breadth of topics addressed in this research, the methodological creativity required to carry it out, and the promise of everyday attention for understanding the basic mechanisms underlying attentional function. This introduction will summarise the everyday attention approach as represented in the contributions to the special issue. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A Feedback Model of Attention Explains the Diverse Effects of Attention on Neural Firing Rates and Receptive Field Structure.

PubMed

Miconi, Thomas; VanRullen, Rufin

2016-02-01

Visual attention has many effects on neural responses, producing complex changes in firing rates, as well as modifying the structure and size of receptive fields, both in topological and feature space. Several existing models of attention suggest that these effects arise from selective modulation of neural inputs. However, anatomical and physiological observations suggest that attentional modulation targets higher levels of the visual system (such as V4 or MT) rather than input areas (such as V1). Here we propose a simple mechanism that explains how a top-down attentional modulation, falling on higher visual areas, can produce the observed effects of attention on neural responses. Our model requires only the existence of modulatory feedback connections between areas, and short-range lateral inhibition within each area. Feedback connections redistribute the top-down modulation to lower areas, which in turn alters the inputs of other higher-area cells, including those that did not receive the initial modulation. This produces firing rate modulations and receptive field shifts. Simultaneously, short-range lateral inhibition between neighboring cells produce competitive effects that are automatically scaled to receptive field size in any given area. Our model reproduces the observed attentional effects on response rates (response gain, input gain, biased competition automatically scaled to receptive field size) and receptive field structure (shifts and resizing of receptive fields both spatially and in complex feature space), without modifying model parameters. Our model also makes the novel prediction that attentional effects on response curves should shift from response gain to contrast gain as the spatial focus of attention drifts away from the studied cell.

Some considerations of two alleged kinds of selective attention.

PubMed

Keren, G

1976-12-01

The present article deals with selective attention phenomena and elaborates on a stimulus material classification, "stimulus set" versus "response set," proposed by Broadbent (1970, 1971)9 Stimulus set is defined by some distinct and conspicuous physical properties that are inherent in the stimulus. Response set is characterized by the meaning it conveys, and thus its properties are determined by cognitive processing on the part of the organism. Broadbent's framework is related to Neisser's (1967) distinction between two perceptual-cognitive processes, namely, preattentive control and focal attention. Three experiments are reported. A before-after paradigm was employed in Experiment 1, together with a sptial arrangement manipulation of relevant versus irrelevant stimuli (being grouped or mixed). The results indicated that before-after instruction had a stronger effect under stimulus set than under response set conditions. Spatial arrangement, on the other hand, affected performances under response set but not under stimulus set conditions. These results were interpreted as supporting the idea that stimulus set material, which is handled by preattentive mechanisms, may be processed in parallel, while response set material requires focal attention that is probably serial in nature. Experiment 2 used a search task with different levels of noise elements. Although subjects were not able to avoid completely the processing of noise elements, they had much more control under stimulus set than under response set conditions. Experiment 3 dealt with memory functions and suggests differential levels of perceptual processing depending on the nature of the stimulus material. This extends the memory framework suggested by Craik and Lockhart (1972). The results of these experiments, together with evidence from other behavioral and physiological studies, lend strong support to the proposed theory. At the theoretical level, it is suggested that the distinction between stimulus and

Two different mechanisms support selective attention at different phases of training.

PubMed

Itthipuripat, Sirawaj; Cha, Kexin; Byers, Anna; Serences, John T

2017-06-01

Selective attention supports the prioritized processing of relevant sensory information to facilitate goal-directed behavior. Studies in human subjects demonstrate that attentional gain of cortical responses can sufficiently account for attention-related improvements in behavior. On the other hand, studies using highly trained nonhuman primates suggest that reductions in neural noise can better explain attentional facilitation of behavior. Given the importance of selective information processing in nearly all domains of cognition, we sought to reconcile these competing accounts by testing the hypothesis that extensive behavioral training alters the neural mechanisms that support selective attention. We tested this hypothesis using electroencephalography (EEG) to measure stimulus-evoked visual responses from human subjects while they performed a selective spatial attention task over the course of ~1 month. Early in training, spatial attention led to an increase in the gain of stimulus-evoked visual responses. Gain was apparent within ~100 ms of stimulus onset, and a quantitative model based on signal detection theory (SDT) successfully linked the magnitude of this gain modulation to attention-related improvements in behavior. However, after extensive training, this early attentional gain was eliminated even though there were still substantial attention-related improvements in behavior. Accordingly, the SDT-based model required noise reduction to account for the link between the stimulus-evoked visual responses and attentional modulations of behavior. These findings suggest that training can lead to fundamental changes in the way attention alters the early cortical responses that support selective information processing. Moreover, these data facilitate the translation of results across different species and across experimental procedures that employ different behavioral training regimes.

Two different mechanisms support selective attention at different phases of training

PubMed Central

Cha, Kexin; Byers, Anna; Serences, John T.

2017-01-01

Selective attention supports the prioritized processing of relevant sensory information to facilitate goal-directed behavior. Studies in human subjects demonstrate that attentional gain of cortical responses can sufficiently account for attention-related improvements in behavior. On the other hand, studies using highly trained nonhuman primates suggest that reductions in neural noise can better explain attentional facilitation of behavior. Given the importance of selective information processing in nearly all domains of cognition, we sought to reconcile these competing accounts by testing the hypothesis that extensive behavioral training alters the neural mechanisms that support selective attention. We tested this hypothesis using electroencephalography (EEG) to measure stimulus-evoked visual responses from human subjects while they performed a selective spatial attention task over the course of ~1 month. Early in training, spatial attention led to an increase in the gain of stimulus-evoked visual responses. Gain was apparent within ~100 ms of stimulus onset, and a quantitative model based on signal detection theory (SDT) successfully linked the magnitude of this gain modulation to attention-related improvements in behavior. However, after extensive training, this early attentional gain was eliminated even though there were still substantial attention-related improvements in behavior. Accordingly, the SDT-based model required noise reduction to account for the link between the stimulus-evoked visual responses and attentional modulations of behavior. These findings suggest that training can lead to fundamental changes in the way attention alters the early cortical responses that support selective information processing. Moreover, these data facilitate the translation of results across different species and across experimental procedures that employ different behavioral training regimes. PMID:28654635

Postcessation weight gain concern as a barrier to smoking cessation: Assessment considerations and future directions.

PubMed

Germeroth, Lisa J; Levine, Michele D

2018-01-01

Concern about postcessation weight gain may be one potential barrier to quitting smoking. In this 'mini-review' of recent literature, we summarize findings on the relationship between postcessation weight gain concern and smoking cessation, and evaluate varied use of postcessation weight gain concern assessments and potential moderators of the postcessation weight gain concern-cessation association. We conducted a search using the terms "smoking" OR "smoking cessation" AND "weight concern" for articles published between January 1, 2011 and December 31, 2016. We identified 17 studies assessing postcessation weight gain concern, seven of which evaluated the postcessation weight gain concern-cessation association. The relationship between postcessation weight gain concern and smoking cessation was mixed. Recent studies varied in their assessments of postcessation weight gain concern, many of which were not validated and assessed correlates of this construct. Studies varied in their adjustment of demographic (e.g., sex), smoking-specific (e.g., smoking level), and weight-specific (e.g., body mass index) variables. The use of non-validated assessments and variability in testing covariates/moderators may contribute to conflicting results regarding the postcessation weight gain concern-cessation relationship. We recommend validating an assessment of postcessation weight gain concern, maintaining vigilance in testing and reporting covariates/moderators, and investigating trajectories of this construct over time and by smoking status to inform future assessment and intervention efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

The attention habit: how reward learning shapes attentional selection.

PubMed

Anderson, Brian A

2016-04-01

There is growing consensus that reward plays an important role in the control of attention. Until recently, reward was thought to influence attention indirectly by modulating task-specific motivation and its effects on voluntary control over selection. Such an account was consistent with the goal-directed (endogenous) versus stimulus-driven (exogenous) framework that had long dominated the field of attention research. Now, a different perspective is emerging. Demonstrations that previously reward-associated stimuli can automatically capture attention even when physically inconspicuous and task-irrelevant challenge previously held assumptions about attentional control. The idea that attentional selection can be value driven, reflecting a distinct and previously unrecognized control mechanism, has gained traction. Since these early demonstrations, the influence of reward learning on attention has rapidly become an area of intense investigation, sparking many new insights. The result is an emerging picture of how the reward system of the brain automatically biases information processing. Here, I review the progress that has been made in this area, synthesizing a wealth of recent evidence to provide an integrated, up-to-date account of value-driven attention and some of its broader implications. © 2015 New York Academy of Sciences.

Generating a taxonomy of spatially cued attention for visual discrimination: Effects of judgment precision and set size on attention

PubMed Central

Hetley, Richard; Dosher, Barbara Anne; Lu, Zhong-Lin

2014-01-01

Attention precues improve the performance of perceptual tasks in many but not all circumstances. These spatial attention effects may depend upon display set size or workload, and have been variously attributed to external noise filtering, stimulus enhancement, contrast gain, or response gain, or to uncertainty or other decision effects. In this study, we document systematically different effects of spatial attention in low- and high-precision judgments, with and without external noise, and in different set sizes in order to contribute to the development of a taxonomy of spatial attention. An elaborated perceptual template model (ePTM) provides an integrated account of a complex set of effects of spatial attention with just two attention factors: a set-size dependent exclusion or filtering of external noise and a narrowing of the perceptual template to focus on the signal stimulus. These results are related to the previous literature by classifying the judgment precision and presence of external noise masks in those experiments, suggesting a taxonomy of spatially cued attention in discrimination accuracy. PMID:24939234

Generating a taxonomy of spatially cued attention for visual discrimination: effects of judgment precision and set size on attention.

PubMed

Hetley, Richard; Dosher, Barbara Anne; Lu, Zhong-Lin

2014-11-01

Attention precues improve the performance of perceptual tasks in many but not all circumstances. These spatial attention effects may depend upon display set size or workload, and have been variously attributed to external noise filtering, stimulus enhancement, contrast gain, or response gain, or to uncertainty or other decision effects. In this study, we document systematically different effects of spatial attention in low- and high-precision judgments, with and without external noise, and in different set sizes in order to contribute to the development of a taxonomy of spatial attention. An elaborated perceptual template model (ePTM) provides an integrated account of a complex set of effects of spatial attention with just two attention factors: a set-size dependent exclusion or filtering of external noise and a narrowing of the perceptual template to focus on the signal stimulus. These results are related to the previous literature by classifying the judgment precision and presence of external noise masks in those experiments, suggesting a taxonomy of spatially cued attention in discrimination accuracy.

Improvements and important considerations for the 5-choice serial reaction time task-An effective measurement of visual attention in rats.

PubMed

Bhandari, Jayant; Daya, Ritesh; Mishra, Ram K

2016-09-01

The 5-choice serial reaction time task (5-CSRTT) is an automated operant conditioning task that measures rodent attention. The task allows the measurement of several parameters such as response accuracy, speed of processing, motivation, and impulsivity. The task has been widely used to investigate attentional processes in rodents for attention deficit and hyperactivity disorder and has expanded to other illnesses such as Alzheimer's disease, depression, and schizophrenia. The 5-CSRTT is accompanied with two significant caveats: a time intensive training period and largely varied individual rat capability to learn and perform the task. Here we provide a regimented acquisition protocol to enhance training for the 5-CSRTT and discuss important considerations for researchers using the 5-CSRTT. We offer guidelines to ensure that inferences on performance in the 5-CSRTT are in fact a result of experimental manipulation rather than training differences, or individual animal capability. According to our findings only rats that have been trained successfully within a limited time frame should be used for the remainder of the study. Currently the 5-CSRTT employs a training period of variable duration and procedure, and its inferences on attention must overcome heterogeneous innate animal differences. The 5-CSRTT offers valuable and valid insights on various rodent attentional processes and their translation to the underpinnings of illnesses such as schizophrenia. The recommendations made here provide important criteria to ensure inferences made from this task are in fact relevant to the attentional processes being measured. Copyright © 2016 Elsevier B.V. All rights reserved.

A Unifying Mechanistic Model of Selective Attention in Spiking Neurons

PubMed Central

Bobier, Bruce; Stewart, Terrence C.; Eliasmith, Chris

2014-01-01

Visuospatial attention produces myriad effects on the activity and selectivity of cortical neurons. Spiking neuron models capable of reproducing a wide variety of these effects remain elusive. We present a model called the Attentional Routing Circuit (ARC) that provides a mechanistic description of selective attentional processing in cortex. The model is described mathematically and implemented at the level of individual spiking neurons, with the computations for performing selective attentional processing being mapped to specific neuron types and laminar circuitry. The model is used to simulate three studies of attention in macaque, and is shown to quantitatively match several observed forms of attentional modulation. Specifically, ARC demonstrates that with shifts of spatial attention, neurons may exhibit shifting and shrinking of receptive fields; increases in responses without changes in selectivity for non-spatial features (i.e. response gain), and; that the effect on contrast-response functions is better explained as a response-gain effect than as contrast-gain. Unlike past models, ARC embodies a single mechanism that unifies the above forms of attentional modulation, is consistent with a wide array of available data, and makes several specific and quantifiable predictions. PMID:24921249

Color-selective attention need not be mediated by spatial attention.

PubMed

Andersen, Søren K; Müller, Matthias M; Hillyard, Steven A

2009-06-08

It is well-established that attention can select stimuli for preferential processing on the basis of non-spatial features such as color, orientation, or direction of motion. Evidence is mixed, however, as to whether feature-selective attention acts by increasing the signal strength of to-be-attended features irrespective of their spatial locations or whether it acts by guiding the spotlight of spatial attention to locations containing the relevant feature. To address this question, we designed a task in which feature-selective attention could not be mediated by spatial selection. Participants observed a display of intermingled dots of two colors, which rapidly and unpredictably changed positions, with the task of detecting brief intervals of reduced luminance of 20% of the dots of one or the other color. Both behavioral indices and electrophysiological measures of steady-state visual evoked potentials showed selectively enhanced processing of the attended-color items. The results demonstrate that feature-selective attention produces a sensory gain enhancement at early levels of the visual cortex that occurs without mediation by spatial attention.

Deconstructing Interocular Suppression: Attention and Divisive Normalization.

PubMed

Li, Hsin-Hung; Carrasco, Marisa; Heeger, David J

2015-10-01

In interocular suppression, a suprathreshold monocular target can be rendered invisible by a salient competitor stimulus presented in the other eye. Despite decades of research on interocular suppression and related phenomena (e.g., binocular rivalry, flash suppression, continuous flash suppression), the neural processing underlying interocular suppression is still unknown. We developed and tested a computational model of interocular suppression. The model included two processes that contributed to the strength of interocular suppression: divisive normalization and attentional modulation. According to the model, the salient competitor induced a stimulus-driven attentional modulation selective for the location and orientation of the competitor, thereby increasing the gain of neural responses to the competitor and reducing the gain of neural responses to the target. Additional suppression was induced by divisive normalization in the model, similar to other forms of visual masking. To test the model, we conducted psychophysics experiments in which both the size and the eye-of-origin of the competitor were manipulated. For small and medium competitors, behavioral performance was consonant with a change in the response gain of neurons that responded to the target. But large competitors induced a contrast-gain change, even when the competitor was split between the two eyes. The model correctly predicted these results and outperformed an alternative model in which the attentional modulation was eye specific. We conclude that both stimulus-driven attention (selective for location and feature) and divisive normalization contribute to interocular suppression.

Deconstructing Interocular Suppression: Attention and Divisive Normalization

PubMed Central

Li, Hsin-Hung; Carrasco, Marisa; Heeger, David J.

2015-01-01

In interocular suppression, a suprathreshold monocular target can be rendered invisible by a salient competitor stimulus presented in the other eye. Despite decades of research on interocular suppression and related phenomena (e.g., binocular rivalry, flash suppression, continuous flash suppression), the neural processing underlying interocular suppression is still unknown. We developed and tested a computational model of interocular suppression. The model included two processes that contributed to the strength of interocular suppression: divisive normalization and attentional modulation. According to the model, the salient competitor induced a stimulus-driven attentional modulation selective for the location and orientation of the competitor, thereby increasing the gain of neural responses to the competitor and reducing the gain of neural responses to the target. Additional suppression was induced by divisive normalization in the model, similar to other forms of visual masking. To test the model, we conducted psychophysics experiments in which both the size and the eye-of-origin of the competitor were manipulated. For small and medium competitors, behavioral performance was consonant with a change in the response gain of neurons that responded to the target. But large competitors induced a contrast-gain change, even when the competitor was split between the two eyes. The model correctly predicted these results and outperformed an alternative model in which the attentional modulation was eye specific. We conclude that both stimulus-driven attention (selective for location and feature) and divisive normalization contribute to interocular suppression. PMID:26517321

Treating attention in mild aphasia: evaluation of attention process training-II.

PubMed

Murray, Laura L; Keeton, R Jessica; Karcher, Laura

2006-01-01

This study examined whether attention processing training-II [Sohlberg, M. M., Johnson, L., Paule, L., Raskin, S. A., & Mateer, C. A. (2001). Attention Process Training-II: A program to address attentional deficits for persons with mild cognitive dysfunction (2nd ed.). Wake Forest, NC: Lash & Associates.; APT-II], when applied in the context of a multiple baseline ABA design, would improve the attention abilities of RW, a patient with mild conduction aphasia and concomitant attention and working memory deficits. We also explored whether APT-II training would enhance RW's auditory comprehension, other cognitive abilities such as memory, and his and his spouse's perceptions of his daily attention and communication difficulties. With treatment, RW improved on trained attention tasks and made modest gains on standardized tests and probes that evaluated cognitive skills related to treatment activities. Nominal change in auditory comprehension and untrained attention and memory functions was observed, and neither RW nor his spouse reported noticeable improvements in his daily attention or communication abilities. These and previous findings indicate that structured attention retraining may enhance specific attention skills, but that positive changes in broader attention and untrained functions are less likely. As a result of reading this article, the participant will be able to: (1) summarize the previous literature regarding attention impairments and treatment approaches for patients with aphasia. (2) describe how Attention Processing Training-II affected the attention, auditory comprehension, and other cognitive abilities of the patient in this study.

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

ERIC Educational Resources Information Center

Sewell, David K.; Smith, Philip L.

2012-01-01

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

Brillouin gain enhancement in nano-scale photonic waveguide

NASA Astrophysics Data System (ADS)

Nouri Jouybari, Soodabeh

2018-05-01

The enhancement of stimulated Brillouin scattering in nano-scale waveguides has a great contribution in the improvement of the photonic devices technology. The key factors in Brillouin gain are the electrostriction force and radiation pressure generated by optical waves in the waveguide. In this article, we have proposed a new scheme of nano-scale waveguide in which the Brillouin gain is considerably improved compared to the previously-reported schemes. The role of radiation pressure in the Brillouin gain was much higher than the role of the electrostriction force. The Brillouin gain strongly depends on the structural parameters of the waveguide and the maximum value of 12127 W-1 m-1 is obtained for the Brillouin gain.

Scope of Attention, Control of Attention, and Intelligence in Children and Adults

PubMed Central

Cowan, Nelson; Fristoe, Nathanael M.; Elliott, Emily M.; Brunner, Ryan P.; Saults, J. Scott

2006-01-01

Recent experimentation has shown that cognitive aptitude measures are predicted by tests of the scope of an individual’s attention or capacity in simple working-memory tasks, and also by the ability to control attention. However, these experiments do not indicate how separate or related the scope and control of attention are. An experiment with 52 children 10 to 11 years old and 52 college students included measures of the scope and control of attention as well as verbal and nonverbal aptitude measures. The children showed little evidence of using sophisticated attentional control, but the scope of attention predicted intelligence in that group. In adults, the scope and control of attention both varied among individuals, and they accounted for considerable individual variance in intelligence. About 1/3 that variance was shared between scope and control, the rest being unique to one or the other. Scope and control of attention appear to be related but distinct contributors to intelligence. PMID:17489300

Loss restlessness and gain calmness: durable effects of losses and gains on choice switching.

PubMed

Yechiam, Eldad; Zahavi, Gal; Arditi, Eli

2015-08-01

While the traditional conceptualization of the effect of losses focuses on bias in the subjective weight of losses compared with respective gains, some accounts suggest more global task-related effects of losses. Based on a recent attentional theory, we predicted a positive after-effect of losses on choice switching in later tasks. In two experimental studies, we found increased choice switching rates in tasks with losses compared to tasks with no losses. Additionally, this heightened shifting behavior was maintained in subsequent tasks that do not include losses, a phenomenon we refer to as "loss restlessness." Conversely, gains were found to have an opposite "calming" effect on choice switching. Surprisingly, the loss restlessness phenomenon was observed following an all-losses payoff regime but not after a task with symmetric mixed gains and losses. This suggests that the unresolved mental account following an all-losses regime increases search behavior. Potential implications to macro level phenomena, such as the leverage effect, are discussed.

Neuronal Response Gain Enhancement prior to Microsaccades.

PubMed

Chen, Chih-Yang; Ignashchenkova, Alla; Thier, Peter; Hafed, Ziad M

2015-08-17

Neuronal response gain enhancement is a classic signature of the allocation of covert visual attention without eye movements. However, microsaccades continuously occur during gaze fixation. Because these tiny eye movements are preceded by motor preparatory signals well before they are triggered, it may be the case that a corollary of such signals may cause enhancement, even without attentional cueing. In six different macaque monkeys and two different brain areas previously implicated in covert visual attention (superior colliculus and frontal eye fields), we show neuronal response gain enhancement for peripheral stimuli appearing immediately before microsaccades. This enhancement occurs both during simple fixation with behaviorally irrelevant peripheral stimuli and when the stimuli are relevant for the subsequent allocation of covert visual attention. Moreover, this enhancement occurs in both purely visual neurons and visual-motor neurons, and it is replaced by suppression for stimuli appearing immediately after microsaccades. Our results suggest that there may be an obligatory link between microsaccade occurrence and peripheral selective processing, even though microsaccades can be orders of magnitude smaller than the eccentricities of peripheral stimuli. Because microsaccades occur in a repetitive manner during fixation, and because these eye movements reset neurophysiological rhythms every time they occur, our results highlight a possible mechanism through which oculomotor events may aid periodic sampling of the visual environment for the benefit of perception, even when gaze is prevented from overtly shifting. One functional consequence of such periodic sampling could be the magnification of rhythmic fluctuations of peripheral covert visual attention. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Antipsychotic-induced weight gain--pharmacogenetic studies].

PubMed

Olajossy-Hilkesberger, Luiza; Godlewska, Beata; Marmurowska-Michałowskal, Halina; Olajossy, Marcin; Landowski, Jerzy

2006-01-01

Drug-naive patients with schizophrenia often present metabolic abnormalities and obesity. Weight gain may be the side effect of treatment with many antipsychotic drugs. Genetic effects, besides many other factors, are known to influence obesity in patients with schizophrenia treated with antipsychotics. Numerous studies of several genes' polymorphisms have been performed. -759C/T polymorphism of 5HT2C gene attracted most attention. In 5 independent studies of this polymorphism the association between T allele with the lower AP-induced weight gain was detected. No associations could be detected between weight gain and other polymorphisms of serotonergic system genes as well as histaminergic system genes. Studies of adrenergic and dopaminergic system have neither produced any unambiguous results. Analysis of the newest candidate genes (SAP-25, leptin gene) confirmed the role of genetic factors in AP-induced weight gain. It is worth emphasising, that the studies have been conducted in relatively small and heterogenic groups and that various treatment strategies were used.

Attention and prediction in human audition: a lesson from cognitive psychophysiology

PubMed Central

Schröger, Erich; Marzecová, Anna; SanMiguel, Iria

2015-01-01

Attention is a hypothetical mechanism in the service of perception that facilitates the processing of relevant information and inhibits the processing of irrelevant information. Prediction is a hypothetical mechanism in the service of perception that considers prior information when interpreting the sensorial input. Although both (attention and prediction) aid perception, they are rarely considered together. Auditory attention typically yields enhanced brain activity, whereas auditory prediction often results in attenuated brain responses. However, when strongly predicted sounds are omitted, brain responses to silence resemble those elicited by sounds. Studies jointly investigating attention and prediction revealed that these different mechanisms may interact, e.g. attention may magnify the processing differences between predicted and unpredicted sounds. Following the predictive coding theory, we suggest that prediction relates to predictions sent down from predictive models housed in higher levels of the processing hierarchy to lower levels and attention refers to gain modulation of the prediction error signal sent up to the higher level. As predictions encode contents and confidence in the sensory data, and as gain can be modulated by the intention of the listener and by the predictability of the input, various possibilities for interactions between attention and prediction can be unfolded. From this perspective, the traditional distinction between bottom-up/exogenous and top-down/endogenous driven attention can be revisited and the classic concepts of attentional gain and attentional trace can be integrated. PMID:25728182

Can LENR Energy Gains Exceed 1000?

NASA Astrophysics Data System (ADS)

Nagel, David J.

2011-03-01

Energy gain is defined as the energy realized from reactions divided by the energy required to produce those reactions. Low Energy Nuclear Reactions (LENR) have already been measured to significantly exceed the energy gain of 10 projected from ITER,possibly 15 years from now. Electrochemical experiments using the Pd-D system have shown energy gains exceeding 10. Gas phase experiments with the Ni-H system were reported to yield energy gains of over 100. Neither of these reports has been adequately verified or reproduced. However, the question in the title still deserves consideration. If, as thought by many, it is possible to trigger nuclear reactions that yield MeV energies with chemical energies of the order of eV, then the most optimistic expectation is that LENR gains could approach one million. Hence, the very tentative answer to the question above is yes. However, if LENR could be initiated with some energy cost, and then continue to ``burn,'' very high energy gains might be realized. Consider a match and a pile of dry logs. The phenomenon termed ``heat after death'' will be examined to see if it might be the initial evidence for nuclear ``burning.''

Using a filtering task to measure the spatial extent of selective attention

PubMed Central

Palmer, John; Moore, Cathleen M.

2009-01-01

The spatial extent of attention was investigated by measuring sensitivity to stimuli at to-be-ignored locations. Observers detected a stimulus at a cued location (target), while ignoring otherwise identical stimuli at nearby locations (foils). Only an attentional cue distinguished target from foil. Several experiments varied the contrast and separation of targets and foils. Two theories of selection were compared: contrast gain and a version of attention switching called an all-or-none mixture model. Results included large effects of separation, rejection of the contrast gain model, and the measurement of the size and profile of the spatial extent of attention. PMID:18405935

Prospect theory reflects selective allocation of attention.

PubMed

Pachur, Thorsten; Schulte-Mecklenbeck, Michael; Murphy, Ryan O; Hertwig, Ralph

2018-02-01

There is a disconnect in the literature between analyses of risky choice based on cumulative prospect theory (CPT) and work on predecisional information processing. One likely reason is that for expectation models (e.g., CPT), it is often assumed that people behaved only as if they conducted the computations leading to the predicted choice and that the models are thus mute regarding information processing. We suggest that key psychological constructs in CPT, such as loss aversion and outcome and probability sensitivity, can be interpreted in terms of attention allocation. In two experiments, we tested hypotheses about specific links between CPT parameters and attentional regularities. Experiment 1 used process tracing to monitor participants' predecisional attention allocation to outcome and probability information. As hypothesized, individual differences in CPT's loss-aversion, outcome-sensitivity, and probability-sensitivity parameters (estimated from participants' choices) were systematically associated with individual differences in attention allocation to outcome and probability information. For instance, loss aversion was associated with the relative attention allocated to loss and gain outcomes, and a more strongly curved weighting function was associated with less attention allocated to probabilities. Experiment 2 manipulated participants' attention to losses or gains, causing systematic differences in CPT's loss-aversion parameter. This result indicates that attention allocation can to some extent cause choice regularities that are captured by CPT. Our findings demonstrate an as-if model's capacity to reflect characteristics of information processing. We suggest that the observed CPT-attention links can be harnessed to inform the development of process models of risky choice. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Window Design Criteria to Avoid Overheating by Excessive Solar Heat Gains.

ERIC Educational Resources Information Center

Loudon, A. G.

Building Research studies show that overheating because of excessive solar heat gains can be troublesome in buildings of lightweight construction with large areas of glazing. The work being done at the Building Research Station provides the data for calculation of peak temperatures resulting from solar heat gain. Attention is given to window size…

Distractor Inhibition: Principles of Operation during Selective Attention

ERIC Educational Resources Information Center

Wyatt, Natalie; Machado, Liana

2013-01-01

Research suggests that although target amplification acts as the main determinant of the efficacy of selective attention, distractor inhibition contributes under some circumstances. Here we aimed to gain insight into the operating principles that regulate the use of distractor inhibition during selective attention. The results suggest that, in…

Attention-driven auditory cortex short-term plasticity helps segregate relevant sounds from noise

PubMed Central

Ahveninen, Jyrki; Hämäläinen, Matti; Jääskeläinen, Iiro P.; Ahlfors, Seppo P.; Huang, Samantha; Raij, Tommi; Sams, Mikko; Vasios, Christos E.; Belliveau, John W.

2011-01-01

How can we concentrate on relevant sounds in noisy environments? A “gain model” suggests that auditory attention simply amplifies relevant and suppresses irrelevant afferent inputs. However, it is unclear whether this suffices when attended and ignored features overlap to stimulate the same neuronal receptive fields. A “tuning model” suggests that, in addition to gain, attention modulates feature selectivity of auditory neurons. We recorded magnetoencephalography, EEG, and functional MRI (fMRI) while subjects attended to tones delivered to one ear and ignored opposite-ear inputs. The attended ear was switched every 30 s to quantify how quickly the effects evolve. To produce overlapping inputs, the tones were presented alone vs. during white-noise masking notch-filtered ±1/6 octaves around the tone center frequencies. Amplitude modulation (39 vs. 41 Hz in opposite ears) was applied for “frequency tagging” of attention effects on maskers. Noise masking reduced early (50–150 ms; N1) auditory responses to unattended tones. In support of the tuning model, selective attention canceled out this attenuating effect but did not modulate the gain of 50–150 ms activity to nonmasked tones or steady-state responses to the maskers themselves. These tuning effects originated at nonprimary auditory cortices, purportedly occupied by neurons that, without attention, have wider frequency tuning than ±1/6 octaves. The attentional tuning evolved rapidly, during the first few seconds after attention switching, and correlated with behavioral discrimination performance. In conclusion, a simple gain model alone cannot explain auditory selective attention. In nonprimary auditory cortices, attention-driven short-term plasticity retunes neurons to segregate relevant sounds from noise. PMID:21368107

Attention-driven auditory cortex short-term plasticity helps segregate relevant sounds from noise.

PubMed

Ahveninen, Jyrki; Hämäläinen, Matti; Jääskeläinen, Iiro P; Ahlfors, Seppo P; Huang, Samantha; Lin, Fa-Hsuan; Raij, Tommi; Sams, Mikko; Vasios, Christos E; Belliveau, John W

2011-03-08

How can we concentrate on relevant sounds in noisy environments? A "gain model" suggests that auditory attention simply amplifies relevant and suppresses irrelevant afferent inputs. However, it is unclear whether this suffices when attended and ignored features overlap to stimulate the same neuronal receptive fields. A "tuning model" suggests that, in addition to gain, attention modulates feature selectivity of auditory neurons. We recorded magnetoencephalography, EEG, and functional MRI (fMRI) while subjects attended to tones delivered to one ear and ignored opposite-ear inputs. The attended ear was switched every 30 s to quantify how quickly the effects evolve. To produce overlapping inputs, the tones were presented alone vs. during white-noise masking notch-filtered ±1/6 octaves around the tone center frequencies. Amplitude modulation (39 vs. 41 Hz in opposite ears) was applied for "frequency tagging" of attention effects on maskers. Noise masking reduced early (50-150 ms; N1) auditory responses to unattended tones. In support of the tuning model, selective attention canceled out this attenuating effect but did not modulate the gain of 50-150 ms activity to nonmasked tones or steady-state responses to the maskers themselves. These tuning effects originated at nonprimary auditory cortices, purportedly occupied by neurons that, without attention, have wider frequency tuning than ±1/6 octaves. The attentional tuning evolved rapidly, during the first few seconds after attention switching, and correlated with behavioral discrimination performance. In conclusion, a simple gain model alone cannot explain auditory selective attention. In nonprimary auditory cortices, attention-driven short-term plasticity retunes neurons to segregate relevant sounds from noise.

Considerations for Community-Based mHealth Initiatives: Insights From Three Beacon Communities

PubMed Central

2013-01-01

Mobile health (mHealth) is gaining widespread attention for its potential to engage patients in their health and health care in their daily lives. Emerging evidence suggests that mHealth interventions can be used effectively to support behavior change, but numerous challenges remain when implementing these programs at the community level. This paper provides an overview of considerations when implementing community-based mHealth initiatives, based on the experiences of three Beacon Communities across the United States that have launched text messaging (short message service, SMS) pilot programs aimed at diabetes risk reduction and disease management. The paper addresses lessons learned and suggests strategies to overcome challenges related to developing text message content, conducting marketing and outreach, enrolling participants, engaging providers, evaluating program effectiveness, and sustaining and scaling the programs. PMID:24128406

Association between Stock Market Gains and Losses and Google Searches

PubMed Central

Arditi, Eli; Yechiam, Eldad; Zahavi, Gal

2015-01-01

Experimental studies in the area of Psychology and Behavioral Economics have suggested that people change their search pattern in response to positive and negative events. Using Internet search data provided by Google, we investigated the relationship between stock-specific events and related Google searches. We studied daily data from 13 stocks from the Dow-Jones and NASDAQ100 indices, over a period of 4 trading years. Focusing on periods in which stocks were extensively searched (Intensive Search Periods), we found a correlation between the magnitude of stock returns at the beginning of the period and the volume, peak, and duration of search generated during the period. This relation between magnitudes of stock returns and subsequent searches was considerably magnified in periods following negative stock returns. Yet, we did not find that intensive search periods following losses were associated with more Google searches than periods following gains. Thus, rather than increasing search, losses improved the fit between people’s search behavior and the extent of real-world events triggering the search. The findings demonstrate the robustness of the attentional effect of losses. PMID:26513371

Spatial attention, feature-based attention and saccades: Three sides of one coin?

PubMed Central

Mazer, James A.

2013-01-01

The last three decades has seen a steady growth of neuroscience research aimed at understanding the functions and sources of top-down attentional modulation in the brain. This correlates with recognition that attention may be a necessary component of sensory systems to support natural behaviors in natural environments. Complexity and clutter are two of the most recognizable hallmarks of natural environments, which can simultaneously contain vitally important and completely irrelevant stimuli. Attention serves as an adaptive filter allowing each sensory modality preferential processing routes for important stimuli while suppressing responses to distracters, thus optimizing use of limited neural resources. In other words, “attention” is the family of mechanisms by which organisms are able to effectively and selectively allocate limited neural resources to achieve specific behavioral goals. This review provides some historical context for considering attentional frameworks and modern neurophysiological attention research, focusing on visual attention. A taxonomy of common attentional effects and neural mechanisms is provided, along with consideration of the specific relationship between attention and saccade planning. We examine the validity of premotor theories of attention, which posit that attention and saccade planning are one and the same. While there is strong evidence that attention and oculomotor planning are similar, with shared neural substrates, there is also evidence that these two functions are not synonymous. Finally, we examine neurophysiological explanations for dysfunction in Attention Deficit Hyperactivity Disorder (ADHD) and the hypothesis that social impairment in Autism Spectrum Disorders (ASD) is partially attributable to perturbations of attentional control circuitry. PMID:21529782

A Review of Methods in the Study of Attention in Autism

ERIC Educational Resources Information Center

Ames, Catherine; Fletcher-Watson, Sue

2010-01-01

Atypical attention, while not a diagnostic feature, is common in individuals with autism spectrum disorders (ASD). The study of these atypicalities has recently gained in both quantity and quality, due in part to an increased focus on attentional atypicalities as one of the earliest signs of ASD in infancy. A range of attentional processes and…

Attention Induced Gain Stabilization in Broad and Narrow-Spiking Cells in the Frontal Eye-Field of Macaque Monkeys

PubMed Central

Brandt, Christian; Dasilva, Miguel; Gotthardt, Sascha; Chicharro, Daniel; Panzeri, Stefano; Distler, Claudia

2016-01-01

Top-down attention increases coding abilities by altering firing rates and rate variability. In the frontal eye field (FEF), a key area enabling top-down attention, attention induced firing rate changes are profound, but its effect on different cell types is unknown. Moreover, FEF is the only cortical area investigated in which attention does not affect rate variability, as assessed by the Fano factor, suggesting that task engagement affects cortical state nonuniformly. We show that putative interneurons in FEF of Macaca mulatta show stronger attentional rate modulation than putative pyramidal cells. Partitioning rate variability reveals that both cell types reduce rate variability with attention, but more strongly so in narrow-spiking cells. The effects are captured by a model in which attention stabilizes neuronal excitability, thereby reducing the expansive nonlinearity that links firing rate and variance. These results show that the effect of attention on different cell classes and different coding properties are consistent across the cortical hierarchy, acting through increased and stabilized neuronal excitability. SIGNIFICANCE STATEMENT Cortical processing is critically modulated by attention. A key feature of this influence is a modulation of “cortical state,” resulting in increased neuronal excitability and resilience of the network against perturbations, lower rate variability, and an increased signal-to-noise ratio. In the frontal eye field (FEF), an area assumed to control spatial attention in human and nonhuman primates, firing rate changes with attention occur, but rate variability, quantified by the Fano factor, appears to be unaffected by attention. Using recently developed analysis tools and models to quantify attention effects on narrow- and broad-spiking cell activity, we show that attention alters cortical state strongly in the FEF, demonstrating that its effect on the neuronal network is consistent across the cortical hierarchy. PMID

The ethics in qualitative health research: special considerations.

PubMed

Peter, Elizabeth

2015-09-01

A sound knowledge of the nature of qualitative research, along with an appreciation of some special ethical considerations, is needed for rigorous reviews to be conducted. The overall character of qualitative research is described with an emphasis on the tendency of qualitative researchers to explore sensitive topics using theoretically informed methods. A number of specific features of qualitative that require additional ethical attention and awareness are also examined including the following: 1) participants are frequently quite vulnerable and require protection because the data collection methods, such as in-depth interviews, can delve into personally and politically charged matters; 2) naturalistic observation can raise concerns regarding privacy and consent; 3) the potential for the identifiability of the results of this research may require extra efforts to maintain confidentiality. Ultimately, Reseach Ethics Committee members must be knowledgeable about qualitative approaches to be able to assess the potential harms and benefits in a protocol carefully. Without this knowledge gaining ethics approval can be overly difficult for researchers and the best practices for protecting human participants can be overlooked.

Eyewitness identification: Bayesian information gain, base-rate effect equivalency curves, and reasonable suspicion.

PubMed

Wells, Gary L; Yang, Yueran; Smalarz, Laura

2015-04-01

We provide a novel Bayesian treatment of the eyewitness identification problem as it relates to various system variables, such as instruction effects, lineup presentation format, lineup-filler similarity, lineup administrator influence, and show-ups versus lineups. We describe why eyewitness identification is a natural Bayesian problem and how numerous important observations require careful consideration of base rates. Moreover, we argue that the base rate in eyewitness identification should be construed as a system variable (under the control of the justice system). We then use prior-by-posterior curves and information-gain curves to examine data obtained from a large number of published experiments. Next, we show how information-gain curves are moderated by system variables and by witness confidence and we note how information-gain curves reveal that lineups are consistently more proficient at incriminating the guilty than they are at exonerating the innocent. We then introduce a new type of analysis that we developed called base rate effect-equivalency (BREE) curves. BREE curves display how much change in the base rate is required to match the impact of any given system variable. The results indicate that even relatively modest changes to the base rate can have more impact on the reliability of eyewitness identification evidence than do the traditional system variables that have received so much attention in the literature. We note how this Bayesian analysis of eyewitness identification has implications for the question of whether there ought to be a reasonable-suspicion criterion for placing a person into the jeopardy of an identification procedure. (c) 2015 APA, all rights reserved).

Losses as Modulators of Attention: Review and Analysis of the Unique Effects of Losses over Gains

ERIC Educational Resources Information Center

Yechiam, Eldad; Hochman, Guy

2013-01-01

It has been shown that in certain situations losses exert a stronger effect on behavior than respective gains, and this has been commonly explained by the argument that losses are given more weight in people's decisions than respective gains. However, although much is understood about the effect of losses on cognitive processes and behavior, 2…

Inferior parietal and right frontal contributions to trial-by-trial adaptations of attention to memory.

PubMed

Kizilirmak, Jasmin M; Rösler, Frank; Bien, Siegfried; Khader, Patrick H

2015-07-21

The attention to memory theory (AtoM) proposes that the same brain regions might be involved in selective processing of perceived stimuli (selective attention) and memory representations (selective retrieval). Although this idea is compelling, given consistently found neural overlap between perceiving and remembering stimuli, recent comparisons brought evidence for overlap as well as considerable differences. Here, we present a paradigm that enables the investigation of the AtoM hypothesis from a novel perspective to gain further insight into the neural resources involved in AtoM. Selective attention in perception is often investigated as a control process that shows lingering effects on immediately following trials. Here, we employed a paradigm capable of modulating selective retrieval in a similarly dynamic manner as in such selective-attention paradigms by inducing trial-to-trial shifts between relevant and irrelevant memory representations as well as changes of the width of the internal focus on memory. We found evidence for an involvement of bilateral inferior parietal lobe and right inferior frontal gyrus in reorienting the attentional focus on previously accessed memory representations. Moreover, we could dissociate the right inferior from the parietal activation in separate contrasts, suggesting that the right inferior frontal gyrus plays a role in facilitating attentional reorienting to memory representations when competing representations have been activated in the preceding trial, potentially by resolving this competition. Our results support the AtoM theory, i.e. that ventral frontal and parietal regions are involved in automatic attentional reorienting in memory, and highlight the importance of further investigations of the overlap and differences between regions involved in internal (memory) and external (perceptual) attentional selection. Copyright © 2015 Elsevier B.V. All rights reserved.

Review of health and productivity gains from better IEQ

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

Fisk, William J.

2000-08-01

The available scientific data suggest that existing technologies and procedures can improve indoor environmental quality (IEQ) in a manner that significantly increases productivity and health. While there is considerable uncertainty in the estimates of the magnitudes of productivity gains that may be obtained, the projected gains are very large. For the U.S., the estimated potential annual savings and productivity gains are $6 to $14 billion from reduced respiratory disease, $2 to $4 billion from reduced allergies and asthma, $10 to $30 billion from reduced sick building syndrome symptoms, and $20 to $160 billion from direct improvements in worker performance thatmore » are unrelated to health. Productivity gains that are quantified and demonstrated could serve as a strong stimulus for energy efficiency measures that simultaneously improve the indoor environment.« less

Dietary protein considerations to support active aging.

PubMed

Wall, Benjamin T; Cermak, Naomi M; van Loon, Luc J C

2014-11-01

Given our rapidly aging world-wide population, the loss of skeletal muscle mass with healthy aging (sarcopenia) represents an important societal and public health concern. Maintaining or adopting an active lifestyle alleviates age-related muscle loss to a certain extent. Over time, even small losses of muscle tissue can hinder the ability to maintain an active lifestyle and, as such, contribute to the development of frailty and metabolic disease. Considerable research focus has addressed the application of dietary protein supplementation to support exercise-induced gains in muscle mass in younger individuals. In contrast, the role of dietary protein in supporting the maintenance (or gain) of skeletal muscle mass in active older persons has received less attention. Older individuals display a blunted muscle protein synthetic response to dietary protein ingestion. However, this reduced anabolic response can largely be overcome when physical activity is performed in close temporal proximity to protein consumption. Moreover, recent evidence has helped elucidate the optimal type and amount of dietary protein that should be ingested by the older adult throughout the day in order to maximize the skeletal muscle adaptive response to physical activity. Evidence demonstrates that when these principles are adhered to, muscle maintenance or hypertrophy over prolonged periods can be further augmented in active older persons. The present review outlines the current understanding of the role that dietary protein occupies in the lifestyle of active older adults as a means to increase skeletal muscle mass, strength and function, and thus support healthier aging.

Automatic Gain Control in Compact Spectrometers.

PubMed

Protopopov, Vladimir

2016-03-01

An image intensifier installed in the optical path of a compact spectrometer may act not only as a fast gating unit, which is widely used for time-resolved measurements, but also as a variable attenuator-amplifier in a continuous wave mode. This opens the possibility of an automatic gain control, a new feature in spectroscopy. With it, the user is relieved from the necessity to manually adjust signal level at a certain value that it is done automatically by means of an electronic feedback loop. It is even more important that automatic gain control is done without changing exposure time, which is an additional benefit in time-resolved experiments. The concept, algorithm, design considerations, and experimental results are presented. © The Author(s) 2016.

The Development of Attention Systems and Working Memory in Infancy

PubMed Central

Reynolds, Greg D.; Romano, Alexandra C.

2016-01-01

In this article, we review research and theory on the development of attention and working memory in infancy using a developmental cognitive neuroscience framework. We begin with a review of studies examining the influence of attention on neural and behavioral correlates of an earlier developing and closely related form of memory (i.e., recognition memory). Findings from studies measuring attention utilizing looking measures, heart rate, and event-related potentials (ERPs) indicate significant developmental change in sustained and selective attention across the infancy period. For example, infants show gains in the magnitude of the attention related response and spend a greater proportion of time engaged in attention with increasing age (Richards and Turner, 2001). Throughout infancy, attention has a significant impact on infant performance on a variety of tasks tapping into recognition memory; however, this approach to examining the influence of infant attention on memory performance has yet to be utilized in research on working memory. In the second half of the article, we review research on working memory in infancy focusing on studies that provide insight into the developmental timing of significant gains in working memory as well as research and theory related to neural systems potentially involved in working memory in early development. We also examine issues related to measuring and distinguishing between working memory and recognition memory in infancy. To conclude, we discuss relations between the development of attention systems and working memory. PMID:26973473

The Development of Attention Systems and Working Memory in Infancy.

PubMed

Reynolds, Greg D; Romano, Alexandra C

2016-01-01

In this article, we review research and theory on the development of attention and working memory in infancy using a developmental cognitive neuroscience framework. We begin with a review of studies examining the influence of attention on neural and behavioral correlates of an earlier developing and closely related form of memory (i.e., recognition memory). Findings from studies measuring attention utilizing looking measures, heart rate, and event-related potentials (ERPs) indicate significant developmental change in sustained and selective attention across the infancy period. For example, infants show gains in the magnitude of the attention related response and spend a greater proportion of time engaged in attention with increasing age (Richards and Turner, 2001). Throughout infancy, attention has a significant impact on infant performance on a variety of tasks tapping into recognition memory; however, this approach to examining the influence of infant attention on memory performance has yet to be utilized in research on working memory. In the second half of the article, we review research on working memory in infancy focusing on studies that provide insight into the developmental timing of significant gains in working memory as well as research and theory related to neural systems potentially involved in working memory in early development. We also examine issues related to measuring and distinguishing between working memory and recognition memory in infancy. To conclude, we discuss relations between the development of attention systems and working memory.

Do disinhibited eaters pay increased attention to food cues?

PubMed

Seage, C H; Lee, M

2017-01-01

The Three Factors Eating Questionnaire's measure of disinhibited eating is a robust predictor of long-term weight gain. This experiment explored if disinhibited eaters display attentional bias to food cues. Participants (N = 45) completed a visual dot probe task which measured responses to food (energy dense and low energy foods) and neutral cues. Picture pairs were displayed either for a 100 ms or 2000 ms duration. All participants displayed attentional bias for energy dense food items. Indices of attentional bias were largest in disinhibited eaters. Attentional bias in disinhibited eaters appeared to be underpinned by facilitated attention. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gain- and Loss-Related Brain Activation Are Associated with Information Search Differences in Risky Gambles: An fMRI and Eye-Tracking Study.

PubMed

Häusler, Alexander Niklas; Oroz Artigas, Sergio; Trautner, Peter; Weber, Bernd

2016-01-01

People differ in the way they approach and handle choices with unsure outcomes. In this study, we demonstrate that individual differences in the neural processing of gains and losses relates to attentional differences in the way individuals search for information in gambles. Fifty subjects participated in two independent experiments. Participants first completed an fMRI experiment involving financial gains and losses. Subsequently, they performed an eye-tracking experiment on binary choices between risky gambles, each displaying monetary outcomes and their respective probabilities. We find that individual differences in gain and loss processing relate to attention distribution. Individuals with a stronger reaction to gains in the ventromedial prefrontal cortex paid more attention to monetary amounts, while a stronger reaction in the ventral striatum to losses was correlated with an increased attention to probabilities. Reaction in the posterior cingulate cortex to losses was also found to correlate with an increased attention to probabilities. Our data show that individual differences in brain activity and differences in information search processes are closely linked.

Gain- and Loss-Related Brain Activation Are Associated with Information Search Differences in Risky Gambles: An fMRI and Eye-Tracking Study

PubMed Central

Trautner, Peter

2016-01-01

Abstract People differ in the way they approach and handle choices with unsure outcomes. In this study, we demonstrate that individual differences in the neural processing of gains and losses relates to attentional differences in the way individuals search for information in gambles. Fifty subjects participated in two independent experiments. Participants first completed an fMRI experiment involving financial gains and losses. Subsequently, they performed an eye-tracking experiment on binary choices between risky gambles, each displaying monetary outcomes and their respective probabilities. We find that individual differences in gain and loss processing relate to attention distribution. Individuals with a stronger reaction to gains in the ventromedial prefrontal cortex paid more attention to monetary amounts, while a stronger reaction in the ventral striatum to losses was correlated with an increased attention to probabilities. Reaction in the posterior cingulate cortex to losses was also found to correlate with an increased attention to probabilities. Our data show that individual differences in brain activity and differences in information search processes are closely linked. PMID:27679814

Neuroscience of attentional processes for addiction medicine: from brain mechanisms to practical considerations.

PubMed

Fadardi, Javad Salehi; Cox, W Miles; Rahmani, Arash

2016-01-01

The present chapter first argues how having a goal for procuring alcohol or other substances leads to the development of a time-binding, dynamic, and goal oriented motivational state termed current concern, as the origin of substance-related attentional bias. Next, it discusses the importance of attentional bias in the development, continuation of, and relapsing to substance abuse. It further proceeds with a review of selective evidence from cognitive psychology that helps account for making decisions about using an addictive substance or refraining from using it. A discussion on the various brain loci that are involved in attentional bias and other kinds of cue reactivity is followed by presenting findings from neurocognitive research. Finally, from an interdisciplinary perspective, the chapter presents new trends and ideas that can be applied to addiction-related cognitive measurement and training. © 2016 Elsevier B.V. All rights reserved.

Graphene plasmons embedded in a gain medium: layer and ribbon plasmons

NASA Astrophysics Data System (ADS)

Altares Menendez, Galaad; Rosolen, Gilles; Maes, Bjorn

2016-12-01

Graphene plasmonics has attracted much attention due to its remarkable properties such as tunable conductivity and extreme confinement. However, losses remain one of the major drawbacks to developing more efficient devices based on graphene plasmons. Here we show that when a gain medium is introduced around a 1D graphene sheet, lossless propagation can be achieved for a critical gain value. Both numerics and analytics are employed; and with the Drude approximation the analytical expression for this critical gain becomes remarkably simple. Furthermore, we examine a single 2D graphene nanoribbon within a gain environment. We report that the plasmonic resonant modes exhibit a spasing effect for a specific value of the surrounding gain. This feature is indicated by an absorption cross section that strongly increases and narrows. Finally, we manage to connect the ribbon results to the 1D sheet critical gain, by taking external coupling into account.

Endogenous attention modulates early selective attention in psychopathy: An ERP investigation.

PubMed

Krusemark, Elizabeth A; Kiehl, Kent A; Newman, Joseph P

2016-10-01

Psychopathic individuals are prone to act on urges without adequate consideration of future consequences or the rights of other individuals. One interpretation of this behavior is that it reflects abnormal selective attention (i.e., a failure to process information that is incongruent with their primary focus of attention; Hiatt, Schmitt, & Newman, Neuropsychology, 18, 50-59, 2004). Unfortunately, it is unclear whether this selective attention abnormality reflects top-down endogenous influences, such as the strength or specificity of attention focus (i.e., top-down set) apart from other, more exogenous (bottom-up), effects on attention. To explore this question, we used an early visual event-related potential (N2pc) in combination with a modified visual search task designed to assess the effect of early endogenous (i.e., top-down) attention on the processing of set-congruent information. The task was administered to a sample of 70 incarcerated adult males, who were assigned to high, intermediate, and low psychopathy groups using Hare's Psychopathy Checklist-Revised (Hare, 2003). Based on the assumption that their failure to process set-incongruent information reflects the exaggerated effects of endogenous attention, we predicted that participants with high psychopathy scores would show an exaggerated N2pc response to set-congruent information. The results supported the hypothesis and provide novel electrophysiological evidence that psychopathy is associated with exaggerated endogenous attention effects during early stages of processing. Further research is needed to examine the implications of this finding for the well-established failure of psychopathic individuals to process set-incongruent information and inhibit inappropriate responses.

Attention is necessary for subliminal instrumental conditioning.

PubMed

Mastropasqua, Tommaso; Turatto, Massimo

2015-08-10

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

Attention is necessary for subliminal instrumental conditioning

PubMed Central

Mastropasqua, Tommaso; Turatto, Massimo

2015-01-01

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

Long-term memory biases auditory spatial attention.

PubMed

Zimmermann, Jacqueline F; Moscovitch, Morris; Alain, Claude

2017-10-01

Long-term memory (LTM) has been shown to bias attention to a previously learned visual target location. Here, we examined whether memory-predicted spatial location can facilitate the detection of a faint pure tone target embedded in real world audio clips (e.g., soundtrack of a restaurant). During an initial familiarization task, participants heard audio clips, some of which included a lateralized target (p = 50%). On each trial participants indicated whether the target was presented from the left, right, or was absent. Following a 1 hr retention interval, participants were presented with the same audio clips, which now all included a target. In Experiment 1, participants showed memory-based gains in response time and d'. Experiment 2 showed that temporal expectations modulate attention, with greater memory-guided attention effects on performance when temporal context was reinstated from learning (i.e., when timing of the target within audio clips was not changed from initially learned timing). Experiment 3 showed that while conscious recall of target locations was modulated by exposure to target-context associations during learning (i.e., better recall with higher number of learning blocks), the influence of LTM associations on spatial attention was not reduced (i.e., number of learning blocks did not affect memory-guided attention). Both Experiments 2 and 3 showed gains in performance related to target-context associations, even for associations that were not explicitly remembered. Together, these findings indicate that memory for audio clips is acquired quickly and is surprisingly robust; both implicit and explicit LTM for the location of a faint target tone modulated auditory spatial attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Neural Net Gains Estimation Based on an Equivalent Model

PubMed Central

Aguilar Cruz, Karen Alicia; Medel Juárez, José de Jesús; Fernández Muñoz, José Luis; Esmeralda Vigueras Velázquez, Midory

2016-01-01

A model of an Equivalent Artificial Neural Net (EANN) describes the gains set, viewed as parameters in a layer, and this consideration is a reproducible process, applicable to a neuron in a neural net (NN). The EANN helps to estimate the NN gains or parameters, so we propose two methods to determine them. The first considers a fuzzy inference combined with the traditional Kalman filter, obtaining the equivalent model and estimating in a fuzzy sense the gains matrix A and the proper gain K into the traditional filter identification. The second develops a direct estimation in state space, describing an EANN using the expected value and the recursive description of the gains estimation. Finally, a comparison of both descriptions is performed; highlighting the analytical method describes the neural net coefficients in a direct form, whereas the other technique requires selecting into the Knowledge Base (KB) the factors based on the functional error and the reference signal built with the past information of the system. PMID:27366146

Neural Net Gains Estimation Based on an Equivalent Model.

PubMed

Aguilar Cruz, Karen Alicia; Medel Juárez, José de Jesús; Fernández Muñoz, José Luis; Esmeralda Vigueras Velázquez, Midory

2016-01-01

A model of an Equivalent Artificial Neural Net (EANN) describes the gains set, viewed as parameters in a layer, and this consideration is a reproducible process, applicable to a neuron in a neural net (NN). The EANN helps to estimate the NN gains or parameters, so we propose two methods to determine them. The first considers a fuzzy inference combined with the traditional Kalman filter, obtaining the equivalent model and estimating in a fuzzy sense the gains matrix A and the proper gain K into the traditional filter identification. The second develops a direct estimation in state space, describing an EANN using the expected value and the recursive description of the gains estimation. Finally, a comparison of both descriptions is performed; highlighting the analytical method describes the neural net coefficients in a direct form, whereas the other technique requires selecting into the Knowledge Base (KB) the factors based on the functional error and the reference signal built with the past information of the system.

Top-Down Beta Rhythms Support Selective Attention via Interlaminar Interaction: A Model

PubMed Central

Lee, Jung H.; Whittington, Miles A.; Kopell, Nancy J.

2013-01-01

Cortical rhythms have been thought to play crucial roles in our cognitive abilities. Rhythmic activity in the beta frequency band, around 20 Hz, has been reported in recent studies that focused on neural correlates of attention, indicating that top-down beta rhythms, generated in higher cognitive areas and delivered to earlier sensory areas, can support attentional gain modulation. To elucidate functional roles of beta rhythms and underlying mechanisms, we built a computational model of sensory cortical areas. Our simulation results show that top-down beta rhythms can activate ascending synaptic projections from L5 to L4 and L2/3, responsible for biased competition in superficial layers. In the simulation, slow-inhibitory interneurons are shown to resonate to the 20 Hz input and modulate the activity in superficial layers in an attention-related manner. The predicted critical roles of these cells in attentional gain provide a potential mechanism by which cholinergic drive can support selective attention. PMID:23950699

Collective Attention and Stock Prices: Evidence from Google Trends Data on Standard and Poor's 100

PubMed Central

Heiberger, Raphael H.

2015-01-01

Today´s connected world allows people to gather information in shorter intervals than ever before, widely monitored by massive online data sources. As a dramatic economic event, recent financial crisis increased public interest for large companies considerably. In this paper, we exploit this change in information gathering behavior by utilizing Google query volumes as a "bad news" indicator for each corporation listed in the Standard and Poor´s 100 index. Our results provide not only an investment strategy that gains particularly in times of financial turmoil and extensive losses by other market participants, but reveal new sectoral patterns between mass online behavior and (bearish) stock market movements. Based on collective attention shifts in search queries for individual companies, hence, these findings can help to identify early warning signs of financial systemic risk. However, our disaggregated data also illustrate the need for further efforts to understand the influence of collective attention shifts on financial behavior in times of regular market activities with less tremendous changes in search volumes. PMID:26258498

Collective attention and stock prices: evidence from Google Trends data on Standard and Poor's 100.

PubMed

Heiberger, Raphael H

2015-01-01

Today´s connected world allows people to gather information in shorter intervals than ever before, widely monitored by massive online data sources. As a dramatic economic event, recent financial crisis increased public interest for large companies considerably. In this paper, we exploit this change in information gathering behavior by utilizing Google query volumes as a "bad news" indicator for each corporation listed in the Standard and Poor´s 100 index. Our results provide not only an investment strategy that gains particularly in times of financial turmoil and extensive losses by other market participants, but reveal new sectoral patterns between mass online behavior and (bearish) stock market movements. Based on collective attention shifts in search queries for individual companies, hence, these findings can help to identify early warning signs of financial systemic risk. However, our disaggregated data also illustrate the need for further efforts to understand the influence of collective attention shifts on financial behavior in times of regular market activities with less tremendous changes in search volumes.

Cardiovascular considerations of attention deficit hyperactivity disorder medications: a report of the European Network on Hyperactivity Disorders work group, European Attention Deficit Hyperactivity Disorder Guidelines Group on attention deficit hyperactivity disorder drug safety meeting.

PubMed

Hamilton, Robert M; Rosenthal, Eric; Hulpke-Wette, Martin; Graham, John G I; Sergeant, Joseph

2012-02-01

Regulatory decisions regarding attention deficit hyperactivity disorder drug licensing and labelling, along with recent statements from professional associations, raise questions of practice regarding the evaluation and treatment of patients with attention deficit hyperactivity disorder. To address these issues for the European community, the European Network for Hyperkinetic Disorders, through its European Attention Deficit Hyperactivity Disorder Guidelines Group, organised a meeting between attention deficit hyperactivity disorder specialists, paediatric cardiovascular specialists, and representatives of the major market authorisation holders for attention deficit hyperactivity disorder medications. This manuscript represents their consensus on cardiovascular aspects of attention deficit hyperactivity disorder medications. Although sudden death has been identified in multiple young individuals on attention deficit hyperactivity disorder medication causing regulatory concern, when analysed for exposure using currently available data, sudden death does not appear to exceed that of the general population. There is no current evidence to suggest an incremental benefit to electrocardiography assessment of the general attention deficit hyperactivity disorder patient. Congenital heart disease patients have an increased prevalence of attention deficit hyperactivity disorder, and can benefit from attention deficit hyperactivity disorder therapies, including medication. The attention deficit hyperactivity disorder specialist is the appropriate individual to evaluate benefit and risk and recommend therapy in all patients, although discussion with a heart specialist is reasonable for congenital heart disease patients. For attention deficit hyperactivity disorder patients with suspected heart disease or risk factor/s for sudden death, assessment by a heart specialist is recommended, as would also be the case for a non-attention deficit hyperactivity disorder patient. The

Neurological soft signs are associated with attentional dysfunction in children with attention deficit hyperactivity disorder.

PubMed

Pitzianti, Mariabernarda; D'Agati, Elisa; Casarelli, Livia; Pontis, Marco; Kaunzinger, Ivo; Lange, Klaus W; Tucha, Oliver; Curatolo, Paolo; Pasini, Augusto

2016-11-01

Inattention is one of the core symptoms of Attention Deficit Hyperactivity Disorder (ADHD). Most of patients with ADHD show motor impairment, consisting in the persistence of neurological soft signs (NSS). Our aim was to evaluate attentional and motor functioning in an ADHD sample and healthy children (HC) and possible link between attentional dysfunction and motor impairment in ADHD. Twenty-seven drug-naive patients with ADHD and 23 HC were tested with a test battery, measuring different aspects of attention. Motor evaluation has provided three primary variables: overflow movements (OM), dysrhythmia and total speed of timed activities. Compared to HC, patients were impaired in a considerable number of attentional processes and showed a greater number of NSS. Significant correlations between disturbances of attention and motor abnormalities were observed in ADHD group. Our findings suggest that attentional processes could be involved in the pathophysiology of the NSS and add scientific evidence to the predictive value of NSS as indicators of the severity of functional impairment in ADHD. Given the marked improvement or complete resolution of NSS following treatment with methylphenidate, we suggest that evaluation of NSS is useful to monitor the effectiveness of pharmacological treatment with MPH in ADHD.

Memory Interventions in the Criminal Justice System: Some Practical Ethical Considerations.

PubMed

Cabrera, Laura Y; Elger, Bernice S

2016-03-01

In recent years, discussion around memory modification interventions has gained attention. However, discussion around the use of memory interventions in the criminal justice system has been mostly absent. In this paper we start by highlighting the importance memory has for human well-being and personal identity, as well as its role within the criminal forensic setting; in particular, for claiming and accepting legal responsibility, for moral learning, and for retribution. We provide examples of memory interventions that are currently available for medical purposes, but that in the future could be used in the forensic setting to modify criminal offenders' memories. In this section we contrast the cases of (1) dampening and (2) enhancing memories of criminal offenders. We then present from a pragmatic approach some pressing ethical issues associated with these types of memory interventions. The paper ends up highlighting how these pragmatic considerations can help establish ethically justified criteria regarding the possibility of interventions aimed at modifying criminal offenders' memories.

Selective attention reduces physiological noise in the external ear canals of humans. I: Auditory attention

PubMed Central

Walsh, Kyle P.; Pasanen, Edward G.; McFadden, Dennis

2014-01-01

In this study, a nonlinear version of the stimulus-frequency OAE (SFOAE), called the nSFOAE, was used to measure cochlear responses from human subjects while they simultaneously performed behavioral tasks requiring, or not requiring, selective auditory attention. Appended to each stimulus presentation, and included in the calculation of each nSFOAE response, was a 30-ms silent period that was used to estimate the level of the inherent physiological noise in the ear canals of our subjects during each behavioral condition. Physiological-noise magnitudes were higher (noisier) for all subjects in the inattention task, and lower (quieter) in the selective auditory-attention tasks. These noise measures initially were made at the frequency of our nSFOAE probe tone (4.0 kHz), but the same attention effects also were observed across a wide range of frequencies. We attribute the observed differences in physiological-noise magnitudes between the inattention and attention conditions to different levels of efferent activation associated with the differing attentional demands of the behavioral tasks. One hypothesis is that when the attentional demand is relatively great, efferent activation is relatively high, and a decrease in the gain of the cochlear amplifier leads to lower-amplitude cochlear activity, and thus a smaller measure of noise from the ear. PMID:24732069

Process-based account for the effects of perceptual attention and executive attention on fluid intelligence: an integrative approach.

PubMed

Ren, Xuezhu; Altmeyer, Michael; Reiss, Siegbert; Schweizer, Karl

2013-02-01

Perceptual attention and executive attention represent two higher-order types of attention and associate with distinctly different ways of information processing. It is hypothesized that these two types of attention implicate different cognitive processes, which are assumed to account for the differential effects of perceptual attention and executive attention on fluid intelligence. Specifically, an encoding process is assumed to be crucial in completing the tasks of perceptual attention while two executive processes, updating and shifting, are stimulated in completing the tasks of executive attention. The proposed hypothesis was tested by means of an integrative approach combining experimental manipulations and psychometric modeling. In a sample of 210 participants the encoding process has proven indispensable in completing the tasks of perceptual attention, and this process accounted for a considerable part of fluid intelligence that was assessed by two figural reasoning tests. In contrast, the two executive processes, updating and shifting, turned out to be necessary in performance according to the tasks of executive attention and these processes accounted for a larger part of the variance in fluid intelligence than that of the processes underlying perceptual attention. Copyright © 2012 Elsevier B.V. All rights reserved.

Potential gains from hospital mergers in Denmark.

PubMed

Kristensen, Troels; Bogetoft, Peter; Pedersen, Kjeld Moeller

2010-12-01

The Danish hospital sector faces a major rebuilding program to centralize activity in fewer and larger hospitals. We aim to conduct an efficiency analysis of hospitals and to estimate the potential cost savings from the planned hospital mergers. We use Data Envelopment Analysis (DEA) to estimate a cost frontier. Based on this analysis, we calculate an efficiency score for each hospital and estimate the potential gains from the proposed mergers by comparing individual efficiencies with the efficiency of the combined hospitals. Furthermore, we apply a decomposition algorithm to split merger gains into technical efficiency, size (scale) and harmony (mix) gains. The motivation for this decomposition is that some of the apparent merger gains may actually be available with less than a full-scale merger, e.g., by sharing best practices and reallocating certain resources and tasks. Our results suggest that many hospitals are technically inefficient, and the expected "best practice" hospitals are quite efficient. Also, some mergers do not seem to lower costs. This finding indicates that some merged hospitals become too large and therefore experience diseconomies of scale. Other mergers lead to considerable cost reductions; we find potential gains resulting from learning better practices and the exploitation of economies of scope. To ensure robustness, we conduct a sensitivity analysis using two alternative returns-to-scale assumptions and two alternative estimation approaches. We consistently find potential gains from improving the technical efficiency and the exploitation of economies of scope from mergers.

Methylphenidate-induced improvements of various measures of attention in adults with attention deficit hyperactivity disorder.

PubMed

Tucha, O; Mecklinger, L; Laufkötter, R; Klein, H E; Walitza, S; Lange, K W

2006-10-01

The present study examined the effect of the stimulant medication methylphenidate (MPH) on attentional functioning of adults with ADHD. Sixteen adults with a diagnosed ADHD without comorbidity were assessed twice, at baseline off MPH and following MPH treatment. The assessment battery consisted of reaction time tasks of low complexity, including measures of alertness--subdivided into tonic and phasic alertness, vigilance, divided attention, flexibility and such aspects of selective attention as including focused attention, inhibition and integration of sensory information. In addition, 16 healthy participants who were matched to adults with ADHD according to sex, age, education level and intellectual functions were also assessed twice using the same test battery. The results of the present study suggest that adults with ADHD off stimulant medication are seriously impaired in various components of attention including vigilance, divided attention, selective attention and flexibility. These impairments of attention were observed primarily in regard to reaction time and its variability. Treatment of adults with ADHD using individually tailored doses of MPH has a positive effect on measures of alertness, vigilance, selective attention, divided attention and flexibility. However, even on MPH adults with ADHD displayed considerable deficits in vigilance and integration of sensory information. The present findings indicate that adults with ADHD are not differentially impaired in attentional processes but may suffer from a more global deficit of attention. Although MPH treatment has been found to be effective in the treatment of the attention deficit of adults with ADHD, additional treatment appears to be necessary.

The Ethics of Biosafety Considerations in Gain-of-Function Research Resulting in the Creation of Potential Pandemic Pathogens

PubMed Central

Lipsitch, Marc; Levinson, Meira

2015-01-01

This paper proposes an ethical framework for evaluating biosafety risks of gain-of-function (GOF) experiments that create novel strains of influenza expected to be virulent and transmissible in humans, so-called potential pandemic pathogens (PPP). Such research raises ethical concerns because of the risk that accidental release from a laboratory could lead to extensive or even global spread of a virulent pathogen. Biomedical research ethics has focused largely on human subjects research, while biosafety concerns about accidental infections, seen largely as a problem of occupational health, have been ignored. GOF/PPP research is an example of a small but important class of research where biosafety risks threaten public health, well beyond the small number of persons conducting the research. We argue that bioethical principles that ordinarily apply only to human subjects research should also apply to research that threatens public health, even if, as in GOF/PPP studies, the research involves no human subjects. Specifically we highlight the Nuremberg Code’s requirements of “fruitful results for the good of society, unprocurable by other methods,” and proportionality of risk and humanitarian benefit, as broad ethical principles that recur in later documents on research ethics and should also apply to certain types of research not involving human subjects. We address several potential objections to this view, and conclude with recommendations for bringing these ethical considerations into policy development. PMID:26320212

Common office procedures and analgesia considerations.

PubMed

Baxter, Amy

2013-10-01

This article reviews common office procedures and analgesia considerations for pediatric outpatients. Layer times of onset of analgesics to coincide with procedures. Pediatric procedural distress is multimodal. Always address parent and child fear and attention, along with pain. Copyright © 2013 Elsevier Inc. All rights reserved.

Practical considerations in Bayesian fusion of point sensors

NASA Astrophysics Data System (ADS)

Johnson, Kevin; Minor, Christian

2012-06-01

Sensor data fusion is and has been a topic of considerable research, but rigorous and quantitative understanding of the benefits of fusing specific types of sensor data remains elusive. Often, sensor fusion is performed on an ad hoc basis with the assumption that overall detection capabilities will improve, only to discover later, after expensive and time consuming laboratory and/or field testing that little advantage was gained. The work presented here will discuss these issues with theoretical and practical considerations in the context of fusing chemical sensors with binary outputs. Results are given for the potential performance gains one could expect with such systems, as well as the practical difficulties involved in implementing an optimal Bayesian fusion strategy with realistic scenarios. Finally, a discussion of the biases that inaccurate statistical estimates introduce into the results and their consequences is presented.

Effects of Response Task and Accessory Stimuli on Redundancy Gain: Tests of the Hemispheric Coactivation Model

ERIC Educational Resources Information Center

Miller, Jeff; Van Nes, Fenna

2007-01-01

Two experiments tested predictions of the hemispheric coactivation model for redundancy gain (J. O. Miller, 2004). Simple reaction time was measured in divided attention tasks with visual stimuli presented to the left or right of fixation or redundantly to both sides. Experiment 1 tested the prediction that redundancy gain--the decrease in…

Attention networks in adolescent anorexia nervosa.

PubMed

Weinbach, Noam; Sher, Helene; Lock, James D; Henik, Avishai

2018-03-01

Anorexia nervosa (AN) usually develops during adolescence when considerable structural and functional brain changes are taking place. Neurocognitive inefficiencies have been consistently found in adults with enduring AN and were suggested to play a role in maintaining the disorder. However, such findings are inconsistent in children and adolescents with AN. The current study conducted a comprehensive assessment of attention networks in adolescents with AN who were not severely underweight during the study using an approach that permits disentangling independent components of attention. Twenty partially weight-restored adolescents with AN (AN-WR) and 24 healthy adolescents performed the Attention Network Test which assesses the efficiency of three main attention networks-executive control, orienting, and alerting. The results revealed abnormal function in the executive control network among adolescents with AN-WR. Specifically, adolescents with AN-WR demonstrated superior ability to suppress attention to task-irrelevant information while focusing on a central task. Moreover, the alerting network modulated this ability. No difference was found between the groups in the speed of orienting attention, but reorienting attention to a target resulted in higher error rates in the AN-WR group. The findings suggest that adolescents with AN have attentional abnormalities that cannot be explained by a state of starvation. These attentional dysregulations may underlie clinical phenotypes of the disorder such as increased attention of details.

Enhancing attention in neurodegenerative diseases: current therapies and future directions

PubMed Central

Davis, Thomas; Coulthard, Elizabeth

2016-01-01

Abstract We all experience at least occasional lapses in attention but in some neurological conditions, loss of attention is pervasive and debilitating. Treating deficits in attention first requires an understanding of the neurobiology of attention, which we now understand to be a set of different cognitive processes. Cholinesterase inhibitors are already established as effective attentional enhancers used in the treatment of certain dementias. Other stimulant agents such as modafanil, amphetamine and methylphenidate have demonstrated limited success in healthy individuals where attention is already optimal and clinical trials in patients with neurological disease are sparse. Dietary and lifestyle changes are gaining increasing prominence, as are experimental treatments such as deep brain stimulation and transcranial magnetic stimulation. As the therapeutic arsenal widens, clinicians will be able to match specific treatments to selective deficits in attention, giving patients a tailored management plan. Here we review common diseases that impair attention and emphasise how an understanding of attentional processing within the brain might lead to improved therapeutic strategies. PMID:28123829

Tuned Normalization Explains the Size of Attention Modulations

PubMed Central

Ni, Amy M.; Ray, Supratim; Maunsell, John H. R.

2012-01-01

SUMMARY The effect of attention on firing rates varies considerably within a single cortical area. The firing rate of some neurons is greatly modulated by attention while others are hardly affected. The reason for this variability across neurons is unknown. We found that the variability in attention modulation across neurons in area MT of macaques can be well explained by variability in the strength of tuned normalization across neurons. The presence of tuned normalization also explains a striking asymmetry in attention effects within neurons: when two stimuli are in a neuron’s receptive field, directing attention to the preferred stimulus modulates firing rates more than directing attention to the non-preferred stimulus. These findings show that much of the neuron-to-neuron variability in modulation of responses by attention depends on variability in the way the neurons process multiple stimuli, rather than differences in the influence of top-down signals related to attention. PMID:22365552

Tuned normalization explains the size of attention modulations.

PubMed

Ni, Amy M; Ray, Supratim; Maunsell, John H R

2012-02-23

The effect of attention on firing rates varies considerably within a single cortical area. The firing rate of some neurons is greatly modulated by attention while others are hardly affected. The reason for this variability across neurons is unknown. We found that the variability in attention modulation across neurons in area MT of macaques can be well explained by variability in the strength of tuned normalization across neurons. The presence of tuned normalization also explains a striking asymmetry in attention effects within neurons: when two stimuli are in a neuron's receptive field, directing attention to the preferred stimulus modulates firing rates more than directing attention to the nonpreferred stimulus. These findings show that much of the neuron-to-neuron variability in modulation of responses by attention depends on variability in the way the neurons process multiple stimuli, rather than differences in the influence of top-down signals related to attention. Copyright © 2012 Elsevier Inc. All rights reserved.

Robust decoding of selective auditory attention from MEG in a competing-speaker environment via state-space modeling✩

PubMed Central

Akram, Sahar; Presacco, Alessandro; Simon, Jonathan Z.; Shamma, Shihab A.; Babadi, Behtash

2015-01-01

The underlying mechanism of how the human brain solves the cocktail party problem is largely unknown. Recent neuroimaging studies, however, suggest salient temporal correlations between the auditory neural response and the attended auditory object. Using magnetoencephalography (MEG) recordings of the neural responses of human subjects, we propose a decoding approach for tracking the attentional state while subjects are selectively listening to one of the two speech streams embedded in a competing-speaker environment. We develop a biophysically-inspired state-space model to account for the modulation of the neural response with respect to the attentional state of the listener. The constructed decoder is based on a maximum a posteriori (MAP) estimate of the state parameters via the Expectation Maximization (EM) algorithm. Using only the envelope of the two speech streams as covariates, the proposed decoder enables us to track the attentional state of the listener with a temporal resolution of the order of seconds, together with statistical confidence intervals. We evaluate the performance of the proposed model using numerical simulations and experimentally measured evoked MEG responses from the human brain. Our analysis reveals considerable performance gains provided by the state-space model in terms of temporal resolution, computational complexity and decoding accuracy. PMID:26436490

Simulations on false gain in recombination-pumped soft-X-ray lasers

NASA Astrophysics Data System (ADS)

Ozaki, T.; Kuroda, H.

1997-10-01

Numerical investigations are performed on false gain due to axial plasma expansion, which is expected to be important in initial proof-of-principle studies of recombination-pumped soft-X-ray lasers with extended capabilities. Modelling calculations of experiments with slab boron nitride targets reveal large false gain coefficients approaching 20 cm-1 in the case of plasmas with short active medium lengths. The false gain in the case of fiber targets is found to be of equal magnitude to that for slabs in the case of plasmas with less than 0.1 cm active medium lengths. Calculations for slab targets predict that adopting a tolerance of ǃ cm-1 for gain will severely restrict the time and the active medium length of the plasma that can be used for error-free observations, while those for fiber targets are found to be considerably relaxed. The effects of false gain in the 54.2 + Na Balmer ! laser is also investigated, again revealing the importance of this phenomena under optimum gain conditions.

Attention Deficit Disorder: Diagnosis, Etiology and Treatment.

ERIC Educational Resources Information Center

Barabasz, Marianne; Barabasz, Arreed

1996-01-01

Provides most recent information on attention deficit disorder including: (1) diagnostic considerations according to the latest behavioral criteria and breakthroughs using neurometric EEG assessment; (2) prevalence; (3) etiologies; (4) neurological basis; and (5) treatments. Evaluates alternatives to medication, behavior modification, cognitive…

How the deployment of attention determines what we see

PubMed Central

Treisman, Anne

2007-01-01

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

Health and productivity gains from better indoor environments and their relationship with building energy efficiency

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

Fisk, William J.

2000-04-01

Theoretical considerations and empirical data suggest that existing technologies and procedures can improve indoor environments in a manner that significantly increases productivity and health. Existing literature contains moderate to strong evidence that characteristics of buildings and indoor environments significantly influence rates of communicable respiratory illness, allergy and asthma symptoms, sick building symptoms, and worker performance. While there is considerable uncertainty in the estimates of the magnitudes of productivity gains that may be obtained by providing better indoor environments, the projected gains are very large. For the U.S., the estimated potential annual savings and productivity gains are $6 to $14 billionmore » from reduced respiratory disease, $2 to $4 billion from reduced allergies and asthma, $10 to $30 billion from reduced sick building syndrome symptoms, and $20 to $160 billion from direct improvements in worker performance that are unrelated to health. Productivity gains that are quantified and demonstrated could serve as a strong stimulus for energy efficiency measures that simultaneously improve the indoor environment.« less

Reward modulates attention independently of action value in posterior parietal cortex

PubMed Central

Peck, Christopher J.; Jangraw, David C.; Suzuki, Mototaka; Efem, Richard; Gottlieb, Jacqueline

2009-01-01

While numerous studies explored the mechanisms of reward-based decisions (the choice of action based on expected gain), few asked how reward influences attention (the selection of information relevant for a decision). Here we show that a powerful determinant of attentional priority is the association between a stimulus and an appetitive reward. A peripheral cue heralded the delivery of reward (RC+) or no reward (RC−); to experience the predicted outcome monkeys made a saccade to a target that appeared unpredictably at the same or opposite location relative to the cue. Although the RC had no operant associations (did not specify the required saccade) they automatically biased attention, such that the RC+ attracted attention and RC− repelled attention from their location. Neurons in the lateral intraparietal area (LIP) encoded these attentional biases, maintaining sustained excitation at the location of an RC+ and inhibition at the location of an RC−. Contrary to the hypothesis that LIP encodes action value, neurons did not encode the expected reward of the saccade. Moreover, the cue-evoked biases were maladaptive, interfering with the required saccade, and they biases increased rather than abating with training, strikingly at odds with an adaptive decision process. After prolonged training valence selectivity appeared at shorter latencies and automatically transferred to a novel task context, suggesting that training produced visual plasticity. The results suggest that reward predictors gain automatic attentional priority regardless of their operant associations, and this valence-specific priority is encoded in LIP independently of the expected reward of an action. PMID:19741125

College Students' Attention Behaviors during Independent Study and Course Level Academic Performance

ERIC Educational Resources Information Center

Wagner, Linda G.

2012-01-01

Students in college make daily choices about how to use their independent study time, including choices about allocation of attention. Based on theoretical considerations and clinical studies, attention and the dividing of attention through multitasking is thought to have a relationship to performance levels. Research is only beginning to explore,…

The ethics of biosafety considerations in gain-of-function research resulting in the creation of potential pandemic pathogens.

PubMed

Evans, Nicholas Greig; Lipsitch, Marc; Levinson, Meira

2015-11-01

This paper proposes an ethical framework for evaluating biosafety risks of gain-of-function (GOF) experiments that create novel strains of influenza expected to be virulent and transmissible in humans, so-called potential pandemic pathogens (PPPs). Such research raises ethical concerns because of the risk that accidental release from a laboratory could lead to extensive or even global spread of a virulent pathogen. Biomedical research ethics has focused largely on human subjects research, while biosafety concerns about accidental infections, seen largely as a problem of occupational health, have been ignored. GOF/PPP research is an example of a small but important class of research where biosafety risks threaten public health, well beyond the small number of persons conducting the research.We argue that bioethical principles that ordinarily apply only to human subjects research should also apply to research that threatens public health, even if, as in GOF/PPP studies, the research involves no human subjects. Specifically we highlight the Nuremberg Code's requirements of 'fruitful results for the good of society, unprocurable by other methods', and proportionality of risk and humanitarian benefit, as broad ethical principles that recur in later documents on research ethics and should also apply to certain types of research not involving human subjects. We address several potential objections to this view, and conclude with recommendations for bringing these ethical considerations into policy development. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Attention model of binocular rivalry

PubMed Central

Rankin, James; Rinzel, John; Carrasco, Marisa; Heeger, David J.

2017-01-01

When the corresponding retinal locations in the two eyes are presented with incompatible images, a stable percept gives way to perceptual alternations in which the two images compete for perceptual dominance. As perceptual experience evolves dynamically under constant external inputs, binocular rivalry has been used for studying intrinsic cortical computations and for understanding how the brain regulates competing inputs. Converging behavioral and EEG results have shown that binocular rivalry and attention are intertwined: binocular rivalry ceases when attention is diverted away from the rivalry stimuli. In addition, the competing image in one eye suppresses the target in the other eye through a pattern of gain changes similar to those induced by attention. These results require a revision of the current computational theories of binocular rivalry, in which the role of attention is ignored. Here, we provide a computational model of binocular rivalry. In the model, competition between two images in rivalry is driven by both attentional modulation and mutual inhibition, which have distinct selectivity (feature vs. eye of origin) and dynamics (relatively slow vs. relatively fast). The proposed model explains a wide range of phenomena reported in rivalry, including the three hallmarks: (i) binocular rivalry requires attention; (ii) various perceptual states emerge when the two images are swapped between the eyes multiple times per second; (iii) the dominance duration as a function of input strength follows Levelt’s propositions. With a bifurcation analysis, we identified the parameter space in which the model’s behavior was consistent with experimental results. PMID:28696323

Hearing in noisy environments: noise invariance and contrast gain control

PubMed Central

Willmore, Ben D B; Cooke, James E; King, Andrew J

2014-01-01

Contrast gain control has recently been identified as a fundamental property of the auditory system. Electrophysiological recordings in ferrets have shown that neurons continuously adjust their gain (their sensitivity to change in sound level) in response to the contrast of sounds that are heard. At the level of the auditory cortex, these gain changes partly compensate for changes in sound contrast. This means that sounds which are structurally similar, but have different contrasts, have similar neuronal representations in the auditory cortex. As a result, the cortical representation is relatively invariant to stimulus contrast and robust to the presence of noise in the stimulus. In the inferior colliculus (an important subcortical auditory structure), gain changes are less reliably compensatory, suggesting that contrast- and noise-invariant representations are constructed gradually as one ascends the auditory pathway. In addition to noise invariance, contrast gain control provides a variety of computational advantages over static neuronal representations; it makes efficient use of neuronal dynamic range, may contribute to redundancy-reducing, sparse codes for sound and allows for simpler decoding of population responses. The circuits underlying auditory contrast gain control are still under investigation. As in the visual system, these circuits may be modulated by factors other than stimulus contrast, forming a potential neural substrate for mediating the effects of attention as well as interactions between the senses. PMID:24907308

Cortical Brain Activity Reflecting Attentional Biasing Toward Reward-Predicting Cues Covaries with Economic Decision-Making Performance

PubMed Central

San Martín, René; Appelbaum, Lawrence G.; Huettel, Scott A.; Woldorff, Marty G.

2016-01-01

Adaptive choice behavior depends critically on identifying and learning from outcome-predicting cues. We hypothesized that attention may be preferentially directed toward certain outcome-predicting cues. We studied this possibility by analyzing event-related potential (ERP) responses in humans during a probabilistic decision-making task. Participants viewed pairs of outcome-predicting visual cues and then chose to wager either a small (i.e., loss-minimizing) or large (i.e., gain-maximizing) amount of money. The cues were bilaterally presented, which allowed us to extract the relative neural responses to each cue by using a contralateral-versus-ipsilateral ERP contrast. We found an early lateralized ERP response, whose features matched the attention-shift-related N2pc component and whose amplitude scaled with the learned reward-predicting value of the cues as predicted by an attention-for-reward model. Consistently, we found a double dissociation involving the N2pc. Across participants, gain-maximization positively correlated with the N2pc amplitude to the most reliable gain-predicting cue, suggesting an attentional bias toward such cues. Conversely, loss-minimization was negatively correlated with the N2pc amplitude to the most reliable loss-predicting cue, suggesting an attentional avoidance toward such stimuli. These results indicate that learned stimulus–reward associations can influence rapid attention allocation, and that differences in this process are associated with individual differences in economic decision-making performance. PMID:25139941

Modulation of attentional networks by food-related disinhibition.

PubMed

Hege, Maike A; Stingl, Krunoslav T; Veit, Ralf; Preissl, Hubert

2017-07-01

The risk of weight gain is especially related to disinhibition, which indicates the responsiveness to external food stimuli with associated disruptions in eating control. We adapted a food-related version of the attention network task and used functional magnetic resonance imaging to study the effects of disinhibition on attentional networks in 19 normal-weight participants. High disinhibition scores were associated with a rapid reorienting response to food pictures after invalid cueing and with an enhanced alerting effect of a warning cue signalizing the upcoming appearance of a food picture. Imaging data revealed activation of a right-lateralized ventral attention network during reorienting. The faster the reorienting and the higher the disinhibition score, the less activation of this network was observed. The alerting contrast showed activation in visual, temporo-parietal and anterior sites. These modulations of attentional networks by food-related disinhibition might be related to an attentional bias to energy dense and palatable food and increased intake of food in disinhibited individuals. Copyright © 2017 Elsevier Inc. All rights reserved.

The Development of Attentional Networks: Cross-Sectional Findings from a Life Span Sample

ERIC Educational Resources Information Center

Waszak, Florian; Li, Shu-Chen; Hommel, Bernhard

2010-01-01

Using a population-based sample of 263 individuals ranging from 6 to 89 years of age, we investigated the gains and losses in the abilities to (a) use exogenous cues to shift attention covertly and (b) ignore conflicting information across the life span. The participants' ability to shift visual attention was tested by a typical Posner-type…

Selective attention without a neocortex.

PubMed

Krauzlis, Richard J; Bogadhi, Amarender R; Herman, James P; Bollimunta, Anil

2018-05-01

Selective attention refers to the ability to restrict neural processing and behavioral responses to a relevant subset of available stimuli, while simultaneously excluding other valid stimuli from consideration. In primates and other mammals, descriptions of this ability typically emphasize the neural processing that takes place in the cerebral neocortex. However, non-mammals such as birds, reptiles, amphibians and fish, which completely lack a neocortex, also have the ability to selectively attend. In this article, we survey the behavioral evidence for selective attention in non-mammals, and review the midbrain and forebrain structures that are responsible. The ancestral forms of selective attention are presumably selective orienting behaviors, such as prey-catching and predator avoidance. These behaviors depend critically on a set of subcortical structures, including the optic tectum (OT), thalamus and striatum, that are highly conserved across vertebrate evolution. In contrast, the contributions of different pallial regions in the forebrain to selective attention have been subject to more substantial changes and reorganization. This evolutionary perspective makes plain that selective attention is not a function achieved de novo with the emergence of the neocortex, but instead is implemented by circuits accrued and modified over hundreds of millions of years, beginning well before the forebrain contained a neocortex. Determining how older subcortical circuits interact with the more recently evolved components in the neocortex will likely be crucial for understanding the complex properties of selective attention in primates and other mammals, and for identifying the etiology of attention disorders. Published by Elsevier Ltd.

Towards zero-threshold optical gain using charged semiconductor quantum dots

DOE PAGES

Wu, Kaifeng; Park, Young -Shin; Lim, Jaehoon; ...

2017-10-16

Colloidal semiconductor quantum dots are attractive materials for the realization of solution-processable lasers. However, their applications as optical-gain media are complicated by a non-unity degeneracy of band-edge states, because of which multiexcitons are required to achieve the lasing regime. This increases the lasing thresholds and leads to very short optical gain lifetimes limited by nonradiative Auger recombination. Here, we show that these problems can be at least partially resolved by employing not neutral but negatively charged quantum dots. By applying photodoping to specially engineered quantum dots with impeded Auger decay, we demonstrate a considerable reduction of the optical gain thresholdmore » due to suppression of ground-state absorption by pre-existing carriers. Moreover, by injecting approximately one electron per dot on average, we achieve a more than twofold reduction in the amplified spontaneous emission threshold, bringing it to the sub-single-exciton level. Furthermore, these measurements indicate the feasibility of ‘zero-threshold’ gain achievable by completely blocking the band-edge state with two electrons.« less

Towards zero-threshold optical gain using charged semiconductor quantum dots

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

Wu, Kaifeng; Park, Young -Shin; Lim, Jaehoon

Colloidal semiconductor quantum dots are attractive materials for the realization of solution-processable lasers. However, their applications as optical-gain media are complicated by a non-unity degeneracy of band-edge states, because of which multiexcitons are required to achieve the lasing regime. This increases the lasing thresholds and leads to very short optical gain lifetimes limited by nonradiative Auger recombination. Here, we show that these problems can be at least partially resolved by employing not neutral but negatively charged quantum dots. By applying photodoping to specially engineered quantum dots with impeded Auger decay, we demonstrate a considerable reduction of the optical gain thresholdmore » due to suppression of ground-state absorption by pre-existing carriers. Moreover, by injecting approximately one electron per dot on average, we achieve a more than twofold reduction in the amplified spontaneous emission threshold, bringing it to the sub-single-exciton level. Furthermore, these measurements indicate the feasibility of ‘zero-threshold’ gain achievable by completely blocking the band-edge state with two electrons.« less

Neuroelectrical signs of selective attention to color in boys with attention-deficit hyperactivity disorder.

PubMed

van der Stelt, O; van der Molen, M; Boudewijn Gunning, W; Kok, A

2001-10-01

In order to gain insight into the functional and macroanatomical loci of visual selective processing deficits that may be basic to attention-deficit hyperactivity disorder (ADHD), the present study examined multi-channel event-related potentials (ERPs) recorded from 7- to 11-year-old boys clinically diagnosed as having ADHD (n=24) and age-matched healthy control boys (n=24) while they performed a visual (color) selective attention task. The spatio-temporal dynamics of several ERP components related to attention to color were characterized using topographic profile analysis, topographic mapping of the ERP and associated scalp current density distributions, and spatio-temporal source potential modeling. Boys with ADHD showed a lower target hit rate, a higher false-alarm rate, and a lower perceptual sensitivity than controls. Also, whereas color attention induced in the ERPs from controls a characteristic early frontally maximal selection positivity (FSP), ADHD boys displayed little or no FSP. Similarly, ADHD boys manifested P3b amplitude decrements that were partially lateralized (i.e., maximal at left temporal scalp locations) as well as affected by maturation. These results indicate that ADHD boys suffer from deficits at both relatively early (sensory) and late (semantic) levels of visual selective information processing. The data also support the hypothesis that the visual selective processing deficits observed in the ADHD boys originate from deficits in the strength of activation of a neural network comprising prefrontal and occipito-temporal brain regions. This network seems to be actively engaged during attention to color and may contain the major intracerebral generating sources of the associated scalp-recorded ERP components.

Children's decision making: When self-interest and moral considerations conflict.

PubMed

Tasimi, Arber; Johnson, Marcia K; Wynn, Karen

2017-09-01

When children's self-interests are at odds with their moral considerations, what do they do? In the current study of 5- and 6-year-olds (N=160), we asked (a) whether children would select the offering of a do-gooder over a neutral individual at a personal cost, (b) whether they would reject the offering of a wrongdoer over a neutral individual at a personal cost, and (c) whether these two types of decisions involve comparable levels of conflict. In the absence of material considerations, children preferred a nice character to a neutral one, but this preference was easily overcome for material gain; children accepted a larger offering from a neutral source over a smaller offering from a nice source. In contrast, children's aversion to negative characters was largely unaffected by the same material consideration; they rejected a larger offering from a mean source in favor of a smaller offering from a neutral source. In addition, children's response times indicated that deciding whether or not to "sell out" to a wrongdoer for personal gain engenders conflict but that deciding whether to take a lesser gain from a do-gooder does not. These findings indicate that children weigh both their own material interests and others' social behaviors when selecting social partners and, importantly, that an aversion to wrongdoers is a more powerful influence on these choices than an attraction to do-gooders. Copyright © 2017 Elsevier Inc. All rights reserved.

Attentive Tracking Disrupts Feature Binding in Visual Working Memory

PubMed Central

Fougnie, Daryl; Marois, René

2009-01-01

One of the most influential theories in visual cognition proposes that attention is necessary to bind different visual features into coherent object percepts (Treisman & Gelade, 1980). While considerable evidence supports a role for attention in perceptual feature binding, whether attention plays a similar function in visual working memory (VWM) remains controversial. To test the attentional requirements of VWM feature binding, here we gave participants an attention-demanding multiple object tracking task during the retention interval of a VWM task. Results show that the tracking task disrupted memory for color-shape conjunctions above and beyond any impairment to working memory for object features, and that this impairment was larger when the VWM stimuli were presented at different spatial locations. These results demonstrate that the role of visuospatial attention in feature binding is not unique to perception, but extends to the working memory of these perceptual representations as well. PMID:19609460

Vehicle yaw stability control via H∞ gain scheduling

NASA Astrophysics Data System (ADS)

Zhang, Jinhua; Sun, Weichao; Feng, Zhiguang

2018-06-01

Yaw stability control (YSC) is rather significant in a vehicle lateral motion, since it can considerably reduce casualties caused by vehicle instability. Nevertheless with the vehicle running, the parameters, such as vehicle mass and moment of inertial, can be perturbed because of variation of capacity, loadage and consumption of fuel, hence some of nominal controllers cannot always work satisfactorily. To overcome the aforementioned deficiency, a gain scheduled H∞ YSC controller is developed in this paper, taking the vehicle mass and moment of inertial as the scheduled variables, now that the gain scheduled H∞ controller can guarantee both the robustness against parameter perturbation and the adjustability of tracking accuracy. Then the constructed controller is verified via numerical simulation and MATLAB-CarSim coalition simulation. The simulation results indicate that the designed controller can indeed improve the vehicle handing performance under circumstance of lateral stability.

Effects of a Mindful Breathing Exercise during Reading Fluency Intervention for Students with Attentional Difficulties

ERIC Educational Resources Information Center

Idler, Alyssa M.; Mercer, Sterett H.; Starosta, Lindsay; Bartfai, Jamie M.

2017-01-01

Students with attentional difficulties are at greater risk for reading difficulties. To address this concern, we examined the extent to which adding a mindful breathing exercise to individual reading fluency interventions would improve gains in reading fluency, student-reported attention, and student-reported stress. In a restricted alternating…

Measurement and Testing Considerations for Native American Education.

ERIC Educational Resources Information Center

Blanchard, Joseph D.

Some of the general considerations and requirements for the establishment of a testing policy and procedures for a large education system are presented. Testing policy is considered necessary to establish a common understanding of the position of testing in the education program, the facilitation of the use of tests for academic gain, and to…

Cortical Brain Activity Reflecting Attentional Biasing Toward Reward-Predicting Cues Covaries with Economic Decision-Making Performance.

PubMed

San Martín, René; Appelbaum, Lawrence G; Huettel, Scott A; Woldorff, Marty G

2016-01-01

Adaptive choice behavior depends critically on identifying and learning from outcome-predicting cues. We hypothesized that attention may be preferentially directed toward certain outcome-predicting cues. We studied this possibility by analyzing event-related potential (ERP) responses in humans during a probabilistic decision-making task. Participants viewed pairs of outcome-predicting visual cues and then chose to wager either a small (i.e., loss-minimizing) or large (i.e., gain-maximizing) amount of money. The cues were bilaterally presented, which allowed us to extract the relative neural responses to each cue by using a contralateral-versus-ipsilateral ERP contrast. We found an early lateralized ERP response, whose features matched the attention-shift-related N2pc component and whose amplitude scaled with the learned reward-predicting value of the cues as predicted by an attention-for-reward model. Consistently, we found a double dissociation involving the N2pc. Across participants, gain-maximization positively correlated with the N2pc amplitude to the most reliable gain-predicting cue, suggesting an attentional bias toward such cues. Conversely, loss-minimization was negatively correlated with the N2pc amplitude to the most reliable loss-predicting cue, suggesting an attentional avoidance toward such stimuli. These results indicate that learned stimulus-reward associations can influence rapid attention allocation, and that differences in this process are associated with individual differences in economic decision-making performance. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

How Can We Second-Guess Attention in the Classroom; A Physiological Answer.

ERIC Educational Resources Information Center

Fletcher, James E.

In preparing instructional materials, consideration must be given to the students' attention. Carl Hagfors has conducted a number of experiments measuring the electrodermal response simultaneously from a number of subjects viewing the same materials. When most subjects were attentive there was a large discursion of the recorder pen. When some were…

Why is joint attention a pivotal skill in autism?

PubMed Central

Charman, Tony

2003-01-01

Joint attention abilities play a crucial role in the development of autism. Impairments in joint attention are among the earliest signs of the disorder and joint attention skills relate to outcome, both in the 'natural course' of autism and through being targeted in early intervention programmes. In the current study, concurrent and longitudinal associations between joint attention and other social communication abilities measured in a sample of infants with autism and related pervasive developmental disorders at age 20 months, and language and symptom severity at age 42 months, were examined. Extending the findings from previous studies, joint attention ability was positively associated with language gains and (lower) social and communication symptoms, and imitation ability was also positively associated with later language. Some specificity in the association between different aspects of joint attention behaviours and outcome was found: declarative, triadic gaze switching predicted language and symptom severity but imperative, dyadic eye contact behaviours did not. Further, although joint attention was associated with later social and language symptoms it was unrelated to repetitive and stereotyped symptoms, suggesting the latter may have a separate developmental trajectory. Possible deficits in psychological and neurological processes that might underlie the impaired development of joint attention in autism are discussed. PMID:12639329

Mood & alcohol-related attentional biases: New considerations for gender differences and reliability of the visual-probe task.

PubMed

Emery, Noah N; Simons, Jeffrey S

2015-11-01

Alcohol-related attentional biases are positively associated with drinking history and may represent a mechanism by which alcohol use behavior is maintained over time. This study was designed to address two unresolved issues regarding alcohol-related attention biases. Specifically, this study tested whether acute changes in positive and negative mood increase attentional biases toward alcohol cues and whether coping and enhancement drinking motives moderate these effects. Participants were 100 college students aged 18-25, who drank alcohol at least once in the last 90 days. In a 2 × 3 mixed design, participants were randomized to one of three mood conditions (neutral, negative, or positive) and completed visual-probe tasks pre- and post-mood-induction. Attentional biases toward alcohol cues were significantly associated with alcohol consumption among men, but not women. Although the mood manipulation was highly successful, attentional biases did not vary as a function of mood condition and hypothesized moderating effects of drinking motives were not significant. The largely null findings of the experiment are discussed in light of the fact that the visual probe task had poor reliability. Issues related to the reliability of visual-probe task are discussed, as more research is needed to evaluate and improve the psychometrics of this method. Copyright © 2015 Elsevier Ltd. All rights reserved.

Meditation-induced states predict attentional control over time.

PubMed

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

2015-12-01

Meditation is becoming an increasingly popular topic for scientific research and various effects of extensive meditation practice (ranging from weeks to several years) on cognitive processes have been demonstrated. Here we show that extensive practice may not be necessary to achieve those effects. Healthy adult non-meditators underwent a brief single session of either focused attention meditation (FAM), which is assumed to increase top-down control, or open monitoring meditation (OMM), which is assumed to weaken top-down control, before performing an Attentional Blink (AB) task - which assesses the efficiency of allocating attention over time. The size of the AB was considerably smaller after OMM than after FAM, which suggests that engaging in meditation immediately creates a cognitive-control state that has a specific impact on how people allocate their attention over time. Copyright © 2015 Elsevier Inc. All rights reserved.

Does visual attention drive the dynamics of bistable perception?

PubMed

Dieter, Kevin C; Brascamp, Jan; Tadin, Duje; Blake, Randolph

2016-10-01

How does attention interact with incoming sensory information to determine what we perceive? One domain in which this question has received serious consideration is that of bistable perception: a captivating class of phenomena that involves fluctuating visual experience in the face of physically unchanging sensory input. Here, some investigations have yielded support for the idea that attention alone determines what is seen, while others have implicated entirely attention-independent processes in driving alternations during bistable perception. We review the body of literature addressing this divide and conclude that in fact both sides are correct-depending on the form of bistable perception being considered. Converging evidence suggests that visual attention is required for alternations in the type of bistable perception called binocular rivalry, while alternations during other types of bistable perception appear to continue without requiring attention. We discuss some implications of this differential effect of attention for our understanding of the mechanisms underlying bistable perception, and examine how these mechanisms operate during our everyday visual experiences.

Gain Modulation in the Central Nervous System: Where Behavior, Neurophysiology, and Computation Meet

PubMed Central

SALINAS, EMILIO; SEJNOWSKI, TERRENCE J.

2010-01-01

Gain modulation is a nonlinear way in which neurons combine information from two (or more) sources, which may be of sensory, motor, or cognitive origin. Gain modulation is revealed when one input, the modulatory one, affects the gain or the sensitivity of the neuron to the other input, without modifying its selectivity or receptive field properties. This type of modulatory interaction is important for two reasons. First, it is an extremely widespread integration mechanism; it is found in a plethora of cortical areas and in some subcortical structures as well, and as a consequence it seems to play an important role in a striking variety of functions, including eye and limb movements, navigation, spatial perception, attentional processing, and object recognition. Second, there is a theoretical foundation indicating that gain-modulated neurons may serve as a basis for a general class of computations, namely, coordinate transformations and the generation of invariant responses, which indeed may underlie all the brain functions just mentioned. This article describes the relationships between computational models, the physiological properties of a variety of gain-modulated neurons, and some of the behavioral consequences of damage to gain-modulated neural representations. PMID:11597102

Attention deficit hyperactivity disorder--a review.

PubMed Central

Williams, C; Wright, B; Partridge, I

1999-01-01

The topic of attention deficit hyperactivity disorder (ADHD) is fascinating and controversial. A variety of stances have been taken by different clinicians, support groups, and the media. A nature/nurture argument has developed that may have a tendency to polarize views. This review aims to present research findings that inform the debate. It deals with symptomatology, aetiology, and prevalence, with assessment for diagnosis, management, and outcome. The importance of comprehensive management taking into consideration not just attention abilities but a range of other factors that have an impact upon them is stressed. Management should be pragmatic, multifaceted, and based around the establishment of good working relationships with family and school. PMID:10621994

Modulation of spatial attention by goals, statistical learning, and monetary reward.

PubMed

Jiang, Yuhong V; Sha, Li Z; Remington, Roger W

2015-10-01

This study documented the relative strength of task goals, visual statistical learning, and monetary reward in guiding spatial attention. Using a difficult T-among-L search task, we cued spatial attention to one visual quadrant by (i) instructing people to prioritize it (goal-driven attention), (ii) placing the target frequently there (location probability learning), or (iii) associating that quadrant with greater monetary gain (reward-based attention). Results showed that successful goal-driven attention exerted the strongest influence on search RT. Incidental location probability learning yielded a smaller though still robust effect. Incidental reward learning produced negligible guidance for spatial attention. The 95 % confidence intervals of the three effects were largely nonoverlapping. To understand these results, we simulated the role of location repetition priming in probability cuing and reward learning. Repetition priming underestimated the strength of location probability cuing, suggesting that probability cuing involved long-term statistical learning of how to shift attention. Repetition priming provided a reasonable account for the negligible effect of reward on spatial attention. We propose a multiple-systems view of spatial attention that includes task goals, search habit, and priming as primary drivers of top-down attention.

Modulation of spatial attention by goals, statistical learning, and monetary reward

PubMed Central

Sha, Li Z.; Remington, Roger W.

2015-01-01

This study documented the relative strength of task goals, visual statistical learning, and monetary reward in guiding spatial attention. Using a difficult T-among-L search task, we cued spatial attention to one visual quadrant by (i) instructing people to prioritize it (goal-driven attention), (ii) placing the target frequently there (location probability learning), or (iii) associating that quadrant with greater monetary gain (reward-based attention). Results showed that successful goal-driven attention exerted the strongest influence on search RT. Incidental location probability learning yielded a smaller though still robust effect. Incidental reward learning produced negligible guidance for spatial attention. The 95 % confidence intervals of the three effects were largely nonoverlapping. To understand these results, we simulated the role of location repetition priming in probability cuing and reward learning. Repetition priming underestimated the strength of location probability cuing, suggesting that probability cuing involved long-term statistical learning of how to shift attention. Repetition priming provided a reasonable account for the negligible effect of reward on spatial attention. We propose a multiple-systems view of spatial attention that includes task goals, search habit, and priming as primary drivers of top-down attention. PMID:26105657

Summary of Pressure Gain Combustion Research at NASA

NASA Technical Reports Server (NTRS)

Perkins, H. Douglas; Paxson, Daniel E.

2018-01-01

NASA has undertaken a systematic exploration of many different facets of pressure gain combustion over the last 25 years in an effort to exploit the inherent thermodynamic advantage of pressure gain combustion over the constant pressure combustion process used in most aerospace propulsion systems. Applications as varied as small-scale UAV's, rotorcraft, subsonic transports, hypersonics and launch vehicles have been considered. In addition to studying pressure gain combustor concepts such as wave rotors, pulse detonation engines, pulsejets, and rotating detonation engines, NASA has studied inlets, nozzles, ejectors and turbines which must also process unsteady flow in an integrated propulsion system. Other design considerations such as acoustic signature, combustor material life and heat transfer that are unique to pressure gain combustors have also been addressed in NASA research projects. In addition to a wide range of experimental studies, a number of computer codes, from 0-D up through 3-D, have been developed or modified to specifically address the analysis of unsteady flow fields. Loss models have also been developed and incorporated into these codes that improve the accuracy of performance predictions and decrease computational time. These codes have been validated numerous times across a broad range of operating conditions, and it has been found that once validated for one particular pressure gain combustion configuration, these codes are readily adaptable to the others. All in all, the documentation of this work has encompassed approximately 170 NASA technical reports, conference papers and journal articles to date. These publications are very briefly summarized herein, providing a single point of reference for all of NASA's pressure gain combustion research efforts. This documentation does not include the significant contributions made by NASA research staff to the programs of other agencies, universities, industrial partners and professional society

Intraband Raman laser gain in a boron nitride coupled quantum well

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

Moorthy, N. Narayana; Peter, A. John, E-mail: a.john.peter@gmail.com

2016-05-23

On-centre impurity related electronic and optical properties are studied in a Boron nitride coupled quantum well. Confined energies for the intraband transition are investigated by studying differential cross section of electron Raman scattering taking into consideration of spatial confinement in a B{sub 0.3}Ga{sub 0.7}N/BN coupled quantum well. Raman gain as a function of incident optical pump intensity is computed for constant well width. The enhancement of Raman gain is observed with the application of pump power. The results can be applied for the potential applications for fabricating some optical devices such as optical switches, infrared photo-detectors and electro-optical modulator.

Automatic Mechanisms for Social Attention Are Culturally Penetrable.

PubMed

Cohen, Adam S; Sasaki, Joni Y; German, Tamsin C; Kim, Heejung S

2017-01-01

Are mechanisms for social attention influenced by culture? Evidence that social attention is triggered automatically by bottom-up gaze cues and is uninfluenced by top-down verbal instructions may suggest it operates in the same way everywhere. Yet considerations from evolutionary and cultural psychology suggest that specific aspects of one's cultural background may have consequence for the way mechanisms for social attention develop and operate. In more interdependent cultures, the scope of social attention may be broader, focusing on more individuals and relations between those individuals. We administered a multi-gaze cueing task requiring participants to fixate a foreground face flanked by background faces and measured shifts in attention using eye tracking. For European Americans, gaze cueing did not depend on the direction of background gaze cues, suggesting foreground gaze alone drives automatic attention shifting; for East Asians, cueing patterns differed depending on whether the foreground cue matched or mismatched background cues, suggesting foreground and background gaze information were integrated. These results demonstrate that cultural background influences the social attention system by shifting it into a narrow or broad mode of operation and, importantly, provides evidence challenging the assumption that mechanisms underlying automatic social attention are necessarily rigid and impenetrable to culture. Copyright © 2015 Cognitive Science Society, Inc.

Contrasting losses and gains increases the predictability of behavior by frontal EEG asymmetry

PubMed Central

Telpaz, Ariel; Yechiam, Eldad

2014-01-01

Frontal asymmetry measured at rest using EEG is considered a stable marker of approach-avoidance behaviors and risk taking. We examined whether without salient cues of attention in the form of losses, predictability is reduced. Fifty-seven participants performed an experiential decision task in a gain-only, loss-only, and mixed (gains and losses) condition. Increased risk taking on the part of individuals with relatively high left frontal activation, as denoted by the Alpha band, was only observed in the task involving both gains and losses. Event-related potential analysis sheds light on the processes leading to this pattern. Left-frontal dominant individuals had increased fronto-central P300 activation following risky compared to safe outcomes, while right-frontal dominant individuals did not show a P300 difference following safe and risky outcomes. This interaction also only emerged when losses were contrasted with gains. The findings highlight the sensitivity of behavioral predictability to cues of valence. PMID:24817845

Beyond ADHD: A Consideration of Attention Deficit Hyperactivity Disorder and Pedagogy in Australian Schools

ERIC Educational Resources Information Center

Prosser, Brenton J.

2008-01-01

A psycho-medical discourse that explains behavioural dysfunction through neurological deficit has dominated debate about attention deficit hyperactivity disorder (ADHD). However, if only medical questions are asked, only medical answers will be found, resulting in more or less drug treatment. When behavioural dysfunction results in impairment…

Interventions for High School Students with Attention-Deficit/Hyperactivity Disorder: Considerations for Future Directions

ERIC Educational Resources Information Center

Fabiano, Gregory A.

2014-01-01

Attention-deficit/hyperactivity disorder is now widely conceptualized as a life course-persistent disorder, present from early childhood, and it results in pronounced impairment in functioning within educational settings, including high school. Current intervention approaches are briefly reviewed, and an approach to framing interventions within a…

Continuous Performance Tasks: Not Just about Sustaining Attention

ERIC Educational Resources Information Center

Roebuck, Hettie; Freigang, Claudia; Barry, Johanna G.

2016-01-01

Purpose: Continuous performance tasks (CPTs) are used to measure individual differences in sustained attention. Many different stimuli have been used as response targets without consideration of their impact on task performance. Here, we compared CPT performance in typically developing adults and children to assess the role of stimulus processing…

Divided visual attention: A comparison of patients with multiple sclerosis and controls, assessed with an optokinetic nystagmus suppression task.

PubMed

Williams, Isla M; Schofield, Peter; Khade, Neha; Abel, Larry A

2016-12-01

Multiple sclerosis (MS) frequently causes impairment of cognitive function. We compared patients with MS with controls on divided visual attention tasks. The MS patients' and controls' stare optokinetic nystagmus (OKN) was recorded in response to a 24°/s full field stimulus. Suppression of the OKN response, judged by the gain, was measured during tasks dividing visual attention between the fixation target and a second stimulus, central or peripheral, static or dynamic. All participants completed the Audio Recorded Cognitive Screen. MS patients had lower gain on the baseline stare OKN. OKN suppression in divided attention tasks was the same in MS patients as in controls but in both groups was better maintained in static than in dynamic tasks. In only dynamic tasks, older age was associated with less effective OKN suppression. MS patients had lower scores on a timed attention task and on memory. There was no significant correlation between attention or memory and eye movement parameters. Attention, a complex multifaceted construct, has different neural combinations for each task. Despite impairments on some measures of attention, MS patients completed the divided visual attention tasks normally. Copyright © 2016 Elsevier Ltd. All rights reserved.

Manipulating the disengage operation of covert visual spatial attention.

PubMed

Danckert, J; Maruff, P

1997-05-01

Processes of covert visual spatial attention have been closely linked to the programming of saccadic eye movements. In particular, it has been hypothesized that the reduction in saccadic latency that occurs in the gap paradigm is due to the prior disengagement of covert visual spatial attention. This explanation has received considerable criticism. No study as yet as attempted to demonstrate a facilitation of the disengagement of attention from a covertly attended object. If such facilitation were possible, it would support the hypothesis that the predisengagement of covert attention is necessary for the generation of express saccades. In two experiments using covert orienting of visual attention tasks (COVAT), with a high probability that targets would appear contralateral to the cued location, we attempted to facilitate the disengagement of covert attention by extinguishing peripheral cues prior to the appearance of targets. We hypothesized that the gap between cue offset and target onset would facilitate disengagement of attention from a covertly attended object. For both experiments, responses to targets appearing after a gap were slower than were responses in the no-gap condition. These results suggest that the prior offset of a covertly attended object does not facilitate the disengagement of attention.

Using neuronal populations to study the mechanisms underlying spatial and feature attention

PubMed Central

Cohen, Marlene R.; Maunsell, John H.R.

2012-01-01

Summary Visual attention affects both perception and neuronal responses. Whether the same neuronal mechanisms mediate spatial attention, which improves perception of attended locations, and non-spatial forms of attention has been a subject of considerable debate. Spatial and feature attention have similar effects on individual neurons. Because visual cortex is retinotopically organized, however, spatial attention can co-modulate local neuronal populations, while feature attention generally requires more selective modulation. We compared the effects of feature and spatial attention on local and spatially separated populations by recording simultaneously from dozens of neurons in both hemispheres of V4. Feature and spatial attention affect the activity of local populations similarly, modulating both firing rates and correlations between pairs of nearby neurons. However, while spatial attention appears to act on local populations, feature attention is coordinated across hemispheres. Our results are consistent with a unified attentional mechanism that can modulate the responses of arbitrary subgroups of neurons. PMID:21689604

Psychosocial influences on weight gain attitudes and behaviors during pregnancy.

PubMed

Dipietro, Janet A; Millet, Sarah; Costigan, Kathleen A; Gurewitsch, Edith; Caulfield, Laura E

2003-10-01

To examine pregnant women's weight-related attitudes and behaviors in relation to a constellation of psychosocial characteristics, prepregnancy body habitus, and gestational weight gain. One hundred-thirty women with low-risk, normal pregnancies. Cross-sectional, observational study assessed attitudes about weight gain at 36 weeks' gestation. Psychosocial characteristics, including anxiety, depression, social support, emotionality, and pregnancy-specific and nonspecific stress appraisal were assessed between 28 and 36 weeks' gestation. Principal components factor analysis, Pearson correlations, t tests, and analysis of variance. A range of positive and negative attitudes about weight gain was expressed. Twenty-one percent (n=27) of the sample endorsed at least one weight-restrictive behavior during pregnancy. Women who reported more weight-restrictive behaviors were more anxious (r=.24, P<.01), depressed (r=.29,P<.001), angry (r=.29, P<.001), stressed (r=.23, P<.01), and felt less uplifted (r=-.21, P<.05) about their pregnancies in general. Higher Positive Pregnancy Body Image scores were associated with feeling better about the pregnancy in general (r=.35, P<.001), fewer depressive symptoms, and less anger (both r=.20, both P<.01). Women who were self conscious about their weight gain felt more hassled by their pregnancies (r=.21, P<.05), greater anger (r=.21, P<.05), and more support from partners (r=.22, P<.05). Prepregnancy body mass index was unrelated, but negative attitudes about weight gain existed even among women who gained within recommended ranges. Women's attitudes about weight gain in pregnancy are imbedded in their orientation toward pregnancy as well as their general psychological functioning. Effective nutrition counseling for pregnant women should include consideration of weight-restrictive behaviors, the degree to which the pregnancy is perceived as positive and uplifting, and whether weight gain attitudes may be associated with their

Attention and Visuospatial Working Memory Share the Same Processing Resources

PubMed Central

Feng, Jing; Pratt, Jay; Spence, Ian

2012-01-01

Attention and visuospatial working memory (VWM) share very similar characteristics; both have the same upper bound of about four items in capacity and they recruit overlapping brain regions. We examined whether both attention and VWM share the same processing resources using a novel dual-task costs approach based on a load-varying dual-task technique. With sufficiently large loads on attention and VWM, considerable interference between the two processes was observed. A further load increase on either process produced reciprocal increases in interference on both processes, indicating that attention and VWM share common resources. More critically, comparison among four experiments on the reciprocal interference effects, as measured by the dual-task costs, demonstrates no significant contribution from additional processing other than the shared processes. These results support the notion that attention and VWM share the same processing resources. PMID:22529826

Operational considerations to reduce solar array loads

NASA Technical Reports Server (NTRS)

Gerstenmaier, W.

1992-01-01

The key parameters associated with solar array plume loads are examined, and operational considerations aimed at minimizing the effect of the Shuttle plumes on the Space Station solar arrays are discussed. These include solar array pointing to reduce loads and restrictions on Shuttle piloting. Particular attention is given to the method used to obtain the forcing functions (thruster time firing histories) for solar array plume calculation.

Does visual attention drive the dynamics of bistable perception?

PubMed Central

Dieter, Kevin C.; Brascamp, Jan; Tadin, Duje; Blake, Randolph

2016-01-01

How does attention interact with incoming sensory information to determine what we perceive? One domain in which this question has received serious consideration is that of bistable perception: a captivating class of phenomena that involves fluctuating visual experience in the face of physically unchanging sensory input. Here, some investigations have yielded support for the idea that attention alone determines what is seen, while others have implicated entirely attention-independent processes in driving alternations during bistable perception. We review the body of literature addressing this divide and conclude that in fact both sides are correct – depending on the form of bistable perception being considered. Converging evidence suggests that visual attention is required for alternations in the type of bistable perception called binocular rivalry, while alternations during other types of bistable perception appear to continue without requiring attention. We discuss some implications of this differential effect of attention for our understanding of the mechanisms underlying bistable perception, and examine how these mechanisms operate during our everyday visual experiences. PMID:27230785

School Radio: The Attention and Involvement of Teenage Pupils and Students.

ERIC Educational Resources Information Center

Armour, Charles

1978-01-01

Considers the problems of gaining the attention of students in the 12 to 20 age group when listening to radio as a class activity. Preparations for listening to radio in school, listener motivation, acceptable programs, teacher and student activities, and supporting visual materials are discussed. (JEG)

Pursuit gain and saccadic intrusions in first-degree relatives of probands with schizophrenia.

PubMed

Clementz, B A; Sweeney, J A; Hirt, M; Haas, G

1990-11-01

Oculomotor functioning of 26 probands with schizophrenia, 12 spectrum and 46 nonspectrum first-degree relatives, and 38 nonpsychiatric control subjects was evaluated. Spectrum relatives had more anticipatory saccades (ASs) and lower pursuit gain than nonspectrum relatives, who had more ASs and lower pursuit gain than control subjects. Probands also had lower pursuit gain than nonspectrum relatives and control subjects but did not differ from other groups on AS frequency. Control subjects had more globally accurate pursuit tracking (root mean square [RMS] error deviation) than both relative groups, whereas probands had the poorest RMS scores. Square wave jerk frequency did not differentiate the groups. Attention enhancement affected the frequency of ASs but did not affect either the other intrusive saccadic event or RMS scores. These results offer evidence that eye-movement dysfunction may serve as a biological marker for schizophrenia.

Towards the quantitative evaluation of visual attention models.

PubMed

Bylinskii, Z; DeGennaro, E M; Rajalingham, R; Ruda, H; Zhang, J; Tsotsos, J K

2015-11-01

Scores of visual attention models have been developed over the past several decades of research. Differences in implementation, assumptions, and evaluations have made comparison of these models very difficult. Taxonomies have been constructed in an attempt at the organization and classification of models, but are not sufficient at quantifying which classes of models are most capable of explaining available data. At the same time, a multitude of physiological and behavioral findings have been published, measuring various aspects of human and non-human primate visual attention. All of these elements highlight the need to integrate the computational models with the data by (1) operationalizing the definitions of visual attention tasks and (2) designing benchmark datasets to measure success on specific tasks, under these definitions. In this paper, we provide some examples of operationalizing and benchmarking different visual attention tasks, along with the relevant design considerations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Studies of relative gain and timing response of fine-mesh photomultiplier tubes in high magnetic fields

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

Sulkosky, V.; Allison, L.; Barber, C.

We investigated the use of Hamamatsu fine-mesh photomultiplier tube assemblies H6152-70 and H6614-70 with regards to their gain and timing resolution in magnetic fields up to 1.9 T. Our results show that the H6614-70 assembly can operate reliably in magnetic fields exceeding 1.5 T, while preserving a reasonable timing resolution even with a gain reduction of a factor of ~100. The reduction of the relative gain of the H6152-70 is similar to the H6614-70's near 1.5 T, but its timing resolution worsens considerably at this high field.

High perceptual load leads to both reduced gain and broader orientation tuning

PubMed Central

Stolte, Moritz; Bahrami, Bahador; Lavie, Nilli

2014-01-01

Due to its limited capacity, visual perception depends on the allocation of attention. The resultant phenomena of inattentional blindness, accompanied by reduced sensory visual cortex response to unattended stimuli in conditions of high perceptual load in the attended task, are now well established (Lavie, 2005; Lavie, 2010, for reviews). However, the underlying mechanisms for these effects remain to be elucidated. Specifically, is reduced perceptual processing under high perceptual load a result of reduced sensory signal gain, broader tuning, or both? We examined this question with psychophysical measures of orientation tuning under different levels of perceptual load in the task performed. Our results show that increased perceptual load leads to both reduced sensory signal and broadening of tuning. These results clarify the effects of attention on elementary visual perception and suggest that high perceptual load is critical for attentional effects on sensory tuning. PMID:24610952

A unique role of endogenous visual-spatial attention in rapid processing of multiple targets

PubMed Central

Guzman, Emmanuel; Grabowecky, Marcia; Palafox, German; Suzuki, Satoru

2012-01-01

Visual spatial attention can be exogenously captured by a salient stimulus or can be endogenously allocated by voluntary effort. Whether these two attention modes serve distinctive functions is debated, but for processing of single targets the literature suggests superiority of exogenous attention (it is faster acting and serves more functions). We report that endogenous attention uniquely contributes to processing of multiple targets. For speeded visual discrimination, response times are faster for multiple redundant targets than for single targets due to probability summation and/or signal integration. This redundancy gain was unaffected when attention was exogenously diverted from the targets, but was completely eliminated when attention was endogenously diverted. This was not due to weaker manipulation of exogenous attention because our exogenous and endogenous cues similarly affected overall response times. Thus, whereas exogenous attention is superior for processing single targets, endogenous attention plays a unique role in allocating resources crucial for rapid concurrent processing of multiple targets. PMID:21517209

Neural mechanisms of selective attention in the somatosensory system

PubMed Central

Hysaj, Kristjana; Niebur, Ernst

2016-01-01

Selective attention allows organisms to extract behaviorally relevant information while ignoring distracting stimuli that compete for the limited resources of their central nervous systems. Attention is highly flexible, and it can be harnessed to select information based on sensory modality, within-modality feature(s), spatial location, object identity, and/or temporal properties. In this review, we discuss the body of work devoted to understanding mechanisms of selective attention in the somatosensory system. In particular, we describe the effects of attention on tactile behavior and corresponding neural activity in somatosensory cortex. Our focus is on neural mechanisms that select tactile stimuli based on their location on the body (somatotopic-based attention) or their sensory feature (feature-based attention). We highlight parallels between selection mechanisms in touch and other sensory systems and discuss several putative neural coding schemes employed by cortical populations to signal the behavioral relevance of sensory inputs. Specifically, we contrast the advantages and disadvantages of using a gain vs. spike-spike correlation code for representing attended sensory stimuli. We favor a neural network model of tactile attention that is composed of frontal, parietal, and subcortical areas that controls somatosensory cells encoding the relevant stimulus features to enable preferential processing throughout the somatosensory hierarchy. Our review is based on data from noninvasive electrophysiological and imaging data in humans as well as single-unit recordings in nonhuman primates. PMID:27334956

Phonological awareness intervention and attention efficiency in children at risk: evidence of effectiveness on visual attention.

PubMed

Porta, María Elsa; Carrada, Mariana Andrea; Ison, Mirta Susana

2016-05-31

Using a pretest and posttest comparison group design, this 20 weeks study investigated the effects of a phonological awareness training program (PATP) on attention efficiency (AE) in 57 children (age = 5 to 6 years) at risk. The experimental group received the PATP (EG; n=30). We obtained pretest and posttest measures of phonological awareness and AE. The ANOVA showed significant interaction effects of the PATP and time on phonological awareness and AE. For both groups, posttest AE score means were higher than pretest score means. Pretest measures showed that the AE score mean for the EG was lower than that for the Control Group (CG; n=31); whereas posttest data showed no between group differences. Contrast analysis showed that the EG gained a greater level of phonological awareness ability and AE over CG. Our results indicate that children's attention efficiency not only improved as they developed, but also increased by means of a PATP.

Threat-Related Attentional Bias in Anxious Youth: A Review

ERIC Educational Resources Information Center

Puliafico, Anthony C.; Kendall, Philip C.

2006-01-01

The research literature suggests that children and adolescents suffering from anxiety disorders experience cognitive distortions that magnify their perceived level of threat in the environment. Of these distortions, an attentional bias toward threat-related information has received the most theoretical and empirical consideration. A large volume…

Directed attention reduces processing of emotional distracters irrespective of valence and arousal level.

PubMed

Wiens, Stefan; Syrjänen, Elmeri

2013-09-01

Emotional stimuli tend to capture attention, and this so-called motivated attention is commonly measured using the early posterior negativity (EPN) and the late positive potential (LPP). We hypothesized that voluntary, directed attention reduces motivated attention more strongly for highly than moderately arousing pleasant or unpleasant pictures. Participants were instructed to direct their attention to either a picture at fixation or the letters flanking the picture. Pictures varied substantially in arousal and valence. When the pictures were attended to, EPN and LPP increased linearly with arousal. When the letters were attended to, these linear effects decreased in the EPN for pleasant and unpleasant pictures and in the LPP for pleasant pictures. Thus, directed attention decreases processing of emotional distracters more strongly for highly than moderately arousing pleasant and unpleasant pictures. These results are consistent with the view that directed attention decreases emotion effects on sensory gain. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Forms of attention and attentional disorders.

PubMed

O'Donnell, Brian F

2002-05-01

Difficulties in attention or concentration are observed in many clinical syndromes. Cognitive studies of normal attention and neuropsychological studies of brain dysfunction indicate that attention reflects a variety of mechanisms. These processes include the startle response, the orienting response, selective attention, vigilance, and divided attention. Understanding the specific mechanisms involved in attention deficits or lapses may be helpful in planning and evaluating remediation programs and in altering patients' environments to compensate for specific attention deficits. In this article, forms of attention and disorders of attention are discussed, with emphasis on their importance to every day activities.

Thalamic control of sensory selection in divided attention.

PubMed

Wimmer, Ralf D; Schmitt, L Ian; Davidson, Thomas J; Nakajima, Miho; Deisseroth, Karl; Halassa, Michael M

2015-10-29

How the brain selects appropriate sensory inputs and suppresses distractors is unknown. Given the well-established role of the prefrontal cortex (PFC) in executive function, its interactions with sensory cortical areas during attention have been hypothesized to control sensory selection. To test this idea and, more generally, dissect the circuits underlying sensory selection, we developed a cross-modal divided-attention task in mice that allowed genetic access to this cognitive process. By optogenetically perturbing PFC function in a temporally precise window, the ability of mice to select appropriately between conflicting visual and auditory stimuli was diminished. Equivalent sensory thalamocortical manipulations showed that behaviour was causally dependent on PFC interactions with the sensory thalamus, not sensory cortex. Consistent with this notion, we found neurons of the visual thalamic reticular nucleus (visTRN) to exhibit PFC-dependent changes in firing rate predictive of the modality selected. visTRN activity was causal to performance as confirmed by bidirectional optogenetic manipulations of this subnetwork. Using a combination of electrophysiology and intracellular chloride photometry, we demonstrated that visTRN dynamically controls visual thalamic gain through feedforward inhibition. Our experiments introduce a new subcortical model of sensory selection, in which the PFC biases thalamic reticular subnetworks to control thalamic sensory gain, selecting appropriate inputs for further processing.

Valuing QALYs in Relation to Equity Considerations Using a Discrete Choice Experiment.

PubMed

van de Wetering, Liesbet; van Exel, Job; Bobinac, Ana; Brouwer, Werner B F

2015-12-01

To judge whether an intervention offers value for money, the incremental costs per gained quality-adjusted life-year (QALY) need to be compared with some relevant threshold, which ideally reflects the monetary value of health gains. Literature suggests that this value may depend on the equity context in which health gains are produced, but the value of a QALY in relation to equity considerations has remained largely unexplored. The objective of this study was to estimate the social marginal willingness to pay (MWTP) for QALY gains in different equity subgroups, using a discrete choice experiment (DCE). Both severity of illness (operationalized as proportional shortfall) and fair innings (operationalized as age) were considered as grounds for differentiating the value of health gains. We obtained a sample of 1205 respondents, representative of the adult population of the Netherlands. The data was analysed using panel mixed multinomial logit (MMNL) and latent class models. The panel MMNL models showed counterintuitive results, with more severe health states reducing the probability of receiving treatment. The latent class models revealed distinct preference patterns in the data. MWTP per QALY was sensitive to severity of disease among a substantial proportion of the public, but not to the age of care recipients. These findings emphasize the importance of accounting for preference heterogeneity among the public on value-laden issues such as prioritizing health care, both in research and decision making. This study emphasises the need to further explore the monetary value of a QALY in relation to equity considerations.

Are videogame training gains specific or general?

PubMed

Oei, Adam C; Patterson, Michael D

2014-01-01

Many recent studies using healthy adults document enhancements in perception and cognition from playing commercial action videogames (AVGs). Playing action games (e.g., Call of Duty, Medal of Honor) is associated with improved bottom-up lower-level information processing skills like visual-perceptual and attentional processes. One proposal states a general improvement in the ability to interpret and gather statistical information to predict future actions which then leads to better performance across different perceptual/attentional tasks. Another proposal claims all the tasks are separately trained in the AVGs because the AVGs and laboratory tasks contain similar demands. We review studies of action and non-AVGs to show support for the latter proposal. To explain transfer in AVGs, we argue that the perceptual and attention tasks share common demands with the trained videogames (e.g., multiple object tracking (MOT), rapid attentional switches, and peripheral vision). In non-AVGs, several studies also demonstrate specific, limited transfer. One instance of specific transfer is the specific enhancement to mental rotation after training in games with a spatial emphasis (e.g., Tetris). In contrast, the evidence for transfer is equivocal where the game and task do not share common demands (e.g., executive functioning). Thus, the "common demands" hypothesis of transfer not only characterizes transfer effects in AVGs, but also non-action games. Furthermore, such a theory provides specific predictions, which can help in the selection of games to train human cognition as well as in the design of videogames purposed for human cognitive and perceptual enhancement. Finally this hypothesis is consistent with the cognitive training literature where most post-training gains are for tasks similar to the training rather than general, non-specific improvements.

Are videogame training gains specific or general?

PubMed Central

Patterson, Michael D.

2014-01-01

Many recent studies using healthy adults document enhancements in perception and cognition from playing commercial action videogames (AVGs). Playing action games (e.g., Call of Duty, Medal of Honor) is associated with improved bottom-up lower-level information processing skills like visual-perceptual and attentional processes. One proposal states a general improvement in the ability to interpret and gather statistical information to predict future actions which then leads to better performance across different perceptual/attentional tasks. Another proposal claims all the tasks are separately trained in the AVGs because the AVGs and laboratory tasks contain similar demands. We review studies of action and non-AVGs to show support for the latter proposal. To explain transfer in AVGs, we argue that the perceptual and attention tasks share common demands with the trained videogames (e.g., multiple object tracking (MOT), rapid attentional switches, and peripheral vision). In non-AVGs, several studies also demonstrate specific, limited transfer. One instance of specific transfer is the specific enhancement to mental rotation after training in games with a spatial emphasis (e.g., Tetris). In contrast, the evidence for transfer is equivocal where the game and task do not share common demands (e.g., executive functioning). Thus, the “common demands” hypothesis of transfer not only characterizes transfer effects in AVGs, but also non-action games. Furthermore, such a theory provides specific predictions, which can help in the selection of games to train human cognition as well as in the design of videogames purposed for human cognitive and perceptual enhancement. Finally this hypothesis is consistent with the cognitive training literature where most post-training gains are for tasks similar to the training rather than general, non-specific improvements. PMID:24782722

An overview of attention deficits after paediatric traumatic brain injury.

PubMed

Ginstfeldt, Tim; Emanuelson, Ingrid

2010-01-01

Attention could be categorized into sustained, selective, shifting, divided and attention span. The primary objective was to evaluate the type of attention deficits that occurs after paediatric traumatic brain injury. Keywords were used such as 'attention', 'child', 'traumatic', 'brain' and 'injury' on MEDLINE articles published in 1991-2009. Articles found through MEDLINE were manually cross-referenced. Out of the examined categorizes, divided and sustained attention seem to be the most vulnerably, frequently displaying deficits in the children with TBI. Attention span seemed to be the most resistant and the shifting and selective categories falling somewhere in between. Most of the recovery is expected within the first year post-injury, even if some individuals continue to improve for years, and deficits often persist into adulthood. The attention domains are not affected to the same extent by TBI and this should be taken into consideration when evaluating a child. The commonly used tests also seem to differ in how sensitive they are in detecting deficits. The definition of attention domains and TBI would benefit to be stricter and agreed upon, to further facilitate research and rehabilitation programmes.

An integrative, experience-based theory of attentional control.

PubMed

Wilder, Matthew H; Mozer, Michael C; Wickens, Christopher D

2011-02-09

Although diverse, theories of visual attention generally share the notion that attention is controlled by some combination of three distinct strategies: (1) exogenous cuing from locally contrasting primitive visual features, such as abrupt onsets or color singletons (e.g., L. Itti, C. Koch, & E. Neiber, 1998), (2) endogenous gain modulation of exogenous activations, used to guide attention to task-relevant features (e.g., V. Navalpakkam & L. Itti, 2007; J. Wolfe, 1994, 2007), and (3) endogenous prediction of likely locations of interest, based on task and scene gist (e.g., A. Torralba, A. Oliva, M. Castelhano, & J. Henderson, 2006). However, little work has been done to synthesize these disparate theories. In this work, we propose a unifying conceptualization in which attention is controlled along two dimensions: the degree of task focus and the contextual scale of operation. Previously proposed strategies-and their combinations-can be viewed as instances of this one mechanism. Thus, this theory serves not as a replacement for existing models but as a means of bringing them into a coherent framework. We present an implementation of this theory and demonstrate its applicability to a wide range of attentional phenomena. The model accounts for key results in visual search with synthetic images and makes reasonable predictions for human eye movements in search tasks involving real-world images. In addition, the theory offers an unusual perspective on attention that places a fundamental emphasis on the role of experience and task-related knowledge.

Coherent Pump-Probe Interactions and Terahertz Intersubband Gain in Semiconductor Quantum Wells

NASA Technical Reports Server (NTRS)

Liu, Ansheng; Ning, Cun-Zheng

1999-01-01

In recent years there has been considerable interest in intersubband-transition-based infrared semiconductor quantum well (QW) lasers because of their potential applications. In the mid-infrared range, both electrically-injected quantum cascade lasers [1] and optically-pumped multiple QW lasers [2] have been experimentally realized. In these studies, optical gain is due to population inversion between the lasing subbands. It was also proposed that stimulated Raman scattering in QW systems can produce net infrared optical gain [3j. In such a nonlinear optical scheme, the appearance of optical gain that may lead to intersubband Raman lasers does not rely on the population inversion. Since, in tile resonant Raman process (Raman gain is the largest in this case), the pump field induces population redistribution among subbands in the QW s ystem, it seems that a realistic estimate of the optical gain has to include this effect. Perturbative calculations used in the previous work [3] may overestimate the Raman gain. In this paper we present a nonperturbative calculation of terahertz gain of optically-pumped semiconductor step quantum wells. Limiting optical transitions within the conduction band of QW, we solve the pump-field-induced nonequilibrium distribution function for each subband of the QW system from a set of coupled rate equations. Both intrasubband and intersubband relaxation processes in the quantum well system are included. Taking into account the coherent interactions between pump and THz (signal) waves, we we derive the susceptibility of the QW system for the THz field. For a GaAs/AlGaAs step QW, we calculate the Thz gain spectrum for different pump frequencies and intensities. Under moderately strong pumping (approximately 0.3 MW/sq cm), a significant THz gain (approximately 300/m) is predicted. It is also shown that the coherent wave interactions (resonant stimulated Raman processes) contribute significantly to the THz gain.

Objective assessment of attention in delirium: a narrative review.

PubMed

Tieges, Zoë; Brown, Laura J E; MacLullich, Alasdair M J

2014-12-01

Inattention is a core feature of delirium, and valid assessment of attention is central to diagnosis. Methods of measuring attention in delirium can be divided into two broad categories: (i) objective neuropsychological testing; and (ii) subjective grading of behaviour during interview and clinical examination. Here, we review and critically evaluate studies of objective neuropsychological testing of attention in delirium. We examine the implications of these studies for delirium detection and monitoring in clinical practice and research, and how these studies inform understanding of the nature of attentional deficits in delirium. Searches of MEDLINE and ISI Web of Knowledge databases were performed to identify studies in which objective tests of attention had been administered to patients with delirium, who had been diagnosed using DSM or ICD criteria. Sixteen publications were identified. The attention tests administered in these studies were grouped into the following categories: measures of attention span, vigilance tests, other pen-and-paper tests (e.g. Trail Making Test) and computerised tests of speeded reaction, vigilance and sustained attention. Patients with delirium showed deficits on all tasks, although most tasks were not considered pure measures of attention. Five papers provided data on differential diagnosis from dementia. Cancellation tests, spatial span tests and computerised tests of sustained attention discriminated delirium from dementia. Five studies presented reliability or validity statistics. The existing evidence base on objective assessment of attention in delirium is small. Objective testing of attention is underdeveloped but shows considerable promise in clinical practice and research. Copyright © 2014 John Wiley & Sons, Ltd.

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.

Translating Head Motion into Attention - Towards Processing of Student's Body-Language

ERIC Educational Resources Information Center

Raca, Mirko; Kidzinski, Lukasz; Dillenbourg, Pierre

2015-01-01

Evidence has shown that student's attention is a crucial factor for engagement and learning gain. Although it can be accurately assessed ad-hoc by an experienced teacher, continuous contact with all students in a large class is difficult to maintain and requires training for novice practitioners. We continue our previous work on investigating…

Suppression effects in feature-based attention

PubMed Central

Wang, Yixue; Miller, James; Liu, Taosheng

2015-01-01

Attending to a feature enhances visual processing of that feature, but it is less clear what occurs to unattended features. Single-unit recording studies in middle temporal (MT) have shown that neuronal modulation is a monotonic function of the difference between the attended and neuron's preferred direction. Such a relationship should predict a monotonic suppressive effect in psychophysical performance. However, past research on suppressive effects of feature-based attention has remained inconclusive. We investigated the suppressive effect for motion direction, orientation, and color in three experiments. We asked participants to detect a weak signal among noise and provided a partially valid feature cue to manipulate attention. We measured performance as a function of the offset between the cued and signal feature. We also included neutral trials where no feature cues were presented to provide a baseline measure of performance. Across three experiments, we consistently observed enhancement effects when the target feature and cued feature coincided and suppression effects when the target feature deviated from the cued feature. The exact profile of suppression was different across feature dimensions: Whereas the profile for direction exhibited a “rebound” effect, the profiles for orientation and color were monotonic. These results demonstrate that unattended features are suppressed during feature-based attention, but the exact suppression profile depends on the specific feature. Overall, the results are largely consistent with neurophysiological data and support the feature-similarity gain model of attention. PMID:26067533

Perspectives on Adolescent Alcohol Use and Consideration of Future Consequences: Results from a Qualitative Study

ERIC Educational Resources Information Center

Harvey, Séamus A.; McKay, Michael T.

2017-01-01

Consideration of future consequences (CFC) is described as the attention that individuals pay to the potential outcomes of their behaviour, and how their behaviour is affected as a result of attention to these outcomes. Greater CFC has been associated with less alcohol use, thus indicating its potential utility in health-promotion initiatives. A…

Ethical Considerations in Filing Personal Bankruptcy: A Hypothetical Case Study

ERIC Educational Resources Information Center

Landry, Robert J., III

2012-01-01

A great deal of research by legal studies scholars pertains to employment law, international law, and corporate governance, as well as other fields including ethics and international law. The fields typically addressed are very important and rightfully receive considerable attention in the scholarship and textbooks. However, bankruptcy as a…

Neural mechanisms of selective attention in the somatosensory system.

PubMed

Gomez-Ramirez, Manuel; Hysaj, Kristjana; Niebur, Ernst

2016-09-01

Selective attention allows organisms to extract behaviorally relevant information while ignoring distracting stimuli that compete for the limited resources of their central nervous systems. Attention is highly flexible, and it can be harnessed to select information based on sensory modality, within-modality feature(s), spatial location, object identity, and/or temporal properties. In this review, we discuss the body of work devoted to understanding mechanisms of selective attention in the somatosensory system. In particular, we describe the effects of attention on tactile behavior and corresponding neural activity in somatosensory cortex. Our focus is on neural mechanisms that select tactile stimuli based on their location on the body (somatotopic-based attention) or their sensory feature (feature-based attention). We highlight parallels between selection mechanisms in touch and other sensory systems and discuss several putative neural coding schemes employed by cortical populations to signal the behavioral relevance of sensory inputs. Specifically, we contrast the advantages and disadvantages of using a gain vs. spike-spike correlation code for representing attended sensory stimuli. We favor a neural network model of tactile attention that is composed of frontal, parietal, and subcortical areas that controls somatosensory cells encoding the relevant stimulus features to enable preferential processing throughout the somatosensory hierarchy. Our review is based on data from noninvasive electrophysiological and imaging data in humans as well as single-unit recordings in nonhuman primates. Copyright © 2016 the American Physiological Society.

Considerations on Geospatial Big Data

NASA Astrophysics Data System (ADS)

LIU, Zhen; GUO, Huadong; WANG, Changlin

2016-11-01

Geospatial data, as a significant portion of big data, has recently gained the full attention of researchers. However, few researchers focus on the evolution of geospatial data and its scientific research methodologies. When entering into the big data era, fully understanding the changing research paradigm associated with geospatial data will definitely benefit future research on big data. In this paper, we look deep into these issues by examining the components and features of geospatial big data, reviewing relevant scientific research methodologies, and examining the evolving pattern of geospatial data in the scope of the four ‘science paradigms’. This paper proposes that geospatial big data has significantly shifted the scientific research methodology from ‘hypothesis to data’ to ‘data to questions’ and it is important to explore the generality of growing geospatial data ‘from bottom to top’. Particularly, four research areas that mostly reflect data-driven geospatial research are proposed: spatial correlation, spatial analytics, spatial visualization, and scientific knowledge discovery. It is also pointed out that privacy and quality issues of geospatial data may require more attention in the future. Also, some challenges and thoughts are raised for future discussion.

Attention and working memory training: A feasibility study in children with neurodevelopmental disorders.

PubMed

Kerns, Kimberly A; Macoun, Sarah; MacSween, Jenny; Pei, Jacqueline; Hutchison, Marnie

2017-01-01

The current study investigated the efficacy of a game-based process specific intervention for improving attention and working memory in children with Fetal Alcohol Spectrum Disorders (FASD) and Autism Spectrum Disorders (ASD). The Caribbean Quest (CQ) is a 'serious game' that consists of five hierarchically structured tasks, delivered in an adaptive format, targeting different aspects of attention and/or working memory. In addition to game play, the intervention incorporates metacognitive strategies provided by trained educational assistants (EAs), to facilitate generalization and far transfer to academic and daily skills. EAs delivered the intervention to children (ages 6-13) during their regular school day, providing children with instruction in metacognitive strategies to improve game play, with participants completing approximately 12 hours of training over an 8 to 12 school week period. Pre- and post-test analyses revealed significant improvement on measures of working memory and attention, including reduced distractibility and improved divided attention skills. Additionally, children showed significant gains in performance on an academic measure of reading fluency, suggesting that training-related gains in attention and working memory transferred to classroom performance. Exit interviews with EAs revealed that the intervention was easily delivered within the school day, that children enjoyed the intervention, and that children transferred metacognitive strategies learned in game play into the classroom. Preliminary results support this game-based process specific intervention as a potentially effective treatment and useful tool for supporting cognitive improvements in children with FASD or ASD, when delivered as part of an overall treatment plan.

Enhancing Academic Achievement for Children with Attention-Deficit Hyperactivity Disorder: Evidence from School-Based Intervention Research

ERIC Educational Resources Information Center

Jitendra, Asha K.; DuPaul, George J.; Someki, Fumio; Tresco, Katy E.

2008-01-01

Although children with Attention-Deficit Hyperactivity Disorder (ADHD) exhibit significant academic difficulties in school settings, considerably less attention is devoted to remediating their academic problems when compared to behavioral and social difficulties. The purpose of this article is to review empirically supported academic interventions…

Attention reorganizes connectivity across networks in a frequency specific manner.

PubMed

Kwon, Soyoung; Watanabe, Masataka; Fischer, Elvira; Bartels, Andreas

2017-01-01

Attention allows our brain to focus its limited resources on a given task. It does so by selective modulation of neural activity and of functional connectivity (FC) across brain-wide networks. While there is extensive literature on activity changes, surprisingly few studies examined brain-wide FC modulations that can be cleanly attributed to attention compared to matched visual processing. In contrast to prior approaches, we used an ultra-long trial design that avoided transients from trial onsets, included slow fluctuations (<0.1Hz) that carry important information on FC, and allowed for frequency-segregated analyses. We found that FC derived from long blocks had a nearly two-fold higher gain compared to FC derived from traditional (short) block designs. Second, attention enhanced intrinsic (negative or positive) correlations across networks, such as between the default-mode network (DMN), the dorsal attention network (DAN), and the visual system (VIS). In contrast attention de-correlated the intrinsically correlated visual regions. Third, the de-correlation within VIS was driven primarily by high frequencies, whereas the increase in DAN-VIS predominantly by low frequencies. These results pinpoint two fundamentally distinct effects of attention on connectivity. Information flow increases between distinct large-scale networks, and de-correlation within sensory cortex indicates decreased redundancy. Copyright © 2016 Elsevier Inc. All rights reserved.

Active Enhancement of Slow Light Based on Plasmon-Induced Transparency with Gain Materials.

PubMed

Zhang, Zhaojian; Yang, Junbo; He, Xin; Han, Yunxin; Zhang, Jingjing; Huang, Jie; Chen, Dingbo; Xu, Siyu

2018-06-03

As a plasmonic analogue of electromagnetically induced transparency (EIT), plasmon-induced transparency (PIT) has drawn more attention due to its potential of realizing on-chip sensing, slow light and nonlinear effect enhancement. However, the performance of a plasmonic system is always limited by the metal ohmic loss. Here, we numerically report a PIT system with gain materials based on plasmonic metal-insulator-metal waveguide. The corresponding phenomenon can be theoretically analyzed by coupled mode theory (CMT). After filling gain material into a disk cavity, the system intrinsic loss can be compensated by external pump beam, and the PIT can be greatly fueled to achieve a dramatic enhancement of slow light performance. Finally, a double-channel enhanced slow light is introduced by adding a second gain disk cavity. This work paves way for a potential new high-performance slow light device, which can have significant applications for high-compact plasmonic circuits and optical communication.

Divided spatial attention and feature-mixing errors.

PubMed

Golomb, Julie D

2015-11-01

Spatial attention is thought to play a critical role in feature binding. However, often multiple objects or locations are of interest in our environment, and we need to shift or split attention between them. Recent evidence has demonstrated that shifting and splitting spatial attention results in different types of feature-binding errors. In particular, when two locations are simultaneously sharing attentional resources, subjects are susceptible to feature-mixing errors; that is, they tend to report a color that is a subtle blend of the target color and the color at the other attended location. The present study was designed to test whether these feature-mixing errors are influenced by target-distractor similarity. Subjects were cued to split attention across two different spatial locations, and were subsequently presented with an array of colored stimuli, followed by a postcue indicating which color to report. Target-distractor similarity was manipulated by varying the distance in color space between the two attended stimuli. Probabilistic modeling in all cases revealed shifts in the response distribution consistent with feature-mixing errors; however, the patterns differed considerably across target-distractor color distances. With large differences in color, the findings replicated the mixing result, but with small color differences, repulsion was instead observed, with the reported target color shifted away from the other attended color.

Keeping pain in mind: a motivational account of attention to pain.

PubMed

Van Damme, Stefaan; Legrain, Valéry; Vogt, Julia; Crombez, Geert

2010-02-01

Attention is a key concept in many theories of pain perception. A clinically popular idea is that pain is more intense in persons who are hypervigilant for or bias their attention to pain information. So far, evidence for such bias in pain patients as compared to healthy persons is inconclusive. Furthermore, studies investigating the effects of distracting attention away from pain have shown contradictory results. In this review, we present a motivational perspective on attentional processing of pain that accounts for these inconclusive research findings. We argue that pain always has to be considered within a context of goal pursuit. From this perspective, two largely unexplored theoretical assumptions are introduced. First, when pain occurs during the pursuit of a certain goal, it may unintentionally capture attention although it is not relevant for the goal. Whether such unintentional attentional capture happens is not only dependent upon the characteristics of the pain but also on the characteristics of the focal goal. Second, attention to pain and pain-related information might be driven by a focal goal related to pain. Attentional processing of pain information will be particularly enhanced when the focal goal is related to pain management (e.g., attempting to gain control). Future research should systematically investigate the role of motivation and goal pursuit in the attentional processing of pain-related information. This motivational perspective offers a powerful framework to explain inter- and intra-individual differences in the deployment of attention to pain-related information.

Irrelevant singletons in visual search do not capture attention but can produce nonspatial filtering costs.

PubMed

Wykowska, Agnieszka; Schubö, Anna

2011-03-01

It is not clear how salient distractors affect visual processing. The debate concerning the issue of whether irrelevant salient items capture spatial attention [e.g., Theeuwes, J., Atchley, P., & Kramer, A. F. On the time course of top-down and bottom-up control of visual attention. In S. Monsell & J. Driver (Eds.), Attention and performance XVIII: Control of cognitive performance (pp. 105-124). Cambridge, MA: MIT Press, 2000] or produce only nonspatial interference in the form of, for example, filtering costs [Folk, Ch. L., & Remington, R. Top-down modulation of preattentive processing: Testing the recovery account of contingent capture. Visual Cognition, 14, 445-465, 2006] has not yet been settled. The present ERP study examined deployment of attention in visual search displays that contained an additional irrelevant singleton. Display-locked N2pc showed that attention was allocated to the target and not to the irrelevant singleton. However, the onset of the N2pc to the target was delayed when the irrelevant singleton was presented in the opposite hemifield relative to the same hemifield. Thus, although attention was successfully focused on the target, the irrelevant singleton produced some interference resulting in a delayed allocation of attention to the target. A subsequent probe discrimination task allowed for locking ERPs to probe onsets and investigating the dynamics of sensory gain control for probes appearing at relevant (target) or irrelevant (singleton distractor) positions. Probe-locked P1 showed sensory gain for probes positioned at the target location but no such effect for irrelevant singletons in the additional singleton condition. Taken together, the present data support the claim that irrelevant singletons do not capture attention. If they produce any interference, it is rather due to nonspatial filtering costs.

Tiered analytics for purity assessment of macrocyclic peptides in drug discovery: Analytical consideration and method development.

PubMed

Qian Cutrone, Jingfang Jenny; Huang, Xiaohua Stella; Kozlowski, Edward S; Bao, Ye; Wang, Yingzi; Poronsky, Christopher S; Drexler, Dieter M; Tymiak, Adrienne A

2017-05-10

Synthetic macrocyclic peptides with natural and unnatural amino acids have gained considerable attention from a number of pharmaceutical/biopharmaceutical companies in recent years as a promising approach to drug discovery, particularly for targets involving protein-protein or protein-peptide interactions. Analytical scientists charged with characterizing these leads face multiple challenges including dealing with a class of complex molecules with the potential for multiple isomers and variable charge states and no established standards for acceptable analytical characterization of materials used in drug discovery. In addition, due to the lack of intermediate purification during solid phase peptide synthesis, the final products usually contain a complex profile of impurities. In this paper, practical analytical strategies and methodologies were developed to address these challenges, including a tiered approach to assessing the purity of macrocyclic peptides at different stages of drug discovery. Our results also showed that successful progression and characterization of a new drug discovery modality benefited from active analytical engagement, focusing on fit-for-purpose analyses and leveraging a broad palette of analytical technologies and resources. Copyright © 2017. Published by Elsevier B.V.

The tightrope between drawing media attention and exaggeration

NASA Astrophysics Data System (ADS)

Savenije, Hubert H. G.

2017-04-01

To draw media attention, it is not sufficient to present your research in a simple and understandable way. The message should also be news-worthy, controversial or surprising. Unfortunately well-balanced, well-founded and considerate statements are seldom attractive to the media. The media want something that creates commotion. This may tempt one to overstate the impact of research results, or to exaggerate its relevance. But this is dangerous, because if you do manage to draw the attention of the media, then the headline maker will surely make your claim bolder then you intended it to be. I had to learn this the hard way. I'll illustrate this with a few examples from my own media experience.

SOAP Opera: Self as Object and Agent in Prioritizing Attention.

PubMed

Truong, Grace; Todd, Rebecca M

2017-06-01

A growing body of evidence has demonstrated that multiple sources of salience tune attentional sets toward aspects of the environment, including affectively and motivationally significant categories of stimuli such as angry faces and reward-associated target locations. Recent evidence further indicates that objects that have gained personal significance through ownership can elicit similar attentional prioritization. Here we discuss current research on sources of attentional prioritization that shape our awareness of the visual world from moment to moment and the underlying neural systems and contextualize what is known about attentional prioritization of our possessions within that research. We review behavioral and neuroimaging research on the influence of self-relevance and ownership on cognition and discuss challenges to this literature stemming from different modes of conceptualizing and operationalizing the self. We argue that ownership taps into both "self-as-object," which characterizes the self as an object with a constellation of traits and attributes, and "self-as-subject," which characterizes the self as an agentic perceiver and knower. Despite an abundance of research probing neural and behavioral indices of self-as-object and its effects on attention, there exists a paucity of research on the influence of self-relevance of attention when self is operationalized from the perspective of a first-person subject. To begin to address this gap, we propose the Self as Ownership in Attentional Prioritization (SOAP) framework to explain how ownership increases salience through attention to external representations of self-identity (i.e., self as object) and attention to contextually mediated permission to act (i.e., self as subject).

A Qualitative Examination of Ethical and Legal Considerations Regarding Dating Violence

ERIC Educational Resources Information Center

Sikes, April; Walley, Cynthia; Hays, Danica G.

2012-01-01

Despite the increased attention to dating violence among adolescents and young adults, limited information is available on ethical and legal considerations specific to this population. Therefore, this qualitative study explores 21 trainees' and practitioners' conceptualization of ethical and legal issues pertaining to adolescent dating violence.…

Tungsten fiber reinforced superalloy composite high temperature component design considerations

NASA Technical Reports Server (NTRS)

Winsa, E. A.

1982-01-01

Tungsten fiber reinforced superalloy composites (TFRS) are intended for use in high temperature turbine components. Current turbine component design methodology is based on applying the experience, sometimes semiempirical, gained from over 30 years of superalloy component design. Current composite component design capability is generally limited to the methodology for low temperature resin matrix composites. Often the tendency is to treat TFRS as just another superalloy or low temperature composite. However, TFRS behavior is significantly different than that of superalloys, and the high environment adds consideration not common in low temperature composite component design. The methodology used for preliminary design of TFRS components are described. Considerations unique to TFRS are emphasized.

A high gain antenna system for airborne satellite communication applications

NASA Technical Reports Server (NTRS)

Maritan, M.; Borgford, M.

1990-01-01

A high gain antenna for commercial aviation satellites communication is discussed. Electromagnetic and practical design considerations as well as candidate systems implementation are presented. An evaluation of these implementation schemes is given, resulting in the selection of a simple top mounted aerodynamic phased array antenna with a remotely located beam steering unit. This concept has been developed into a popular product known as the Canadian Marconi Company CMA-2100. A description of the technical details is followed by a summary of results from the first production antennas.

Loss-Aversion or Loss-Attention: The Impact of Losses on Cognitive Performance

ERIC Educational Resources Information Center

Yechiam, Eldad; Hochman, Guy

2013-01-01

Losses were found to improve cognitive performance, and this has been commonly explained by increased weighting of losses compared to gains (i.e., loss aversion). We examine whether effects of losses on performance could be modulated by two alternative processes: an attentional effect leading to increased sensitivity to task incentives; and a…

Attention reduces spatial uncertainty in human ventral temporal cortex.

PubMed

Kay, Kendrick N; Weiner, Kevin S; Grill-Spector, Kalanit

2015-03-02

Ventral temporal cortex (VTC) is the latest stage of the ventral "what" visual pathway, which is thought to code the identity of a stimulus regardless of its position or size [1, 2]. Surprisingly, recent studies show that position information can be decoded from VTC [3-5]. However, the computational mechanisms by which spatial information is encoded in VTC are unknown. Furthermore, how attention influences spatial representations in human VTC is also unknown because the effect of attention on spatial representations has only been examined in the dorsal "where" visual pathway [6-10]. Here, we fill these significant gaps in knowledge using an approach that combines functional magnetic resonance imaging and sophisticated computational methods. We first develop a population receptive field (pRF) model [11, 12] of spatial responses in human VTC. Consisting of spatial summation followed by a compressive nonlinearity, this model accurately predicts responses of individual voxels to stimuli at any position and size, explains how spatial information is encoded, and reveals a functional hierarchy in VTC. We then manipulate attention and use our model to decipher the effects of attention. We find that attention to the stimulus systematically and selectively modulates responses in VTC, but not early visual areas. Locally, attention increases eccentricity, size, and gain of individual pRFs, thereby increasing position tolerance. However, globally, these effects reduce uncertainty regarding stimulus location and actually increase position sensitivity of distributed responses across VTC. These results demonstrate that attention actively shapes and enhances spatial representations in the ventral visual pathway. Copyright © 2015 Elsevier Ltd. All rights reserved.

Attention reduces spatial uncertainty in human ventral temporal cortex

PubMed Central

Kay, Kendrick N.; Weiner, Kevin S.; Grill-Spector, Kalanit

2014-01-01

SUMMARY Ventral temporal cortex (VTC) is the latest stage of the ventral ‘what’ visual pathway, which is thought to code the identity of a stimulus regardless of its position or size [1, 2]. Surprisingly, recent studies show that position information can be decoded from VTC [3–5]. However, the computational mechanisms by which spatial information is encoded in VTC are unknown. Furthermore, how attention influences spatial representations in human VTC is also unknown because the effect of attention on spatial representations has only been examined in the dorsal ‘where’ visual pathway [6–10]. Here we fill these significant gaps in knowledge using an approach that combines functional magnetic resonance imaging and sophisticated computational methods. We first develop a population receptive field (pRF) model [11, 12] of spatial responses in human VTC. Consisting of spatial summation followed by a compressive nonlinearity, this model accurately predicts responses of individual voxels to stimuli at any position and size, explains how spatial information is encoded, and reveals a functional hierarchy in VTC. We then manipulate attention and use our model to decipher the effects of attention. We find that attention to the stimulus systematically and selectively modulates responses in VTC, but not early visual areas. Locally, attention increases eccentricity, size, and gain of individual pRFs, thereby increasing position tolerance. However, globally, these effects reduce uncertainty regarding stimulus location and actually increase position sensitivity of distributed responses across VTC. These results demonstrate that attention actively shapes and enhances spatial representations in the ventral visual pathway. PMID:25702580

Enhancing Spatial Attention and Working Memory in Younger and Older Adults.

PubMed

Rolle, Camarin E; Anguera, Joaquin A; Skinner, Sasha N; Voytek, Bradley; Gazzaley, Adam

2017-09-01

Daily experiences demand both focused and broad allocation of attention for us to interact efficiently with our complex environments. Many types of attention have shown age-related decline, although there is also evidence that such deficits may be remediated with cognitive training. However, spatial attention abilities have shown inconsistent age-related differences, and the extent of potential enhancement of these abilities remains unknown. Here, we assessed spatial attention in both healthy younger and older adults and trained this ability in both age groups for 5 hr over the course of 2 weeks using a custom-made, computerized mobile training application. We compared training-related gains on a spatial attention assessment and spatial working memory task to age-matched controls who engaged in expectancy-matched, active placebo computerized training. Age-related declines in spatial attention abilities were observed regardless of task difficulty. Spatial attention training led to improved focused and distributed attention abilities as well as improved spatial working memory in both younger and older participants. No such improvements were observed in either of the age-matched control groups. Note that these findings were not a function of improvements in simple response time, as basic motoric function did not change after training. Furthermore, when using change in simple response time as a covariate, all findings remained significant. These results suggest that spatial attention training can lead to enhancements in spatial working memory regardless of age.

Enhancing Spatial Attention and Working Memory in Younger and Older Adults

PubMed Central

Rolle, Camarin E.; Anguera, Joaquin A.; Skinner, Sasha N.; Voytek, Bradley; Gazzaley, Adam

2018-01-01

Daily experiences demand both focused and broad allocation of attention for us to interact efficiently with our complex environments. Many types of attention have shown age-related decline, although there is also evidence that such deficits may be remediated with cognitive training. However, spatial attention abilities have shown inconsistent age-related differences, and the extent of potential enhancement of these abilities remains unknown. Here, we assessed spatial attention in both healthy younger and older adults and trained this ability in both age groups for 5 hr over the course of 2 weeks using a custom-made, computerized mobile training application. We compared training-related gains on a spatial attention assessment and spatial working memory task to age-matched controls who engaged in expectancy-matched, active placebo computerized training. Age-related declines in spatial attention abilities were observed regardless of task difficulty. Spatial attention training led to improved focused and distributed attention abilities as well as improved spatial working memory in both younger and older participants. No such improvements were observed in either of the age-matched control groups. Note that these findings were not a function of improvements in simple response time, as basic motoric function did not change after training. Furthermore, when using change in simple response time as a covariate, all findings remained significant. These results suggest that spatial attention training can lead to enhancements in spatial working memory regardless of age. PMID:28654361

Differences in children's thinking and learning during attentional focus instruction.

PubMed

Perreault, Melanie E; French, Karen E

2016-02-01

Considerable evidence supports the motor learning advantage associated with an external focus of attention; however, very few studies have investigated attentional focus effects with children despite individual functional constraints that have the potential to impact use of instructional content. Thus, the purpose of this study was to determine the effect of attentional focus instruction on motor learning in children. Participants (n=42) aged 9-11years were randomly assigned to one of three gender-stratified groups: (1) control, (2) internal focus, or (3) external focus. Following initial instructions and task demonstration, participants performed 100 modified free throws over two days while receiving additional cues respective to their attentional focus condition and returned approximately 48h later to perform 20 additional free throws. Results revealed no significant learning differences between groups. However, responses to retrospective verbal reports suggest that the use of external focus content during practice may have contributed to some participants' superior performance in retention. Future research should continue to examine attentional focus effects across a variety of ages and incorporate retrospective verbal reports in order to examine children's thoughts during attentional focus instruction. Copyright © 2015 Elsevier B.V. All rights reserved.

Motivation and attention following hemispheric stroke.

PubMed

Olgiati, E; Russell, C; Soto, D; Malhotra, P

2016-01-01

Spatial neglect (SN) is an extremely common disorder of attention; it is most frequently a consequence of stroke, especially to the right cerebral hemisphere. The current view of SN is that it is not a unitary deficit but a multicomponent syndrome. Crucially, it has been repeatedly shown that it has a considerable negative impact on rehabilitation outcome. Although a number of behavioral and pharmacological therapies have been developed, none of these appears to be applicable to all patients with SN or has proved unequivocally successful in clinical trials. One potential avenue for therapeutic intervention in neglect relates to the interaction between motivation and attention. A number of investigators, including ourselves, have observed a possible motivational component to the syndrome and showed that motivational stimulation can temporarily improve attention in patients with SN. In this chapter we review previous work looking at how motivation can modulate attention in healthy individuals and how it may be affected by neurological disease before discussing how motivational impairments may contribute to neglect, and how motivation has been used to modulate neglect. In the final section, we present recent experimental work examining how reward interacts with attentional biases in patients with SN. In this study, we adapted the classic Landmark task to explore the mechanisms behind the effect of reward in SN, and found that centrally located stimuli that were explicitly associated with reward appeared to improve neglect and reduce rightward bias. Our results suggest that positive motivation, in the form of anticipated monetary reward, may influence attentional bias via more general mechanisms, such as alerting and task engagement, rather than directly increasing salience of items in contralesional space. We conclude by discussing how motivation might be practically integrated into the rehabilitation of patients with this debilitating disorder. © 2016 Elsevier B

Rewards boost sustained attention through higher effort: A value-based decision making approach.

PubMed

Massar, Stijn A A; Lim, Julian; Sasmita, Karen; Chee, Michael W L

2016-10-01

Maintaining sustained attention over time is an effortful process limited by finite cognitive resources. Recent theories describe the role of motivation in the allocation of such resources as a decision process: the costs of effortful performance are weighed against its gains. We examined this hypothesis by combining methods from attention research and decision neuroscience. Participants first performed a sustained attention task at different levels of reward. They then performed a reward-discounting task, measuring the subjective costs of performance. Results demonstrated that higher rewards led to improved performance (Exp 1-3), and enhanced attentional effort (i.e. pupil diameter; Exp 2 & 3). Moreover, discounting curves constructed from the choice task indicated that subjects devalued rewards that came at the cost of staying vigilant for a longer duration (Exp 1 & 2). Motivation can thus boost sustained attention through increased effort, while sustained performance is regarded as a cost against which rewards are discounted. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Therapeutic considerations in special patients.

PubMed

Little, J W; Falace, D A

1984-07-01

Careful attention to patients' histories and their medical problems and consultation with their physicians should provide sound bases for selection of drugs. Antibiotic prophylaxis for patients with cardiovascular disorders is described for American Heart Association standards, but for other indications sound judgment based on the principles of antibiotic prophylaxis must be the rule. Patients with end-stage renal disease and severe liver impairment may be at risk with certain drugs. The most critical time for consideration of use of drugs during pregnancy is the first trimester. However, careful selection of drugs for use during the balance of the term can reduce the risk of harm to the mother and fetus.

Could I Have Attention-Deficit/Hyperactivity Disorder (ADHD)? Finding an Answer to ADHD as an Adult

MedlinePlus

... in attention and concentration and can provide the skills for improving organization and efficiency in daily tasks. It can also address feelings of low self-esteem and help adults with ADHD gain confidence, as ...

Pre-pregnancy body mass index and gestational weight gain and their effects on pregnancy and birth outcomes: a cohort study in West Sumatra, Indonesia.

PubMed

Soltani, Hora; Lipoeto, Nur I; Fair, Frankie J; Kilner, Karen; Yusrawati, Y

2017-11-09

Indonesia has a considerably high incidence of maternal and infant mortality. The country has however been experiencing a social and economic transition, influencing its general population demographics and nutritional status including the state of health and nutrition of pregnant women. This study aimed to explore body mass index (BMI) and gestational weight gain (GWG), and their relationship with pregnancy outcomes in a sample of Indonesian pregnant women. This observational cohort study included a total of 607 pregnant women who were recruited in 2010 from maternity clinics in Western Sumatra, Indonesia. Multiple logistic and regression analyses were undertaken to compare pregnancy and birth outcomes for different BMI and GWG, using normal weight women and women with a recommended weight gain as the referent groups. The prevalence of underweight (BMI < 18.5 kg/m 2 ) in pregnancy was high at 20.1%; while 21.7% of women were overweight (BMI: 23.0-27.4 kg/m 2 ) and 5.3% obese (BMI ≥ 27.5 kg/m 2 ) using the Asian BMI classifications. The incidence of overweight (BMI: 25.0-29.9 kg/m 2 ) and obese (BMI ≥ 30.0 kg/m 2 ) according to the international BMI classifications were 13.5% and 1.1% respectively. The majority of women gained inadequate weight in pregnancy compared to the Institute of Medicine (IOM) recommendations, especially those who had a normal BMI. Birthweight adjusted mean difference aMD (95% confidence interval) 205 (46,365) and the odds of macrosomia adjusted odds ratio aOR 13.46 (2.32-77.99) significantly increased in obese women compared to those with a normal BMI. Birthweight aMD -139 (-215, -64) significantly decreased in women with inadequate GWG compared to those with recommended GWG, while SGA aOR 5.44 (1.36, 21.77) and prematurity aOR 3.55 (1.23, 10.21) increased. Low nutritional status and inadequate GWG remain a cause for concern in these women. The higher odds of macrosomia with increasing maternal BMI and higher odds of

Financial gains and risks in pay-for-performance bonus algorithms.

PubMed

Cromwell, Jerry; Drozd, Edward M; Smith, Kevin; Trisolini, Michael

2007-01-01

Considerable attention has been given to evidence-based process indicators associated with quality of care, while much less attention has been given to the structure and key parameters of the various pay-for-performance (P4P) bonus and penalty arrangements using such measures. In this article we develop a general model of quality payment arrangements and discuss the advantages and disadvantages of the key parameters. We then conduct simulation analyses of four general P4P payment algorithms by varying seven parameters, including indicator weights, indicator intercorrelation, degree of uncertainty regarding intervention effectiveness, and initial baseline rates. Bonuses averaged over several indicators appear insensitive to weighting, correlation, and the number of indicators. The bonuses are sensitive to disease manager perceptions of intervention effectiveness, facing challenging targets, and the use of actual-to-target quality levels versus rates of improvement over baseline.

Attentional Filter Training but Not Memory Training Improves Decision-Making.

PubMed

Schmicker, Marlen; Müller, Patrick; Schwefel, Melanie; Müller, Notger G

2017-01-01

Decision-making has a high practical relevance for daily performance. Its relation to other cognitive abilities such as executive control and memory is not fully understood. Here we asked whether training of either attentional filtering or memory storage would influence decision-making as indexed by repetitive assessments of the Iowa Gambling Task (IGT). The IGT was developed to assess and simulate real-life decision-making (Bechara et al., 2005). In this task, participants gain or lose money by developing advantageous or disadvantageous decision strategies. On five consecutive days we trained 29 healthy young adults (20-30 years) either in working memory (WM) storage or attentional filtering and measured their IGT scores after each training session. During memory training (MT) subjects performed a computerized delayed match-to-sample task where two displays of bars were presented in succession. During filter training (FT) participants had to indicate whether two simultaneously presented displays of bars matched or not. Whereas in MT the relevant target stimuli stood alone, in FT the targets were embedded within irrelevant distractors (bars in a different color). All subjects within each group improved their performance in the trained cognitive task. For the IGT, we observed an increase over time in the amount of money gained in the FT group only. Decision-making seems to be influenced more by training to filter out irrelevant distractors than by training to store items in WM. Selective attention could be responsible for the previously noted relationship between IGT performance and WM and is therefore more important for enhancing efficiency in decision-making.

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

PubMed

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

2016-08-01

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

Sustained selective attention to competing amplitude-modulations in human auditory cortex.

PubMed

Riecke, Lars; Scharke, Wolfgang; Valente, Giancarlo; Gutschalk, Alexander

2014-01-01

Auditory selective attention plays an essential role for identifying sounds of interest in a scene, but the neural underpinnings are still incompletely understood. Recent findings demonstrate that neural activity that is time-locked to a particular amplitude-modulation (AM) is enhanced in the auditory cortex when the modulated stream of sounds is selectively attended to under sensory competition with other streams. However, the target sounds used in the previous studies differed not only in their AM, but also in other sound features, such as carrier frequency or location. Thus, it remains uncertain whether the observed enhancements reflect AM-selective attention. The present study aims at dissociating the effect of AM frequency on response enhancement in auditory cortex by using an ongoing auditory stimulus that contains two competing targets differing exclusively in their AM frequency. Electroencephalography results showed a sustained response enhancement for auditory attention compared to visual attention, but not for AM-selective attention (attended AM frequency vs. ignored AM frequency). In contrast, the response to the ignored AM frequency was enhanced, although a brief trend toward response enhancement occurred during the initial 15 s. Together with the previous findings, these observations indicate that selective enhancement of attended AMs in auditory cortex is adaptive under sustained AM-selective attention. This finding has implications for our understanding of cortical mechanisms for feature-based attentional gain control.

Sustained Selective Attention to Competing Amplitude-Modulations in Human Auditory Cortex

PubMed Central

Riecke, Lars; Scharke, Wolfgang; Valente, Giancarlo; Gutschalk, Alexander

2014-01-01

Auditory selective attention plays an essential role for identifying sounds of interest in a scene, but the neural underpinnings are still incompletely understood. Recent findings demonstrate that neural activity that is time-locked to a particular amplitude-modulation (AM) is enhanced in the auditory cortex when the modulated stream of sounds is selectively attended to under sensory competition with other streams. However, the target sounds used in the previous studies differed not only in their AM, but also in other sound features, such as carrier frequency or location. Thus, it remains uncertain whether the observed enhancements reflect AM-selective attention. The present study aims at dissociating the effect of AM frequency on response enhancement in auditory cortex by using an ongoing auditory stimulus that contains two competing targets differing exclusively in their AM frequency. Electroencephalography results showed a sustained response enhancement for auditory attention compared to visual attention, but not for AM-selective attention (attended AM frequency vs. ignored AM frequency). In contrast, the response to the ignored AM frequency was enhanced, although a brief trend toward response enhancement occurred during the initial 15 s. Together with the previous findings, these observations indicate that selective enhancement of attended AMs in auditory cortex is adaptive under sustained AM-selective attention. This finding has implications for our understanding of cortical mechanisms for feature-based attentional gain control. PMID:25259525

Attentional capture and engagement during the attentional blink: A "camera" metaphor of attention.

PubMed

Zivony, Alon; Lamy, Dominique

2016-11-01

Identification of a target is impaired when it follows a previous target within 500 ms, suggesting that our attentional system suffers from severe temporal limitations. Although control-disruption theories posit that such impairment, known as the attentional blink (AB), reflects a difficulty in matching incoming information with the current attentional set, disrupted-engagement theories propose that it reflects a delay in later processes leading to transient enhancement of potential targets. Here, we used a variant of the contingent-capture rapid serial visual presentation (RSVP) paradigm (Folk, Ester, & Troemel, 2009) to adjudicate these competing accounts. Our results show that a salient distractor that shares the target color captures attention to the same extent whether it appears within or outside the blink, thereby invalidating the notion that control over the attentional set is compromised during the blink. In addition, our results show that during the blink, not the attention-capturing object itself but the item immediately following it, is selected, indicating that the AB manifests as a delay between attentional capture and attentional engagement. We therefore conclude that attentional capture and attentional engagement can be dissociated as separate stages of attentional selection. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Understanding relevance of health research: considerations in the context of research impact assessment.

PubMed

Dobrow, Mark J; Miller, Fiona A; Frank, Cy; Brown, Adalsteinn D

2017-04-17

With massive investment in health-related research, above and beyond investments in the management and delivery of healthcare and public health services, there has been increasing focus on the impact of health research to explore and explain the consequences of these investments and inform strategic planning. Relevance is reflected by increased attention to the usability and impact of health research, with research funders increasingly engaging in relevance assessment as an input to decision processes. Yet, it is unclear whether relevance is a synonym for or predictor of impact, a necessary condition or stage in achieving it, or a distinct aim of the research enterprise. The main aim of this paper is to improve our understanding of research relevance, with specific objectives to (1) unpack research relevance from both theoretical and practical perspectives, and (2) outline key considerations for its assessment. Our approach involved the scholarly strategy of review and reflection. We prepared a draft paper based on an exploratory review of literature from various fields, and gained from detailed and insightful analysis and critique at a roundtable discussion with a group of key health research stakeholders. We also solicited review and feedback from a small sample of expert reviewers. Research relevance seems increasingly important in justifying research investments and guiding strategic research planning. However, consideration of relevance has been largely tacit in the health research community, often depending on unexplained interpretations of value, fit and potential for impact. While research relevance seems a necessary condition for impact - a process or component of efforts to make rigorous research usable - ultimately, relevance stands apart from research impact. Careful and explicit consideration of research relevance is vital to gauge the overall value and impact of a wide range of individual and collective research efforts and investments. To improve

Baking soda as an abrasive in toothpastes: Mechanism of action and safety and effectiveness considerations.

PubMed

Hara, Anderson T; Turssi, Cecilia P

2017-11-01

Toothpastes can be formulated with different abrasive systems, depending on their intended clinical application. This formulation potentially affects their effectiveness and safety and, therefore, requires proper understanding. In this article, the authors focused on abrasive aspects of toothpastes containing sodium bicarbonate (baking soda), which have gained considerable attention because of their low abrasivity and good compatibility, while providing clinical effectiveness (further detailed in the other articles of this special issue). The authors first appraised the role of toothpaste abrasivity on tooth wear, exploring some underlying processes and the existing methods to determine toothpaste abrasivity. The authors reviewed the available data on the abrasivity of toothpastes containing baking soda and reported a summary of findings highlighting the clinical implications. On the basis of the collected evidence, baking soda has an intrinsic low-abrasive nature because of its comparatively lower hardness in relation to enamel and dentin. Baking soda toothpastes also may contain other ingredients, which can increase their stain removal effectiveness and, consequently, abrasivity. Even those formulations have abrasivity well within the safety limit regulatory agencies have established and, therefore, can be considered safe. Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.

Alcohol Warning Label Awareness and Attention: A Multi-method Study.

PubMed

Pham, Cuong; Rundle-Thiele, Sharyn; Parkinson, Joy; Li, Shanshi

2018-01-01

Evaluation of alcohol warning labels requires careful consideration ensuring that research captures more than awareness given that labels may not be prominent enough to attract attention. This study investigates attention of current in market alcohol warning labels and examines whether attention can be enhanced through theoretically informed design. Attention scores obtained through self-report methods are compared to objective measures (eye-tracking). A multi-method experimental design was used delivering four conditions, namely control, colour, size and colour and size. The first study (n = 559) involved a self-report survey to measure attention. The second study (n = 87) utilized eye-tracking to measure fixation count and duration and time to first fixation. Analysis of Variance (ANOVA) was utilized. Eye-tracking identified that 60% of participants looked at the current in market alcohol warning label while 81% looked at the optimized design (larger and red). In line with observed attention self-reported attention increased for the optimized design. The current study casts doubt on dominant practices (largely self-report), which have been used to evaluate alcohol warning labels. Awareness cannot be used to assess warning label effectiveness in isolation in cases where attention does not occur 100% of the time. Mixed methods permit objective data collection methodologies to be triangulated with surveys to assess warning label effectiveness. Attention should be incorporated as a measure in warning label effectiveness evaluations. Colour and size changes to the existing Australian warning labels aided by theoretically informed design increased attention. © The Author 2017. Medical Council on Alcohol and Oxford University Press. All rights reserved.

The development and feasibility of an online aphasia group intervention and networking program - TeleGAIN.

PubMed

Pitt, Rachelle; Theodoros, Deborah; Hill, Anne J; Russell, Trevor

2017-09-04

Aphasia group therapy offers many benefits, however people with aphasia report difficulty accessing groups and speech-language pathologists are faced with many challenges in providing aphasia group therapy. Telerehabilitation may offer an alternative service delivery option. An online aphasia group therapy program - Telerehabilitation Group Aphasia Intervention and Networking (TeleGAIN) - has been developed according to the guidelines of the Medical Research Council (MRC) framework for complex interventions. The purpose of this paper is to describe the development of TeleGAIN and the results of a pilot trial to determine feasibility and acceptability. The development of TeleGAIN was informed through literature reviews in relevant topic areas, consideration of expert opinion and application of the social cognitive theory. TeleGAIN was then modelled through a feasibility pilot trial with four people with aphasia. TeleGAIN appeared to be feasible and acceptable to participants and able to be implemented as planned. Participant satisfaction with treatment was high and results suggested some potential for improvements in language functioning and communication-related quality of life. TeleGAIN appeared to be feasible and acceptable, however the study highlighted issues related to technology, clinical implementation and participant-specific factors that should be addressed prior to a larger trial.

Attention.

PubMed

Callahan, Patrick M; Terry, Alvin V

2015-01-01

The ability to focus one's attention on important environmental stimuli while ignoring irrelevant stimuli is fundamental to human cognition and intellectual function. Attention is inextricably linked to perception, learning and memory, and executive function; however, it is often impaired in a variety of neuropsychiatric disorders, including Alzheimer's disease, schizophrenia, depression, and attention deficit hyperactivity disorder (ADHD). Accordingly, attention is considered as an important therapeutic target in these disorders. The purpose of this chapter is to provide an overview of the most common behavioral paradigms of attention that have been used in animals (particularly rodents) and to review the literature where these tasks have been employed to elucidate neurobiological substrates of attention as well as to evaluate novel pharmacological agents for their potential as treatments for disorders of attention. These paradigms include two tasks of sustained attention that were developed as rodent analogues of the human Continuous Performance Task (CPT), the Five-Choice Serial Reaction Time Task (5-CSRTT) and the more recently introduced Five-Choice Continuous Performance Task (5C-CPT), and the Signal Detection Task (SDT) which was designed to emphasize temporal components of attention.

Attentional Resources in Visual Tracking through Occlusion: The High-Beams Effect

ERIC Educational Resources Information Center

Flombaum, Jonathan I.; Scholl, Brian J.; Pylyshyn, Zenon W.

2008-01-01

A considerable amount of research has uncovered heuristics that the visual system employs to keep track of objects through periods of occlusion. Relatively little work, by comparison, has investigated the online resources that support this processing. We explored how attention is distributed when featurally identical objects become occluded during…

Toward a New Philosophical Anthropology of Education: Fuller Considerations of Social Constructivism

ERIC Educational Resources Information Center

Fleury, Stephen; Garrison, Jim

2014-01-01

Philosophical anthropology is philosophical inquiry into human nature that seeks to answer the fundamental question of what generally characterizes human beings and differentiates them from other creatures and things. Political theories considerably influence educational theories. We call attention to the fact that the three main political…

Considerations and Strategies for Teaching Online Counseling Skills: Establishing Relationships in Cyberspace

ERIC Educational Resources Information Center

Trepal, Heather; Haberstroh, Shane; Duffey, Thelma; Evans, Marcheta

2007-01-01

As technology advances and the use of online counseling becomes more routine, attention must be paid to instruction regarding online counseling skills. The authors present considerations for teaching basic online counseling skills to master's-level counseling students. Recommendations are made for helping students to establish and maintain…

Spatial attention determines the nature of nonverbal number representation.

PubMed

Hyde, Daniel C; Wood, Justin N

2011-09-01

Coordinated studies of adults, infants, and nonhuman animals provide evidence for two systems of nonverbal number representation: a "parallel individuation" system that represents individual items and a "numerical magnitude" system that represents the approximate cardinal value of a group. However, there is considerable debate about the nature and functions of these systems, due largely to the fact that some studies show a dissociation between small (1-3) and large (>3) number representation, whereas others do not. Using event-related potentials, we show that it is possible to determine which system will represent the numerical value of a small number set (1-3 items) by manipulating spatial attention. Specifically, when attention can select individual objects, an early brain response (N1) scales with the cardinal value of the display, the signature of parallel individuation. In contrast, when attention cannot select individual objects or is occupied by another task, a later brain response (P2p) scales with ratio, the signature of the approximate numerical magnitude system. These results provide neural evidence that small numbers can be represented as approximate numerical magnitudes. Further, they empirically demonstrate the importance of early attentional processes to number representation by showing that the way in which attention disperses across a scene determines which numerical system will deploy in a given context.

Positive association between attention-deficit/ hyperactivity disorder medication use and academic achievement during elementary school.

PubMed

Scheffler, Richard M; Brown, Timothy T; Fulton, Brent D; Hinshaw, Stephen P; Levine, Peter; Stone, Susan

2009-05-01

Approximately 4.4 million (7.8%) children in the United States have been diagnosed with attention-deficit/hyperactivity disorder, and 56% of affected children take prescription medications to treat the disorder. Attention-deficit/hyperactivity disorder is strongly linked with low academic achievement, but the association between medication use and academic achievement in school settings is largely unknown. Our objective was to determine if reported medication use for attention-deficit/hyperactivity disorder is positively associated with academic achievement during elementary school. To estimate the association between reported medication use and standardized mathematics and reading achievement scores for a US sample of 594 children with attention-deficit/hyperactivity disorder, we used 5 survey waves between kindergarten and fifth grade from the nationally representative Early Childhood Longitudinal Study--Kindergarten Class of 1998-1999 to estimate a first-differenced regression model, which controlled for time-invariant confounding variables. Medicated children had a mean mathematics score that was 2.9 points higher than the mean score of unmedicated peers with attention-deficit/hyperactivity disorder. Children who were medicated for a longer duration (at >2 waves) had a mean reading score that was 5.4 points higher than the mean score of unmedicated peers with attention-deficit/hyperactivity disorder. The medication-reading association was lower for children who had an individualized education program than for those without such educational accommodation. The finding of a positive association between medication use and standardized mathematics and reading test scores is important, given the high prevalence of attention-deficit/hyperactivity disorder and its association with low academic achievement. The 2.9-point mathematics and 5.4-point reading score differences are comparable with score gains of 0.19 and 0.29 school years, respectively, but these gains are

Attention to Color Sharpens Neural Population Tuning via Feedback Processing in the Human Visual Cortex Hierarchy.

PubMed

Bartsch, Mandy V; Loewe, Kristian; Merkel, Christian; Heinze, Hans-Jochen; Schoenfeld, Mircea A; Tsotsos, John K; Hopf, Jens-Max

2017-10-25

Attention can facilitate the selection of elementary object features such as color, orientation, or motion. This is referred to as feature-based attention and it is commonly attributed to a modulation of the gain and tuning of feature-selective units in visual cortex. Although gain mechanisms are well characterized, little is known about the cortical processes underlying the sharpening of feature selectivity. Here, we show with high-resolution magnetoencephalography in human observers (men and women) that sharpened selectivity for a particular color arises from feedback processing in the human visual cortex hierarchy. To assess color selectivity, we analyze the response to a color probe that varies in color distance from an attended color target. We find that attention causes an initial gain enhancement in anterior ventral extrastriate cortex that is coarsely selective for the target color and transitions within ∼100 ms into a sharper tuned profile in more posterior ventral occipital cortex. We conclude that attention sharpens selectivity over time by attenuating the response at lower levels of the cortical hierarchy to color values neighboring the target in color space. These observations support computational models proposing that attention tunes feature selectivity in visual cortex through backward-propagating attenuation of units less tuned to the target. SIGNIFICANCE STATEMENT Whether searching for your car, a particular item of clothing, or just obeying traffic lights, in everyday life, we must select items based on color. But how does attention allow us to select a specific color? Here, we use high spatiotemporal resolution neuromagnetic recordings to examine how color selectivity emerges in the human brain. We find that color selectivity evolves as a coarse to fine process from higher to lower levels within the visual cortex hierarchy. Our observations support computational models proposing that feature selectivity increases over time by attenuating the

Behavioral and neural stability of attention bias to threat in healthy adolescents

PubMed Central

Britton, Jennifer C.; Sequeira, Stefanie; Ronkin, Emily G.; Chen, Gang; Bar-Haim, Yair; Shechner, Tomer; Ernst, Monique; Fox, Nathan A.; Leibenluft, Ellen; Pine, Daniel S.

2016-01-01

Considerable translational research on anxiety examines attention bias to threat and the efficacy of attention training in reducing symptoms. Imaging research on the stability of brain functions engaged by attention bias tasks could inform such research. Perturbed fronto-amygdala function consistently arises in attention bias research on adolescent anxiety. The current report examines the stability of the activation and functional connectivity of these regions on the dot-probe task. Functional magnetic resonance imaging (fMRI) activation and connectivity data were acquired with the dot-probe task in 39 healthy youth (f =18, Mean Age = 13.71 years, SD = 2.31) at two time points, separated by approximately nine weeks. Intraclass-correlations demonstrate good reliability in both neural activation for the ventrolateral PFC and task-specific connectivity for fronto-amygdala circuitry. Behavioral measures showed generally poor test-retest reliability. These findings suggest potential avenues for future brain imaging work by highlighting brain circuitry manifesting stable functioning on the dot-probe attention bias task. PMID:27129757

The development of sentence interpretation: effects of perceptual, attentional and semantic interference.

PubMed

Leech, Robert; Aydelott, Jennifer; Symons, Germaine; Carnevale, Julia; Dick, Frederic

2007-11-01

How does the development and consolidation of perceptual, attentional, and higher cognitive abilities interact with language acquisition and processing? We explored children's (ages 5-17) and adults' (ages 18-51) comprehension of morphosyntactically varied sentences under several competing speech conditions that varied in the degree of attentional demands, auditory masking, and semantic interference. We also evaluated the relationship between subjects' syntactic comprehension and their word reading efficiency and general 'speed of processing'. We found that the interactions between perceptual and attentional processes and complex sentence interpretation changed considerably over the course of development. Perceptual masking of the speech signal had an early and lasting impact on comprehension, particularly for more complex sentence structures. In contrast, increased attentional demand in the absence of energetic auditory masking primarily affected younger children's comprehension of difficult sentence types. Finally, the predictability of syntactic comprehension abilities by external measures of development and expertise is contingent upon the perceptual, attentional, and semantic milieu in which language processing takes place.

Gain weighted eigenspace assignment

NASA Technical Reports Server (NTRS)

Davidson, John B.; Andrisani, Dominick, II

1994-01-01

This report presents the development of the gain weighted eigenspace assignment methodology. This provides a designer with a systematic methodology for trading off eigenvector placement versus gain magnitudes, while still maintaining desired closed-loop eigenvalue locations. This is accomplished by forming a cost function composed of a scalar measure of error between desired and achievable eigenvectors and a scalar measure of gain magnitude, determining analytical expressions for the gradients, and solving for the optimal solution by numerical iteration. For this development the scalar measure of gain magnitude is chosen to be a weighted sum of the squares of all the individual elements of the feedback gain matrix. An example is presented to demonstrate the method. In this example, solutions yielding achievable eigenvectors close to the desired eigenvectors are obtained with significant reductions in gain magnitude compared to a solution obtained using a previously developed eigenspace (eigenstructure) assignment method.

Forgiveness and Consideration of Future Consequences in Aggressive Driving

PubMed Central

Moore, Michael; Dahlen, Eric R.

2008-01-01

Most research on aggressive driving has focused on identifying aspects of driver personality which will exacerbate it (e.g., sensation seeking, impulsiveness, driving anger, etc.). The present study was designed to examine two theoretically relevant but previously unexplored personality factors predicted to reduce the risk of aggressive driving: trait forgiveness and consideration of future consequences. The utility of these variables in predicting aggressive driving and driving anger expression was evaluated among 316 college student volunteers. Hierarchical multiple regressions permitted an analysis of the incremental validity of these constructs beyond respondent gender, age, miles driven per week, and driving anger. Both forgiveness and consideration of future consequences contributed to the prediction of aggressive driving and driving anger expression, independent of driving anger. Research on aggressive driving may be enhanced by greater attention to adaptive, potentially risk-reducing traits. Moreover, forgiveness and consideration of future consequences may have implications for accident prevention. PMID:18760093

Effects of Color Stimulation and Information on the Copying Performance of Attention-Problem Adolescents.

ERIC Educational Resources Information Center

Zentall, Sydney S.; And Others

The optimal stimulaton theory (which proposes that hyperactive children are more readily underaroused than nonhyperactive children and should thus derive greater gains from stimulation added to repetitive copying tasks than comparisons) was tested with 16 adolescents, rating high on attention and behavior problems, and 16 controls. Matched pairs…

Neurocognitive pattern analysis reveals classificatory hierarchy of attention deficits in schizophrenia.

PubMed

Shen, Christina; Popescu, Florin C; Hahn, Eric; Ta, Tam T M; Dettling, Michael; Neuhaus, Andres H

2014-07-01

Attention deficits, among other cognitive deficits, are frequently observed in schizophrenia. Although valid and reliable neurocognitive tasks have been established to assess attention deficits in schizophrenia, the hierarchical value of those tests as diagnostic discriminants on a single-subject level remains unclear. Thus, much research is devoted to attention deficits that are unlikely to be translated into clinical practice. On the other hand, a clear hierarchy of attention deficits in schizophrenia could considerably aid diagnostic decisions and may prove beneficial for longitudinal monitoring of therapeutic advances. To propose a diagnostic hierarchy of attention deficits in schizophrenia, we investigated several facets of attention in 86 schizophrenia patients and 86 healthy controls using a set of established attention tests. We applied state-of-the-art machine learning algorithms to determine attentive test variables that enable an automated differentiation between schizophrenia patients and healthy controls. After feature preranking, hypothesis building, and hypothesis validation, the polynomial support vector machine classifier achieved a classification accuracy of 90.70% ± 2.9% using psychomotor speed and 3 different attention parameters derived from sustained and divided attention tasks. Our study proposes, to the best of our knowledge, the first hierarchy of attention deficits in schizophrenia by identifying the most discriminative attention parameters among a variety of attention deficits found in schizophrenia patients. Our results offer a starting point for hierarchy building of schizophrenia-associated attention deficits and contribute to translating these concepts into diagnostic and therapeutic practice on a single-subject level. © The Author 2013. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

A Mathematical Diet Model

ERIC Educational Resources Information Center

Toumasis, Charalampos

2004-01-01

Emphasis on problem solving and mathematical modeling has gained considerable attention in the last few years. Connecting mathematics to other subjects and to the real world outside the classroom has received increased attention in mathematics programs. This article describes an application of simple differential equations in the field of…

A Review of Mindfulness Research Related to Alleviating Math and Science Anxiety

ERIC Educational Resources Information Center

Ahmed, Khalique; Trager, Bradley; Rodwell, Megan; Foinding, Linda; Lopez, Cori

2017-01-01

Defined as nonjudgmentally paying attention to the present moment (Kabat-Zinn, 1994), modern-day mindfulness has gained considerable attention in various science fields. However, despite this growth, many uses of mindfulness remain unexplored. In this paper, we focus on the application of mindfulness programs in educational settings, specifically…

An attentional theory of emotional influences on risky decisions.

PubMed

Levine, Daniel S; Ramirez, Patrick A

2013-01-01

It is well known that choices between gambles can depend not only on the probabilities of gains or losses but also on the emotional richness of the items to be gained or lost. Rottenstreich and Hsee (2001) demonstrated that overweighting of low probabilities is magnified if the possible events are emotionally rich, such as a kiss versus an amount of money. Ramirez (2010) showed that persistence in the face of comparable numerically presented losses is greater when the scenario involves taking care of a pet (emotionally richer) versus a business (emotionally poorer). Much of this phenomenon is captured in a neural network model of the Rottenstreich-Hsee data (Levine, 2012). The model is based on interactions among the orbitofrontal cortex, amygdala, cingulate, striatum, thalamus, and premotor cortex that implement categorization of multiattribute vectors representing choice options, in a manner consistent with the gists of fuzzy trace theory. Before categorization, the vectors are weighted by selective attention to attributes that are either emotionally salient or task relevant, with increasing emotional arousal shifting the attentional weights away from numerical attributes such as precise probabilities. This interpretation is supported by the data of Hsee and Rottenstreich (2004) showing that how much participants would pay to save endangered animals is not influenced by the number to be saved if they see pictures but is influenced by the number if they are given verbal descriptions. The theory suggests a few open questions. How are the selective attentional signals represented in the interactions between prefrontal cortex and subcortical areas? Would the salience of numerical attributes still be reduced with high arousal in highly numerate participants? Would the differences between the pet and business scenarios be altered if the positive or negative feedback participants received were shown via pictures rather than numbers? Copyright © 2013 Elsevier B.V. All

No objectively measured sleep disturbances in children with attention-deficit/hyperactivity disorder.

PubMed

Bergwerff, Catharina E; Luman, Marjolein; Oosterlaan, Jaap

2016-10-01

The main goal of this study was to gain more insight into sleep disturbances in children with attention-deficit/hyperactivity disorder, using objective measures of sleep quality and quantity. The evidence for sleep problems in children with attention-deficit/hyperactivity disorder thus far is inconsistent, which might be explained by confounding influences of comorbid internalizing and externalizing problems and low socio-economic status. We therefore investigated the mediating and moderating role of these factors in the association between attention-deficit/hyperactivity disorder and sleep problems. To control for the effects of stimulant medication use, all participants were tested free of medication. Sixty-three children with attention-deficit/hyperactivity disorder and 61 typically developing children, aged 6-13 years, participated. Sleep was monitored for one to three school nights using actigraphy. Parent and teacher questionnaires assessed symptoms of attention-deficit/hyperactivity disorder, internalizing behaviour, oppositional defiant disorder and conduct disorder. Results showed no differences between the attention-deficit/hyperactivity disorder and typically developing group in any sleep parameter. Within the attention-deficit/hyperactivity disorder group, severity of attention-deficit/hyperactivity disorder symptoms was not related to sleep quality or quantity. Moderation analyses in the attention-deficit/hyperactivity disorder group showed an interaction effect between attention-deficit/hyperactivity disorder symptoms and internalizing and externalizing behaviour on total sleep time, time in bed and average sleep bout duration. The results of our study suggest that having attention-deficit/hyperactivity disorder is not a risk factor for sleep problems. Internalizing and externalizing behaviour moderate the association between attention-deficit/hyperactivity disorder and sleep, indicating a complex interplay between psychiatric symptoms and sleep. �

Attentional Bias to Food Cues in Youth with Loss of Control Eating

PubMed Central

Shank, Lisa M.; Tanofsky-Kraff, Marian; Nelson, Eric E.; Shomaker, Lauren B.; Ranzenhofer, Lisa M.; Hannallah, Louise M.; Field, Sara E.; Vannucci, Anna; Bongiorno, Diana M.; Brady, Sheila M.; Condarco, Tania; Demidowich, Andrew; Kelly, Nichole R.; Cassidy, Omni; Simmons, W. Kyle; Engel, Scott G.; Pine, Daniel S.; Yanovski, Jack A.

2014-01-01

Emerging data indicate that adults with binge eating may exhibit an attentional bias toward highly palatable foods, which may promote obesogenic eating patterns and excess weight gain. However, it is unknown to what extent youth with loss of control (LOC) eating display a similar bias. We therefore studied 76 youth (14.5±2.3y; 86.8% female; BMI-z 1.7± .73) with (n=47) and without (n=29) reported LOC eating. Following a breakfast to reduce hunger, youth participated in a computerized visual probe task of sustained attention that assessed reaction time to pairs of pictures consisting of high palatable foods, low palatable foods, and neutral household objects. Although sustained attentional bias did not differ by LOC eating presence and was unrelated to body weight, a two-way interaction between BMI-z and LOC eating was observed (p = .01), such that only among youth with LOC eating, attentional bias toward high palatable foods versus neutral objects was positively associated with BMI-z. These findings suggest that LOC eating and body weight interact in their association with attentional bias to highly palatable foods cues, and may partially explain the mixed literature linking attentional bias to food cues with excess body weight. PMID:25435490

Dynamic Excitatory and Inhibitory Gain Modulation Can Produce Flexible, Robust and Optimal Decision-making

PubMed Central

Niyogi, Ritwik K.; Wong-Lin, KongFatt

2013-01-01

Behavioural and neurophysiological studies in primates have increasingly shown the involvement of urgency signals during the temporal integration of sensory evidence in perceptual decision-making. Neuronal correlates of such signals have been found in the parietal cortex, and in separate studies, demonstrated attention-induced gain modulation of both excitatory and inhibitory neurons. Although previous computational models of decision-making have incorporated gain modulation, their abstract forms do not permit an understanding of the contribution of inhibitory gain modulation. Thus, the effects of co-modulating both excitatory and inhibitory neuronal gains on decision-making dynamics and behavioural performance remain unclear. In this work, we incorporate time-dependent co-modulation of the gains of both excitatory and inhibitory neurons into our previous biologically based decision circuit model. We base our computational study in the context of two classic motion-discrimination tasks performed in animals. Our model shows that by simultaneously increasing the gains of both excitatory and inhibitory neurons, a variety of the observed dynamic neuronal firing activities can be replicated. In particular, the model can exhibit winner-take-all decision-making behaviour with higher firing rates and within a significantly more robust model parameter range. It also exhibits short-tailed reaction time distributions even when operating near a dynamical bifurcation point. The model further shows that neuronal gain modulation can compensate for weaker recurrent excitation in a decision neural circuit, and support decision formation and storage. Higher neuronal gain is also suggested in the more cognitively demanding reaction time than in the fixed delay version of the task. Using the exact temporal delays from the animal experiments, fast recruitment of gain co-modulation is shown to maximize reward rate, with a timescale that is surprisingly near the experimentally fitted

Attention modulates spatial priority maps in the human occipital, parietal and frontal cortices

PubMed Central

Sprague, Thomas C.; Serences, John T.

2014-01-01

Computational theories propose that attention modulates the topographical landscape of spatial ‘priority’ maps in regions of visual cortex so that the location of an important object is associated with higher activation levels. While single-unit recording studies have demonstrated attention-related increases in the gain of neural responses and changes in the size of spatial receptive fields, the net effect of these modulations on the topography of region-level priority maps has not been investigated. Here, we used fMRI and a multivariate encoding model to reconstruct spatial representations of attended and ignored stimuli using activation patterns across entire visual areas. These reconstructed spatial representations reveal the influence of attention on the amplitude and size of stimulus representations within putative priority maps across the visual hierarchy. Our results suggest that attention increases the amplitude of stimulus representations in these spatial maps, particularly in higher visual areas, but does not substantively change their size. PMID:24212672

The adjunctive use of metformin to treat or prevent atypical antipsychotic-induced weight gain: a review.

PubMed

Khan, Ahsan Y; Macaluso, Matthew; McHale, Robert J; Dahmen, Megan M; Girrens, Kathrine; Ali, Faryal

2010-09-01

Patients with schizophrenia have a greater incidence of being overweight or obese compared with the general population. Such individuals are often treated with second-generation (atypical) antipsychotics (SGAs), which are associated with weight gain, dyslipidemia, and other metabolic derangements. As a result, frequent monitoring of weight and other metabolic parameters is recommended. In addition, several pharmacologic strategies to help prevent or reduce SGA-induced weight gain have been proposed. Despite this, clinicians often struggle to manage obesity and metabolic issues in such patients. Metformin has attracted attention as a potential treatment option because it is thought to result in weight reduction and improved glycemic control in obese patients with and without type 2 diabetes mellitus. This article focuses on relevant pharmacologic aspects of metformin and reviews currently available evidence on the use of metformin as an augmentation agent for the treatment or prevention of SGA-induced weight gain.

Task Engagement, Cerebral Blood Flow Velocity, and Diagnostic Monitoring for Sustained Attention

ERIC Educational Resources Information Center

Matthews, Gerald; Warm, Joel S.; Reinerman-Jones, Lauren E.; Langheim, Lisa K.; Washburn, David A.; Tripp, Lloyd

2010-01-01

Loss of vigilance may lead to impaired performance in various applied settings including military operations, transportation, and industrial inspection. Individuals differ considerably in sustained attention, but individual differences in vigilance have proven to be hard to predict. The dependence of vigilance on workload factors is consistent…

Owners' direct gazes increase dogs' attention-getting behaviors.

PubMed

Ohkita, Midori; Nagasawa, Miho; Kazutaka, Mogi; Kikusui, Takefumi

2016-04-01

This study examined whether dogs gain information about human's attention via their gazes and whether they change their attention-getting behaviors (i.e., whining and whimpering, looking at their owners' faces, pawing, and approaching their owners) in response to their owners' direct gazes. The results showed that when the owners gazed at their dogs, the durations of whining and whimpering and looking at the owners' faces were longer than when the owners averted their gazes. In contrast, there were no differences in duration of pawing and likelihood of approaching the owners between the direct and averted gaze conditions. Therefore, owners' direct gazes increased the behaviors that acted as distant signals and did not necessarily involve touching the owners. We suggest that dogs are sensitive to human gazes, and this sensitivity may act as attachment signals to humans, and may contribute to close relationships between humans and dogs. Copyright © 2016 Elsevier B.V. All rights reserved.

Detached and distracted: ERP correlates of altered attentional function in depersonalisation.

PubMed

Schabinger, Nadine; Gillmeister, Helge; Berti, Stefan; Michal, Matthias; Beutel, Manfred E; Adler, Julia

2018-04-01

Depersonalisation (DP) is a psychological condition marked by feelings of disembodiment. In everyday life, it is frequently associated with concentration problems. The present study used visual event-related potentials (ERPs) in a Posner-type spatial cueing task with valid, invalid and spatially neutral cues to delineate the potential neurophysiological correlates of these concentration problems. Altered attentional functioning at early, sensory stages was found in DP patients but not in anxiety- and depression-matched psychosomatic patients without DP. Specifically, DP was associated with decreased suppression of stimuli at unattended locations, shown as absent processing costs for invalidly versus neutrally cued stimuli over P1 (135-150 ms). Attentional benefits at N1, and all attentional effects at later, cognitive processing stages (P2-N2, P3) were similar in both groups. We propose that this insufficient early suppression of unattended stimuli may result from atypical sensory gain control in DP. Copyright © 2018 Elsevier B.V. All rights reserved.

Positive valence music restores executive control over sustained attention

PubMed Central

Lewis, Bridget A.

2017-01-01

Music sometimes improves performance in sustained attention tasks. But the type of music employed in previous investigations has varied considerably, which can account for equivocal results. Progress has been hampered by lack of a systematic database of music varying in key characteristics like tempo and valence. The aims of this study were to establish a database of popular music varying along the dimensions of tempo and valence and to examine the impact of music varying along these dimensions on restoring attentional resources following performance of a sustained attention to response task (SART) vigil. Sixty-nine participants rated popular musical selections that varied in valence and tempo to establish a database of four musical types: fast tempo positive valence, fast tempo negative valence, slow tempo positive valence, and slow tempo negative valence. A second group of 89 participants performed two blocks of the SART task interspersed with either no break or a rest break consisting of 1 of the 4 types of music or silence. Presenting positive valence music (particularly of slow tempo) during an intermission between two successive blocks of the SART significantly decreased miss rates relative to negative valence music or silence. Results support an attentional restoration theory of the impact of music on sustained attention, rather than arousal theory and demonstrate a means of restoring sustained attention. Further, the results establish the validity of a music database that will facilitate further investigations of the impact of music on performance. PMID:29145395

Positive valence music restores executive control over sustained attention.

PubMed

Baldwin, Carryl L; Lewis, Bridget A

2017-01-01

Music sometimes improves performance in sustained attention tasks. But the type of music employed in previous investigations has varied considerably, which can account for equivocal results. Progress has been hampered by lack of a systematic database of music varying in key characteristics like tempo and valence. The aims of this study were to establish a database of popular music varying along the dimensions of tempo and valence and to examine the impact of music varying along these dimensions on restoring attentional resources following performance of a sustained attention to response task (SART) vigil. Sixty-nine participants rated popular musical selections that varied in valence and tempo to establish a database of four musical types: fast tempo positive valence, fast tempo negative valence, slow tempo positive valence, and slow tempo negative valence. A second group of 89 participants performed two blocks of the SART task interspersed with either no break or a rest break consisting of 1 of the 4 types of music or silence. Presenting positive valence music (particularly of slow tempo) during an intermission between two successive blocks of the SART significantly decreased miss rates relative to negative valence music or silence. Results support an attentional restoration theory of the impact of music on sustained attention, rather than arousal theory and demonstrate a means of restoring sustained attention. Further, the results establish the validity of a music database that will facilitate further investigations of the impact of music on performance.

From struggles to resource gains in interprofessional service networks: Key findings from a multiple case study.

PubMed

Toiviainen, Hanna; Kira, Mari

2017-07-01

In interprofessional service networks, employees cross professional boundaries to collaborate with colleagues and clients with expertise and values different from their own. It can be a struggle to adopt shared work practices and deal with "multivoicedness." At the same time, networks allow members to engage in meaningful service provision, gain a broader understanding of the service provided, and obtain social support. Intertwined network struggles and resource gains have received limited attention in the interprofessional care literature to date. The aim of the study was to investigate the learning potential of the co-existing struggles and resource gains. This article reports findings from two interprofessional networks. Interviews were conducted with 19 employees and thematically analysed. Three types of struggles and six types of resource gains of networking were identified. The struggles relate, first, to the assumptions of networking following similar practices to those in a home organisation; second, to the challenges of dealing with the multivoicedness of networking; and, third, to the experienced gap between the networking ideals and the reality of cooperation. At the same time, the network members experience gains in emotional resources (e.g., stronger sense of meaningfulness at work), cognitive resources (e.g., understanding the customer needs from alternative perspectives), and social resources (e.g., being able to rely on other professionals' competence). Learning potential emerged from the dynamics between coexisting struggles and resource gains.

The role of attention during retrieval in working-memory span: a dual-task study.

PubMed

Healey, M Karl; Miyake, Akira

2009-04-01

We tested the hypothesis that retrieving target words in operation span (OSpan) involves attention-demanding processes. Participants completed the standard OSpan task and a modified version in which all equations preceded all target words. Recall took place under either full attention or easy versus hard divided-attention conditions. Recall suffered under divided attention with the recall decrement being greater for the hard secondary task. Moreover, secondary-task performance was disrupted more by the standard OSpan task than by the modified version with the hard secondary task showing the larger decrement. Finally, the time taken to start recalling the first word was considerably longer for the standard version than for the modified version. These results are consistent with the proposal that successful OSpan task performance in part involves the attention-demanding retrieval of targets from long-term memory.

Losses, gain, and lasing in organic and perovskite active materials (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pourdavoud, Neda; Riedl, Thomas J.

2016-09-01

Organic solid state lasers (OSLs) based on semiconducting polymers or small molecules have seen some significant progress over the past decade. Highly efficient organic gain materials combined with high-Q resonator geometries (distributed feedback (DFB), VCSEL, etc.) have enabled OSLs, optically pumped by simple inorganic laser diodes or even LEDs. However, some fundamental goals remain to be reached, like continuous wave (cw) operation and injection lasing. I will address various loss mechanisms related to accumulated triplet excitons or long-lived polarons that in combination with the particular photo-physics of organic gain media state the dominant road-blocks on the way to reach these goals. I will discuss the recent progress in fundamental understanding of these loss processes, which now provides a solid basis for modelling, e.g. of laser dynamics. Avenues to mitigate these fundamental loss mechanisms, e.g. by alternative materials will be presented. In this regard, a class of gain materials based on organo-lead halide perovskites re-entered the scene as light emitters, recently. Enjoying a tremendous lot of attention as active material for solution processed solar cells with a 20+% efficiency, they have recently unveiled their exciting photo-physics for lasing applications. Optically pumped lasing in these materials has been achieved. I will discuss some of the unique properties that render this class of materials a promising candidate to overcome some of the limitations of "classical" organic gain media.

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

PubMed

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

2016-02-12

In our daily lives, our capacity to selectively attend to stimuli within or across sensory modalities enables enhanced perception of the surrounding world. While previous research on selective attention has studied this phenomenon extensively, two important questions still remain unanswered: (1) how selective attention to a single modality impacts sensory integration processes, and (2) the mechanism by which selective attention improves perception. We explored how selective attention impacts performance in both a spatial task and a temporal numerosity judgment task, and employed a Bayesian Causal Inference model to investigate the computational mechanism(s) impacted by selective attention. We report three findings: (1) in the spatial domain, selective attention improves precision of the visual sensory representations (which were relatively precise), but not the auditory sensory representations (which were fairly noisy); (2) in the temporal domain, selective attention improves the sensory precision in both modalities (both of which were fairly reliable to begin with); (3) in both tasks, selective attention did not exert a significant influence over the tendency to integrate sensory stimuli. Therefore, it may be postulated that a sensory modality must possess a certain inherent degree of encoding precision in order to benefit from selective attention. It also appears that in certain basic perceptual tasks, the tendency to integrate crossmodal signals does not depend significantly on selective attention. We conclude with a discussion of how these results relate to recent theoretical considerations of selective attention. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Tracking the location of visuospatial attention in a contingent capture paradigm.

PubMed

Leblanc, Emilie; Prime, David J; Jolicoeur, Pierre

2008-04-01

Currently, there is considerable controversy regarding the degree to which top-down control can affect attentional capture by salient events. According to the contingent capture hypothesis, attentional capture by a salient stimulus is contingent on a match between the properties of the stimulus and top-down attentional control settings. In contrast, bottom-up saliency accounts argue that the initial capture of attention is determined solely by the relative salience of the stimulus, and the effect of top-down attentional control is limited to effects on the duration of attentional engagement on the capturing stimulus. In the present study, we tested these competing accounts by utilizing the N2pc event-related potential component to track the locus of attention during an attentional capture task. The results were completely consistent with the contingent capture hypothesis: An N2pc wave was elicited only by distractors that possessed the target-defining attribute. In a second experiment, we expanded upon this finding by exploring the effect of target-distractor similarity on the duration that attention dwells at the distractor location. In this experiment, only distractors possessing the target-defining attribute (color) captured visuospatial attention to their location and the N2pc increased in duration and in magnitude when the capture distractor also shared a second target attribute (category membership). Finally, in three additional control experiments, we replicated the finding of an N2pc generated by distractors, only if they shared the target-defining attribute. Thus, our results demonstrate that attentional control settings influence both which stimuli attract attention and to what extent they are processed.

Growth and change in attention problems, disruptive behavior, and achievement from kindergarten to fifth grade.

PubMed

Claessens, Amy; Dowsett, Chantelle

2014-12-01

Despite widespread interest in children's adjustment problems, existing research does not provide conclusive evidence regarding the direction of the associations of achievement with classroom attention problems and disruptive behavior over the course of elementary school. Using a nationally representative sample of 16,260 kindergarteners, this study examined the temporal sequence of achievement, classroom attention problems, and disruptive behavior, focusing on how changes in skills and problems unfold across key periods between kindergarten and fifth grade. Results indicate that improvements in attention during the earliest years of schooling predict achievement gains through third grade. However, changes in disruptive behavior do not predict subsequent changes in achievement. Evidence linking changes in achievement to changes in classroom attention problems and disruptive behavior was less consistent. These findings point to the need to develop and examine early interventions that can improve attention skills as a mechanism for improving children's academic trajectories in elementary school. © The Author(s) 2014.

Individual differences in selective attention predict speech identification at a cocktail party.

PubMed

Oberfeld, Daniel; Klöckner-Nowotny, Felicitas

2016-08-31

Listeners with normal hearing show considerable individual differences in speech understanding when competing speakers are present, as in a crowded restaurant. Here, we show that one source of this variance are individual differences in the ability to focus selective attention on a target stimulus in the presence of distractors. In 50 young normal-hearing listeners, the performance in tasks measuring auditory and visual selective attention was associated with sentence identification in the presence of spatially separated competing speakers. Together, the measures of selective attention explained a similar proportion of variance as the binaural sensitivity for the acoustic temporal fine structure. Working memory span, age, and audiometric thresholds showed no significant association with speech understanding. These results suggest that a reduced ability to focus attention on a target is one reason why some listeners with normal hearing sensitivity have difficulty communicating in situations with background noise.

Evaluation of balloon trajectory forecast routines for GAINS

NASA Astrophysics Data System (ADS)

Collander, R.; Girz, C.

The Global Air-ocean IN-situ System (GAINS) is a global observing system designed to augment current environmental observing and monitoring networks. GAINS is a network of long-duration, stratospheric platforms that carry onboard sensors and hundreds of dropsondes to acquire meteorological, air chemistry, and climate data over oceans and in remote land regions of the globe. Although GAINS platforms will include balloons and Remotely Operated Aircraft (ROA), the scope of this paper is limited to balloon-based platforms. A primary goal of GAINS balloon test flights is post-flight recovery of the balloon shell and payload, which requires information on the expected flight path and landing site prior to launch. Software has been developed for the prediction of the balloon trajectory and landing site, with separate versions written to generate predictions based upon rawinsonde data and model output. Balloon positions are calculated in 1-min increments based on wind data from the closest rawinsonde site or model grid point, given a known launch point, ascent and descent rate and flight duration. For short flights (< 6h), rawinsonde winds interpolated to 10-mb levels are used for trajectory calculations. Predictions for flight durations of 6 to 48h are based upon the initialization and 3 h forecast wind fields from NOAA's global aviation- (AVN) and Rapid Update Cycle (RUC) models. Given a limited number of actual balloon launches, trajectories computed from a chronological series of hourly RUC initializations are used as the baseline for comparison purposes. These baseline trajectories are compared to trajectory predictions from the rawinsonde and model-based versions on a monthly and seasonal basis over a 1-year period (January 1 - December 31, 2001) for flight durations of 3h, 6h and 48h. Predicted trajectories diverge from the baseline path, with the divergence increasing with increasing time. We examine the zonal, meridional and net magnitudes of these deviations, and

The influence of anaesthetists' experience on workload, performance and visual attention during simulated critical incidents.

PubMed

Schulz, Christian M; Schneider, Erich; Kohlbecher, Stefan; Hapfelmeier, Alexander; Heuser, Fabian; Wagner, Klaus J; Kochs, Eberhard F; Schneider, Gerhard

2014-10-01

Development of accurate Situation Awareness (SA) depends on experience and may be impaired during excessive workload. In order to gain adequate SA for decision making and performance, anaesthetists need to distribute visual attention effectively. Therefore, we hypothesized that in more experienced anaesthetists performance is better and increase of physiological workload is less during critical incidents. Additionally, we investigated the relation between physiological workload indicators and distribution of visual attention. In fifteen anaesthetists, the increase of pupil size and heart rate was assessed in course of a simulated critical incident. Simulator log files were used for performance assessment. An eye-tracking device (EyeSeeCam) provided data about the anaesthetists' distribution of visual attention. Performance was assessed as time until definitive treatment. T tests and multivariate generalized linear models (MANOVA) were used for retrospective statistical analysis. Mean pupil diameter increase was 8.1% (SD ± 4.3) in the less experienced and 15.8% (±10.4) in the more experienced subjects (p = 0.191). Mean heart rate increase was 10.2% (±6.7) and 10.5% (±8.3, p = 0.956), respectively. Performance did not depend on experience. Pupil diameter and heart rate increases were associated with a shift of visual attention from monitoring towards manual tasks (not significant). For the first time, the following four variables were assessed simultaneously: physiological workload indicators, performance, experience, and distribution of visual attention between "monitoring" and "manual" tasks. However, we were unable to detect significant interactions between these variables. This experimental model could prove valuable in the investigation of gaining and maintaining SA in the operation theatre.

Attention to memory: orienting attention to sound object representations.

PubMed

Backer, Kristina C; Alain, Claude

2014-01-01

Despite a growing acceptance that attention and memory interact, and that attention can be focused on an active internal mental representation (i.e., reflective attention), there has been a paucity of work focusing on reflective attention to 'sound objects' (i.e., mental representations of actual sound sources in the environment). Further research on the dynamic interactions between auditory attention and memory, as well as its degree of neuroplasticity, is important for understanding how sound objects are represented, maintained, and accessed in the brain. This knowledge can then guide the development of training programs to help individuals with attention and memory problems. This review article focuses on attention to memory with an emphasis on behavioral and neuroimaging studies that have begun to explore the mechanisms that mediate reflective attentional orienting in vision and more recently, in audition. Reflective attention refers to situations in which attention is oriented toward internal representations rather than focused on external stimuli. We propose four general principles underlying attention to short-term memory. Furthermore, we suggest that mechanisms involved in orienting attention to visual object representations may also apply for orienting attention to sound object representations.

Gain and power optimization of the wireless optical system with multilevel modulation.

PubMed

Liu, Xian

2008-06-01

When used in an outdoor environment to expedite networking access, the performance of wireless optical communication systems is affected by transmitter sway. In the design of such systems, much attention has been paid to developing power-efficient schemes. However, the bandwidth efficiency is also an important issue. One of the most natural approaches to promote bandwidth efficiency is to use multilevel modulation. This leads to multilevel pulse amplitude modulation in the context of intensity modulation and direct detection. We develop a model based on the four-level pulse amplitude modulation. We show that the model can be formulated as an optimization problem in terms of the transmitter power, bit error probability, transmitter gain, and receiver gain. The technical challenges raised by modeling and solving the problem include the analytical and numerical treatments for the improper integrals of the Gaussian functions coupled with the erfc function. The results demonstrate that, at the optimal points, the power penalty paid to the doubled bandwidth efficiency is around 3 dB.

A meta-analysis of decision-making and attention in adults with ADHD.

PubMed

Mowinckel, Athanasia M; Pedersen, Mads Lund; Eilertsen, Espen; Biele, Guido

2015-05-01

Deficient reward processing has gained attention as an important aspect of ADHD, but little is known about reward-based decision-making (DM) in adults with ADHD. This article summarizes research on DM in adult ADHD and contextualizes DM deficits by comparing them to attention deficits. Meta-analytic methods were used to calculate average effect sizes for different DM domains and continuous performance task (CPT) measures. None of the 59 included studies (DM: 12 studies; CPT: 43; both: 4) had indications of publication bias. DM and CPT measures showed robust, small to medium effects. Large effect sizes were found for a drift diffusion model analysis of the CPT. The results support the existence of DM deficits in adults with ADHD, which are of similar magnitude as attention deficits. These findings warrant further examination of DM in adults with ADHD to improve the understanding of underlying neurocognitive mechanisms. © 2014 SAGE Publications.

Effect of feature-selective attention on neuronal responses in macaque area MT

PubMed Central

Chen, X.; Hoffmann, K.-P.; Albright, T. D.

2012-01-01

Attention influences visual processing in striate and extrastriate cortex, which has been extensively studied for spatial-, object-, and feature-based attention. Most studies exploring neural signatures of feature-based attention have trained animals to attend to an object identified by a certain feature and ignore objects/displays identified by a different feature. Little is known about the effects of feature-selective attention, where subjects attend to one stimulus feature domain (e.g., color) of an object while features from different domains (e.g., direction of motion) of the same object are ignored. To study this type of feature-selective attention in area MT in the middle temporal sulcus, we trained macaque monkeys to either attend to and report the direction of motion of a moving sine wave grating (a feature for which MT neurons display strong selectivity) or attend to and report its color (a feature for which MT neurons have very limited selectivity). We hypothesized that neurons would upregulate their firing rate during attend-direction conditions compared with attend-color conditions. We found that feature-selective attention significantly affected 22% of MT neurons. Contrary to our hypothesis, these neurons did not necessarily increase firing rate when animals attended to direction of motion but fell into one of two classes. In one class, attention to color increased the gain of stimulus-induced responses compared with attend-direction conditions. The other class displayed the opposite effects. Feature-selective activity modulations occurred earlier in neurons modulated by attention to color compared with neurons modulated by attention to motion direction. Thus feature-selective attention influences neuronal processing in macaque area MT but often exhibited a mismatch between the preferred stimulus dimension (direction of motion) and the preferred attention dimension (attention to color). PMID:22170961

Effect of feature-selective attention on neuronal responses in macaque area MT.

PubMed

Chen, X; Hoffmann, K-P; Albright, T D; Thiele, A

2012-03-01

Attention influences visual processing in striate and extrastriate cortex, which has been extensively studied for spatial-, object-, and feature-based attention. Most studies exploring neural signatures of feature-based attention have trained animals to attend to an object identified by a certain feature and ignore objects/displays identified by a different feature. Little is known about the effects of feature-selective attention, where subjects attend to one stimulus feature domain (e.g., color) of an object while features from different domains (e.g., direction of motion) of the same object are ignored. To study this type of feature-selective attention in area MT in the middle temporal sulcus, we trained macaque monkeys to either attend to and report the direction of motion of a moving sine wave grating (a feature for which MT neurons display strong selectivity) or attend to and report its color (a feature for which MT neurons have very limited selectivity). We hypothesized that neurons would upregulate their firing rate during attend-direction conditions compared with attend-color conditions. We found that feature-selective attention significantly affected 22% of MT neurons. Contrary to our hypothesis, these neurons did not necessarily increase firing rate when animals attended to direction of motion but fell into one of two classes. In one class, attention to color increased the gain of stimulus-induced responses compared with attend-direction conditions. The other class displayed the opposite effects. Feature-selective activity modulations occurred earlier in neurons modulated by attention to color compared with neurons modulated by attention to motion direction. Thus feature-selective attention influences neuronal processing in macaque area MT but often exhibited a mismatch between the preferred stimulus dimension (direction of motion) and the preferred attention dimension (attention to color).

Distractor inhibition: principles of operation during selective attention.

PubMed

Wyatt, Natalie; Machado, Liana

2013-02-01

Research suggests that although target amplification acts as the main determinant of the efficacy of selective attention, distractor inhibition contributes under some circumstances. Here we aimed to gain insight into the operating principles that regulate the use of distractor inhibition during selective attention. The results suggest that, in contrast to target amplification, distractor inhibition does not onset earlier or strengthen in response to advance location information. Instead, when the location of the impending distractor was predictable, evidence of inhibitory processing weakened. Furthermore, the results suggest that distractor inhibition does not operate as a compensatory mechanism for target amplification, as evidenced by the lack of an increase in inhibitory effects when reliance on target amplification was disrupted. Unexpected emergence of inhibitory effects for improbable targets provided evidence that distractor inhibition was at work even when no inhibitory effects manifested. Overall, the pattern of inhibitory effects is interpreted as indicating that, although distractor inhibition mounts primarily reactively rather than preemptively, advance information can help prevent overreaction to the distractor. Of course, less overreaction reduces the chances of behavioral inhibitory effects manifesting even when distractor inhibition has contributed to selective attention; thus, interpreting an absence of inhibitory effects should be done cautiously. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Gain-of-function experiments: time for a real debate.

PubMed

Duprex, W Paul; Fouchier, Ron A M; Imperiale, Michael J; Lipsitch, Marc; Relman, David A

2015-01-01

According to the WHO, dual use research of concern (DURC) is "life sciences research that is intended for benefit, but which might easily be misapplied to do harm". Recent studies, particularly those on influenza viruses, have led to renewed attention on DURC, as there is an ongoing debate over whether the benefits of gain-of-function (GOF) experiments that result in an increase in the transmission and/or pathogenicity of potential pandemic pathogens (PPPs) are outweighed by concerns over biosecurity and biosafety. In this Viewpoint article, proponents and opponents of GOF experiments discuss the benefits and risks associated with these studies, as well as the implications of the current debate for the scientific community and the general public, and suggest how the current discussion should move forward.

Motor contributions to the temporal precision of auditory attention.

PubMed

Morillon, Benjamin; Schroeder, Charles E; Wyart, Valentin

2014-10-15

In temporal-or dynamic-attending theory, it is proposed that motor activity helps to synchronize temporal fluctuations of attention with the timing of events in a task-relevant stream, thus facilitating sensory selection. Here we develop a mechanistic behavioural account for this theory by asking human participants to track a slow reference beat, by noiseless finger pressing, while extracting auditory target tones delivered on-beat and interleaved with distractors. We find that overt rhythmic motor activity improves the segmentation of auditory information by enhancing sensitivity to target tones while actively suppressing distractor tones. This effect is triggered by cyclic fluctuations in sensory gain locked to individual motor acts, scales parametrically with the temporal predictability of sensory events and depends on the temporal alignment between motor and attention fluctuations. Together, these findings reveal how top-down influences associated with a rhythmic motor routine sharpen sensory representations, enacting auditory 'active sensing'.

Helping adolescents with attention-deficit/ hyperactivity disorder transition toward adulthood.

PubMed

Gotlieb, Edward M; Gotlieb, Jaquelin S

2009-04-01

Pediatricians can help adolescents with attention-deficit/hyperactivity disorder prepare to enter post-high school training and the workforce. In this article peer-reviewed studies and other resources for informing patients of the issues ahead are identified. We discuss preventive counseling, including long-term monitoring, adherence to treatment, driving, tobacco, alcohol, and other drug usage, career planning, and intimacy. The current status of insurance coverage for young adults and federal programs to assist students with attention-deficit/hyperactivity disorder are reviewed also. Consideration is given for applying for precollege testing and college accommodations and traveling abroad with medications. Pediatricians and young adults are directed to Web-based and other self-management information and tools.

Attention Increases Spike Count Correlations between Visual Cortical Areas.

PubMed

Ruff, Douglas A; Cohen, Marlene R

2016-07-13

Visual attention, which improves perception of attended locations or objects, has long been known to affect many aspects of the responses of neuronal populations in visual cortex. There are two nonmutually exclusive hypotheses concerning the neuronal mechanisms that underlie these perceptual improvements. The first hypothesis, that attention improves the information encoded by a population of neurons in a particular cortical area, has considerable physiological support. The second hypothesis is that attention improves perception by selectively communicating relevant visual information. This idea has been tested primarily by measuring interactions between neurons on very short timescales, which are mathematically nearly independent of neuronal interactions on longer timescales. We tested the hypothesis that attention changes the way visual information is communicated between cortical areas on longer timescales by recording simultaneously from neurons in primary visual cortex (V1) and the middle temporal area (MT) in rhesus monkeys. We used two independent and complementary approaches. Our correlative experiment showed that attention increases the trial-to-trial response variability that is shared between the two areas. In our causal experiment, we electrically microstimulated V1 and found that attention increased the effect of stimulation on MT responses. Together, our results suggest that attention affects both the way visual stimuli are encoded within a cortical area and the extent to which visual information is communicated between areas on behaviorally relevant timescales. Visual attention dramatically improves the perception of attended stimuli. Attention has long been thought to act by selecting relevant visual information for further processing. It has been hypothesized that this selection is accomplished by increasing communication between neurons that encode attended information in different cortical areas. We recorded simultaneously from neurons in primary

Attention Increases Spike Count Correlations between Visual Cortical Areas

PubMed Central

Cohen, Marlene R.

2016-01-01

Visual attention, which improves perception of attended locations or objects, has long been known to affect many aspects of the responses of neuronal populations in visual cortex. There are two nonmutually exclusive hypotheses concerning the neuronal mechanisms that underlie these perceptual improvements. The first hypothesis, that attention improves the information encoded by a population of neurons in a particular cortical area, has considerable physiological support. The second hypothesis is that attention improves perception by selectively communicating relevant visual information. This idea has been tested primarily by measuring interactions between neurons on very short timescales, which are mathematically nearly independent of neuronal interactions on longer timescales. We tested the hypothesis that attention changes the way visual information is communicated between cortical areas on longer timescales by recording simultaneously from neurons in primary visual cortex (V1) and the middle temporal area (MT) in rhesus monkeys. We used two independent and complementary approaches. Our correlative experiment showed that attention increases the trial-to-trial response variability that is shared between the two areas. In our causal experiment, we electrically microstimulated V1 and found that attention increased the effect of stimulation on MT responses. Together, our results suggest that attention affects both the way visual stimuli are encoded within a cortical area and the extent to which visual information is communicated between areas on behaviorally relevant timescales. SIGNIFICANCE STATEMENT Visual attention dramatically improves the perception of attended stimuli. Attention has long been thought to act by selecting relevant visual information for further processing. It has been hypothesized that this selection is accomplished by increasing communication between neurons that encode attended information in different cortical areas. We recorded simultaneously

Comparing gains and losses.

PubMed

McGraw, A Peter; Larsen, Jeff T; Kahneman, Daniel; Schkade, David

2010-10-01

Loss aversion in choice is commonly assumed to arise from the anticipation that losses have a greater effect on feelings than gains, but evidence for this assumption in research on judged feelings is mixed. We argue that loss aversion is present in judged feelings when people compare gains and losses and assess them on a common scale. But many situations in which people judge and express their feelings lack these features. When judging their feelings about an outcome, people naturally consider a context of similar outcomes for comparison (e.g., they consider losses against other losses). This process permits gains and losses to be normed separately and produces psychological scale units that may not be the same in size or meaning for gains and losses. Our experiments show loss aversion in judged feelings for tasks that encourage gain-loss comparisons, but not tasks that discourage them, particularly those using bipolar scales.

Effect of distracting faces on visual selective attention in the monkey.

PubMed

Landman, Rogier; Sharma, Jitendra; Sur, Mriganka; Desimone, Robert

2014-12-16

In primates, visual stimuli with social and emotional content tend to attract attention. Attention might be captured through rapid, automatic, subcortical processing or guided by slower, more voluntary cortical processing. Here we examined whether irrelevant faces with varied emotional expressions interfere with a covert attention task in macaque monkeys. In the task, the monkeys monitored a target grating in the periphery for a subtle color change while ignoring distracters that included faces appearing elsewhere on the screen. The onset time of distracter faces before the target change, as well as their spatial proximity to the target, was varied from trial to trial. The presence of faces, especially faces with emotional expressions interfered with the task, indicating a competition for attentional resources between the task and the face stimuli. However, this interference was significant only when faces were presented for greater than 200 ms. Emotional faces also affected saccade velocity and reduced pupillary reflex. Our results indicate that the attraction of attention by emotional faces in the monkey takes a considerable amount of processing time, possibly involving cortical-subcortical interactions. Intranasal application of the hormone oxytocin ameliorated the interfering effects of faces. Together these results provide evidence for slow modulation of attention by emotional distracters, which likely involves oxytocinergic brain circuits.

Is that disgust I see? Political ideology and biased visual attention.

PubMed

Oosterhoff, Benjamin; Shook, Natalie J; Ford, Cameron

2018-01-15

Considerable evidence suggests that political liberals and conservatives vary in the way they process and respond to valenced (i.e., negative versus positive) information, with conservatives generally displaying greater negativity biases than liberals. Less is known about whether liberals and conservatives differentially prioritize certain forms of negative information over others. Across two studies using eye-tracking methodology, we examined differences in visual attention to negative scenes and facial expressions based on self-reported political ideology. In Study 1, scenes rated high in fear, disgust, sadness, and neutrality were presented simultaneously. Greater endorsement of socially conservative political attitudes was associated with less attentional engagement (i.e., lower dwell time) of disgust scenes and more attentional engagement toward neutral scenes. Socially conservative political attitudes were not significantly associated with visual attention to fear or sad scenes. In Study 2, images depicting facial expressions of fear, disgust, sadness, and neutrality were presented simultaneously. Greater endorsement of socially conservative political attitudes was associated with greater attentional engagement with facial expressions depicting disgust and less attentional engagement toward neutral faces. Visual attention to fearful or sad faces was not related to social conservatism. Endorsement of economically conservative political attitudes was not consistently associated with biases in visual attention across both studies. These findings support disease-avoidance models and suggest that social conservatism may be rooted within a greater sensitivity to disgust-related information. Copyright © 2017 Elsevier B.V. All rights reserved.

WebQuest Learning as Perceived by Higher-Education Learners

ERIC Educational Resources Information Center

Zheng, Robert; Stucky, Bradd; McAlack, Matt; Menchaca, Mike; Stoddart, Sue

2005-01-01

The WebQuest as an inquiry-oriented approach in web learning has gained considerable attention from educators and has been integrated widely into curricula in K-12 and higher education. It is considered to be an effective way to organize chaotic internet resources and help learners gain new knowledge through a guided learning environment.…

Posttraumatic stress disorder and fear of emotions: the role of attentional control.

PubMed

Sippel, Lauren M; Marshall, Amy D

2013-06-01

Individuals with posttraumatic stress disorder (PTSD) experience elevated concerns about their capacity to control, and the consequences of, strong emotions that occur in response to trauma reminders. Anxiety is theorized to compromise attentional control (Eysenck, Derakshan, Santos, & Calvo, 2007). In turn, diminished attentional control may increase vulnerability to threat cues and emotional reactivity (Ehlers & Clark, 2001). Consequently, attentional control may play a role in the fear of emotions frequently experienced by individuals with PTSD. Study participants included 64 men and 64 women with a mean age of 37 years, 86% of whom were White, non-Hispanic. Participants experienced an average of 7.68 types of traumatic events, most commonly including motor vehicle accidents and intimate partner violence. PTSD symptoms positively correlated with fear of emotions (r = .53) and negatively correlated with attentional control (r = -.38). Attentional control was negatively correlated with fear emotions (r = -.77) and partially mediated the link between PTSD and fear of emotions (R(2) = .22). Given the findings regarding top-down attentional control, these results have implications for cognitive and emotional processing theories of PTSD and emphasize the importance of clinical consideration of fear of emotions and attentional control in the treatment of PTSD. Copyright © 2013 International Society for Traumatic Stress Studies.

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

PubMed

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

2016-06-01

Adults with attention deficit hyperactivity disorder (ADHD) show attentional dysfunction such as distractibility and mind-wandering, especially in lengthy tasks. However, fundamentals of dysfunction are ambiguous and relationships of neuropsychological test parameters with self-report measures of ADHD symptoms are marginal. We hypothesize that basic deficits in sustaining attention explain more complex attentional dysfunction in persons with ADHD and relate to ADHD symptoms. Attentional function was analyzed by computing ex-Gaussian parameters for 3 time Blocks in a 20 min test of sustained alertness. Changes in performance across these blocks were analyzed by comparing adult persons with ADHD (n = 24) with healthy matched controls (n = 24) and correlated with neuropsychological measures of selective and divided attention as well as self-report measures of ADHD symptoms. We found a significantly steeper increase in the number of slow responses (ex-Gaussian parameter τ) in persons with ADHD with time on task in basic sustained alertness. They also performed significantly worse in tasks of sustained selective and divided attention. However, after controlling for an increase in τ during the alertness task, significant differences between groups disappeared for divided and partly selective attention. Increases in τ in the sustained alertness task correlated significantly with self-report measures of ADHD symptoms. Our results provide evidence that very basic deficits in sustaining attention in adults with ADHD are related to infrequent slow responses (=attentional lapses), with changes over time being relevant for more complex attentional function and experienced ADHD symptoms in everyday life. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Anatomical knowledge gain through a clay-modeling exercise compared to live and video observations.

PubMed

Kooloos, Jan G M; Schepens-Franke, Annelieke N; Bergman, Esther M; Donders, Rogier A R T; Vorstenbosch, Marc A T M

2014-01-01

Clay modeling is increasingly used as a teaching method other than dissection. The haptic experience during clay modeling is supposed to correspond to the learning effect of manipulations during exercises in the dissection room involving tissues and organs. We questioned this assumption in two pretest-post-test experiments. In these experiments, the learning effects of clay modeling were compared to either live observations (Experiment I) or video observations (Experiment II) of the clay-modeling exercise. The effects of learning were measured with multiple choice questions, extended matching questions, and recognition of structures on illustrations of cross-sections. Analysis of covariance with pretest scores as the covariate was used to elaborate the results. Experiment I showed a significantly higher post-test score for the observers, whereas Experiment II showed a significantly higher post-test score for the clay modelers. This study shows that (1) students who perform clay-modeling exercises show less gain in anatomical knowledge than students who attentively observe the same exercise being carried out and (2) performing a clay-modeling exercise is better in anatomical knowledge gain compared to the study of a video of the recorded exercise. The most important learning effect seems to be the engagement in the exercise, focusing attention and stimulating time on task. © 2014 American Association of Anatomists.

Active rc filter permits easy trade-off of amplifier gain and sensitivity to gain

NASA Technical Reports Server (NTRS)

Kerwin, W. J.; Shaffer, C. V.

1968-01-01

Passive RC network was designed with zeros of transmission in the right half of the complex frequency plane in the feedback loop of a simple negative-gain amplifier. The proper positioning provides any desired trade-off between amplifier gain and sensitivity to amplifier gain.

Women and substance abuse: gender, age, and cultural considerations.

PubMed

Stevens, Sally J; Andrade, Rosi A C; Ruiz, Bridget S

2009-01-01

Historically, data has shown that a smaller percentage of women use alcohol and illicit substances compared to men, and that frequency of use has been lower among women compared to use among men. Although this data on usage may be true, researchers also acknowledge that substance use among women has been a hidden issue, one not realistically acknowledged by society, especially prior to the mid-1960s. Along with this, more recent data indicates that rates of substance use among women are increasing. Factors contributing to this increase in substance abuse have begun to receive considerable attention, and recent research suggests that many issues exist that are unique to substance use among women. The purpose of this article is to discuss gender specific considerations in women's substance abuse by examining the history of substance use among women; analyzing gender-specific factors, including physiological factors, trauma-related factors, mental health issues, and cultural considerations that impact on women's substance use; articulating treatment approaches for working with substance abusing women and girls; and providing recommendations for further research in this area.

[Considering human peculiarities in attention to health care through dialogue and assistance].

PubMed

Pereira, Adriana Dall'Asta; de Freitas, Hilda Maria Barbosa; Ferreira, Carla Lizandra de Lima; Marchiori, Mara Regina Caino Teixeira; Souza, Martha Helena Teixeira; Backes, Dirce Stein

2010-03-01

The aim of this qualitative exploratory research is to understand how health workers relate to the main object of their work--the user--both subject and author of his/her life history. Eleven nursing practitioners from a Basic Health Unit participated in a semi-structured instrument, in March and April, 2008. The speeches revealed two converging themes: (1) Consideration of human peculiarities in attention to health care; and (2) dialogue and assistance as interactive possibilities. We found that the attention to health care is broadening the debates over valuing human peculiarities through dialogue and assistance as interactive possibilities.

Individual differences in selective attention predict speech identification at a cocktail party

PubMed Central

Oberfeld, Daniel; Klöckner-Nowotny, Felicitas

2016-01-01

Listeners with normal hearing show considerable individual differences in speech understanding when competing speakers are present, as in a crowded restaurant. Here, we show that one source of this variance are individual differences in the ability to focus selective attention on a target stimulus in the presence of distractors. In 50 young normal-hearing listeners, the performance in tasks measuring auditory and visual selective attention was associated with sentence identification in the presence of spatially separated competing speakers. Together, the measures of selective attention explained a similar proportion of variance as the binaural sensitivity for the acoustic temporal fine structure. Working memory span, age, and audiometric thresholds showed no significant association with speech understanding. These results suggest that a reduced ability to focus attention on a target is one reason why some listeners with normal hearing sensitivity have difficulty communicating in situations with background noise. DOI: http://dx.doi.org/10.7554/eLife.16747.001 PMID:27580272

Improved Gain Microstrip Patch Antenna

DTIC Science & Technology

2015-08-06

08-2015 Publication Improved Gain Microstrip Patch Antenna David A. Tonn Naval Under Warfare Center Division, Newport 1176 Howell St., Code 00L...GAIN MICROSTRIP PATCH ANTENNA STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and used by or for the...patch antenna having increased gain, and an apparatus for increasing the gain and bandwidth of an existing microstrip patch antenna . (2) Description

Candy and the Brain: Neural Response to Candy Gains and Losses

PubMed Central

Luking, Katherine R; Barch, Deanna M

2013-01-01

Incentive processing is a critical component of a host of cognitive processes including attention, motivation, and learning. Neuroimaging studies have clarified the neural systems underlying processing of primary and secondary rewards in adults. However, current reward paradigms have hindered comparison across these reward types as well as between age groups. To address methodological issues regarding timing of incentive delivery (during versus post-scan) and the age-appropriateness of the incentive type we utilized fMRI and a modified version of a card guessing game (CGG), where candy pieces delivered post-scan served as the reinforcer, to investigate neural responses to incentives. Healthy young adults aged 22–26 years won and lost large and small amounts of candy based on their ability to guess the number on a mystery card. BOLD activity was compared following candy gain (large/small), loss (large/small) and neutral feedback. During candy gains, adults recruited regions typically involved in response to monetary and other rewards such as the caudate, putamen, and orbitofrontal cortex. During losses, adults displayed greater deactivation in the hippocampus compared to neutral and gain feedback. Additionally, individual difference analyses suggested a negative relationship between reward sensitivity (assessed by behavioral inhibition/behavioral activation scales) and the difference between high and low magnitude losses in the caudate and lateral orbitofrontal cortex. Also within the striatum greater punishment sensitivity was positively related to the difference in activity following high compared to low gains. Overall these results show strong overlap with those from previous monetary versions of the CGG and provide a baseline for future work with developmental populations. PMID:23519971

Candy and the brain: neural response to candy gains and losses.

PubMed

Luking, Katherine R; Barch, Deanna M

2013-09-01

Incentive processing is a critical component of a host of cognitive processes, including attention, motivation, and learning. Neuroimaging studies have clarified the neural systems underlying processing of primary and secondary rewards in adults. However, current reward paradigms have hindered comparisons across these reward types as well as between age groups. To address methodological issues regarding the timing of incentive delivery (during scan vs. postscan) and the age-appropriateness of the incentive type, we utilized fMRI and a modified version of a card-guessing game (CGG), in which candy pieces delivered postscan served as the reinforcer, to investigate neural responses to incentives. Healthy young adults 22-26 years of age won and lost large and small amounts of candy on the basis of their ability to guess the number on a mystery card. BOLD activity was compared following candy gain (large/small), loss (large/small), and neutral feedback. During candy gains, adults recruited regions typically involved in response to monetary and other rewards, such as the caudate, putamen, and orbitofrontal cortex. During losses, they displayed greater deactivation in the hippocampus than in response to neutral and gain feedback. Additionally, individual-difference analyses suggested a negative relationship between reward sensitivity (assessed by the Behavioral Inhibition/Behavioral Activation Scales) and the difference between high- and low-magnitude losses in the caudate and lateral orbitofrontal cortex. Also within the striatum, greater punishment sensitivity was positively related to the difference in activity following high as compared to low gains. Overall, these results show strong overlap with those from previous monetary versions of the CGG and provide a baseline for future work with developmental populations.

Attention processes in chronic fatigue syndrome: attentional bias for health-related threat and the role of attentional control.

PubMed

Hou, Ruihua; Moss-Morris, Rona; Risdale, Anna; Lynch, Jeannette; Jeevaratnam, Preshan; Bradley, Brendan P; Mogg, Karin

2014-01-01

Cognitive behavioural models of chronic fatigue syndrome (CFS) propose that attention processes, specifically, enhanced selective attention to health-threat related cues, may play an important role in symptom maintenance. The current study investigated attentional bias towards health-threat stimuli in CFS. It also examined whether individuals with CFS have impaired executive attention, and whether this was related to attentional bias. 27 participants with CFS and 35 healthy controls completed a Visual Probe Task measuring attentional bias, and an Attention Network Test measuring executive attention, alerting and orienting. Participants also completed self-report measures of CFS and mood symptoms. Compared to the control group, the CFS group showed greater attentional bias for health-threat words than pictures; and the CFS group was significantly impaired in executive attention. Furthermore, CFS individuals with poor executive attention showed greater attentional bias to health-threat related words, compared not only to controls but also to CFS individuals with good executive attention. Thus, this study revealed a significant relationship between attentional bias and executive attention in CFS: attentional bias to threat was primarily evident in those with impaired executive attention control. Taking account of individual differences in executive attention control in current intervention models may be beneficial for CFS. Copyright © 2013 Elsevier Ltd. All rights reserved.

Direct-conversion flat-panel imager with avalanche gain: Feasibility investigation for HARP-AMFPI

PubMed Central

Wronski, M. M.; Rowlands, J. A.

2008-01-01

The authors are investigating the concept of a direct-conversion flat-panel imager with avalanche gain for low-dose x-ray imaging. It consists of an amorphous selenium (a-Se) photoconductor partitioned into a thick drift region for x-ray-to-charge conversion and a relatively thin region called high-gain avalanche rushing photoconductor (HARP) in which the charge undergoes avalanche multiplication. An active matrix of thin film transistors is used to read out the electronic image. The authors call the proposed imager HARP active matrix flat panel imager (HARP-AMFPI). The key advantages of HARP-AMFPI are its high spatial resolution, owing to the direct-conversion a-Se layer, and its programmable avalanche gain, which can be enabled during low dose fluoroscopy to overcome electronic noise and disabled during high dose radiography to prevent saturation of the detector elements. This article investigates key design considerations for HARP-AMFPI. The effects of electronic noise on the imaging performance of HARP-AMFPI were modeled theoretically and system parameters were optimized for radiography and fluoroscopy. The following imager properties were determined as a function of avalanche gain: (1) the spatial frequency dependent detective quantum efficiency; (2) fill factor; (3) dynamic range and linearity; and (4) gain nonuniformities resulting from electric field strength nonuniformities. The authors results showed that avalanche gains of 5 and 20 enable x-ray quantum noise limited performance throughout the entire exposure range in radiography and fluoroscopy, respectively. It was shown that HARP-AMFPI can provide the required gain while maintaining a 100% effective fill factor and a piecewise dynamic range over five orders of magnitude (10−7–10−2 R∕frame). The authors have also shown that imaging performance is not significantly affected by the following: electric field strength nonuniformities, avalanche noise for x-ray energies above 1 keV and direct

The impact of dialogic book-sharing training on infant language and attention: a randomized controlled trial in a deprived South African community

PubMed Central

Vally, Zahir; Murray, Lynne; Tomlinson, Mark; Cooper, Peter J.

2015-01-01

Background Dialogic book-sharing is an interactive form of shared reading. It has been shown in high income countries (HICs) to be of significant benefit to child cognitive development. Evidence for such benefit in low and middle income countries (LMICs) is scarce, although a feasibility study of our own produced encouraging findings. Accordingly, we aimed to establish the impact on child language and attention of providing training in dialogic booksharing to carers of infants in an impoverished South African community. Methods We conducted a randomized controlled trial in Khayelitsha, an informal settlement in South Africa. Mothers of infants aged between 14 and 16 months were recruited and randomized to either eight weeks of manualized training in dialogic book-sharing or a no-intervention control group. Independent assessments were made of infant language and attention at baseline and following training. The trial was registered (ISRCTN39953901). Results Ninety one carer-infant dyads were recruited and randomized to the intervention group (n = 49) or the control group (n = 42), 82 (90%) of whom were available for follow-up assessments. On a standardized carer report of infant vocabulary, compared to those in the control group, carers who received the intervention reported a significantly greater increase in the number of words understood by their infants as well as a larger increase in the number of words that their infant understood and could vocalize. Intervention group children also showed substantially greater gains on a measure of sustained attention. Conclusions In line with evidence from HICs, a dialogic book-sharing programme delivered to an impoverished South African sample was shown to be of considerable benefit to the development of child language and focussed attention. The training programme, which is simple and inexpensive to deliver, has the potential to benefit child cognitive development in LMIC contexts where such development is commonly

Attentional capture by evaluative stimuli: gain- and loss-connoting colors boost the additional-singleton effect.

PubMed

Wentura, Dirk; Müller, Philipp; Rothermund, Klaus

2014-06-01

In a valence induction task, one color acquired positive valence by indicating the chance to win money (in the case of fast and correct responses), and a different color acquired negative valence by indicating the danger to lose money (in the case of slow or incorrect responses). In the additional-singleton trials of a visual search task, the task-irrelevant singleton color was either the positive one, the negative one, or one of two neutral colors. We found an additional-singleton effect (i.e., longer RTs with a singleton color than in the no-singleton control condition). This effect was significantly increased for the two valent colors (with no differences between them) relative to the two neutral colors (with no differences between them, either). This result favors the hypothesis that the general relevance of stimuli elicits attentional capture, rather than the negativity bias hypothesis.

Affective associations with negativity: Why popular peers attract youths' visual attention.

PubMed

Lansu, Tessa A M; Troop-Gordon, Wendy

2017-10-01

Visual attention to high-status peers is well documented, but whether this attentional bias is due to high-status individuals' leadership and prosocial characteristics or due to their more agonistic behaviors has yet to be examined. To identify the affective associations that may underlie visual attention for high-status versus low-status peers, 122 early adolescents (67 girls; M age =11.0years, SD=0.7) completed a primed attention paradigm. Visual attention was measured using eye tracking as participants looked simultaneously at photographs of two classmates: one nominated by peers as popular and one nominated by peers as unpopular. Prior to each trial, the early adolescents were presented with a positive prime, the word "nice"; a negative prime, the word "stupid"; or no prime. Primary analyses focused on first-gaze preference and total gaze time The results showed a stronger first gaze preference for popular peers than for unpopular peers in the no-prime and negative prime trials than in the positive prime trials. The visual preference for a popular peer, thus, was attenuated by the positive prime. These findings are consistent with the notion that youths may visually attend to high-status peers due to their association with more negative characteristics and the threat they may pose to youths' own social standing and ability to gain interpersonal resources. Copyright © 2017 Elsevier Inc. All rights reserved.

Predicting Clinical Gains and Side Effects of Stimulant Medication in Pediatric Attention-Deficit/Hyperactivity Disorder by Combining Measures From qEEG and ERPs in a Cued GO/NOGO Task.

PubMed

Ogrim, Geir; Kropotov, Juri D

2018-06-01

The study aim was to develop 2 scales: predicting clinical gains and risk of acute side effects of stimulant medication in pediatric attention-deficit/hyperactivity disorder (ADHD), combining measures from EEG spectra, event-related potentials (ERPs), and a cued visual GO/NOGO task. Based on 4-week systematic medication trials, 87 ADHD patients aged 8 to 17 years were classified as responders (REs, n = 62) or non-REs (n = 25), and belonging to the side effects (SEs, n = 42) or no-SEs (n = 45) groups. Before starting the trial, a 19-channel EEG was registered twice: Test 1 (T1) without medication and T2 on a single dose of stimulant medication a few days before the trial. EEG was registered T1 and T2: 3 minutes eyes-closed, 3 minutes eyes-open, and 20 minutes cued GO/NOGO. EEG spectra, ERPs, omissions, commissions, reaction time (RT), and RT variability were computed. Groups were compared at T1 and T2 on quantitative EEG (qEEG), ERPs and behavioral parameters; effect sizes ( d) were estimated. Variables with d > 0.5 were converted to quartiles, multiplied by corresponding d, and summed to obtain 2 global scales. Six variables differed significantly between REs and non-REs (T1: theta/alpha ratio, P3NOGO amplitude. Differences T2-T1: Omissions, RT variability, P3NOGO, contingent negative variation [CNV]). The global scale d was 1.86. Accuracy (receiver operating characteristic) was 0.92. SEs and no-SEs differed significantly on 4 variables. (T1: RT, T2: novelty component and alpha peak frequency, and RT changes. Global scale d = 1.08 and accuracy = 0.78. Gains and side effects of stimulants in pediatric ADHD can be predicted with high accuracy by combining EEG spectra, ERPs, and behavior from baseline and single-dose tests. ClinicalTrials.gov identifier: NCT02695355.

Attentional bias to food-related visual cues: is there a role in obesity?

PubMed

Doolan, K J; Breslin, G; Hanna, D; Gallagher, A M

2015-02-01

The incentive sensitisation model of obesity suggests that modification of the dopaminergic associated reward systems in the brain may result in increased awareness of food-related visual cues present in the current food environment. Having a heightened awareness of these visual food cues may impact on food choices and eating behaviours with those being most aware of or demonstrating greater attention to food-related stimuli potentially being at greater risk of overeating and subsequent weight gain. To date, research related to attentional responses to visual food cues has been both limited and conflicting. Such inconsistent findings may in part be explained by the use of different methodological approaches to measure attentional bias and the impact of other factors such as hunger levels, energy density of visual food cues and individual eating style traits that may influence visual attention to food-related cues outside of weight status alone. This review examines the various methodologies employed to measure attentional bias with a particular focus on the role that attentional processing of food-related visual cues may have in obesity. Based on the findings of this review, it appears that it may be too early to clarify the role visual attention to food-related cues may have in obesity. Results however highlight the importance of considering the most appropriate methodology to use when measuring attentional bias and the characteristics of the study populations targeted while interpreting results to date and in designing future studies.

Chewing and Attention: A Positive Effect on Sustained Attention

PubMed Central

Onozuka, Minoru

2015-01-01

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

In vitro Studies of the Gain and Exchange of Calcium in Frog Skeletal Muscle

PubMed Central

Cosmos, Ethel; Harris, Eric J.

1961-01-01

(1) The Ca++, Na+, and K+ contents of frog sartorius muscles were found analytically after exposure to various media including some containing labeled Ca++. (2) During storage in media with 100 to 120 mM Na+ and 1 mM Ca++ both Na+ and Ca++ are gained while K+ is lost; there is a high correlation between Na+ and Ca++ gains. (3) When Ca++ gain occurs from a solution containing labeled Ca++ there is also some exchange of the original Ca++ with the labeled Ca++. The amount exchanged is considerably less (e.g. 50 per cent) than the total amount of labeled Ca++ taken up by the tissue. (4) When the external Na+ concentration is reduced to 30 mM the amount of labeled Ca++ taken up is increased. Part of the increase is attributable to a greater net gain and part to a greater degree of exchange. (5) It is pointed out that muscles which have been loaded in vitro with labeled Ca++ will not provide a valid measure of the exchangeability of the normal Ca++ content present at the time of dissection. (6) Comparison is made between results obtained using Sr89 and Ca45 as labels for the Ca++. Little, if any, difference is perceptible. PMID:13695749

Is goal-directed attentional guidance just intertrial priming? A review.

PubMed

Lamy, Dominique F; Kristjánsson, Arni

2013-07-01

According to most models of selective visual attention, our goals at any given moment and saliency in the visual field determine attentional priority. But selection is not carried out in isolation--we typically track objects through space and time. This is not well captured within the distinction between goal-directed and saliency-based attentional guidance. Recent studies have shown that selection is strongly facilitated when the characteristics of the objects to be attended and of those to be ignored remain constant between consecutive selections. These studies have generated the proposal that goal-directed or top-down effects are best understood as intertrial priming effects. Here, we provide a detailed overview and critical appraisal of the arguments, experimental strategies, and findings that have been used to promote this idea, along with a review of studies providing potential counterarguments. We divide this review according to different types of attentional control settings that observers are thought to adopt during visual search: feature-based settings, dimension-based settings, and singleton detection mode. We conclude that priming accounts for considerable portions of effects attributed to top-down guidance, but that top-down guidance can be independent of intertrial priming.

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,…

Gain-switching characteristics and fast transient response of three-terminal size-effect modulation laser

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

Suemune, I.; Takeoka, T.; Yamanashi, M.

1986-09-01

Gain-switching characteristics of the proposed size-effect modulation light sources are investigated. For realizing the laser operation, the consideration of the screening effect on the applied electric fields due to the high concentration of carriers is indispensable. In this respect, the authors propose a separate-confinement-hereto-multiple-quantum-well (SCH-MQW) structure as the most suitable one for gain switching. The key point of the structure is the sufficiently high heterobarriers at the clad-barrier interfaces to prevent carrier leakage. The examinations of the transient response clarify that they are principally photon-lifetime limited. Employing the three-terminal character of the proposed laser, the fast pulse modulation up tomore » 12 Gbits/s, which is almost free from the relaxation oscillations and the pattern effects, is predicted.« less

Motor contributions to the temporal precision of auditory attention

PubMed Central

Morillon, Benjamin; Schroeder, Charles E.; Wyart, Valentin

2014-01-01

In temporal—or dynamic—attending theory, it is proposed that motor activity helps to synchronize temporal fluctuations of attention with the timing of events in a task-relevant stream, thus facilitating sensory selection. Here we develop a mechanistic behavioural account for this theory by asking human participants to track a slow reference beat, by noiseless finger pressing, while extracting auditory target tones delivered on-beat and interleaved with distractors. We find that overt rhythmic motor activity improves the segmentation of auditory information by enhancing sensitivity to target tones while actively suppressing distractor tones. This effect is triggered by cyclic fluctuations in sensory gain locked to individual motor acts, scales parametrically with the temporal predictability of sensory events and depends on the temporal alignment between motor and attention fluctuations. Together, these findings reveal how top-down influences associated with a rhythmic motor routine sharpen sensory representations, enacting auditory ‘active sensing’. PMID:25314898

Reducing attentional capture of emotion by broadening attention: increased global attention reduces early electrophysiological responses to negative stimuli.

PubMed

Gable, Philip A; Harmon-Jones, Eddie

2012-05-01

Decades of research has shown the influence of emotion on attentional capture, and more recently, the influence of emotion on neurophysiological processes related to attentional capture. The current research tested whether some of the earliest neurophysiological underpinnings of emotive attentional processes can be influenced by attentional manipulations of broadening versus narrowing. Previous research has shown that negative affects high in motivational intensity (e.g., disgust, fear) cause a relative narrowing of attentional scope (Gable and Harmon-Jones, 2010a; Easterbrook, 1959). Because of the strong link between motivation and attention, attentional scope should also influence the attentional capture of negative stimuli. The current study manipulated a local attentional scope or global attentional scope, then measured attentional capture towards disgust and neutral pictures using the N1 event-related potential component. Results revealed that a manipulated global attentional scope reduced N1 amplitude towards disgust pictures compared to a manipulated local attentional scope. Copyright © 2012 Elsevier B.V. All rights reserved.

Capturing Attention When Attention "Blinks"

ERIC Educational Resources Information Center

Wee, Serena; Chua, Fook K.

2004-01-01

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

Telecommuting: Occupational health considerations for employee health and safety.

PubMed

Healy, M L

2000-06-01

1. Information technology has moved "work" out of a centralized location. Employees who telecommute pose significant challenges and considerations for the practice of occupational health nursing. 2. Employer and employee benefits associated with telecommuting are reportedly associated with high levels of job satisfaction. However, the occupational health and safety risks of this new work environment need to be fully assessed and understood. 3. The ergonomic controls to minimize the risk of repetitive motion injuries are the same for both office and home locations. Additional attention need to be paid to implementing risk controls for other physical hazards and psychosocial considerations, as well as personal safety and security issues. 4. The scope of occupational health nursing practice needs to remain dynamic, recognizing the impact new technologies have on the workplace, to continue to meet the needs of the changing workplace.

Association of gestational weight gain expectations with advice on actual weight gain

USDA-ARS?s Scientific Manuscript database

To examine pregnant women's gestational weight gain expectations/advice from various sources (i.e., self, family/friends, physician) and the impact of these sources of expectations/advice on actual measured gestational weight gain. Pregnant women (n=230, 87.4% Caucasian, second pregnancy) in a cohor...

Optical gain in colloidal quantum dots achieved with direct-current electrical pumping

NASA Astrophysics Data System (ADS)

Lim, Jaehoon; Park, Young-Shin; Klimov, Victor I.

2018-01-01

Chemically synthesized semiconductor quantum dots (QDs) can potentially enable solution-processable laser diodes with a wide range of operational wavelengths, yet demonstrations of lasing from the QDs are still at the laboratory stage. An important challenge--realization of lasing with electrical injection--remains unresolved, largely due to fast nonradiative Auger recombination of multicarrier states that represent gain-active species in the QDs. Here we present population inversion and optical gain in colloidal nanocrystals realized with direct-current electrical pumping. Using continuously graded QDs, we achieve a considerable suppression of Auger decay such that it can be outpaced by electrical injection. Further, we apply a special current-focusing device architecture, which allows us to produce high current densities (j) up to ~18 A cm-2 without damaging either the QDs or the injection layers. The quantitative analysis of electroluminescence and current-modulated transmission spectra indicates that with j = 3-4 A cm-2 we achieve the population inversion of the band-edge states.

Weight Gain during Pregnancy

MedlinePlus

... Global Map Premature Birth Report Cards Careers Archives Pregnancy Before or between pregnancies Nutrition, weight & fitness Prenatal ... fitness > Weight gain during pregnancy Weight gain during pregnancy E-mail to a friend Please fill in ...

Asthma Triggers: Gain Control

MedlinePlus

... Centers Asthma Contact Us Share Asthma Triggers: Gain Control Breathing Freely: Controlling Asthma Triggers This video features ... Air Quality: Biological Pollutants Help Your Child Gain Control Over Asthma Top of Page Molds About Molds ...

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

PubMed

Takeda, Toshinobu; Ando, Mizuho; Kumagai, Keiko

2015-06-01

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

Water quality in Gaines Creek and Gaines Creek arm of Eufaula Lake, Oklahoma

USGS Publications Warehouse

Kurklin, J.K.

1990-01-01

Based on samples collected from May 1978 to May 1980 and analyzed for major anions, nitrogen, trace elements, phytoplankton, and bacteria, the water in Gaines Creek and the Gaines Creek arm of Eufaula Lake was similar with respect to suitability for municipal use. Water from Gaines Creek had a pH range of 5.7 to 7.6 and a maximum specific conductance of 97 microsiemens per centimeter at 25o Celsius, whereas water from the Gaines Creek arm of Eufaula Lake had a pH range of 6.0 to 9.2 and a maximum specific conductance of 260 microsiemens per centimeter at 25o Celsius. Dissolved oxygen, pH, temperature, and specific conductance values for the lake varied with depth. With the exceptions of cadmium, iron, lead, and manganese, trace-element determinations of samples were within recommended national primary and secondary drinking-water standards. When compared to the National Academy of Sciences water-quality criteria, phytoplankton and bacteria counts exceeded recommendations; however, water from either Gaines Creek or Eufaula Lake could be treated similarly and used as a municipal water supply.

Climate Change Professional Development Approaches: Design Considerations, Teacher Enactment, and Student Learning

NASA Astrophysics Data System (ADS)

Drewes, A.; Henderson, J.; Mouza, C.

2017-12-01

Climate change is one of the most pressing challenges facing society, and climate change educational models are emerging in response. This study investigates the implementation and enactment of a climate change professional development model for science educators and its impact on student learning. Using an intrinsic case study methodology, we focused analytic attention on how one teacher made specific curricular, pedagogical, and content decisions, and the implications of those decisions for student's conceptual learning.The research presented here reports on the instructional design, pedagogical enactment, and subsequent effects on student learning of a climate change professional development (PD) model in the United States. Using anthropological theories of conceptual travel, we traced salient ideas from the PD through instructional delivery and into the evidence of student reasoning. We sought to address the following research questions: 1) How did a middle school teacher integrate climate change concepts into her science curriculum following PD participation? and 2) How did climate change instruction influence student understanding of key climate change constructs?From observation of the classroom instruction, we determined that the teacher effectively integrated new climate change information into her pre-existing schema. Additionally, through retrospective analysis of the PD, we found the design of the PD foregrounded the causes, mechanisms and likely effects of anthropogenic climate change at the expense of mitigation and adaptation strategies, and this differentially shaped how climate change was taught in the teacher's classroom. Analysis of student reasoning evidence showed that students gained an increased understanding of the enhanced greenhouse effect and the implications of human activity on this enhanced effect at statistically significant levels and with moderate effect sizes. However, students demonstrated a limited, though non-significant gain on

The "Dual Usage Problem" in the Explanations of "Joint Attention" and Children's Socioemotional Development: A Reconceptualization

ERIC Educational Resources Information Center

Tasker, Susan L.; Schmidt, Louis A.

2008-01-01

The term "joint attention", which first gained currency in the early 1960s in studies of the development of language and symbolic thought, remains significant in the developmental literature. However, its meaning is unclear. A definitional problem exists similar to what Patterson [Patterson, M. L. (1982). "A sequential functional model of…

Role of attentional tags in working memory-driven attentional capture.

PubMed

Kuo, Chun-Yu; Chao, Hsuan-Fu

2014-08-01

Recent studies have demonstrated that the contents of working memory capture attention when performing a visual search task. However, it remains an intriguing and unresolved question whether all kinds of items stored in working memory capture attention. The present study investigated this issue by manipulating the attentional tags (target or distractor) associated with information maintained in working memory. The results showed that working memory-driven attentional capture is a flexible process, and that attentional tags associated with items stored in working memory do modulate attentional capture. When items were tagged as a target, they automatically captured attention; however, when items were tagged as a distractor, attentional capture was reduced.

Social Image Captioning: Exploring Visual Attention and User Attention

PubMed Central

Chu, Xiaoliang; Zhang, Weishan; Wei, Yiwei; Sun, Weichen; Wu, Chunlei

2018-01-01

Image captioning with a natural language has been an emerging trend. However, the social image, associated with a set of user-contributed tags, has been rarely investigated for a similar task. The user-contributed tags, which could reflect the user attention, have been neglected in conventional image captioning. Most existing image captioning models cannot be applied directly to social image captioning. In this work, a dual attention model is proposed for social image captioning by combining the visual attention and user attention simultaneously.Visual attention is used to compress a large mount of salient visual information, while user attention is applied to adjust the description of the social images with user-contributed tags. Experiments conducted on the Microsoft (MS) COCO dataset demonstrate the superiority of the proposed method of dual attention. PMID:29470409

Social Image Captioning: Exploring Visual Attention and User Attention.

PubMed

Wang, Leiquan; Chu, Xiaoliang; Zhang, Weishan; Wei, Yiwei; Sun, Weichen; Wu, Chunlei

2018-02-22

Image captioning with a natural language has been an emerging trend. However, the social image, associated with a set of user-contributed tags, has been rarely investigated for a similar task. The user-contributed tags, which could reflect the user attention, have been neglected in conventional image captioning. Most existing image captioning models cannot be applied directly to social image captioning. In this work, a dual attention model is proposed for social image captioning by combining the visual attention and user attention simultaneously.Visual attention is used to compress a large mount of salient visual information, while user attention is applied to adjust the description of the social images with user-contributed tags. Experiments conducted on the Microsoft (MS) COCO dataset demonstrate the superiority of the proposed method of dual attention.

Visual attention to food cues in obesity: an eye-tracking study.

PubMed

Doolan, Katy J; Breslin, Gavin; Hanna, Donncha; Murphy, Kate; Gallagher, Alison M

2014-12-01

Based on the theory of incentive sensitization, the aim of this study was to investigate differences in attentional processing of food-related visual cues between normal-weight and overweight/obese males and females. Twenty-six normal-weight (14M, 12F) and 26 overweight/obese (14M, 12F) adults completed a visual probe task and an eye-tracking paradigm. Reaction times and eye movements to food and control images were collected during both a fasted and fed condition in a counterbalanced design. Participants had greater visual attention towards high-energy-density food images compared to low-energy-density food images regardless of hunger condition. This was most pronounced in overweight/obese males who had significantly greater maintained attention towards high-energy-density food images when compared with their normal-weight counterparts however no between weight group differences were observed for female participants. High-energy-density food images appear to capture visual attention more readily than low-energy-density food images. Results also suggest the possibility of an altered visual food cue-associated reward system in overweight/obese males. Attentional processing of food cues may play a role in eating behaviors thus should be taken into consideration as part of an integrated approach to curbing obesity. © 2014 The Obesity Society.

A spatial approach of magnitude-squared coherence applied to selective attention detection.

PubMed

Bonato Felix, Leonardo; de Souza Ranaudo, Fernando; D'affonseca Netto, Aluizio; Ferreira Leite Miranda de Sá, Antonio Mauricio

2014-05-30

Auditory selective attention is the human ability of actively focusing in a certain sound stimulus while avoiding all other ones. This ability can be used, for example, in behavioral studies and brain-machine interface. In this work we developed an objective method - called Spatial Coherence - to detect the side where a subject is focusing attention to. This method takes into consideration the Magnitude Squared Coherence and the topographic distribution of responses among electroencephalogram electrodes. The individuals were stimulated with amplitude-modulated tones binaurally and were oriented to focus attention to only one of the stimuli. The results indicate a contralateral modulation of ASSR in the attention condition and are in agreement with prior studies. Furthermore, the best combination of electrodes led to a hit rate of 82% for 5.03 commands per minute. Using a similar paradigm, in a recent work, a maximum hit rate of 84.33% was achieved, but with a greater a classification time (20s, i.e. 3 commands per minute). It seems that Spatial Coherence is a useful technique for detecting focus of auditory selective attention. Copyright © 2014 Elsevier B.V. All rights reserved.

Numerical investigation into the injection-locking phenomena of gain switched lasers for optical frequency comb generation

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

Ó Dúill, Sean P., E-mail: sean.oduill@dcu.ie; Anandarajah, Prince M.; Zhou, Rui

2015-05-25

We present detailed numerical simulations of the laser dynamics that describe optical frequency comb formation by injection-locking a gain-switched laser. The typical rate equations for semiconductor lasers including stochastic carrier recombination and spontaneous emission suffice to show the injection-locking behavior of gain switched lasers, and we show how the optical frequency comb evolves starting from the free-running state, right through the final injection-locked state. Unlike the locking of continuous wave lasers, we show that the locking range for gain switched lasers is considerably greater because injection locking can be achieved by injecting at frequencies close to one of the combmore » lines. The quality of the comb lines is formally assessed by calculating the frequency modulation (FM)-noise spectral density and we show that under injection-locking conditions the FM-noise spectral density of the comb lines tend to that of the maser laser.« less

Evaluation of methods for the assessment of attention while driving.

PubMed

Kircher, Katja; Ahlstrom, Christer

2018-05-01

The ability to assess the current attentional state of the driver is important for many aspects of driving, not least in the field of partial automation for transfer of control between vehicle and driver. Knowledge about the driver's attentional state is also necessary for the assessment of the effects of additional tasks on attention. The objective of this paper is to evaluate different methods that can be used to assess attention, first theoretically, and then empirically in a controlled field study and in the laboratory. Six driving instructors participated in all experimental conditions of the study, delivering within-subjects data for all tested methods. Additional participants were recruited for some of the conditions. The test route consisted of 14km of motorway with low to moderate traffic, which was driven three times per participant per condition. The on-road conditions were: baseline, driving with eye tracking and self-paced visual occlusion, and driving while thinking aloud. The laboratory conditions were: Describing how attention should be distributed on a motorway, and thinking aloud while watching a video from the baseline drive. The results show that visual occlusion, especially in combination with eye tracking, was appropriate for assessing spare capacity. The think aloud protocol was appropriate to gain insight about the driver's actual mental representation of the situation at hand. Expert judgement in the laboratory was not reliable for the assessment of drivers' attentional distribution in traffic. Across all assessment techniques, it is evident that meaningful assessment of attention in a dynamic traffic situation can only be achieved when the infrastructure layout, surrounding road users, and intended manoeuvres are taken into account. This requires advanced instrumentation of the vehicle, and subsequent data reduction, analysis and interpretation are demanding. In conclusion, driver attention assessment in real traffic is a complex task, but

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…

Interventions for attention problems after pediatric traumatic brain injury: what is the evidence?

PubMed

Backeljauw, Barynia; Kurowski, Brad G

2014-09-01

To gain an understanding of the current state of the evidence for management of attention problems after traumatic brain injury (TBI) in children, determine gaps in the literature, and make recommendations for future research. TYPE: Focused systematic review. PubMed/Medline and PsychINFO databases were searched for relevant articles published in English during the last 20 years. Keywords included "attention" "attention deficit and disruptive behavior disorders," and "brain injuries." Studies were limited to children. Titles were examined first and eliminated based on lack of relevancy to attention problems after brain injury in children. This was followed by an abstract and full text review. Article quality was determined based on the US Preventative Services Task Force recommendations for evidence grading. Four pharmacologic and 10 cognitive therapy intervention studies were identified. These studies varied in level of evidence quality but were primarily nonrandomized or cohort studies. There are studies that demonstrate benefits of varying pharmacologic and cognitive therapies for the management of attention problems after TBI. However, there is a paucity of evidence available to definitively guide management of attention problems after pediatric TBI. Larger randomized, controlled trials and multicenter studies are needed to elucidate optimal treatment strategies in this population. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Leading Gainful Employment Metric Reporting

ERIC Educational Resources Information Center

Powers, Kristina; MacPherson, Derek

2016-01-01

This chapter will address the importance of intercampus involvement in reporting of gainful employment student-level data that will be used in the calculation of gainful employment metrics by the U.S. Department of Education. The authors will discuss why building relationships within the institution is critical for effective gainful employment…

What Goes through an Examiner's Mind? Using Verbal Protocols to Gain Insights into the GCSE Marking Process

ERIC Educational Resources Information Center

Suto, W. M. Irenka; Greatorex, Jackie

2008-01-01

The process of examination marking is complex, requiring examiners to engage in a variety of cognitive operations. While consideration has been given to marking practices in a few specific contexts, those of General Certificate of Secondary Education (GCSE) examiners have yet to receive serious attention. This study's aims, therefore, were: first,…

Contingent attentional capture or delayed allocation of attention?

NASA Technical Reports Server (NTRS)

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

2001-01-01

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

Magnitude and determinants of inadequate third-trimester weight gain in rural Bangladesh

PubMed Central

Hasan, S. M. Tafsir; Rahman, Sabuktagin; Locks, Lindsey Mina; Rahman, Mizanur; Hore, Samar Kumar; Saqeeb, Kazi Nazmus; Khan, Md. Alfazal

2018-01-01

, third-trimester weight gain was in general poor. Maternal characteristics such as short stature, low BMI, advanced age, parity, low level of education and socioeconomic status, being Hindu, intake of arsenic contaminated water, and conceiving during monsoon or dry season were the risk factors for inadequate weight gain in the third trimester. Special attention should be given during prenatal care to women with the risk factors identified in this study. PMID:29698483

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.

Artificial consciousness and the consciousness-attention dissociation.

PubMed

Haladjian, Harry Haroutioun; Montemayor, Carlos

2016-10-01

Artificial Intelligence is at a turning point, with a substantial increase in projects aiming to implement sophisticated forms of human intelligence in machines. This research attempts to model specific forms of intelligence through brute-force search heuristics and also reproduce features of human perception and cognition, including emotions. Such goals have implications for artificial consciousness, with some arguing that it will be achievable once we overcome short-term engineering challenges. We believe, however, that phenomenal consciousness cannot be implemented in machines. This becomes clear when considering emotions and examining the dissociation between consciousness and attention in humans. While we may be able to program ethical behavior based on rules and machine learning, we will never be able to reproduce emotions or empathy by programming such control systems-these will be merely simulations. Arguments in favor of this claim include considerations about evolution, the neuropsychological aspects of emotions, and the dissociation between attention and consciousness found in humans. Ultimately, we are far from achieving artificial consciousness. Copyright © 2016 Elsevier Inc. All rights reserved.

Aging and Attentional Control

PubMed Central

Tsang, Pamela S.

2013-01-01

The research examines the structural bottleneck account and the resource account of the substantial dual-task deficits among older adults. Procedures from two common dual-task methodologies--the psychological refractory period and the relative-priority manipulation--were used to encourage maximization of the joint performance. Performance and time-sharing strategies from subjects between the ages of 20 and 70 were examined. Age-related declines in time-sharing efficiency and in the precision of the executive control process were observed. The age-related effect was larger when two manual responses were required than when one manual and one vocal response were required but no evidence for obligatory sequential processing was found. Except for the most demanding conditions, comparable practice effects were observed between the younger and older subjects, suggesting considerable cognitive plasticity in the older subjects. Implications for the two attentional accounts were discussed. PMID:23281799

Preliminary investigation of visual attention to human figures in photographs: potential considerations for the design of aided AAC visual scene displays.

PubMed

Wilkinson, Krista M; Light, Janice

2011-12-01

Many individuals with complex communication needs may benefit from visual aided augmentative and alternative communication systems. In visual scene displays (VSDs), language concepts are embedded into a photograph of a naturalistic event. Humans play a central role in communication development and might be important elements in VSDs. However, many VSDs omit human figures. In this study, the authors sought to describe the distribution of visual attention to humans in naturalistic scenes as compared with other elements. Nineteen college students observed 8 photographs in which a human figure appeared near 1 or more items that might be expected to compete for visual attention (such as a Christmas tree or a table loaded with food). Eye-tracking technology allowed precise recording of participants' gaze. The fixation duration over a 7-s viewing period and latency to view elements in the photograph were measured. Participants fixated on the human figures more rapidly and for longer than expected based on the size of these figures, regardless of the other elements in the scene. Human figures attract attention in a photograph even when presented alongside other attractive distracters. Results suggest that humans may be a powerful means to attract visual attention to key elements in VSDs.

Spontaneous attention to faces in Asperger syndrome using ecologically valid static stimuli.

PubMed

Hanley, Mary; McPhillips, Martin; Mulhern, Gerry; Riby, Deborah M

2013-11-01

Previous eye tracking research on the allocation of attention to social information by individuals with autism spectrum disorders is equivocal and may be in part a consequence of variation in stimuli used between studies. The current study explored attention allocation to faces, and within faces, by individuals with Asperger syndrome using a range of static stimuli where faces were either viewed in isolation or viewed in the context of a social scene. Results showed that faces were viewed typically by the individuals with Asperger syndrome when presented in isolation, but attention to the eyes was significantly diminished in comparison to age and IQ-matched typical viewers when faces were viewed as part of social scenes. We show that when using static stimuli, there is evidence of atypicality for individuals with Asperger syndrome depending on the extent of social context. Our findings shed light on the previous explanations of gaze behaviour that have emphasised the role of movement in atypicalities of social attention in autism spectrum disorders and highlight the importance of consideration of the realistic portrayal of social information for future studies.

A Polymer-Dispersed Liquid Crystal-Based Dynamic Gain Equalizer

NASA Astrophysics Data System (ADS)

Barge, M.; Battarel, D.; de Bougrenet de La Tocnaye, J. L.

2005-08-01

This paper presents results obtained with a spatial light modulator (SLM) using a polymer-dispersed liquid-crystal (LC) material to provide dynamic gain equalization (DGE) for wavelength-division multiplexing (WDM) networks. We show the benefit of using a nonchannelized approach to adjust some physical parameters such as the ripple and the maximum obtainable attenuation slope for the spectra to be equalized. Particular attention is paid here to polarization dependence that can result from parasitic anisotropic multiple path interferences as well as induced anisotropy due to a planar transverse field when using a free-space SLM structure. In this frame, we demonstrate an original approach using a depolarizing prism that is only appropriate to such choice of material and that mitigates these effects. Finally, material engineering to widen the operating temperature range is also shortly presented in this paper.

Training attentional control in older adults

PubMed Central

MacKay-Brandt, Anna

2013-01-01

Recent research has demonstrated benefits for older adults from training attentional control using a variable priority strategy, but the construct validity of the training task and the degree to which benefits of training transfer to other contexts are unclear. The goal of this study was to characterize baseline performance on the training task in a sample of 105 healthy older adults and to test for transfer of training in a subset (n = 21). Training gains after 5 days and extent of transfer was compared to another subset (n = 20) that served as a control group. Baseline performance on the training task was characterized by a two-factor model of working memory and processing speed. Processing speed correlated with the training task. Training gains in speed and accuracy were reliable and robust (ps <.001, η2 = .57 to .90). Transfer to an analogous task was observed (ps <.05, η2 = .10 to .17). The beneficial effect of training did not translate to improved performance on related measures of processing speed. This study highlights the robust effect of training and transfer to a similar context using a variable priority training task. Although processing speed is an important aspect of the training task, training benefit is either related to an untested aspect of the training task or transfer of training is limited to the training context. PMID:21728889

Training attentional control in older adults.

PubMed

Mackay-Brandt, Anna

2011-07-01

Recent research has demonstrated benefits for older adults from training attentional control using a variable priority strategy, but the construct validity of the training task and the degree to which benefits of training transfer to other contexts are unclear. The goal of this study was to characterize baseline performance on the training task in a sample of 105 healthy older adults and to test for transfer of training in a subset (n = 21). Training gains after 5 days and extent of transfer was compared to another subset (n = 20) that served as a control group. Baseline performance on the training task was characterized by a two-factor model of working memory and processing speed. Processing speed correlated with the training task. Training gains in speed and accuracy were reliable and robust (ps <.001, η(2) = .57 to .90). Transfer to an analogous task was observed (ps <.05, η(2) = .10 to .17). The beneficial effect of training did not translate to improved performance on related measures of processing speed. This study highlights the robust effect of training and transfer to a similar context using a variable priority training task. Although processing speed is an important aspect of the training task, training benefit is either related to an untested aspect of the training task or transfer of training is limited to the training context.

Reduced attentional blink for gambling-related stimuli in problem gamblers.

PubMed

Brevers, Damien; Cleeremans, Axel; Tibboel, Helen; Bechara, Antoine; Kornreich, Charles; Verbanck, Paul; Noël, Xavier

2011-09-01

Although there is considerable information concerning the attentional biases in psychoactive substance use and misuse, much less is known about the contribution of attentional processing in problem gambling. The aim of this study was to examine whether problem gamblers (PrG) exhibit attentional bias at the level of the encoding processing stage. Forty PrG and 35 controls participated in an attentional blink (AB) paradigm in which they were required to identify both gambling and neutral words that appeared in a rapid serial visual presentation. Explicit motivation (e.g., intrinsic/arousal, extrinsic, amotivation) toward the gambling cues was recorded. A diminished AB effect for gambling-related words compared to neutral targets was identified in PrG. In contrast, AB was similar when either gambling-related or neutral words were presented to controls. Furthermore, there was a significant positive correlation between the reduced AB for gambling-related words and the sub-score of intrinsic/arousal motivation to gamble in PrG. Such findings suggest that the PrG group exhibits an enhanced ability to process gambling-related information, which is associated with their desire to gamble for arousal reasons. Theoretical and clinical implications of these results are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Attention modulates maintenance of representations in visual short-term memory.

PubMed

Kuo, Bo-Cheng; Stokes, Mark G; Nobre, Anna Christina

2012-01-01

Recent studies have shown that selective attention is of considerable importance for encoding task-relevant items into visual short-term memory (VSTM) according to our behavioral goals. However, it is not known whether top-down attentional biases can continue to operate during the maintenance period of VSTM. We used ERPs to investigate this question across two experiments. Specifically, we tested whether orienting attention to a given spatial location within a VSTM representation resulted in modulation of the contralateral delay activity (CDA), a lateralized ERP marker of VSTM maintenance generated when participants selectively encode memory items from one hemifield. In both experiments, retrospective cues during the maintenance period could predict a specific item (spatial retrocue) or multiple items (neutral retrocue) that would be probed at the end of the memory delay. Our results revealed that VSTM performance is significantly improved by orienting attention to the location of a task-relevant item. The behavioral benefit was accompanied by modulation of neural activity involved in VSTM maintenance. Spatial retrocues reduced the magnitude of the CDA, consistent with a reduction in memory load. Our results provide direct evidence that top-down control modulates neural activity associated with maintenance in VSTM, biasing competition in favor of the task-relevant information.

Fast-acting sprinkler system design considerations for propellant manufacture

NASA Astrophysics Data System (ADS)

Matthews, A. L.; Crable, J. M.; Kristoff, P. T.

1984-08-01

Fast-acting sprinkler systems for detection and suppression of fires in propellant operations, which require activation in the millisecond range in order to be effective, can be easily defeated unless particular attention is paid to design and maintenance details. Of primary consideration are detector selection and placement in processes to minimize the effect of environmental influences. Also important are nozzle placement, water flow density, water supply pressure, and pattern and sloping of piping. When all of these design criteria are properly implemented, water application can occur within 100 ms of fire detection.

Social Attention, Joint Attention and Sustained Attention in Autism Spectrum Disorder and Williams Syndrome: Convergences and Divergences.

PubMed

Vivanti, Giacomo; Fanning, Peter A J; Hocking, Darren R; Sievers, Stephanie; Dissanayake, Cheryl

2017-06-01

There is limited knowledge on shared and syndrome-specific attentional profiles in autism spectrum disorder (ASD) and Williams syndrome (WS). Using eye-tracking, we examined attentional profiles of 35 preschoolers with ASD, 22 preschoolers with WS and 20 typically developing children across social and non-social dimensions of attention. Children with ASD and those with WS presented with overlapping deficits in spontaneous visual engagement with the target of others' attention and in sustained attention. Children with ASD showed syndrome-specific abnormalities in monitoring and following a person's referential gaze, as well as a lack of preferential attention to social stimuli. Children with ASD and WS present with shared as well as syndrome-specific abnormalities across social and non-social dimensions of attention.

Height gain during early childhood is an important predictor of schooling and mathematics ability outcomes.

PubMed

Gandhi, Mihir; Ashorn, Per; Maleta, Kenneth; Teivaanmäki, Tiina; Duan, Xiaolian; Cheung, Yin Bun

2011-08-01

To examine the association between height gain at different stages of early childhood and schooling and cognitive outcomes in 12-year-old Malawian children. A prospective cohort study looking at the growth and development of 325 rural Malawian children. Main outcome measures were highest school grade completed, number of times repeating grades and percentage of correctly answered mathematical questions at 12 years of age. Height-for-age at 1 month and conditional height gain for 6, 18 and 60 months were used as predictors. Ordinal logistic and linear regression analyses were used to estimate the association and adjust for confounder. The conditional height gain during 18-60 months was positively associated with mathematics test results (p=0.003) and negatively associated with number of times repeating grades (p=0.011). It was not significantly associated with highest grade completed (p=0.194) if those who never attended school were included as having completed zero grade, but was positively (p=0.049) associated with this outcome among those who ever attended school. Height gain during the 18-60 months period of age was related to schooling and mathematics ability at age 12 years. The importance of promoting catch-up growth after the period when stunting is common should receive attention. © 2011 The Author(s)/Acta Paediatrica © 2011 Foundation Acta Paediatrica.

Direct-conversion flat-panel imager with avalanche gain: Feasibility investigation for HARP-AMFPI

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

Wronski, M. M.; Rowlands, J. A.

2008-12-15

The authors are investigating the concept of a direct-conversion flat-panel imager with avalanche gain for low-dose x-ray imaging. It consists of an amorphous selenium (a-Se) photoconductor partitioned into a thick drift region for x-ray-to-charge conversion and a relatively thin region called high-gain avalanche rushing photoconductor (HARP) in which the charge undergoes avalanche multiplication. An active matrix of thin film transistors is used to read out the electronic image. The authors call the proposed imager HARP active matrix flat panel imager (HARP-AMFPI). The key advantages of HARP-AMFPI are its high spatial resolution, owing to the direct-conversion a-Se layer, and its programmablemore » avalanche gain, which can be enabled during low dose fluoroscopy to overcome electronic noise and disabled during high dose radiography to prevent saturation of the detector elements. This article investigates key design considerations for HARP-AMFPI. The effects of electronic noise on the imaging performance of HARP-AMFPI were modeled theoretically and system parameters were optimized for radiography and fluoroscopy. The following imager properties were determined as a function of avalanche gain: (1) the spatial frequency dependent detective quantum efficiency; (2) fill factor; (3) dynamic range and linearity; and (4) gain nonuniformities resulting from electric field strength nonuniformities. The authors results showed that avalanche gains of 5 and 20 enable x-ray quantum noise limited performance throughout the entire exposure range in radiography and fluoroscopy, respectively. It was shown that HARP-AMFPI can provide the required gain while maintaining a 100% effective fill factor and a piecewise dynamic range over five orders of magnitude (10{sup -7}-10{sup -2} R/frame). The authors have also shown that imaging performance is not significantly affected by the following: electric field strength nonuniformities, avalanche noise for x-ray energies above 1 keV and

Connectivity supporting attention in children with attention deficit hyperactivity disorder

PubMed Central

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

2014-01-01

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

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

Sex Differences in the Experience of Unwanted Sexual Attention and Behaviors during Childhood

ERIC Educational Resources Information Center

Whealin, Julia M.; Zinzow, Heidi M.; Salstrom, Seoka A.; Jackson, Joan L.

2007-01-01

Girls receive considerable amounts of unwanted sexual attention (UWSA) and behaviors (UWSB). Less is known about boys' unwanted sexual experiences. The primary goal of this study was to obtain a descriptive profile of the types and perpetrators of childhood UWSA/B. Secondary goals were to examine sex differences in emotional reactions to UWSA/B…

Invention and Gain Analysis.

ERIC Educational Resources Information Center

Weber, Robert J.; Dixon, Stacey

1989-01-01

Gain analysis is applied to the invention of the sewing needle as well as different sewing implements and modes of sewing. The analysis includes a two-subject experiment. To validate the generality of gain heuristics and underlying switching processes, the invention of the assembly line is also analyzed. (TJH)

ADHD in school-aged youth: Management and special treatment considerations in the primary care setting.

PubMed

Weed, Elizabeth D

Attention-deficit/hyperactivity disorder is considered one of the most common neurodevelopmental disorders of childhood. Primary care providers are in the unique position of providing comprehensive care-routine care, well child visits, immunizations, and other healthcare needs-to a majority of children and adolescents with attention-deficit/hyperactivity disorder. As such, primary care providers are pivotal in the diagnosis, management, and treatment of this population. This article will address special treatment considerations to aid in the management of attention-deficit/hyperactivity disorder in the primary care setting, including substance use disorders and diversion, cardiac issues and stimulant medication, medication holidays and follow-up monitoring. The database of PubMed was searched using keywords that included attention-deficit/hyperactivity disorder, children, prevalence, medication holidays, safety, cardiovascular, cardiac, blood pressure, substance use, diversion, adverse drug reactions; inclusion dates were January 1, 2011 to September 30, 2015. © The Author(s) 2016.

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…

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

PubMed

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

2011-09-01

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

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

Altering attentional control settings causes persistent biases of visual attention.

PubMed

Knight, Helen C; Smith, Daniel T; Knight, David C; Ellison, Amanda

2016-01-01

Attentional control settings have an important role in guiding visual behaviour. Previous work within cognitive psychology has found that the deployment of general attentional control settings can be modulated by training. However, research has not yet established whether long-term modifications of one particular type of attentional control setting can be induced. To address this, we investigated persistent alterations to feature search mode, also known as an attentional bias, towards an arbitrary stimulus in healthy participants. Subjects were biased towards the colour green by an information sheet. Attentional bias was assessed using a change detection task. After an interval of either 1 or 2 weeks, participants were then retested on the same change detection task, tested on a different change detection task where colour was irrelevant, or were biased towards an alternative colour. One experiment included trials in which the distractor stimuli (but never the target stimuli) were green. The key finding was that green stimuli in the second task attracted attention, despite this impairing task performance. Furthermore, inducing a second attentional bias did not override the initial bias toward green objects. The attentional bias also persisted for at least two weeks. It is argued that this persistent attentional bias is mediated by a chronic change to participants' attentional control settings, which is aided by long-term representations involving contextual cueing. We speculate that similar changes to attentional control settings and continuous cueing may relate to attentional biases observed in psychopathologies. Targeting these biases may be a productive approach to treatment.

Utilization of reward-prospect enhances preparatory attention and reduces stimulus conflict.

PubMed

van den Berg, Berry; Krebs, Ruth M; Lorist, Monicque M; Woldorff, Marty G

2014-06-01

The prospect of gaining money is an incentive widely at play in the real world. Such monetary motivation might have particularly strong influence when the cognitive system is challenged, such as when needing to process conflicting stimulus inputs. Here, we employed manipulations of reward-prospect and attentional-preparation levels in a cued-Stroop stimulus conflict task, along with the high temporal resolution of electrical brain recordings, to provide insight into the mechanisms by which reward-prospect and attention interact and modulate cognitive task performance. In this task, the cue indicated whether or not the participant needed to prepare for an upcoming Stroop stimulus and, if so, whether there was the potential for monetary reward (dependent on performance on that trial). Both cued attention and cued reward-prospect enhanced preparatory neural activity, as reflected by increases in the hallmark attention-related negative-polarity ERP slow wave (contingent negative variation [CNV]) and reductions in oscillatory Alpha activity, which was followed by enhanced processing of the subsequent Stroop stimulus. In addition, similar modulations of preparatory neural activity (larger CNVs and reduced Alpha) predicted shorter versus longer response times (RTs) to the subsequent target stimulus, consistent with such modulations reflecting trial-to-trial variations in attention. Particularly striking were the individual differences in the utilization of reward-prospect information. In particular, the size of the reward effects on the preparatory neural activity correlated across participants with the degree to which reward-prospect both facilitated overall task performance (shorter RTs) and reduced conflict-related behavioral interference. Thus, the prospect of reward appears to recruit attentional preparation circuits to enhance processing of task-relevant target information.

Utilization of reward-prospect enhances preparatory attention and reduces stimulus conflict

PubMed Central

van den Berg, Berry; Krebs, Ruth M.; Lorist, Monicque M.; Woldorff, Marty G.

2015-01-01

The prospect of gaining money is an incentive widely at play in the real world. Such monetary motivation might have particularly strong influence when the cognitive system is challenged, such as when needing to process conflicting stimulus inputs. Here, we employed manipulations of reward-prospect and attentional-preparation levels in a cued-Stroop stimulus-conflict task, along with the high temporal resolution of electrical brain recordings, to provide insight into the mechanisms by which reward-prospect and attention interact and modulate cognitive-task performance. In this task the cue indicated whether or not the subject needed to prepare for an upcoming Stroop stimulus, and if so, whether there was the potential for monetary reward (dependent on performance on that trial). Both cued-attention and cued-reward-prospect enhanced preparatory neural activity, as reflected by increases in the hallmark attention-related negative-polarity ERP slow wave (CNV) and reductions in oscillatory Alpha activity, which was followed by enhanced processing of the subsequent Stroop stimulus. In addition, similar modulations of preparatory neural activity (larger CNVs and reduced Alpha) predicted faster versus slower response times (RTs) to the subsequent target stimulus, consistent with such modulations reflecting trial-to-trial variations in attention. Particularly striking were the individual differences in the utilization of reward-prospect information. In particular, the size of the reward effects on the preparatory neural activity correlated across-subjects with the degree to which reward-prospect both facilitated overall task performance (faster RTs) and reduced conflict-related behavioral interference. Thus, the prospect of reward appears to recruit attentional preparation circuits to enhance processing of task-relevant target information. PMID:24820263

Attentional cueing: fearful body postures capture attention with saccades.

PubMed

Bannerman, Rachel L; Milders, Maarten; Sahraie, Arash

2010-05-01

According to theories of attention and emotion, threat-related stimuli (e.g., negative facial expressions) capture and hold attention. Despite these theories, previous examination of attentional cueing by threat showed no enhanced capture at brief durations. One explanation for the absence of attentional capture effects may be related to the sensitivity of the manual response measure employed. Here we extended beyond facial expressions and investigated the time course of orienting attention towards fearful body postures in the exogenous cueing task. Cue duration (20, 40, 60, or 100 ms), orientation (upright or inverted), and response mode (saccadic eye movement or manual keypress) were manipulated across three experiments. In the saccade mode, both enhanced attentional capture and impaired disengagement from fearful bodies were evident and limited to rapid cue durations (20 and 40 ms), suggesting that saccadic cueing effects emerge rapidly and are short lived. In the manual mode, fearful bodies impacted only upon the disengagement component of attention at 100 ms, suggesting that manual cueing effects emerge over longer periods of time. No cueing modulation was found for inverted presentation, suggesting that valence, not low-level image confounds, was responsible for the cueing effects. Importantly, saccades could reveal threat biases at brief cue durations consistent with current theories of emotion and attention.

Loop gain stabilizing with an all-digital automatic-gain-control method for high-precision fiber-optic gyroscope.

PubMed

Zheng, Yue; Zhang, Chunxi; Li, Lijing; Song, Lailiang; Chen, Wen

2016-06-10

For a fiber-optic gyroscope (FOG) using electronic dithers to suppress the dead zone, without a fixed loop gain, the deterministic compensation for the dither signals in the control loop of the FOG cannot remain accurate, resulting in the dither residuals in the FOG rotation rate output and the navigation errors in the inertial navigation system. An all-digital automatic-gain-control method for stabilizing the loop gain of the FOG is proposed. By using a perturbation square wave to measure the loop gain of the FOG and adding an automatic gain control loop in the conventional control loop of the FOG, we successfully obtain the actual loop gain and make the loop gain converge to the reference value. The experimental results show that in the case of 20% variation in the loop gain, the dither residuals are successfully eliminated and the standard deviation of the FOG sampling outputs is decreased from 2.00  deg/h to 0.62  deg/h (sampling period 2.5 ms, 10 points smoothing). With this method, the loop gain of the FOG can be stabilized over the operation temperature range and in the long-time application, which provides a solid foundation for the engineering applications of the high-precision FOG.

Attention and memory evaluation across the life span: heterogeneous effects of age and education.

PubMed

Gómez-Pérez, Esther; Ostrosky-Solís, Feggy

2006-05-01

The developmental sequences of attention and memory were studied by utilizing normative data derived from the neuropsychological battery named NEUROPSI ATTENTION AND MEMORY. A sample of 521 Spanish-speaking individuals, aged 6 to 85 years, participated in this study. In the adult sample, educational level ranged from 0 to 22 years of education. Data from subtests measuring orientation, attention and concentration, executive functions, working memory, immediate and delayed verbal memory, and immediate and delayed visual memory were included. The factor structure of the analyzed battery is presented. The effects of age and education on this structure were analyzed. Results suggested that although attention and memory are related, their developmental sequences are separated from one another. During childhood, the development of selective and sustained attention, attentional-working memory, and executive functions showed a fast improvement in performance. Development of verbal memory and place and person orientation showed a slower increment in scores. In the adult sample it was found that factors related to memory are sensitive to age, whereas those related to attention and executive functions are sensitive to education. The consideration of both the developmental sequence, as well as differential effects of education, can improve the sensitivity and specificity of neuropsychological measures, allowing early diagnosis of cognitive dysfunction and implementation of adequate rehabilitation programs.

Maternal pre-pregnancy obesity and gestational weight gain influence neonatal neurobehaviour.

PubMed

Aubuchon-Endsley, Nicki; Morales, Monique; Giudice, Christina; Bublitz, Margaret H; Lester, Barry M; Salisbury, Amy L; Stroud, Laura R

2017-04-01

Maternal weight before and during pregnancy is associated with offspring neurobehaviour in childhood. We investigated maternal weight prior to and during pregnancy in relation to neonatal neurobehaviour. We hypothesized that maternal obesity and excessive gestational weight gain would be associated with poor neonatal attention and affective functioning. Participants (n = 261) were recruited, weighed and interviewed during their third trimester of pregnancy. Pre-pregnancy weight was self-reported and validated for 210 participants, with robust agreement with medical chart review (r = 0.99). Neurobehaviour was measured with the NICU Network Neurobehavioural Scale (NNNS) administered on Days 2 and 32 postpartum. Maternal exclusion criteria included severe or persistent physical or mental health conditions (e.g. chronic disease or diagnoses of Bipolar Disorder or Psychotic Spectrum Disorders), excessive substance use, and social service/foster care involvement or difficulty understanding English. Infants were from singleton, full-term (37-42 weeks gestation) births with no major medical concerns. Outcome variables were summary scores on the NNNS (n = 75-86). For women obese prior to pregnancy, those gaining in excess of Institute of Medicine guidelines had infants with poorer regulation, lower arousal and higher lethargy. There were no main effects of maternal pre-pregnancy body mass index on neurobehaviour. Women gaining above Institute of Medicine recommendations had neonates with better quality of movement. Additional studies to replicate and extend results past the neonatal period are needed. Results could support underlying mechanisms explaining associations between maternal perinatal weight and offspring outcomes. These mechanisms may inform future prevention/intervention strategies. © 2016 Blackwell Publishing Ltd. © 2016 Blackwell Publishing Ltd.

Kids, Candy, Brain and Behavior: Age Differences in Responses to Candy Gains and Losses

PubMed Central

Luking, Katherine R; Luby, Joan; Barch, Deanna M

2014-01-01

The development of reward-related neural systems, from adolescence through adulthood, has received much recent attention in the developmental neuroimaging literature. However, few studies have investigated behavioral and neural responses to both gains and losses in pre-pubertal child populations. To address this gap in the literature, in the present study healthy children aged 7–11 years and young-adults completed an fMRI card-guessing game using candy pieces delivered post-scan as an incentive. Age differences in behavioral and neural responses to candy gains/losses were investigated. Adults and children displayed similar responses to gains, but robust age differences were observed following candy losses within the caudate, thalamus, insula, and hippocampus. Interestingly, when task behavior was included as a factor in post-hoc mediation analyses, activation following loss within the caudate/thalamus related to task behavior and relationships with age were no longer significant. Conversely, relationships between response to loss and age within the hippocampus and insula remained significant even when controlling for behavior, with children showing heightened loss responses within the dorsal/posterior insula. These results suggest that both age and task behavior influence responses within the extended reward circuitry, and that children seem to be more sensitive than adults to loss feedback particularly within the dorsal/posterior insula. PMID:24534632

Weight gain following treatment of hyperthyroidism.

PubMed

Dale, J; Daykin, J; Holder, R; Sheppard, M C; Franklyn, J A

2001-08-01

Patients frequently express concern that treating hyperthyroidism will lead to excessive weight gain. This study aimed to determine the extent of, and risk factors for, weight gain in an unselected group of hyperthyroid patients. We investigated 162 consecutive hyperthyroid patients followed for at least 6 months. Height, weight, clinical features, biochemistry and management were recorded at each clinic visit. Documented weight gain was 5.42 +/- 0.46 kg (mean +/- SE) and increase in BMI was 8.49 +/- 0.71%, over a mean 24.2 +/- 1.6 months. Pre-existing obesity, Graves' disease causing hyperthyroidism, weight loss before presentation and length of follow-up each independently predicted weight gain. Patients treated with thionamides or radioiodine gained a similar amount of weight (thionamides, n = 87, 5.16 +/- 0.63 kg vs. radioiodine, n = 62, 4.75 +/- 0.57 kg, P = 0.645), but patients who underwent thyroidectomy (n = 13) gained more weight (10.27 +/- 2.56 kg vs. others, P = 0.007). Development of hypothyroidism (even transiently) was associated with weight gain (never hypothyroid, n = 102, 4.57 +/- 0.52 kg, transiently hypothyroid, n = 29, 5.37 +/- 0.85 kg, on T4, n = 31, 8.06 +/- 1.42 kg, P = 0.014). This difference remained after correcting for length of follow-up. In the whole cohort, weight increased by 3.95 +/- 0.40 kg at 1 year (n = 144) to 9.91 +/- 1.62 kg after 4 years (n = 27) (P = 0.008), representing a mean weight gain of 3.66 +/- 0.44 kg/year. We have demonstrated marked weight gain after treatment of hyperthyroidism. Pre-existing obesity, a diagnosis of Graves' disease and prior weight loss independently predicted weight gain and weight continued to rise with time. Patients who became hypothyroid, despite T4 replacement, gained most weight.

IMAGES: A digital computer program for interactive modal analysis and gain estimation for eigensystem synthesis

NASA Technical Reports Server (NTRS)

Jones, R. L.

1984-01-01

An interactive digital computer program for modal analysis and gain estimation for eigensystem synthesis was written. Both mathematical and operation considerations are described; however, the mathematical presentation is limited to those concepts essential to the operational capability of the program. The program is capable of both modal and spectral synthesis of multi-input control systems. It is user friendly, has scratchpad capability and dynamic memory, and can be used to design either state or output feedback systems.

Study of gain-coupled distributed feedback laser based on high order surface gain-coupled gratings

NASA Astrophysics Data System (ADS)

Gao, Feng; Qin, Li; Chen, Yongyi; Jia, Peng; Chen, Chao; Cheng, LiWen; Chen, Hong; Liang, Lei; Zeng, Yugang; Zhang, Xing; Wu, Hao; Ning, Yongqiang; Wang, Lijun

2018-03-01

Single-longitudinal-mode, gain-coupled distributed feedback (DFB) lasers based on high order surface gain-coupled gratings are achieved. Periodic surface metal p-contacts with insulated grooves realize gain-coupled mechanism. To enhance gain contrast in the quantum wells without the introduction of effective index-coupled effect, groove length and depth were well designed. Our devices provided a single longitudinal mode with the maximum CW output power up to 48.8 mW/facet at 971.31 nm at 250 mA without facet coating, 3dB linewidth (<3.2 pm) and SMSR (>39 dB). Optical bistable characteristic was observed with a threshold current difference. Experimentally, devices with different cavity lengths were contrasted on power-current and spectrum characteristics. Due to easy fabrication technique and stable performance, it provides a method of fabricating practical gain-coupled distributed feedback lasers for commercial applications.

Space Tourism: Orbital Debris Considerations

NASA Astrophysics Data System (ADS)

Mahmoudian, N.; Shajiee, S.; Moghani, T.; Bahrami, M.

2002-01-01

Space activities after a phase of research and development, political competition and national prestige have entered an era of real commercialization. Remote sensing, earth observation, and communication are among the areas in which this growing industry is facing competition and declining government money. A project like International Space Station, which draws from public money, has not only opened a window of real multinational cooperation, but also changed space travel from a mere fantasy into a real world activity. Besides research activities for sending man to moon and Mars and other outer planets, space travel has attracted a considerable attention in recent years in the form of space tourism. Four countries from space fairing nations are actively involved in the development of space tourism. Even, nations which are either in early stages of space technology development or just beginning their space activities, have high ambitions in this area. This is worth noting considering their limited resources. At present, trips to space are available, but limited and expensive. To move beyond this point to generally available trips to orbit and week long stays in LEO, in orbital hotels, some of the required basic transportations, living requirements, and technological developments required for long stay in orbit are already underway. For tourism to develop to a real everyday business, not only the price has to come down to meaningful levels, but also safety considerations should be fully developed to attract travelers' trust. A serious hazard to space activities in general and space tourism in particular is space debris in earth orbit. Orbiting debris are man-made objects left over by space operations, hazardous to space missions. Since the higher density of debris population occurs in low earth orbit, which is also the same orbit of interest to space tourism, a careful attention should be paid to the effect of debris on tourism activities. In this study, after a

Effective connectivity of ascending and descending frontal-thalamic pathways during sustained attention: Complex brain network interactions in adolescence

PubMed Central

Jagtap, Pranav; Diwadkar, Vaibhav A.

2016-01-01

Frontal-thalamic interactions are crucial for bottom-up gating and top-down control, yet have not been well studied from brain network perspectives. We applied network modeling of fMRI signals (Dynamic Causal Modeling; DCM) to investigate frontal-thalamic interactions during an attention task with parametrically varying levels of demand. fMRI was collected while subjects participated in a sustained continuous performance task with low and high attention demands. 162 competing model architectures were employed in DCM to evaluate hypotheses on bilateral frontal-thalamic connections and their modulation by attention demand, selected at a second level using Bayesian Model Selection. The model architecture evinced significant contextual modulation by attention of ascending (thalamus → dPFC) and descending (dPFC → thalamus) pathways. However, modulation of these pathways was asymmetric: While positive modulation of the ascending pathway was comparable across attention demand, modulation of the descending pathway was significantly greater when attention demands were increased. Increased modulation of the (dPFC → thalamus) pathway in response to increased attention demand constitutes novel evidence of attention-related gain in the connectivity of the descending attention pathway. By comparison demand-independent modulation of the ascending (thalamus → dPFC) pathway suggests unbiased thalamic inputs to the cortex in the context of the paradigm. PMID:27145923

Optical gain in colloidal quantum dots achieved with direct-current electrical pumping

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

Lim, Jaehoon; Park, Young-Shin; Klimov, Victor Ivanovich

Chemically synthesized semiconductor quantum dots (QDs) can potentially enable solution-processable laser diodes with a wide range of operational wavelengths, yet demonstrations of lasing from the QDs are still at the laboratory stage. An important challenge—realization of lasing with electrical injection—remains unresolved, largely due to fast nonradiative Auger recombination of multicarrier states that represent gain-active species in the QDs. Here in this paper, we present population inversion and optical gain in colloidal nanocrystals realized with direct-current electrical pumping. Using continuously graded QDs, we achieve a considerable suppression of Auger decay such that it can be outpaced by electrical injection. Further, wemore » apply a special current-focusing device architecture, which allows us to produce high current densities (j) up to ~18 A cm -2 without damaging either the QDs or the injection layers. The quantitative analysis of electroluminescence and current-modulated transmission spectra indicates that with j = 3-4 A cm -2 we achieve the population inversion of the band-edge states.« less

Optical gain in colloidal quantum dots achieved with direct-current electrical pumping

DOE PAGES

Lim, Jaehoon; Park, Young-Shin; Klimov, Victor Ivanovich

2017-11-20

Chemically synthesized semiconductor quantum dots (QDs) can potentially enable solution-processable laser diodes with a wide range of operational wavelengths, yet demonstrations of lasing from the QDs are still at the laboratory stage. An important challenge—realization of lasing with electrical injection—remains unresolved, largely due to fast nonradiative Auger recombination of multicarrier states that represent gain-active species in the QDs. Here in this paper, we present population inversion and optical gain in colloidal nanocrystals realized with direct-current electrical pumping. Using continuously graded QDs, we achieve a considerable suppression of Auger decay such that it can be outpaced by electrical injection. Further, wemore » apply a special current-focusing device architecture, which allows us to produce high current densities (j) up to ~18 A cm -2 without damaging either the QDs or the injection layers. The quantitative analysis of electroluminescence and current-modulated transmission spectra indicates that with j = 3-4 A cm -2 we achieve the population inversion of the band-edge states.« less

Optimization of control gain by operator adjustment

NASA Technical Reports Server (NTRS)

Kruse, W.; Rothbauer, G.

1973-01-01

An optimal gain was established by measuring errors at 5 discrete control gain settings in an experimental set-up consisting of a 2-dimensional, first-order pursuit tracking task performed by subjects (S's). No significant experience effect on optimum gain setting was found in the first experiment. During the second experiment, in which control gain was continuously adjustable, high experienced S's tended to reach the previously determined optimum gain quite accurately and quickly. Less experienced S's tended to select a marginally optimum gain either below or above the experimentally determined optimum depending on initial control gain setting, although mean settings of both groups were equal. This quick and simple method is recommended for selecting control gains for different control systems and forcing functions.

Some Considerations on the Dynamics of Nanometric Suspensions in Fluid Media

NASA Astrophysics Data System (ADS)

Lungu, Mihai; Neculae, Adrian; Bunoiu, Madalin

2009-05-01

Nano-sized particles received considerable interest in the last decade. The manipulation of nanoparticles is becoming an important issue as they are more and more produced as a result of material synthesis and combustion emission. The nanometric particles represent a very important threat for human health because they can readily enter the human body through inhalation and their toxicity is relatively high due to the large specific surface area. The separation of the nano-sized particles into distinct bands, spatially separated one of each other had also brought recently considerable attention in many scientific areas; the usages of nanoparticles are very promising for the new technologies. The behavior of a suspension of sub-micronic particles under the action of dielectrophoretic force is numerically investigated and a theoretical model is proposed.

Considerations and caveats in anti-virulence drug development

PubMed Central

Maura, Damien; Ballok, Alicia E.; Rahme, Laurence G.

2016-01-01

As antibiotic resistance remains a major public health threat, anti-virulence therapy research is gaining interest. Hundreds of potential anti-virulence compounds have been examined, but very few have made it to clinical trials and none have been approved. This review surveys the current anti-virulence research field with a focus on the highly resistant and deadly ESKAPE pathogens, especially Pseudomonas aeruginosa. We discuss timely considerations and caveats in anti-virulence drug development, including target identification, administration, preclinical development, and metrics for success in clinical trials. Development of a defined pipeline for anti-virulence agents, which differs in important ways from conventional antibiotics, is imperative for the future success of these critically needed drugs. PMID:27318551

Optical antenna gain. I - Transmitting antennas

NASA Technical Reports Server (NTRS)

Klein, B. J.; Degnan, J. J.

1974-01-01

The gain of centrally obscured optical transmitting antennas is analyzed in detail. The calculations, resulting in near- and far-field antenna gain patterns, assume a circular antenna illuminated by a laser operating in the TEM-00 mode. A simple polynomial equation is derived for matching the incident source distribution to a general antenna configuration for maximum on-axis gain. An interpretation of the resultant gain curves allows a number of auxiliary design curves to be drawn that display the losses in antenna gain due to pointing errors and the cone angle of the beam in the far field as a function of antenna aperture size and its central obscuration. The results are presented in a series of graphs that allow the rapid and accurate evaluation of the antenna gain which may then be substituted into the conventional range equation.

Short-term mindfulness intervention reduces the negative attentional effects associated with heavy media multitasking.

PubMed

Gorman, Thomas E; Green, C Shawn

2016-04-18

Recent research suggests that frequently switching between various forms of media (i.e. 'media multitasking') is associated with diminished attentional abilities, a disconcerting result given the prevalence of media multitasking in today's society. In the present study, we sought to investigate the extent to which the deficits associated with frequent media multitasking can be temporarily ameliorated via a short-term mindfulness intervention previously shown to produce beneficial effects on the attentional abilities of normally functioning individuals. Consistent with previous work, we found: (1) that heavy media multitaskers showed generally poorer attentional abilities than light media multitaskers and (2) that all participants showed benefits from the short-term mindfulness intervention. Furthermore, we found that the benefits of the short-term mindfulness intervention were not equivalently large across participants. Instead, these benefits were disproportionately large in the heavy media multitaskers. While the positive outcomes were short-lived, this opens the possibility of performing long-term interventions with the goal of realizing lasting gains in this population.

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.

Using Survival Analysis to Improve Estimates of Life Year Gains in Policy Evaluations.

PubMed

Meacock, Rachel; Sutton, Matt; Kristensen, Søren Rud; Harrison, Mark

2017-05-01

Policy evaluations taking a lifetime horizon have converted estimated changes in short-term mortality to expected life year gains using general population life expectancy. However, the life expectancy of the affected patients may differ from the general population. In trials, survival models are commonly used to extrapolate life year gains. The objective was to demonstrate the feasibility and materiality of using parametric survival models to extrapolate future survival in health care policy evaluations. We used our previous cost-effectiveness analysis of a pay-for-performance program as a motivating example. We first used the cohort of patients admitted prior to the program to compare 3 methods for estimating remaining life expectancy. We then used a difference-in-differences framework to estimate the life year gains associated with the program using general population life expectancy and survival models. Patient-level data from Hospital Episode Statistics was utilized for patients admitted to hospitals in England for pneumonia between 1 April 2007 and 31 March 2008 and between 1 April 2009 and 31 March 2010, and linked to death records for the period from 1 April 2007 to 31 March 2011. In our cohort of patients, using parametric survival models rather than general population life expectancy figures reduced the estimated mean life years remaining by 30% (9.19 v. 13.15 years, respectively). However, the estimated mean life year gains associated with the program are larger using survival models (0.380 years) compared to using general population life expectancy (0.154 years). Using general population life expectancy to estimate the impact of health care policies can overestimate life expectancy but underestimate the impact of policies on life year gains. Using a longer follow-up period improved the accuracy of estimated survival and program impact considerably.

Relations between the Test of Variables of Attention (TOVA) and the Children's Memory Scale (CMS).

PubMed

Riccio, Cynthia A; Garland, Beth H; Cohen, Morris J

2007-09-01

There is considerable overlap in the constructs of attention and memory. The objective of this study was to examine the relationship between the Test of Variables of Attention (TOVA), a measure of attention, to components of memory and learning as measured by the Children's Memory Scale (CMS). Participants (N = 105) were consecutive referrals to an out-patient facility, generally for learning or behavior problems, who were administered both the TOVA and the CMS. Significant correlations were found between the omissions score on the TOVA and subscales of the CMS. TOVA variability and TOVA reaction time correlated significantly with subscales of the CMS as well. TOVA commission errors did not correlate significantly with any CMS Index. Although significant, the correlation coefficients indicate that the CMS and TOVA are measuring either different constructs or similar constructs but in different ways. As such, both measures may be useful in distinguishing memory from attention problems.

Space-based visual attention: a marker of immature selective attention in toddlers?

PubMed

Rivière, James; Brisson, Julie

2014-11-01

Various studies suggested that attentional difficulties cause toddlers' failure in some spatial search tasks. However, attention is not a unitary construct and this study investigated two attentional mechanisms: location selection (space-based attention) and object selection (object-based attention). We investigated how toddlers' attention is distributed in the visual field during a manual search task for objects moving out of sight, namely the moving boxes task. Results show that 2.5-year-olds who failed this task allocated more attention to the location of the relevant object than to the object itself. These findings suggest that in some manual search tasks the primacy of space-based attention over object-based attention could be a marker of immature selective attention in toddlers. © 2014 Wiley Periodicals, Inc.

Using fitness parameters to evaluate three oilseed Brassicaceae species as potential oil crops in two contrasting environments

USDA-ARS?s Scientific Manuscript database

Thlaspi arvense and Camelina sativa have gained considerable attention as biofuel crops. But in some areas, these species, including C. microcarpa, are becoming rare weeds because of agriculture intensification. Including them as crops could guarantee their conservation in agricultural systems. The ...

Attention to Threats and Combat-Related Posttraumatic Stress Symptoms

PubMed Central

Wald, Ilan; Degnan, Kathryn A.; Gorodetsky, Elena; Charney, Dennis S.; Fox, Nathan A.; Fruchter, Eyal; Goldman, David; Lubin, Gad; Pine, Daniel S.; Bar-Haim, Yair

2015-01-01

Importance Combat places soldiers at risk for post-traumatic stress disorder (PTSD). The excessive rates of PTSD and other adjustment disorders in soldiers returning home make it imperative to identify risk and resilience factors that could be targeted by novel therapeutic treatments. Objective To investigate the interplay among attention to threat, combat exposure, and other risk factors for PTSD symptoms in soldiers deployed to combat. Design and Setting Longitudinal prospective study of Israeli Defense Force infantry soldiers carried out in 2008 through 2010. Repeated measurements during a 1-year period included baseline and predeployment data collected in training camps and deployment data collected in the combat theater. Participants Infantry soldiers (1085 men; mean age,18.8 years). Main Outcome Measures Postcombat PTSD symptoms. Results Soldiers developed threat vigilance during combat deployment, particularly when they were exposed to high-intensity combat, as indicated by faster response times to targets appearing at the location of threat relative to neutral stimuli (P < .001). Threat-related attention bias also interacted with combat exposure to predict risk for PTSD (P <.05). Bias toward threat at recruitment (P <.001) and bias away from threat just before deployment (P < .05) predicted postcombat PTSD symptoms. Moreover, these threat-related attention associations with PTSD were moderated by genetic and environmental factors, including serotonin transporter (5-HTTLPR) genotype. Conclusions and Relevance Combat exposure interacts with threat-related attention to place soldiers at risk for PTSD, and interactions with other risk factors account for considerable variance in PTSD vulnerability. Understanding these associations informs research on novel attention bias modification techniques and prevention of PTSD. PMID:23407816

Considerations When Including Students with Disabilities in Test Security Policies. NCEO Policy Directions. Number 23

ERIC Educational Resources Information Center

Lazarus, Sheryl; Thurlow, Martha

2015-01-01

Sound test security policies and procedures are needed to ensure test security and confidentiality, and to help prevent cheating. In this era when cheating on tests draws regular media attention, there is a need for thoughtful consideration of the ways in which possible test security measures may affect accessibility for some students with…

Gaining Insights on Nasopharyngeal Carcinoma Treatment Outcome Using Clinical Data Mining Techniques.

PubMed

Ghaibeh, A Ammar; Kasem, Asem; Ng, Xun Jin; Nair, Hema Latha Krishna; Hirose, Jun; Thiruchelvam, Vinesh

2018-01-01

The analysis of Electronic Health Records (EHRs) is attracting a lot of research attention in the medical informatics domain. Hospitals and medical institutes started to use data mining techniques to gain new insights from the massive amounts of data that can be made available through EHRs. Researchers in the medical field have often used descriptive statistics and classical statistical methods to prove assumed medical hypotheses. However, discovering new insights from large amounts of data solely based on experts' observations is difficult. Using data mining techniques and visualizations, practitioners can find hidden knowledge, identify interesting patterns, or formulate new hypotheses to be further investigated. This paper describes a work in progress on using data mining methods to analyze clinical data of Nasopharyngeal Carcinoma (NPC) cancer patients. NPC is the fifth most common cancer among Malaysians, and the data analyzed in this study was collected from three states in Malaysia (Kuala Lumpur, Sabah and Sarawak), and is considered to be the largest up-to-date dataset of its kind. This research is addressing the issue of cancer recurrence after the completion of radiotherapy and chemotherapy treatment. We describe the procedure, problems, and insights gained during the process.

X chromosome gain is related to increased androgen receptor expression in male breast cancer.

PubMed

Di Oto, Enrico; Biserni, Giovanni B; Varga, Zsuzsanna; Morandi, Luca; Cucchi, Maria C; Masetti, Riccardo; Foschini, Maria P

2018-05-25

X chromosome gain has been previously described in male breast cancer (MBC). Androgen receptor (AR) gene is located on X chromosome. The aim of this study was to investigate the role of the X chromosome gain in the development of MBC and its relation with AR gene copy number and expression.The X chromosome status was assessed in 66 cases of male invasive and in situ duct breast carcinoma, in 34 cases of gynecomastia associated with cancer, and in 11 cases of tumor-free gynecomastia. Cases were tested by fluorescence in situ hybridization (FISH) to assess the X chromosome status and AR amplification. AR expression was studied by immunohistochemistry (IHC). In addition, AR methylation status was assessed.X chromosome gain was observed in 74.7% of invasive duct carcinoma, in 20.6% of in situ duct carcinoma, and in 14.6% of gynecomastia when associated with cancer, while all cases of tumor-free gynecomastia showed wild X chromosome asset. AR gene copy number when increased paralleled the number of X chromosomes. AR IHC expression was observed in 100% of MBC tested. AR gene methylation status revealed low level or absence of methylation.These data suggest that X chromosome can play a role in the neoplastic transformation of male breast epithelium. X chromosome gain is paralleled by AR gene polysomy. Polysomic AR genes show low methylation levels and high AR protein expression on IHC. These data should be taken into consideration for MBC treatment planning.

Basic modelling of transport in 2D wave-mechanical nanodots and billiards with balanced gain and loss mediated by complex potentials

NASA Astrophysics Data System (ADS)

Berggren, Karl-Fredrik; Tellander, Felix; Yakimenko, Irina

2018-05-01

Non-Hermitian quantum mechanics with parity-time (PT) symmetry is presently gaining great interest, especially within the fields of photonics and optics. Here, we give a brief overview of low-dimensional semiconductor nanodevices using the example of a quantum dot with input and output leads, which are mimicked by imaginary potentials for gain and loss, and how wave functions, particle flow, coalescence of levels and associated breaking of PT symmetry may be analysed within such a framework. Special attention is given to the presence of exceptional points and symmetry breaking. Related features for musical string instruments and ‘wolf-notes’ are outlined briefly with suggestions for further experiments.

Effect of tone mapping operators on visual attention deployment

NASA Astrophysics Data System (ADS)

Narwaria, Manish; Perreira Da Silva, Matthieu; Le Callet, Patrick; Pepion, Romuald

2012-10-01

High Dynamic Range (HDR) images/videos require the use of a tone mapping operator (TMO) when visualized on Low Dynamic Range (LDR) displays. From an artistic intention point of view, TMOs are not necessarily transparent and might induce different behavior to view the content. In this paper, we investigate and quantify how TMOs modify visual attention (VA). To that end both objective and subjective tests in the form of eye-tracking experiments have been conducted on several still image content that have been processed by 11 different TMOs. Our studies confirm that TMOs can indeed modify human attention and fixation behavior significantly. Therefore our studies suggest that VA needs consideration for evaluating the overall perceptual impact of TMOs on HDR content. Since the existing studies so far have only considered the quality or aesthetic appeal angle, this study brings in a new perspective regarding the importance of VA in HDR content processing for visualization on LDR displays.

Attention without awareness: Attentional modulation of perceptual grouping without awareness.

PubMed

Lo, Shih-Yu

2018-04-01

Perceptual grouping is the process through which the perceptual system combines local stimuli into a more global perceptual unit. Previous studies have shown attention to be a modulatory factor for perceptual grouping. However, these studies mainly used explicit measurements, and, thus, whether attention can modulate perceptual grouping without awareness is still relatively unexplored. To clarify the relationship between attention and perceptual grouping, the present study aims to explore how attention interacts with perceptual grouping without awareness. The task was to judge the relative lengths of two centrally presented horizontal bars while a railway-shaped pattern defined by color similarity was presented in the background. Although the observers were unaware of the railway-shaped pattern, their line-length judgment was biased by that pattern, which induced a Ponzo illusion, indicating grouping without awareness. More importantly, an attentional modulatory effect without awareness was manifested as evident by the observer's performance being more often biased when the railway-shaped pattern was formed by an attended color than when it was formed by an unattended one. Also, the attentional modulation effect was shown to be dynamic, being more pronounced with a short presentation time than a longer one. The results of the present study not only clarify the relationship between attention and perceptual grouping but also further contribute to our understanding of attention and awareness by corroborating the dissociation between attention and awareness.

Gaining Momentum: How Media Influences Public Opinion To Push Civil-Military Decision Makers Into Formulating Foreign Policy

DTIC Science & Technology

2016-02-09

1 AIR WAR COLLEGE AIR UNIVERSITY GAINING MOMENTUM: HOW MEDIA INFLUENCES PUBLIC OPINION TO PUSH CIVIL-MILITARY DECISION MAKERS INTO...engagements from the past, evidence suggest the media or press does have an influence over public opinion, especially during times of war and humanitarian...changes and that leaders must take into consideration that public opinion and the media may provide a large amount of influence over how the nation

Visual attention.

PubMed

Evans, Karla K; Horowitz, Todd S; Howe, Piers; Pedersini, Roccardo; Reijnen, Ester; Pinto, Yair; Kuzmova, Yoana; Wolfe, Jeremy M

2011-09-01

A typical visual scene we encounter in everyday life is complex and filled with a huge amount of perceptual information. The term, 'visual attention' describes a set of mechanisms that limit some processing to a subset of incoming stimuli. Attentional mechanisms shape what we see and what we can act upon. They allow for concurrent selection of some (preferably, relevant) information and inhibition of other information. This selection permits the reduction of complexity and informational overload. Selection can be determined both by the 'bottom-up' saliency of information from the environment and by the 'top-down' state and goals of the perceiver. Attentional effects can take the form of modulating or enhancing the selected information. A central role for selective attention is to enable the 'binding' of selected information into unified and coherent representations of objects in the outside world. In the overview on visual attention presented here we review the mechanisms and consequences of selection and inhibition over space and time. We examine theoretical, behavioral and neurophysiologic work done on visual attention. We also discuss the relations between attention and other cognitive processes such as automaticity and awareness. WIREs Cogni Sci 2011 2 503-514 DOI: 10.1002/wcs.127 For further resources related to this article, please visit the WIREs website. Copyright © 2011 John Wiley & Sons, Ltd.

Conducting a qualitative child interview: methodological considerations.

PubMed

Kortesluoma, Riitta-Liisa; Hentinen, Maija; Nikkonen, Merja

2003-06-01

Studies of children have a long history, but the literature related to young children consists for the most part of studies on rather than with children and taking little account of what is regarded as significant and meaningful by children themselves. Researchers have relied almost exclusively on adults when collecting data about children's thoughts, feelings and experiences. Interviewing children, however, gives an opportunity to gain information about their subjective experiences. The purpose of this article is to illustrate the theoretical premises of child interviewing, as well as to describe some practical methodological solutions used during interviews. Factors that influence data gathered from children and strategies for taking these factors into consideration during the interview are also described. This paper is based on literature and the experience of one of the authors in interviewing children aged from 4 to 11 years about their experiences of pain. A consideration of literature dealing with the principles of child interviewing shows that there is surprisingly little guidance available on conversational methods involving children. The empirical and conceptual foundation for child interviewing is not very clear. Novice researchers especially may need recommendations about how to conduct a qualitative child interview. The method must suit both the purpose and the context.

The evaluation of a mass media campaign aimed at weight gain prevention among young Dutch adults.

PubMed

Wammes, Birgitte; Oenema, Anke; Brug, Johannes

2007-11-01

The objective was to evaluate a 3-year nationwide mass media campaign aimed at preventing weight gain. The campaign was aimed primarily at raising awareness of the importance of weight-gain prevention and bringing these issues to the attention of the Dutch public. Eleven serial, independent, cross-sectional, population-based telephone surveys were used to assess campaign awareness and impact (N ranged between 483 and 493 for each of the 11 surveys). The surveys were conducted before and after six campaign waves. Multiple linear and logistic regression analyses were used to test for trends over time and for differences among the surveys for campaign awareness, message recall, perceived body weight status, overweight-related risk perceptions, attitudes, perceived social support, self-efficacy expectations, and motivations for preventing weight gain. Campaign awareness ranged from 61% after the 1st campaign wave to 88.4% after the final wave. The campaign's television broadcasting activities were an important source of campaign awareness, from both the campaign's television commercials and television-based free publicity. Message recall ranged from 41.9% to 68.1%. Small positive differences were found in attitudes, perceived social support, and intentions for preventing weight gain. Additionally, the results suggest mixed effects on self-efficacy expectations and a negative effect on risk perception. The campaign resulted in high campaign awareness, especially as a result of television commercials and free publicity on television. The results suggest that the campaign was able to create more positive attitudes and motivation but lower risk perceptions and efficacy for preventing weight gain.

Optical antenna gain. III - The effect of secondary element support struts on transmitter gain

NASA Technical Reports Server (NTRS)

Klein, B. J.; Degnan, J. J.

1976-01-01

The effect of a secondary-element spider support structure on optical antenna transmitter gain is analyzed. An expression describing the influence of the struts on the axial gain, in both the near and far fields, is derived as a function of the number of struts and their width. It is found that, for typical systems, the struts degrade the on-axis gain by less than 0.4 dB, and the first side-lobe level is not increased significantly. Contour plots have also been included to show the symmetry of the far-field distributions for three- and four-support members.

High-gain magnetized inertial fusion.

PubMed

Slutz, Stephen A; Vesey, Roger A

2012-01-13

Magnetized inertial fusion (MIF) could substantially ease the difficulty of reaching plasma conditions required for significant fusion yields, but it has been widely accepted that the gain is not sufficient for fusion energy. Numerical simulations are presented showing that high-gain MIF is possible in cylindrical liner implosions based on the MagLIF concept [S. A. Slutz et al Phys. Plasmas 17, 056303 (2010)] with the addition of a cryogenic layer of deuterium-tritium (DT). These simulations show that a burn wave propagates radially from the magnetized hot spot into the surrounding much denser cold DT given sufficient hot-spot areal density. For a drive current of 60 MA the simulated gain exceeds 100, which is more than adequate for fusion energy applications. The simulated gain exceeds 1000 for a drive current of 70 MA.

Video photographic considerations for measuring the proximity of a probe aircraft with a smoke seeded trailing vortex

NASA Technical Reports Server (NTRS)

Childers, Brooks A.; Snow, Walter L.

1990-01-01

Considerations for acquiring and analyzing 30 Hz video frames from charge coupled device (CCD) cameras mounted in the wing tips of a Beech T-34 aircraft are described. Particular attention is given to the characterization and correction of optical distortions inherent in the data.

Perceptual Learning and Attention: Reduction of Object Attention Limitations with Practice

PubMed Central

Dosher, Barbara Anne; Han, Songmei; Lu, Zhong-Lin

2012-01-01

Perceptual learning has widely been claimed to be attention driven; attention assists in choosing the relevant sensory information and attention may be necessary in many cases for learning. In this paper, we focus on the interaction of perceptual learning and attention – that perceptual learning can reduce or eliminate the limitations of attention, or, correspondingly, that perceptual learning depends on the attention condition. Object attention is a robust limit on performance. Two attributes of a single attended object may be reported without loss, while the same two attributes of different objects can exhibit a substantial dual-report deficit due to the sharing of attention between objects. The current experiments document that this fundamental dual-object report deficit can be reduced, or eliminated, through perceptual learning that is partially specific to retinal location. This suggests that alternative routes established by practice may reduce the competition between objects for processing resources. PMID:19796653

[Attention deficit syndrome. Basic aspects of its diagnosis and treatment].

PubMed

Arriada-Mendicoa, N; Otero-Siliceo, E

The attention deficit syndrome is one of the commonest behavior disorders of infancy, although it is considerably underestimated. The aetiology of attention deficit syndrome is multifactorial since genetic, environmental, nutritional and psychosocial factors have been found to be associated with its development. Diagnosis depends mainly on the identification of behavior changes especially of inattention, impulsiveness and hyperactivity: it should be made at home and at school and based on the exclusion of severe organic and neurological disorders which also present initially with similar characteristics. Electrophysiological studies may be useful since multiple electroencephalographic changes have been reported, as have prolonged latency of III and V waves of brain stem evoked potentials, The best management requires educational therapy combined with controlled medical treatment. Use of stimulants should be carefully considered and the tricyclic drugs are preferably the first pharmacological option. Current findings regarding the repercussions of attention deficit syndrome in adults shows the need for early diagnosis and treatment of the condition so as to avoid severe personality disorders including antisocial and criminal behavior. It is essential that the parents and the child himself understand the condition in order to achieve satisfactory results of long term treatment.

Some design considerations for a synthetic aperture optical telescope array

NASA Astrophysics Data System (ADS)

Scott, P. W.

1984-01-01

Several design considerations inherent in the configuration of phased array transmission of multiwavelength laser beams are discussed. Attention is focused on the U.S.A.F. phased array (PHASAR) demonstration project, where problems have been encountered in dividing the beam(s), controlling the optical path differences between subapertures, and expanding individual beams.A piston-driven path length adjustment mechanism has been selected, along with an active control system and proven components for stability maintenance. The necessity of developing broadband, high reflectivity low phase shift coatings for the system mirrors is stressed.

A chaotic model of sustaining attention problem in attention deficit disorder

NASA Astrophysics Data System (ADS)

Baghdadi, G.; Jafari, S.; Sprott, J. C.; Towhidkhah, F.; Hashemi Golpayegani, M. R.

2015-01-01

The problem of keeping an attention level is one of the common symptoms of attention deficit disorder. Dopamine deficiency is introduced as one of the causes of this disorder. Based on some physiological facts about the attention control mechanism and chaos intermittency, a behavioral model is presented in this paper. This model represents the problem of undesired alternation of attention level, and can also suggest different valuable predictions about a possible cause of attention deficit disorder. The proposed model reveals that there is a possible interaction between different neurotransmitters which help the individual to adaptively inhibit the attention switching over time. The result of this study can be used to examine and develop a new practical and more appropriate treatment for the problem of sustaining attention.

The impact of dialogic book-sharing training on infant language and attention: a randomized controlled trial in a deprived South African community.

PubMed

Vally, Zahir; Murray, Lynne; Tomlinson, Mark; Cooper, Peter J

2015-08-01

Dialogic book-sharing is an interactive form of shared reading. It has been shown in high income countries (HICs) to be of significant benefit to child cognitive development. Evidence for such benefit in low and middle income countries (LMICs) is scarce, although a feasibility study of our own produced encouraging findings. Accordingly, we aimed to establish the impact on child language and attention of providing training in dialogic booksharing to carers of infants in an impoverished South African community. We conducted a randomized controlled trial in Khayelitsha, an informal settlement in South Africa. Mothers of infants aged between 14 and 16 months were recruited and randomized to either 8 weeks of manualized training in dialogic book-sharing or a no-intervention control group. Independent assessments were made of infant language and attention at baseline and following training. The trial was registered (ISRCTN39953901). Ninety one carer-infant dyads were recruited and randomized to the intervention group (n = 49) or the control group (n = 42), 82 (90%) of whom were available for follow-up assessments. On a standardized carer report of infant vocabulary, compared to those in the control group, carers who received the intervention reported a significantly greater increase in the number of words understood by their infants as well as a larger increase in the number of words that their infant understood and could vocalize. Intervention group children also showed substantially greater gains on a measure of sustained attention. In line with evidence from HICs, a dialogic book-sharing programme delivered to an impoverished South African sample was shown to be of considerable benefit to the development of child language and focussed attention. The training programme, which is simple and inexpensive to deliver, has the potential to benefit child cognitive development in LMIC contexts where such development is commonly compromised. © 2014 Association for Child

The problem of latent attentional capture: Easy visual search conceals capture by task-irrelevant abrupt onsets.

PubMed

Gaspelin, Nicholas; Ruthruff, Eric; Lien, Mei-Ching

2016-08-01

Researchers are sharply divided regarding whether irrelevant abrupt onsets capture spatial attention. Numerous studies report that they do and a roughly equal number report that they do not. This puzzle has inspired numerous attempts at reconciliation, none gaining general acceptance. The authors propose that abrupt onsets routinely capture attention, but the size of observed capture effects depends critically on how long attention dwells on distractor items which, in turn, depends critically on search difficulty. In a series of spatial cuing experiments, the authors show that irrelevant abrupt onsets produce robust capture effects when visual search is difficult, but not when search is easy. Critically, this effect occurs even when search difficulty varies randomly across trials, preventing any strategic adjustments of the attentional set that could modulate probability of capture by the onset cue. The authors argue that easy visual search provides an insensitive test for stimulus-driven capture by abrupt onsets: even though onsets truly capture attention, the effects of capture can be latent. This observation helps to explain previous failures to find capture by onsets, nearly all of which used an easy visual search. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The Problem of Latent Attentional Capture: Easy Visual Search Conceals Capture by Task-Irrelevant Abrupt Onsets

PubMed Central

Gaspelin, Nicholas; Ruthruff, Eric; Lien, Mei-Ching

2016-01-01

Researchers are sharply divided regarding whether irrelevant abrupt onsets capture spatial attention. Numerous studies report that they do and a roughly equal number report that they do not. This puzzle has inspired numerous attempts at reconciliation, none gaining general acceptance. We propose that abrupt onsets routinely capture attention, but the size of observed capture effects depends critically on how long attention dwells on distractor items which, in turn, depends critically on search difficulty. In a series of spatial cuing experiments, we show that irrelevant abrupt onsets produce robust capture effects when visual search is difficult, but not when search is easy. Critically, this effect occurs even when search difficulty varies randomly across trials, preventing any strategic adjustments of the attentional set that could modulate probability of capture by the onset cue. We argue that easy visual search provides an insensitive test for stimulus-driven capture by abrupt onsets: even though onsets truly capture attention, the effects of capture can be latent. This observation helps to explain previous failures to find capture by onsets, nearly all of which employed an easy visual search. PMID:26854530

Improving attention control in dysphoria through cognitive training: transfer effects on working memory capacity and filtering efficiency.

PubMed

Owens, Max; Koster, Ernst H W; Derakshan, Nazanin

2013-03-01

Impaired filtering of irrelevant information from working memory is thought to underlie reduced working memory capacity for relevant information in dysphoria. The current study investigated whether training-related gains in working memory performance on the adaptive dual n-back task could result in improved inhibitory function. Efficacy of training was monitored in a change detection paradigm allowing measurement of a sustained event-related potential asymmetry sensitive to working memory capacity and the efficient filtering of irrelevant information. Dysphoric participants in the training group showed training-related gains in working memory that were accompanied by gains in working memory capacity and filtering efficiency compared to an active control group. Results provide important initial evidence that behavioral performance and neural function in dysphoria can be improved by facilitating greater attentional control. Copyright © 2013 Society for Psychophysiological Research.

Individual differences in attention strategies during detection, fine discrimination, and coarse discrimination

PubMed Central

Hecker, Elizabeth A.; Serences, John T.; Srinivasan, Ramesh

2013-01-01

Interacting with the environment requires the ability to flexibly direct attention to relevant features. We examined the degree to which individuals attend to visual features within and across Detection, Fine Discrimination, and Coarse Discrimination tasks. Electroencephalographic (EEG) responses were measured to an unattended peripheral flickering (4 or 6 Hz) grating while individuals (n = 33) attended to orientations that were offset by 0°, 10°, 20°, 30°, 40°, and 90° from the orientation of the unattended flicker. These unattended responses may be sensitive to attentional gain at the attended spatial location, since attention to features enhances early visual responses throughout the visual field. We found no significant differences in tuning curves across the three tasks in part due to individual differences in strategies. We sought to characterize individual attention strategies using hierarchical Bayesian modeling, which grouped individuals into families of curves that reflect attention to the physical target orientation (“on-channel”) or away from the target orientation (“off-channel”) or a uniform distribution of attention. The different curves were related to behavioral performance; individuals with “on-channel” curves had lower thresholds than individuals with uniform curves. Individuals with “off-channel” curves during Fine Discrimination additionally had lower thresholds than those assigned to uniform curves, highlighting the perceptual benefits of attending away from the physical target orientation during fine discriminations. Finally, we showed that a subset of individuals with optimal curves (“on-channel”) during Detection also demonstrated optimal curves (“off-channel”) during Fine Discrimination, indicating that a subset of individuals can modulate tuning optimally for detection and discrimination. PMID:23678013

Legal, ethical and practical considerations in research involving nurses with dyslexia.

PubMed

Gillin, Nicola

2015-09-01

To discuss the legal, ethical and practical considerations in UK studies involving nurses with dyslexia and medication administration errors (MAEs). Nurses with dyslexia are a vulnerable population as they are susceptible to misrepresentation in research, especially that which involves a sensitive topic such as MAEs. Nurses with dyslexia may be particularly vulnerable to research that could exploit, implicate or attribute unsafe practice to them and their disability. Special consideration should be exercised when researching this population. Despite the potential for legal, ethical and practical issues, MAEs and nurses with dyslexia are under-researched areas and warrant further research. Benefits can be gained, not only by participants but also those with a vested interest in how best to support dyslexic nurses in clinical practice. Through effective design, risks can be identified and minimised, and the research made viable, ethically sound and ultimately beneficial to all those involved.

Attention-Deficit/Hyperactivity Disorder (ADHD) and Obesity: Update 2016.

PubMed

Cortese, Samuele; Tessari, Luca

2017-01-01

While psychiatric comorbidities of attention-deficit/hyperactivity disorder (ADHD) have been extensively explored, less attention has been paid to somatic conditions possibly associated with this disorder. However, mounting evidence in the last decade pointed to a possible significant association between ADHD and certain somatic conditions, including obesity. This papers provides an update of a previous systematic review on the relationship between obesity and ADHD (Cortese and Vincenzi, Curr Top Behav Neurosci 9:199-218, 2012), focusing on pertinent peer-reviewed empirical papers published since 2012. We conducted a systematic search in PubMed, Ovid, and Web of Knowledge databases (search dates: from January 1st, 2012, to July 16th, 2016). We retained a total of 41 studies, providing information on the prevalence of obesity in individuals with ADHD, focusing on the rates of ADHD in individuals with obesity, or reporting data useful to gain insight into possible mechanisms underlying the putative association between ADHD and obesity. Overall, over the past 4 years, an increasing number of studies have assessed the prevalence of obesity in individuals with ADHD or the rates of ADHD in patients with obesity. Although findings are mixed across individual studies, meta-analytic evidence shows a significant association between ADHD and obesity, regardless of possible confounding factors such as psychiatric comorbidities. An increasing number of studies have also addressed possible mechanisms underlying the link between ADHD and obesity, highlighting the role, among others, of abnormal eating patterns, sedentary lifestyle, and possible common genetic alterations. Importantly, recent longitudinal studies support a causal role of ADHD in contributing to weight gain. The next generation of studies in the field should explore if and to which extent the treatment of comorbid ADHD in individuals with obesity may lead to long-term weight loss, ultimately improving their

Dogs' (Canis familiaris) attention to human perception: Influence of breed groups and life experiences.

PubMed

Heberlein, Marianne T E; Turner, Dennis C; Manser, Marta B

2017-02-01

Attending to the perception of others may help individuals gaining information from conspecifics, or help in competitive situations. Dogs (Canis familiaris) are attentive to humans' signals and their attentional state. We investigated whether dogs of different breed groups differ in their ability to pay attention to human's perception, first according to the genetic relatedness between dog breeds, and second according to working style differences. Once dogs had learned to leave forbidden food on the floor, they were confronted with 2 food items to which only they had unrestricted visual access. The owners saw either none or 1 food item through a transparent barrier. Our results showed that dogs pay attention to the perception of humans, whereby differences between breed groups became obvious. Within different genetic groups, ancient and hunting type dogs performed similarly, they were more attentive to their owners' perception than shepherd and the mastiff type dogs. When comparing dogs classified according to their working style, independent workers and family dogs were attentive to the owner's perception, while cooperative workers seemed not. The dogs' choice could not be explained by a general or training induced preference for eating behind an opaque screen, or by an influence of the owner's possible intention to prevent the dog from taking the food item he could see. Our study confirms that dogs are attentive/sensitive to human's perception, but genetic and working style differences among the breeds, as well as dog sport experiences explain part of the variation seen in their performance. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Predicting Digital Informal Learning: An Empirical Study among Chinese University Students

ERIC Educational Resources Information Center

He, Tao; Zhu, Chang; Questier, Frederik

2018-01-01

Although the adoption of digital technology has gained considerable attention in higher education, currently research mainly focuses on implementation in formal learning contexts. Investigating what factors influence students' digital informal learning is still unclear and limited. To understand better university students' digital informal…

Experimental protocol for biodiesel production with isolation of alkenones as coproducts from commercial Isochrysis algal biomass

USDA-ARS?s Scientific Manuscript database

The need to replace petroleum fuels with alternatives from renewable and more environmentally sustainable sources is of growing importance. Biomass-derived biofuels have gained considerable attention in this regard, however first generation biofuels from edible crops like corn ethanol or soybean bio...

Reducing Inequality in Academic Success for Incoming College Students: A Randomized Trial of Growth Mindset and Belonging Interventions

ERIC Educational Resources Information Center

Broda, Michael; Yun, John; Schneider, Barbara; Yeager, David S.; Walton, Gregory M.; Diemer, Matthew

2018-01-01

Light-touch social psychological interventions have gained considerable attention for their potential to improve academic outcomes for underrepresented and/or disadvantaged students in postsecondary education. While findings from previous interventions have demonstrated positive effects for racial and ethnic minority and first-generation students…

Drench application of fish-derived protein hydrolysates affects lettuce growth, chlorophyll content, and gas exchange

USDA-ARS?s Scientific Manuscript database

The use of biostimulants to enhance crop production has gained considerable momentum because of its contribution to agroecological sustainability. Protein hydrolysates (PHs) are an important group of plant biostimulants that have received increasing attention in recent years due to their positive ef...

Determination of the STIS CCD Gain

NASA Astrophysics Data System (ADS)

Riley, Allyssa; Monroe, TalaWanda; Lockwood, Sean

2016-09-01

This report summarizes the analysis and absolute gain results of the STIS Cycle 23 special calibration program 14424 that was designed to measure the gain of amplifiers A, C and D at nominal gain settings of 1 and 4 e-/DN. We used the mean-variance technique and the results indicate a <3.5% change in the gain for amplifier D from when it was originally calculated pre-flight. We compared these values to previous measurements from Cycles 17 through 23. This report outlines the observations, methodology, and results of the mean-variance technique.

Measurement of Antenna Bore-Sight Gain

NASA Technical Reports Server (NTRS)

Fortinberry, Jarrod; Shumpert, Thomas

2016-01-01

The absolute or free-field gain of a simple antenna can be approximated using standard antenna theory formulae or for a more accurate prediction, numerical methods may be employed to solve for antenna parameters including gain. Both of these methods will result in relatively reasonable estimates but in practice antenna gain is usually verified and documented via measurements and calibration. In this paper, a relatively simple and low-cost, yet effective means of determining the bore-sight free-field gain of a VHF/UHF antenna is proposed by using the Brewster angle relationship.

IQ Gains and the Binet Decrements.

ERIC Educational Resources Information Center

Flynn, James R.

1984-01-01

Thorndike's Stanford-Binet data suggest that from 1932 to 1971-72 preschool children enjoyed greater IQ gains than older children, possibly due to the rise of television. Additional analysis indicated that gains were either due to sampling error or totally antedated 1947. Gains of 12 IQ points were found for Americans. (Author/EGS)

Safe mobility for elderly drivers--considerations based on expert and self-assessment.

PubMed

Broberg, Thomas; Dukic Willstrand, Tania

2014-05-01

To further understand the needs of the growing population of elderly drivers and create solutions for safe mobility it is important to understand the driving scenarios and aspects in day to day traffic that may be of challenge for this group. More so, individual differences in how drivers perceive their own driving ability may have an effect on how individuals limit their mobility and/or increase their exposure to risk situations, with a potential negative effect on safety. In this study two sets of assessments have been used in order to identify scenarios and aspects needing consideration in creating safe mobility for elderly drivers; an expert assessment using on-road driving together with assessments through semi structured in-depth interviews. This combination also enables categorisation of the drivers, comparing their own perception of their driving performance with the expert assessment based on actual on-road driving. Four different categories of drivers were identified: adequate (positive), over, under and adequate (negative) estimators. A number of important aspects were identified in the study. Adapting speed to the situation and driving too fast, especially on straight roads in the city, is one aspect. Seeking the attention of other road users at intersections and roundabouts is another important consideration identified. Awareness of difficulties related to speed adaptation and attention was low amongst all the driver categories. However, a difference in attitude was seen in the categories with a more humble and acceptant attitude amongst the adequate and under estimator groups, as compared to the over estimators suggesting that the aspect of attitudes is another important factor for consideration. Copyright © 2014 Elsevier Ltd. All rights reserved.

Audio-visual synchrony and feature-selective attention co-amplify early visual processing.

PubMed

Keitel, Christian; Müller, Matthias M

2016-05-01

Our brain relies on neural mechanisms of selective attention and converging sensory processing to efficiently cope with rich and unceasing multisensory inputs. One prominent assumption holds that audio-visual synchrony can act as a strong attractor for spatial attention. Here, we tested for a similar effect of audio-visual synchrony on feature-selective attention. We presented two superimposed Gabor patches that differed in colour and orientation. On each trial, participants were cued to selectively attend to one of the two patches. Over time, spatial frequencies of both patches varied sinusoidally at distinct rates (3.14 and 3.63 Hz), giving rise to pulse-like percepts. A simultaneously presented pure tone carried a frequency modulation at the pulse rate of one of the two visual stimuli to introduce audio-visual synchrony. Pulsed stimulation elicited distinct time-locked oscillatory electrophysiological brain responses. These steady-state responses were quantified in the spectral domain to examine individual stimulus processing under conditions of synchronous versus asynchronous tone presentation and when respective stimuli were attended versus unattended. We found that both, attending to the colour of a stimulus and its synchrony with the tone, enhanced its processing. Moreover, both gain effects combined linearly for attended in-sync stimuli. Our results suggest that audio-visual synchrony can attract attention to specific stimulus features when stimuli overlap in space.

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

PubMed

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 explains

Qualitative differences in the guidance of attention during single-color and multiple-color visual search: behavioral and electrophysiological evidence.

PubMed

Grubert, Anna; Eimer, Martin

2013-10-01

To find out whether attentional target selection can be effectively guided by top-down task sets for multiple colors, we measured behavioral and ERP markers of attentional target selection in an experiment where participants had to identify color-defined target digits that were accompanied by a single gray distractor object in the opposite visual field. In the One Color task, target color was constant. In the Two Color task, targets could have one of two equally likely colors. Color-guided target selection was less efficient during multiple-color relative to single-color search, and this was reflected by slower response times and delayed N2pc components. Nontarget-color items that were presented in half of all trials captured attention and gained access to working memory when participants searched for two colors, but were excluded from attentional processing in the One Color task. Results demonstrate qualitative differences in the guidance of attentional target selection between single-color and multiple-color visual search. They suggest that top-down attentional control can be applied much more effectively when it is based on a single feature-specific attentional template. PsycINFO Database Record (c) 2013 APA, all rights reserved.

[Attention and aging].

PubMed

Siéroff, Eric; Piquard, Ambre

2004-12-01

Due to progress in the cognitive theories in the last twenty years, the description of attentional deficits associated with normal or pathological aging has substantially improved. In this article, attentional deficits are presented according to Posner theory, which describes three sub-systems in a global network of attention: vigilance, selective attention, command. This theory not only characterizes the functions of these subsystems, but gives precise indications about their anatomical and neurochemical substrates. Several clinical tests can be described for each of these different subsystems. The main attentional deficits are presented in the second part of this paper: if some decline of the attentional command occurs in normal aging, a real deficit in this subsystem is found in most degenerative processes (frontotemporal dementia, Alzheimer and Parkinson diseases). Alzheimer disease is also frequently associated with a deficit of selective spatial attention, early in the evolution of the disease.

Kids, candy, brain and behavior: age differences in responses to candy gains and losses.

PubMed

Luking, Katherine R; Luby, Joan L; Barch, Deanna M

2014-07-01

The development of reward-related neural systems, from adolescence through adulthood, has received much recent attention in the developmental neuroimaging literature. However, few studies have investigated behavioral and neural responses to both gains and losses in pre-pubertal child populations. To address this gap in the literature, in the present study healthy children aged 7-11 years and young-adults completed an fMRI card-guessing game using candy pieces delivered post-scan as an incentive. Age differences in behavioral and neural responses to candy gains/losses were investigated. Adults and children displayed similar responses to gains, but robust age differences were observed following candy losses within the caudate, thalamus, insula, and hippocampus. Interestingly, when task behavior was included as a factor in post hoc mediation analyses, activation following loss within the caudate/thalamus related to task behavior and relationships with age were no longer significant. Conversely, relationships between response to loss and age within the hippocampus and insula remained significant even when controlling for behavior, with children showing heightened loss responses within the dorsal/posterior insula. These results suggest that both age and task behavior influence responses within the extended reward circuitry, and that children seem to be more sensitive than adults to loss feedback particularly within the dorsal/posterior insula. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Evidence-Based Considerations and Recommendations for Athletic Trainers Caring for Patients With Attention-Deficit/Hyperactivity Disorder.

PubMed

Wolfe, Elizabeth S; Madden, Kelly J

2016-10-01

Patients with attention-deficit/hyperactivity disorder (ADHD) can be noncompliant, impulsive, and disruptive in an athletic training or physical rehabilitation facility. Athletic trainers (ATs) are valuable and essential health care providers for active patients with ADHD. However, for a patient with ADHD to have a successful outcome in a busy athletic training environment, the AT or health care provider must tailor the treatment setting to the patient's needs. To educate and raise awareness among ATs about patients with ADHD and to provide ATs with strategies and tools that will allow them to treat patients with ADHD more effectively. We retrieved and reviewed articles from PubMed, PsychINFO, and Ovid without date restrictions. Search words were attention deficit hyperactivity disorder plus 1 of the following topics or search words: athletic training, athletics, coaching, sport, or sport psychology. Any ADHD articles that were not applicable or translatable in good faith to athletic training, physical rehabilitation, or sport and exercise were excluded. Nonpharmacologic interventions were reviewed and amassed into categories from which the recommendations were created. No statistical analyses were conducted for this review. We identified 1241 articles, and 86 met the inclusion criteria. Five groups of evidence were observed: (1) goal setting and coaching, (2) reinforcements and outcomes, (3) routines and treatment timing, (4) simplified feedback and instructions, and (5) environmental control. Reliable evidence suggests that these techniques can be translated and applied within an athletic training and physical rehabilitation setting. Athletic trainers are a vital component in providing health care for patients with ADHD. Using goal contagion creates a structured environment and positive reinforcements that accommodate patients with ADHD. Furthermore, ATs may use the evidence-based recommendations in this review to create a treatment and physical rehabilitation

Involuntary transfer of a top-down attentional set into the focus of attention: evidence from a contingent attentional capture paradigm.

PubMed

Moore, Katherine Sledge; Weissman, Daniel H

2010-08-01

In the present study, we investigated whether involuntarily directing attention to a target-colored distractor causes the corresponding attentional set to enter a limited-capacity focus of attention, thereby facilitating the identification of a subsequent target whose color matches the same attentional set. As predicted, in Experiment 1, contingent attentional capture effects from a target-colored distractor were only one half to one third as large when subsequent target identification relied on the same (vs. a different) attentional set. In Experiment 2, this effect was eliminated when all of the target colors matched the same attentional set, arguing against bottom-up perceptual priming of the distractor's color as an alternative account of our findings. In Experiment 3, this effect was reversed when a target-colored distractor appeared after the target, ruling out a feature-based interference account of our findings. We conclude that capacity limitations in working memory strongly influence contingent attentional capture when multiple attentional sets guide selection.

Effective connectivity of ascending and descending frontalthalamic pathways during sustained attention: Complex brain network interactions in adolescence.

PubMed

Jagtap, Pranav; Diwadkar, Vaibhav A

2016-07-01

Frontal-thalamic interactions are crucial for bottom-up gating and top-down control, yet have not been well studied from brain network perspectives. We applied network modeling of fMRI signals [dynamic causal modeling (DCM)] to investigate frontal-thalamic interactions during an attention task with parametrically varying levels of demand. fMRI was collected while subjects participated in a sustained continuous performance task with low and high attention demands. 162 competing model architectures were employed in DCM to evaluate hypotheses on bilateral frontal-thalamic connections and their modulation by attention demand, selected at a second level using Bayesian model selection. The model architecture evinced significant contextual modulation by attention of ascending (thalamus → dPFC) and descending (dPFC → thalamus) pathways. However, modulation of these pathways was asymmetric: while positive modulation of the ascending pathway was comparable across attention demand, modulation of the descending pathway was significantly greater when attention demands were increased. Increased modulation of the (dPFC → thalamus) pathway in response to increased attention demand constitutes novel evidence of attention-related gain in the connectivity of the descending attention pathway. By comparison demand-independent modulation of the ascending (thalamus → dPFC) pathway suggests unbiased thalamic inputs to the cortex in the context of the paradigm. Hum Brain Mapp 37:2557-2570, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

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

PubMed

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

2017-06-01

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. Copyright © 2017 Elsevier B.V. All rights reserved.

Selective attention and drug related attention bias in methadone maintenance patients.

PubMed

Nejati, Majid; Nejati, Vahid; Mohammadi, Mohammad Reza

2011-01-01

One of the main problems of the drug abusers is drug related attention bias, which causes craving, and as a result drive the drug abusers to take narcotics. Methadone is used as a maintenance treatment for drug abusers. The purpose of this study is evaluation of the effect of Methadone maintenance therapy (MMT) on selective attention and drug related attention bias. This study investigated drug cue-related attention bias and selective attention in 16 methadone-maintained patients before and 45 days after methadone therapy period. Stroop color-word test and addiction Stroop test were used as measurement methods. Results show less reaction time and higher accuracy in Color-Word Stroop Test after MMT and less delay for addict related word in addiction Stroop test. It is concluded that methadone can improve selective attention capability and reduce drug related attention bias.

Biofeedback-based self-alert training reduces alpha activity and stabilizes accuracy in the Sustained Attention to Response Task.

PubMed

Braun, Niclas; Debener, Stefan; Sölle, Ariane; Kranczioch, Cornelia; Hildebrandt, Helmut

2015-01-01

Deficits in sustaining attention are common in various organic brain diseases. A recent study proposed self-alert training (SAT) as a technique to improve sustained attention. In the SAT, individuals learn to gain volitional control over their own state of arousal by means of electrodermal biofeedback. In this study, we investigated the behavioral, electrodermal, and electroencephalogram correlates of the SAT with a blinded, randomized, and active-controlled pre-post study design. Sustained attention capacity was assessed with the Sustained Attention to Response Task (SART). The SAT resulted in strong phasic increases in skin conductance response (SCR), but endogenous control of SCR without feedback was problematic. Electroencephalogram analysis revealed stronger alpha reduction during SART for the SAT than for the control group. Behaviorally, the SAT group performed more accurately and more slowly after intervention than the control group. The study provides further evidence that SAT helps to maintain SART accuracy over prolonged periods of time. Whether this accuracy is more related to sustained attention or response inhibition is discussed.

Visual environment, attention allocation, and learning in young children: when too much of a good thing may be bad.

PubMed

Fisher, Anna V; Godwin, Karrie E; Seltman, Howard

2014-07-01

A large body of evidence supports the importance of focused attention for encoding and task performance. Yet young children with immature regulation of focused attention are often placed in elementary-school classrooms containing many displays that are not relevant to ongoing instruction. We investigated whether such displays can affect children's ability to maintain focused attention during instruction and to learn the lesson content. We placed kindergarten children in a laboratory classroom for six introductory science lessons, and we experimentally manipulated the visual environment in the classroom. Children were more distracted by the visual environment, spent more time off task, and demonstrated smaller learning gains when the walls were highly decorated than when the decorations were removed. © The Author(s) 2014.

Capture versus suppression of attention by salient singletons: electrophysiological evidence for an automatic attend-to-me signal.

PubMed

Sawaki, Risa; Luck, Steven J

2010-08-01

There is considerable controversy about whether salient singletons capture attention in a bottom-up fashion, irrespective of top-down control settings. One possibility is that salient singletons always generate an attention capture signal, but this signal can be actively suppressed to avoid capture. In the present study, we investigated this issue by using event-related potential recordings, focusing on N2pc (N2-posterior-contralateral; a measure of attentional deployment) and Pd (distractor positivity; a measure of attentional suppression). Participants searched for a specific letter within one of two regions, and irrelevant color singletons were sometimes present. We found that the irrelevant singletons did not elicit N2pc but instead elicited Pd; this occurred equally within the attended and unattended regions. These findings suggest that salient singletons may automatically produce an attend-to-me signal, irrespective of top-down control settings, but this signal can be overridden by an active suppression process to prevent the actual capture of attention.

Social Attention, Joint Attention and Sustained Attention in Autism Spectrum Disorder and Williams Syndrome: Convergences and Divergences

ERIC Educational Resources Information Center

Vivanti, Giacomo; Fanning, Peter A. J.; Hocking, Darren R.; Sievers, Stephanie; Dissanayake, Cheryl

2017-01-01

There is limited knowledge on shared and syndrome-specific attentional profiles in autism spectrum disorder (ASD) and Williams syndrome (WS). Using eye-tracking, we examined attentional profiles of 35 preschoolers with ASD, 22 preschoolers with WS and 20 typically developing children across social and non-social dimensions of attention. Children…

[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.

Deficient attention is hard to find: applying the perceptual load model of selective attention to attention deficit hyperactivity disorder subtypes.

PubMed

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

2005-11-01

Whether selective attention is a primary deficit in childhood Attention Deficit Hyperactivity Disorder (ADHD) remains in active debate. We used the perceptual load paradigm to examine both early and late selective attention in children with the Primarily Inattentive (ADHD-I) and Combined subtypes (ADHD-C) of ADHD. No evidence emerged for selective attention deficits in either of the subtypes, but sluggish cognitive tempo was associated with abnormal early selection. At least some, and possibly most, children with DSM-IV ADHD have normal selective attention. Results support the move away from theories of attention dysfunction as primary in ADHD-C. In ADHD-I, this was one of the first formal tests of posterior attention network dysfunction, and results did not support that theory. However, ADHD children with sluggish cognitive tempo (SCT) warrant more study for possible early selective attention deficits.

A weight-gain-for-gestational-age z score chart for the assessment of maternal weight gain in pregnancy.

PubMed

Hutcheon, Jennifer A; Platt, Robert W; Abrams, Barbara; Himes, Katherine P; Simhan, Hyagriv N; Bodnar, Lisa M

2013-05-01

To establish the unbiased relation between maternal weight gain in pregnancy and perinatal health, a classification for maternal weight gain is needed that is uncorrelated with gestational age. The goal of this study was to create a weight-gain-for-gestational-age percentile and z score chart to describe the mean, SD, and selected percentiles of maternal weight gain throughout pregnancy in a contemporary cohort of US women. The study population was drawn from normal-weight women with uncomplicated, singleton pregnancies who delivered at the Magee-Womens Hospital in Pittsburgh, PA, 1998-2008. Analyses were based on a randomly selected subset of 648 women for whom serial prenatal weight measurements were available through medical chart record abstraction (6727 weight measurements). The pattern of maternal weight gain throughout gestation was estimated by using a random-effects regression model. The estimates were used to create a chart with the smoothed means, percentiles, and SDs of gestational weight gain for each week of pregnancy. This chart allows researchers to express total weight gain as an age-standardized z score, which can be used in epidemiologic analyses to study the association between pregnancy weight gain and adverse or physiologic pregnancy outcomes independent of gestational age.

Exploring attentional biases towards facial expressions of pain in men and women.

PubMed

Keogh, E; Cheng, F; Wang, S

2018-05-14

Interpersonal factors may help explain why men and women differ in their perception and expression of pain. Whilst the focus is often on the person in pain, how observers respond to those in pain is important. This study explored whether male-female differences exist in the way observers attend to expressions of pain in others. Fifty-three adults (26 females) completed a visual dot-probe task, to measure selective attentional biases to facial expressions of pain and fear. Expression pairs (e.g. pain/neutral) were displayed by either the same male or female actor, and in two different viewing duration conditions: 150 and 1250 ms. Dot-probes appeared in either a congruent or incongruent location to the target expression. No evidence was found for sex-related attentional biases towards pain or fear. However, when examining congruency and incongruency indexes separately, differences emerged. The congruency index analysis indicated that in the 150-ms presentation condition, both men and women were slower during congruent female pain/neutral trials when compared to neutral/neutral trials, and relatively faster at responding during congruent male pain/neutral trials. There is utility in exploring the attentional processes involved in the decoding of pain-related expressions to understand the influence of sex and gender differences in pain. Although male-female differences were found, this was most clearly related to the actor. Our results point to an early attentional mechanism that orients attention away from female expressions of pain. Future consideration of sex- and gender-related contextual factors in attentional processing is warranted. Sex-related factors seem to affect how observers view the pain of others. Our results point to an early attentional mechanism that orients the attention of observers away from female expressions of pain. © 2018 European Pain Federation - EFIC®.

Charge Gain, Voltage Gain, and Node Capacitance of the SAPHIRA Detector Pixel by Pixel

NASA Astrophysics Data System (ADS)

Pastrana, Izabella M.; Hall, Donald N. B.; Baker, Ian M.; Jacobson, Shane M.; Goebel, Sean B.

2018-01-01

The University of Hawai`i Institute for Astronomy has partnered with Leonardo (formerly Selex) in the development of HgCdTe linear mode avalanche photodiode (L-APD) SAPHIRA detectors. The SAPHIRA (Selex Avalanche Photodiode High-speed Infra-Red Array) is ideally suited for photon-starved astronomical observations, particularly near infrared (NIR) adaptive optics (AO) wave-front sensing. I have measured the stability, and linearity with current, of a 1.7-um (10% spectral bandpass) infrared light emitting diode (IR LED) used to illuminate the SAPHIRA and have then utilized this source to determine the charge gain (in e-/ADU), voltage gain (in uV/ADU), and node capacitance (in fF) for each pixel of the 320x256@24um SAPHIRA. These have previously only been averages over some sub-array. Determined from the ratio of the temporal averaged signal level to variance under constant 1.7-um LED illumination, I present the charge gain pixel-by-pixel in a 64x64 sub-array at the center of the active area of the SAPHIRA (analyzed separately as four 32x32 sub-arrays) to be about 1.6 e-/ADU (σ=0.5 e-/ADU). Additionally, the standard technique of varying the pixel reset voltage (PRV) in 10 mV increments and recording output frames for the same 64x64 subarray found the voltage gain per pixel to be about 11.7 uV/ADU (σ=0.2 uV/ADU). Finally, node capacitance was found to be approximately 23 fF (σ=6 fF) utilizing the aforementioned charge and voltage gain measurements. I further discuss the linearity measurements of the 1.7-um LED used in the charge gain characterization procedure.

Effect of intermittent kangaroo mother care on weight gain of low birth weight neonates with delayed weight gain.

PubMed

Samra, Nashwa M; Taweel, Amal El; Cadwell, Karin

2013-01-01

To evaluate intermittent Kangaroo Mother Care (KMC) with additional opportunities to breastfeed on weight gain of low birth weight (LBW) neonates with delayed weight gain. 40 LBW neonates were followed to see whether KMC with additional opportunities to breastfeed improved weight gain. In the KMC group, the mean age of regaining birth weight was significantly less (15.68 vs. 24.56 days) and the average daily weight gain was significantly higher (22.09 vs. 10.39 g, p < .001) than controls. KMC with additional opportunities to breastfeed was found to be an effective intervention for LBWs with delayed weight gain and should be considered to be an effective strategy.

Measuring attention in very old adults using the Test of Everyday Attention.

PubMed

van der Leeuw, Guusje; Leveille, Suzanne G; Jones, Richard N; Hausdorff, Jeffrey M; McLean, Robert; Kiely, Dan K; Gagnon, Margaret; Milberg, William P

2017-09-01

There is a need for validated measures of attention for use in longitudinal studies of older populations. We studied 249 participants aged 80 to 101 years using the population-based MOBILIZE Boston Study. Four subscales of the Test of Everyday Attention (TEA) were included, measuring attention switching, selective, sustained and divided attention and a neuropsychological battery including validated measures of multiple cognitive domains measuring attention, executive function and memory. The TEA previously has not been validated in persons aged 80 and older. Among participants who completed the TEA, scores on other attentional measures strongly with TEA domains (R=.60-.70). Proportions of participants with incomplete TEA subscales ranged from 8% (selective attention) to 19% (attentional switching). Reasons for not completing TEA tests included failure to comprehend test instructions despite repetition and practice. These results demonstrate the challenges and potential value of the Test of Everyday Attention in studies of very old populations.

Computational Psychiatry of ADHD: Neural Gain Impairments across Marrian Levels of Analysis

PubMed Central

Hauser, Tobias U.; Fiore, Vincenzo G.; Moutoussis, Michael; Dolan, Raymond J.

2016-01-01

Attention-deficit hyperactivity disorder (ADHD), one of the most common psychiatric disorders, is characterised by unstable response patterns across multiple cognitive domains. However, the neural mechanisms that explain these characteristic features remain unclear. Using a computational multilevel approach, we propose that ADHD is caused by impaired gain modulation in systems that generate this phenotypic increased behavioural variability. Using Marr's three levels of analysis as a heuristic framework, we focus on this variable behaviour, detail how it can be explained algorithmically, and how it might be implemented at a neural level through catecholamine influences on corticostriatal loops. This computational, multilevel, approach to ADHD provides a framework for bridging gaps between descriptions of neuronal activity and behaviour, and provides testable predictions about impaired mechanisms. PMID:26787097

Cold-Blooded Attention: Finger Temperature Predicts Attentional Performance.

PubMed

Vergara, Rodrigo C; Moënne-Loccoz, Cristóbal; Maldonado, Pedro E

2017-01-01

Thermal stress has been shown to increase the chances of unsafe behavior during industrial and driving performances due to reductions in mental and attentional resources. Nonetheless, establishing appropriate safety standards regarding environmental temperature has been a major problem, as modulations are also be affected by the task type, complexity, workload, duration, and previous experience with the task. To bypass this attentional and thermoregulatory problem, we focused on the body rather than environmental temperature. Specifically, we measured tympanic, forehead, finger and environmental temperatures accompanied by a battery of attentional tasks. We considered a 10 min baseline period wherein subjects were instructed to sit and relax, followed by three attentional tasks: a continuous performance task (CPT), a flanker task (FT) and a counting task (CT). Using multiple linear regression models, we evaluated which variable(s) were the best predictors of performance. The results showed a decrement in finger temperature due to instruction and task engagement that was absent when the subject was instructed to relax. No changes were observed in tympanic or forehead temperatures, while the environmental temperature remained almost constant for each subject. Specifically, the magnitude of the change in finger temperature was the best predictor of performance in all three attentional tasks. The results presented here suggest that finger temperature can be used as a predictor of alertness, as it predicted performance in attentional tasks better than environmental temperature. These findings strongly support that peripheral temperature can be used as a tool to prevent unsafe behaviors and accidents.

Social Categorization on Perception Bias in the Practice of Microteaching

ERIC Educational Resources Information Center

Hong, Jon-Chao; Hwang, Ming-Yueh; Lu, Chow-Chin; Tsai, Chi-Ruei

2017-01-01

Microteaching has gained considerable attention for its effectiveness in rapid and contextual training in professional development programs. However, the interpretive quality of the teaching demonstration and peer feedback may influence individuals' attribution and self-correction, leading to ineffective learning. In this study, a microteaching…

Attentional load and attentional boost: a review of data and theory.

PubMed

Swallow, Khena M; Jiang, Yuhong V

2013-01-01

Both perceptual and cognitive processes are limited in capacity. As a result, attention is selective, prioritizing items and tasks that are important for adaptive behavior. However, a number of recent behavioral and neuroimaging studies suggest that, at least under some circumstances, increasing attention to one task can enhance performance in a second task (e.g., the attentional boost effect). Here we review these findings and suggest a new theoretical framework, the dual-task interaction model, that integrates these findings with current views of attentional selection. To reconcile the attentional boost effect with the effects of attentional load, we suggest that temporal selection results in a temporally specific enhancement across modalities, tasks, and spatial locations. Moreover, the effects of temporal selection may be best observed when the attentional system is optimally tuned to the temporal dynamics of incoming stimuli. Several avenues of research motivated by the dual-task interaction model are then discussed.

Attentional Load and Attentional Boost: A Review of Data and Theory

PubMed Central

Swallow, Khena M.; Jiang, Yuhong V.

2013-01-01

Both perceptual and cognitive processes are limited in capacity. As a result, attention is selective, prioritizing items and tasks that are important for adaptive behavior. However, a number of recent behavioral and neuroimaging studies suggest that, at least under some circumstances, increasing attention to one task can enhance performance in a second task (e.g., the attentional boost effect). Here we review these findings and suggest a new theoretical framework, the dual-task interaction model, that integrates these findings with current views of attentional selection. To reconcile the attentional boost effect with the effects of attentional load, we suggest that temporal selection results in a temporally specific enhancement across modalities, tasks, and spatial locations. Moreover, the effects of temporal selection may be best observed when the attentional system is optimally tuned to the temporal dynamics of incoming stimuli. Several avenues of research motivated by the dual-task interaction model are then discussed. PMID:23730294

Plasticity of visual attention in Isha yoga meditation practitioners before and after a 3-month retreat

PubMed Central

Braboszcz, Claire; Cahn, B. Rael; Balakrishnan, Bhavani; Maturi, Raj K.; Grandchamp, Romain; Delorme, Arnaud

2013-01-01

Meditation has lately received considerable interest from cognitive neuroscience. Studies suggest that daily meditation leads to long lasting attentional and neuronal plasticity. We present changes related to the attentional systems before and after a 3 month intensive meditation retreat. We used three behavioral psychophysical tests - a Stroop task, an attentional blink task, and a global-local letter task-to assess the effect of Isha yoga meditation on attentional resource allocation. 82 Isha yoga practitioners were tested at the beginning and at the end of the retreat. Our results showed an increase in correct responses specific to incongruent stimuli in the Stroop task. Congruently, a positive correlation between previous meditation experience and accuracy to incongruent Stroop stimuli was also observed at baseline. We also observed a reduction of the attentional blink. Unexpectedly, a negative correlation between previous meditation experience and attentional blink performance at baseline was observed. Regarding spatial attention orientation as assessed using the global-local letter task, participants showed a bias toward local processing. Only slight differences in performance were found pre- vs. post- meditation retreat. Biasing toward the local stimuli in the global-local task and negative correlation of previous meditation experience with attentional blink performance is consistent with Isha practices being focused-attention practices. Given the relatively small effect sizes and the absence of a control group, our results do not allow clear support nor rejection of the hypothesis of meditation-driven neuronal plasticity in the attentional system for Isha yoga practice. PMID:24376429

Top-Down Control of Visual Attention by the Prefrontal Cortex. Functional Specialization and Long-Range Interactions

PubMed Central

Paneri, Sofia; Gregoriou, Georgia G.

2017-01-01

The ability to select information that is relevant to current behavioral goals is the hallmark of voluntary attention and an essential part of our cognition. Attention tasks are a prime example to study at the neuronal level, how task related information can be selectively processed in the brain while irrelevant information is filtered out. Whereas, numerous studies have focused on elucidating the mechanisms of visual attention at the single neuron and population level in the visual cortices, considerably less work has been devoted to deciphering the distinct contribution of higher-order brain areas, which are known to be critical for the employment of attention. Among these areas, the prefrontal cortex (PFC) has long been considered a source of top-down signals that bias selection in early visual areas in favor of the attended features. Here, we review recent experimental data that support the role of PFC in attention. We examine the existing evidence for functional specialization within PFC and we discuss how long-range interactions between PFC subregions and posterior visual areas may be implemented in the brain and contribute to the attentional modulation of different measures of neural activity in visual cortices. PMID:29033784

Top-Down Control of Visual Attention by the Prefrontal Cortex. Functional Specialization and Long-Range Interactions.

PubMed

Paneri, Sofia; Gregoriou, Georgia G

2017-01-01

The ability to select information that is relevant to current behavioral goals is the hallmark of voluntary attention and an essential part of our cognition. Attention tasks are a prime example to study at the neuronal level, how task related information can be selectively processed in the brain while irrelevant information is filtered out. Whereas, numerous studies have focused on elucidating the mechanisms of visual attention at the single neuron and population level in the visual cortices, considerably less work has been devoted to deciphering the distinct contribution of higher-order brain areas, which are known to be critical for the employment of attention. Among these areas, the prefrontal cortex (PFC) has long been considered a source of top-down signals that bias selection in early visual areas in favor of the attended features. Here, we review recent experimental data that support the role of PFC in attention. We examine the existing evidence for functional specialization within PFC and we discuss how long-range interactions between PFC subregions and posterior visual areas may be implemented in the brain and contribute to the attentional modulation of different measures of neural activity in visual cortices.

Saccade preparation is required for exogenous attention but not endogenous attention or IOR.

PubMed

Smith, Daniel T; Schenk, Thomas; Rorden, Chris

2012-12-01

Covert attention is tightly coupled with the control of eye movements, but there is controversy about how tight this coupling is. The premotor theory of attention proposes that activation of the eye movement system is necessary to produce shifts of attention. In this study, we experimentally prevented healthy participants from planning or executing eye movements and observed the effect on exogenous attention, inhibition of return (IOR), and endogenous attention. The participants experienced a deficit of exogenous attentional facilitation that was specific to locations that were inaccessible by saccade. In contrast, their ability to endogenously orient attention was preserved, as was IOR. These results show that (a) exogenous attention depends on motor preparation, (b) IOR is independent of motor preparation and exogenous attention, and (c) endogenous attention is independent of motor preparation. Although these data are consistent with a weak version of the premotor theory, we believe they can be better explained by a biased competition account of visual attention.

Comparison of Video Head Impulse Test (vHIT) Gains Between Two Commercially Available Devices and by Different Gain Analytical Methods.

PubMed

Lee, Sang Hun; Yoo, Myung Hoon; Park, Jun Woo; Kang, Byung Chul; Yang, Chan Joo; Kang, Woo Suk; Ahn, Joong Ho; Chung, Jong Woo; Park, Hong Ju

2018-06-01

To evaluate whether video head impulse test (vHIT) gains are dependent on the measuring device and method of analysis. Prospective study. vHIT was performed in 25 healthy subjects using two devices simultaneously. vHIT gains were compared between these instruments and using five different methods of comparing position and velocity gains during head movement intervals. The two devices produced different vHIT gain results with the same method of analysis. There were also significant differences in the vHIT gains measured using different analytical methods. The gain analytic method that compares the areas under the velocity curve (AUC) of the head and eye movements during head movements showed lower vHIT gains than a method that compared the peak velocities of the head and eye movements. The former method produced the vHIT gain with the smallest standard deviation among the five procedures tested in this study. vHIT gains differ in normal subjects depending on the device and method of analysis used, suggesting that it is advisable for each device to have its own normal values. Gain calculations that compare the AUC of the head and eye movements during the head movements show the smallest variance.

Controlling gain one photon at a time

PubMed Central

Schwartz, Gregory W; Rieke, Fred

2013-01-01

Adaptation is a salient property of sensory processing. All adaptational or gain control mechanisms face the challenge of obtaining a reliable estimate of the property of the input to be adapted to and obtaining this estimate sufficiently rapidly to be useful. Here, we explore how the primate retina balances the need to change gain rapidly and reliably when photons arrive rarely at individual rod photoreceptors. We find that the weakest backgrounds that decrease the gain of the retinal output signals are similar to those that increase human behavioral threshold, and identify a novel site of gain control in the retinal circuitry. Thus, surprisingly, the gain of retinal signals begins to decrease essentially as soon as background lights are detectable; under these conditions, gain control does not rely on a highly averaged estimate of the photon count, but instead signals from individual photon absorptions trigger changes in gain. DOI: http://dx.doi.org/10.7554/eLife.00467.001 PMID:23682314

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.

Selection history alters attentional filter settings persistently and beyond top-down control.

PubMed

Kadel, Hanna; Feldmann-Wüstefeld, Tobias; Schubö, Anna

2017-05-01

Visual selective attention is known to be guided by stimulus-based (bottom-up) and goal-oriented (top-down) control mechanisms. Recent work has pointed out that selection history (i.e., the bias to prioritize items that have been previously attended) can result in a learning experience that also has a substantial impact on subsequent attention guidance. The present study examined to what extent goal-oriented top-down control mechanisms interact with an observer's individual selection history in guiding attention. Selection history was manipulated in a categorization task in a between-subjects design, where participants learned that either color or shape was the response-relevant dimension. The impact of this experience was assessed in a compound visual search task with an additional color distractor. Top-down preparation for each search trial was enabled by a pretrial task cue (Experiment 1) or a fixed, predictable trial sequence (Experiment 2). Reaction times and ERPs served as indicators of attention deployment. Results showed that attention was captured by the color distractor when participants had learned that color predicted the correct response in the categorization learning task, suggesting that a bias for predictive stimulus features had developed. The possibility to prepare for the search task reduced the bias, but could not entirely overrule this selection history effect. In Experiment 3, both tasks were performed in separate sessions, and the bias still persisted. These results indicate that selection history considerably shapes selective attention and continues to do so persistently even when the task allowed for high top-down control. © 2017 Society for Psychophysiological Research.

Effect of Intermittent Kangaroo Mother Care on Weight Gain of Low Birth Weight Neonates With Delayed Weight Gain

PubMed Central

Samra, Nashwa M.; Taweel, Amal El; Cadwell, Karin

2013-01-01

Objective: To evaluate intermittent Kangaroo Mother Care (KMC) with additional opportunities to breastfeed on weight gain of low birth weight (LBW) neonates with delayed weight gain. Methods: 40 LBW neonates were followed to see whether KMC with additional opportunities to breastfeed improved weight gain. Results: In the KMC group, the mean age of regaining birth weight was significantly less (15.68 vs. 24.56 days) and the average daily weight gain was significantly higher (22.09 vs. 10.39 g, p < .001) than controls. Conclusion: KMC with additional opportunities to breastfeed was found to be an effective intervention for LBWs with delayed weight gain and should be considered to be an effective strategy. PMID:24868132

Short-term mindfulness intervention reduces the negative attentional effects associated with heavy media multitasking

PubMed Central

Gorman, Thomas E.; Green, C. Shawn

2016-01-01

Recent research suggests that frequently switching between various forms of media (i.e. ‘media multitasking’) is associated with diminished attentional abilities, a disconcerting result given the prevalence of media multitasking in today’s society. In the present study, we sought to investigate the extent to which the deficits associated with frequent media multitasking can be temporarily ameliorated via a short-term mindfulness intervention previously shown to produce beneficial effects on the attentional abilities of normally functioning individuals. Consistent with previous work, we found: (1) that heavy media multitaskers showed generally poorer attentional abilities than light media multitaskers and (2) that all participants showed benefits from the short-term mindfulness intervention. Furthermore, we found that the benefits of the short-term mindfulness intervention were not equivalently large across participants. Instead, these benefits were disproportionately large in the heavy media multitaskers. While the positive outcomes were short-lived, this opens the possibility of performing long-term interventions with the goal of realizing lasting gains in this population. PMID:27086504

Moving attention - Evidence for time-invariant shifts of visual selective attention

NASA Technical Reports Server (NTRS)

Remington, R.; Pierce, L.

1984-01-01

Two experiments measured the time to shift spatial selective attention across the visual field to targets 2 or 10 deg from central fixation. A central arrow cued the most likely target location. The direction of attention was inferred from reaction times to expected, unexpected, and neutral locations. The development of a spatial attentional set with time was examined by presenting target probes at varying times after the cue. There were no effects of distance on the time course of the attentional set. Reaction times for far locations were slower than for near, but the effects of attention were evident by 150 msec in both cases. Spatial attention does not shift with a characteristic, fixed velocity. Rather, velocity is proportional to distance, resulting in a movement time that is invariant over the distances tested.

College Freshmen Students’ Perspectives on Weight Gain Prevention in the Digital Age: Web-Based Survey

PubMed Central

Turner-McGrievy, Gabrielle; Larsen, Chelsea A; Magradey, Karen; Brandt, Heather M; Wilcox, Sara; Sundstrom, Beth; West, Delia Smith

2017-01-01

Background College freshmen are highly vulnerable to experiencing weight gain, and this phenomenon is associated with an increased risk of chronic diseases and mortality in older adulthood. Technology offers an attractive and scalable way to deliver behavioral weight gain prevention interventions for this population. Weight gain prevention programs that harness the appeal and widespread reach of Web-based technologies (electronic health or eHealth) are increasingly being evaluated in college students. Yet, few of these interventions are informed by college students’ perspectives on weight gain prevention and related lifestyle behaviors. Objective The objective of this study was to assess college freshmen students’ concern about weight gain and associated topics, as well as their interest in and delivery medium preferences for eHealth programs focused on these topics. Methods Web-based surveys that addressed college freshmen students’ (convenience sample of N=50) perspectives on weight gain prevention were administered at the beginning and end of the fall 2015 semester as part of a longitudinal investigation of health-related issues and experiences in first semester college freshmen. Data on weight gain prevention-related concerns and corresponding interest in eHealth programs targeting topics of potential concern, as well as preferred program delivery medium and current technology use were gathered and analyzed using descriptive statistics. Results A considerable proportion of the freshmen sample expressed concern about weight gain (74%, 37/50) and both traditional (healthy diet: 86%, 43/50; physical activity: 64%, 32/50) and less frequently addressed (stress: 82%, 41/50; sleep: 74%, 37/50; anxiety and depression: 60%, 30/50) associated topics within the context of behavioral weight gain prevention. The proportion of students who reported interest in eHealth promotion programs targeting these topics was also generally high (ranging from 52% [26/50] for stress

Modification of saccadic gain by reinforcement

PubMed Central

Paeye, Céline; Wallman, Josh

2011-01-01

Control of saccadic gain is often viewed as a simple compensatory process in which gain is adjusted over many trials by the postsaccadic retinal error, thereby maintaining saccadic accuracy. Here, we propose that gain might also be changed by a reinforcement process not requiring a visual error. To test this hypothesis, we used experimental paradigms in which retinal error was removed by extinguishing the target at the start of each saccade and either an auditory tone or the vision of the target on the fovea was provided as reinforcement after those saccades that met an amplitude criterion. These reinforcement procedures caused a progressive change in saccade amplitude in nearly all subjects, although the rate of adaptation differed greatly among subjects. When we reversed the contingencies and reinforced those saccades landing closer to the original target location, saccade gain changed back toward normal gain in most subjects. When subjects had saccades adapted first by reinforcement and a week later by conventional intrasaccadic step adaptation, both paradigms yielded similar degrees of gain changes and similar transfer to new amplitudes and to new starting positions of the target step as well as comparable rates of recovery. We interpret these changes in saccadic gain in the absence of postsaccadic retinal error as showing that saccade adaptation is not controlled by a single error signal. More generally, our findings suggest that normal saccade adaptation might involve general learning mechanisms rather than only specialized mechanisms for motor calibration. PMID:21525366

Moving to Capture Children's Attention: Developing a Methodology for Measuring Visuomotor Attention.

PubMed

Hill, Liam J B; Coats, Rachel O; Mushtaq, Faisal; Williams, Justin H G; Aucott, Lorna S; Mon-Williams, Mark

2016-01-01

Attention underpins many activities integral to a child's development. However, methodological limitations currently make large-scale assessment of children's attentional skill impractical, costly and lacking in ecological validity. Consequently we developed a measure of 'Visual Motor Attention' (VMA)-a construct defined as the ability to sustain and adapt visuomotor behaviour in response to task-relevant visual information. In a series of experiments, we evaluated the capability of our method to measure attentional processes and their contributions in guiding visuomotor behaviour. Experiment 1 established the method's core features (ability to track stimuli moving on a tablet-computer screen with a hand-held stylus) and demonstrated its sensitivity to principled manipulations in adults' attentional load. Experiment 2 standardised a format suitable for use with children and showed construct validity by capturing developmental changes in executive attention processes. Experiment 3 tested the hypothesis that children with and without coordination difficulties would show qualitatively different response patterns, finding an interaction between the cognitive and motor factors underpinning responses. Experiment 4 identified associations between VMA performance and existing standardised attention assessments and thereby confirmed convergent validity. These results establish a novel approach to measuring childhood attention that can produce meaningful functional assessments that capture how attention operates in an ecologically valid context (i.e. attention's specific contribution to visuomanual action).

Variable gain for a wind turbine pitch control

NASA Technical Reports Server (NTRS)

Seidel, R. C.; Birchenough, A. G.

1981-01-01

The gain variation is made in the software logic of the pitch angle controller. The gain level is changed depending upon the level of power error. The control uses low gain for low pitch activity the majority of the time. If the power exceeds ten percent offset above rated, the gain is increased to a higher gain to more effectively limit power. A variable gain control functioned well in tests on the Mod-0 wind turbine.

Sex differences in the experience of unwanted sexual attention and behaviors during childhood.

PubMed

Whealin, Julia M; Zinzow, Heidi M; Salstrom, Seoka A; Jackson, Joan L

2007-01-01

Girls receive considerable amounts of unwanted sexual attention (UWSA) and behaviors (UWSB). Less is known about boys' unwanted sexual experiences. The primary goal of this study was to obtain a descriptive profile of the types and perpetrators of childhood UWSA/B. Secondary goals were to examine sex differences in emotional reactions to UWSA/B and influence of perpetrator. As many as 100 male and 100 female undergraduates completed the Exposure to Sexual Attention Scale and the Emotional Reaction Checklist. Results indicated that the majority of participants experienced UWSA/B during childhood, with females reporting higher rates of UWSB than males. Sex differences were also observed regarding types of perpetrators and emotional reactions. Findings are discussed as they relate to the sociocultural norms in which children are reared.

Substrate effects in high gain, low operating voltage SnSe2 photoconductor

NASA Astrophysics Data System (ADS)

Krishna, Murali; Kallatt, Sangeeth; Majumdar, Kausik

2018-01-01

High gain photoconductive devices find wide spread applications in low intensity light detection. Ultra-thin layered materials have recently drawn a lot of attention from researchers in this regard. However, in general, a large operating voltage is required to obtain large responsivity in these devices. In addition, the characteristics are often confounded by substrate induced trap effects. Here we report multi-layer SnSe2 based photoconductive devices using two different structures: (1) SiO2 substrate supported inter-digitated electrode (IDE), and (2) suspended channel. The IDE device exhibits a responsivity of ≈ {10}3 A W-1 and ≈ 8.66× {10}4 A W-1 at operating voltages of 1 mV and 100 mV, respectively—a superior low voltage performance over existing literature on planar 2D structures. However, the responsivity reduces by more than two orders of magnitude, while the transient response improves for the suspended device—providing insights into the critical role played by the channel-substrate interface in the gain mechanism. The results, on one hand, are promising for highly sensitive photoconductive applications consuming ultra-low power, and on the other hand, show a generic methodology that could be applied to other layered material based photoconductive devices as well for extracting the intrinsic behavior.

Contrast Gain Control in Auditory Cortex

PubMed Central

Rabinowitz, Neil C.; Willmore, Ben D.B.; Schnupp, Jan W.H.; King, Andrew J.

2011-01-01

Summary The auditory system must represent sounds with a wide range of statistical properties. One important property is the spectrotemporal contrast in the acoustic environment: the variation in sound pressure in each frequency band, relative to the mean pressure. We show that neurons in ferret auditory cortex rescale their gain to partially compensate for the spectrotemporal contrast of recent stimulation. When contrast is low, neurons increase their gain, becoming more sensitive to small changes in the stimulus, although the effectiveness of contrast gain control is reduced at low mean levels. Gain is primarily determined by contrast near each neuron's preferred frequency, but there is also a contribution from contrast in more distant frequency bands. Neural responses are modulated by contrast over timescales of ∼100 ms. By using contrast gain control to expand or compress the representation of its inputs, the auditory system may be seeking an efficient coding of natural sounds. PMID:21689603

Attentional Capture with Rapidly Changing Attentional Control Settings

ERIC Educational Resources Information Center

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

2010-01-01

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

Relating lab to life: Decrements in attention over time predict math productivity among children with ADHD.

PubMed

Fosco, Whitney D; Hawk, Larry W

2017-02-01

A child's ability to sustain attention over time (AOT) is critical in attention-deficit/hyperactivity disorder (ADHD), yet no prior work has examined the extent to which a child's decrement in AOT on laboratory tasks relates to clinically-relevant behavior. The goal of this study is to provide initial evidence for the criterion validity of laboratory assessments of AOT. A total of 20 children with ADHD (7-12 years of age) who were enrolled in a summer treatment program completed two lab attention tasks (a continuous performance task and a self-paced choice discrimination task) and math seatwork. Analyses focused on relations between attention task parameters and math productivity. Individual differences in overall attention (OA) measures (averaged across time) accounted for 23% of the variance in math productivity, supporting the criterion validity of lab measures of attention. The criterion validity was enhanced by consideration of changes in AOT. Performance on all laboratory attention measures deteriorated as time-on-task increased, and individual differences in the decrement in AOT accounted for 40% of the variance in math productivity. The only variable to uniquely predict math productivity was from the self-paced choice discrimination task. This study suggests that attention tasks in the lab do predict a clinically-relevant target behavior in children with ADHD, supporting their use as a means to study attention processes in a controlled environment. Furthermore, this prediction is improved when attention is examined as a function of time-on-task and when the attentional demands are consistent between lab and life contexts.

ADHD in 140 Characters or Less: An Analysis of Twitter Commentary on Attention Deficit Hyperactivity Disorder in Saudi Arabia

ERIC Educational Resources Information Center

Alharbi, Rabab S.

2017-01-01