WorldWideScience

Sample records for rapidly shifting attention

  1. Shifting Attention

    Science.gov (United States)

    Ingram, Jenni

    2014-01-01

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

  2. Saccade-synchronized rapid attention shifts in macaque visual cortical area MT.

    Science.gov (United States)

    Yao, Tao; Treue, Stefan; Krishna, B Suresh

    2018-03-06

    While making saccadic eye-movements to scan a visual scene, humans and monkeys are able to keep track of relevant visual stimuli by maintaining spatial attention on them. This ability requires a shift of attentional modulation from the neuronal population representing the relevant stimulus pre-saccadically to the one representing it post-saccadically. For optimal performance, this trans-saccadic attention shift should be rapid and saccade-synchronized. Whether this is so is not known. We trained two rhesus monkeys to make saccades while maintaining covert attention at a fixed spatial location. We show that the trans-saccadic attention shift in cortical visual medial temporal (MT) area is well synchronized to saccades. Attentional modulation crosses over from the pre-saccadic to the post-saccadic neuronal representation by about 50 ms after a saccade. Taking response latency into account, the trans-saccadic attention shift is well timed to maintain spatial attention on relevant stimuli, so that they can be optimally tracked and processed across saccades.

  3. Rapid top-down control over template-guided attention shifts to multiple objects.

    Science.gov (United States)

    Grubert, Anna; Fahrenfort, Johannes; Olivers, Christian N L; Eimer, Martin

    2017-02-01

    Previous research has shown that when observers search for targets defined by a particular colour, attention can be directed rapidly and independently to two target objects that appear in close temporal proximity. We investigated how such rapid attention shifts are modulated by task instructions to selectively attend versus ignore one of these objects. Two search displays that both contained a colour-defined target and a distractor in a different colour were presented in rapid succession, with a stimulus onset asynchrony (SOA) of 100ms. In different blocks, participants were instructed to attend and respond to target-colour objects in the first display and to ignore these objects in the second display, or vice versa. N2pc components were measured to track the allocation of spatial attention to target-colour objects in these two displays. When participants responded to the second display, irrelevant target-colour objects in the first display still triggered N2pc components, demonstrating task-set contingent attentional capture while a feature-specific target template is active. Critically, when participants responded to the first display instead, no N2pc was elicited by target-colour items in the second display, indicating that they no longer rapidly captured attention. However, these items still elicited a longer-latency contralateral negativity (SPCN component), suggesting that attention was oriented towards template-matching objects in working memory. This dissociation between N2pc and SPCN components shows that rapid attentional capture and subsequent attentional selection processes within working memory can be independent. We suggest that early attentional orienting mechanisms can be inhibited when task-set matching objects are no longer task-relevant, and that this type of inhibitory control is a rapid but transient process. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Visual attention shifting in autism spectrum disorders.

    Science.gov (United States)

    Richard, Annette E; Lajiness-O'Neill, Renee

    2015-01-01

    Abnormal visual attention has been frequently observed in autism spectrum disorders (ASD). Abnormal shifting of visual attention is related to abnormal development of social cognition and has been identified as a key neuropsychological finding in ASD. Better characterizing attention shifting in ASD and its relationship with social functioning may help to identify new targets for intervention and improving social communication in these disorders. Thus, the current study investigated deficits in attention shifting in ASD as well as relationships between attention shifting and social communication in ASD and neurotypicals (NT). To investigate deficits in visual attention shifting in ASD, 20 ASD and 20 age- and gender-matched NT completed visual search (VS) and Navon tasks with attention-shifting demands as well as a set-shifting task. VS was a feature search task with targets defined in one of two dimensions; Navon required identification of a target letter presented at the global or local level. Psychomotor and processing speed were entered as covariates. Relationships between visual attention shifting, set shifting, and social functioning were also examined. ASD and NT showed comparable costs of shifting attention. However, psychomotor and processing speed were slower in ASD than in NT, and psychomotor and processing speed were positively correlated with attention-shifting costs on Navon and VS, respectively, for both groups. Attention shifting on VS and Navon were correlated among NT, while attention shifting on Navon was correlated with set shifting among ASD. Attention-shifting costs on Navon were positively correlated with restricted and repetitive behaviors among ASD. Relationships between attention shifting and psychomotor and processing speed, as well as relationships between measures of different aspects of visual attention shifting, suggest inefficient top-down influences over preattentive visual processing in ASD. Inefficient attention shifting may be

  5. Ambiguity Produces Attention Shifts in Category Learning

    Science.gov (United States)

    Vadillo, Miguel A.; Orgaz, Cristina; Luque, David; Nelson, James Byron

    2016-01-01

    It has been suggested that people and nonhuman animals protect their knowledge from interference by shifting attention toward the context when presented with information that contradicts their previous beliefs. Despite that suggestion, no studies have directly measured changes in attention while participants are exposed to an interference…

  6. Exploring Insight: Focus on Shifts of Attention

    Science.gov (United States)

    Palatnik, Alik; Koichu, Boris

    2015-01-01

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

  7. Pay Attention!: Sluggish Multisensory Attentional Shifting as a Core Deficit in Developmental Dyslexia.

    Science.gov (United States)

    Krause, Margaret B

    2015-11-01

    The aim of this review is to provide a background on the neurocognitive aspects of the reading process and review neuroscientific studies of individuals with developmental dyslexia, which provide evidence for amodal processing deficits. Hari, Renvall, and Tanskanen (2001) propose amodal sluggish attentional shifting (SAS) as a causal factor for temporal processing deficits in dyslexia. Undergirding this theory is the notion that when dyslexics are faced with rapid sequences of stimuli, their automatic attentional systems fail to disengage efficiently, which leads to difficulty when moving from one item to the next (Lallier et al., ). This results in atypical perception of rapid stimulus sequences. Until recently, the SAS theory, particularly the examination of amodal attentional deficits, was studied solely through the use of behavioural measures (Facoetti et al., ; Facoetti, Lorusso, Cattaneo, Galli, & Molteni, ). This paper examines evidence within the literature that provides a basis for further exploration of amodal SAS as an underlying deficit in developmental dyslexia. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Attentional Set-Shifting in Fragile X Syndrome

    Science.gov (United States)

    Van der Molen, M. J. W.; Van der Molen, M. W.; Ridderinkhof, K. R.; Hamel, B. C. J.; Curfs, L. M. G.; Ramakers, G. J. A.

    2012-01-01

    The ability to flexibly adapt to the changing demands of the environment is often reported as a core deficit in fragile X syndrome (FXS). However, the cognitive processes that determine this attentional set-shifting deficit remain elusive. The present study investigated attentional set-shifting ability in fragile X syndrome males with the…

  9. Quantifying attention shifts in augmented reality image-guided neurosurgery.

    Science.gov (United States)

    Léger, Étienne; Drouin, Simon; Collins, D Louis; Popa, Tiberiu; Kersten-Oertel, Marta

    2017-10-01

    Image-guided surgery (IGS) has allowed for more minimally invasive procedures, leading to better patient outcomes, reduced risk of infection, less pain, shorter hospital stays and faster recoveries. One drawback that has emerged with IGS is that the surgeon must shift their attention from the patient to the monitor for guidance. Yet both cognitive and motor tasks are negatively affected with attention shifts. Augmented reality (AR), which merges the realworld surgical scene with preoperative virtual patient images and plans, has been proposed as a solution to this drawback. In this work, we studied the impact of two different types of AR IGS set-ups (mobile AR and desktop AR) and traditional navigation on attention shifts for the specific task of craniotomy planning. We found a significant difference in terms of the time taken to perform the task and attention shifts between traditional navigation, but no significant difference between the different AR set-ups. With mobile AR, however, users felt that the system was easier to use and that their performance was better. These results suggest that regardless of where the AR visualisation is shown to the surgeon, AR may reduce attention shifts, leading to more streamlined and focused procedures.

  10. Exogenous and endogenous shifts of attention in perihand space.

    Science.gov (United States)

    Le Bigot, Nathalie; Grosjean, Marc

    2016-07-01

    While some studies have found that attentional orienting is altered in perihand space, most have not. One reason for such discrepancies may be related to the types of cues (uninformative and informative) that have been used, as they are known to induce different types of shifts of attention (exogenous and endogenous, respectively). To systematically address this question, two experiments were performed in which an uninformative peripheral cue (Experiment 1) or an informative central cue (Experiment 2) preceded a peripheral target with a short (100-150 ms) stimulus-onset asynchrony. Participants performed the task with their left hand, right hand, both hands, or no hands near the display. Cueing effects were obtained in both experiments, but they were only modulated by hand position in Experiment 1, with larger effects observed in the right- and both-hand conditions. These findings suggest that exogenous attention shifts are affected by hand proximity, while endogenous shifts are not.

  11. The effects of sequential attention shifts within visual working memory

    Directory of Open Access Journals (Sweden)

    Qi eLi

    2014-09-01

    Full Text Available Previous studies have shown conflicting data as to whether it is possible to sequentially shift spatial attention among visual working memory (VWM representations. The present study investigated this issue by asynchronously presenting attentional cues during the retention interval of a change detection task. In particular, we focused on two types of sequential attention shifts: 1 orienting attention to one location, and then withdrawing attention from it, and 2 switching the focus of attention from one location to another. In Experiment 1, a withdrawal cue was presented after a spatial retro-cue to measure the effect of withdrawing attention. The withdrawal cue significantly reduced the cost of invalid spatial cues, but surprisingly, did not attenuate the benefit of valid spatial cues. This indicates that the withdrawal cue only triggered the activation of facilitative components but not inhibitory components of attention. In Experiment 2, two spatial retro-cues were presented successively to examine the effect of switching the focus of attention. We observed benefits of both the first and second cues in sequential cueing, indicating that participants were able to reorient attention from one location to another within VWM, and the reallocation of attention did not attenuate memory at the first cued location. In Experiment 3, we found that reducing the validity of the preceding spatial cue did lead to a significant reduction in its benefit. However, performance at the first-cued location was still better than the neutral baseline or performance at the uncued locations, indicating that the first cue benefit might have been preserved both partially under automatic control and partially under voluntary control. Our findings revealed new properties of dynamic attentional control in VWM maintenance.

  12. The effects of sequential attention shifts within visual working memory.

    Science.gov (United States)

    Li, Qi; Saiki, Jun

    2014-01-01

    Previous studies have shown conflicting data as to whether it is possible to sequentially shift spatial attention among visual working memory (VWM) representations. The present study investigated this issue by asynchronously presenting attentional cues during the retention interval of a change detection task. In particular, we focused on two types of sequential attention shifts: (1) orienting attention to one location, and then withdrawing attention from it, and (2) switching the focus of attention from one location to another. In Experiment 1, a withdrawal cue was presented after a spatial retro-cue to measure the effect of withdrawing attention. The withdrawal cue significantly reduced the cost of invalid spatial cues, but surprisingly, did not attenuate the benefit of valid spatial cues. This indicates that the withdrawal cue only triggered the activation of facilitative components but not inhibitory components of attention. In Experiment 2, two spatial retro-cues were presented successively to examine the effect of switching the focus of attention. We observed equivalent benefits of the first and second spatial cues, suggesting that participants were able to reorient attention from one location to another within VWM, and the reallocation of attention did not attenuate memory at the first-cued location. In Experiment 3, we found that reducing the validity of the preceding spatial cue did lead to a significant reduction in its benefit. However, performance was still better at first-cued locations than at uncued and neutral locations, indicating that the first cue benefit might have been preserved both partially under automatic control and partially under voluntary control. Our findings revealed new properties of dynamic attentional control in VWM maintenance.

  13. The effects of sequential attention shifts within visual working memory

    Science.gov (United States)

    Li, Qi; Saiki, Jun

    2014-01-01

    Previous studies have shown conflicting data as to whether it is possible to sequentially shift spatial attention among visual working memory (VWM) representations. The present study investigated this issue by asynchronously presenting attentional cues during the retention interval of a change detection task. In particular, we focused on two types of sequential attention shifts: (1) orienting attention to one location, and then withdrawing attention from it, and (2) switching the focus of attention from one location to another. In Experiment 1, a withdrawal cue was presented after a spatial retro-cue to measure the effect of withdrawing attention. The withdrawal cue significantly reduced the cost of invalid spatial cues, but surprisingly, did not attenuate the benefit of valid spatial cues. This indicates that the withdrawal cue only triggered the activation of facilitative components but not inhibitory components of attention. In Experiment 2, two spatial retro-cues were presented successively to examine the effect of switching the focus of attention. We observed equivalent benefits of the first and second spatial cues, suggesting that participants were able to reorient attention from one location to another within VWM, and the reallocation of attention did not attenuate memory at the first-cued location. In Experiment 3, we found that reducing the validity of the preceding spatial cue did lead to a significant reduction in its benefit. However, performance was still better at first-cued locations than at uncued and neutral locations, indicating that the first cue benefit might have been preserved both partially under automatic control and partially under voluntary control. Our findings revealed new properties of dynamic attentional control in VWM maintenance. PMID:25237306

  14. Attentional Capture with Rapidly Changing Attentional Control Settings

    Science.gov (United States)

    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…

  15. Moving attention - Evidence for time-invariant shifts of visual selective attention

    Science.gov (United States)

    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.

  16. Distinct representations for shifts of spatial attention and changes of reward contingencies in the human brain.

    Science.gov (United States)

    Tosoni, Annalisa; Shulman, Gordon L; Pope, Anna L W; McAvoy, Mark P; Corbetta, Maurizio

    2013-06-01

    Success in a dynamically changing world requires both rapid shifts of attention to the location of important objects and the detection of changes in motivational contingencies that may alter future behavior. Here we addressed the relationship between these two processes by measuring the blood-oxygenation-level-dependent (BOLD) signal during a visual search task in which the location and the color of a salient cue respectively indicated where a rewarded target would appear and the monetary gain (large or small) associated with its detection. While cues that either shifted or maintained attention were presented every 4 to 8 sec, the reward magnitude indicated by the cue changed roughly every 30 sec, allowing us to distinguish a change in expected reward magnitude from a maintained state of expected reward magnitude. Posterior cingulate cortex was modulated by cues signaling an increase in expected reward magnitude, but not by cues for shifting versus maintaining spatial attention. Dorsal fronto-parietal regions in precuneus and frontal eye field (FEF) also showed increased BOLD activity for changes in expected reward magnitude from low to high, but in addition showed large independent modulations for shifting versus maintaining attention. In particular, the differential activation for shifting versus maintaining attention was not affected by expected reward magnitude. These results indicate that BOLD activations for shifts of attention and increases in expected reward magnitude are largely separate. Finally, visual cortex showed sustained spatially selective signals that were significantly enhanced when greater reward magnitude was expected, but this reward-related modulation was not observed in spatially selective regions of dorsal fronto-parietal cortex. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Attention shifts the language network reflecting paradigm presentation

    Directory of Open Access Journals (Sweden)

    Kathrin eKollndorfer

    2013-11-01

    Full Text Available Objectives: Functional magnetic resonance imaging (fMRI is a reliable and non-invasive method with which to localize language function in pre-surgical planning. In clinical practice, visual stimulus presentation is often difficult or impossible, due to the patient’s restricted language or attention abilities. Therefore, our aim was to investigate modality-specific differences in visual and auditory stimulus presentation.Methods: Ten healthy subjects participated in an fMRI study comprising two experiments with visual and auditory stimulus presentation. In both experiments, two language paradigms (one for language comprehension and one for language production used in clinical practice were investigated. In addition to standard data analysis by the means of the general linear model (GLM, independent component analysis (ICA was performed to achieve more detailed information on language processing networks.Results: GLM analysis revealed modality-specific brain activation for both language paradigms for the contrast visual > auditory in the area of the intraparietal sulcus and the hippocampus, two areas related to attention and working memory. Using group ICA, a language network was detected for both paradigms independent of stimulus presentation modality. The investigation of language lateralization revealed no significant variations. Visually presented stimuli further activated an attention-shift network, which could not be identified for the auditory presented language.Conclusion: The results of this study indicate that the visually presented language stimuli additionally activate an attention-shift network. These findings will provide important information for pre-surgical planning in order to preserve reading abilities after brain surgery, significantly improving surgical outcomes. Our findings suggest that the presentation modality for language paradigms should be adapted on behalf of individual indication.

  18. Rapid and reliable protein structure determination via chemical shift threading.

    Science.gov (United States)

    Hafsa, Noor E; Berjanskii, Mark V; Arndt, David; Wishart, David S

    2018-01-01

    Protein structure determination using nuclear magnetic resonance (NMR) spectroscopy can be both time-consuming and labor intensive. Here we demonstrate how chemical shift threading can permit rapid, robust, and accurate protein structure determination using only chemical shift data. Threading is a relatively old bioinformatics technique that uses a combination of sequence information and predicted (or experimentally acquired) low-resolution structural data to generate high-resolution 3D protein structures. The key motivations behind using NMR chemical shifts for protein threading lie in the fact that they are easy to measure, they are available prior to 3D structure determination, and they contain vital structural information. The method we have developed uses not only sequence and chemical shift similarity but also chemical shift-derived secondary structure, shift-derived super-secondary structure, and shift-derived accessible surface area to generate a high quality protein structure regardless of the sequence similarity (or lack thereof) to a known structure already in the PDB. The method (called E-Thrifty) was found to be very fast (often chemical shift refinement, these results suggest that protein structure determination, using only NMR chemical shifts, is becoming increasingly practical and reliable. E-Thrifty is available as a web server at http://ethrifty.ca .

  19. Action video games improve reading abilities and visual-to-auditory attentional shifting in English-speaking children with dyslexia.

    Science.gov (United States)

    Franceschini, Sandro; Trevisan, Piergiorgio; Ronconi, Luca; Bertoni, Sara; Colmar, Susan; Double, Kit; Facoetti, Andrea; Gori, Simone

    2017-07-19

    Dyslexia is characterized by difficulties in learning to read and there is some evidence that action video games (AVG), without any direct phonological or orthographic stimulation, improve reading efficiency in Italian children with dyslexia. However, the cognitive mechanism underlying this improvement and the extent to which the benefits of AVG training would generalize to deep English orthography, remain two critical questions. During reading acquisition, children have to integrate written letters with speech sounds, rapidly shifting their attention from visual to auditory modality. In our study, we tested reading skills and phonological working memory, visuo-spatial attention, auditory, visual and audio-visual stimuli localization, and cross-sensory attentional shifting in two matched groups of English-speaking children with dyslexia before and after they played AVG or non-action video games. The speed of words recognition and phonological decoding increased after playing AVG, but not non-action video games. Furthermore, focused visuo-spatial attention and visual-to-auditory attentional shifting also improved only after AVG training. This unconventional reading remediation program also increased phonological short-term memory and phoneme blending skills. Our report shows that an enhancement of visuo-spatial attention and phonological working memory, and an acceleration of visual-to-auditory attentional shifting can directly translate into better reading in English-speaking children with dyslexia.

  20. The Role of Intrinsic Motivations in Attention Allocation and Shifting

    Directory of Open Access Journals (Sweden)

    Dario edi Nocera

    2014-04-01

    Full Text Available The concepts of attention and intrinsic motivations are of great interest within adaptive robotic systems, and can be exploited in order to guide, activate, and coordinate multiple concurrent behaviors. Attention allocation strategies represent key capabilities of human beings, which are strictly connected with action selection and execution mechanisms, while intrinsic motivations directly affect the allocation of attentional resources. In this paper we propose a model of Reinforcement Learning (RL, where both these capabilities are involved. RL is deployed to learn how to allocate attentional resources in a behavior-based robotic system, while action selection is obtained as a side effect of the resulting motivated attentional behaviors. Moreover, the influence of intrinsic motivations in attention orientation is obtained by introducing rewards associated with curiosity drives. In this way, the learning process is affected not only by goal-specific rewards, but also by intrinsic motivations.

  1. Functional connectivity between prefrontal and parietal cortex drives visuo-spatial attention shifts.

    Science.gov (United States)

    Heinen, Klaartje; Feredoes, Eva; Ruff, Christian C; Driver, Jon

    2017-05-01

    It is well established that the frontal eye-fields (FEF) in the dorsal attention network (DAN) guide top-down selective attention. In addition, converging evidence implies a causal role for the FEF in attention shifting, which is also known to recruit the ventral attention network (VAN) and fronto-striatal regions. To investigate the causal influence of the FEF as (part of) a central hub between these networks, we applied thetaburst transcranial magnetic stimulation (TBS) off-line, combined with functional magnetic resonance (fMRI) during a cued visuo-spatial attention shifting paradigm. We found that TBS over the right FEF impaired performance on a visual discrimination task in both hemifields following attention shifts, while only left hemifield performance was affected when participants were cued to maintain the focus of attention. These effects recovered ca. 20min post stimulation. Furthermore, particularly following attention shifts, TBS suppressed the neural signal in bilateral FEF, right inferior and superior parietal lobule (IPL/SPL) and bilateral supramarginal gyri (SMG). Immediately post stimulation, functional connectivity was impaired between right FEF and right SMG as well as right putamen. Importantly, the extent of decreased connectivity between right FEF and right SMG correlated with behavioural impairment following attention shifts. The main finding of this study demonstrates that influences from right FEF on SMG in the ventral attention network causally underly attention shifts, presumably by enabling disengagement from the current focus of attention. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Spatially distributed encoding of covert attentional shifts in human thalamus

    DEFF Research Database (Denmark)

    Hulme, Oliver J; Whiteley, Louise Emma; Shipp, Stewart

    2010-01-01

    /central-intralaminar (oculomotor thalamus), caudal intralaminar/parafascicular, suprageniculate/limitans, and medial pulvinar/lateral posterior. Hence, the cortical network generating a top-down control signal for relocating attention acts in concert with a spatially selective thalamic apparatus-the set of active nuclei mirroring...... the thalamic territory of cortical "eye-field" areas, thus supporting theories which propose the visuomotor origins of covert attentional selection.......Spatial attention modulates signal processing within visual nuclei of the thalamus--but do other nuclei govern the locus of attention in top-down mode? We examined functional MRI (fMRI) data from three subjects performing a task requiring covert attention to 1 of 16 positions in a circular array...

  3. Right Hemispheric Dominance in Gaze-Triggered Reflexive Shift of Attention in Humans

    Science.gov (United States)

    Okada, Takashi; Sato, Wataru; Toichi, Motomi

    2006-01-01

    Recent findings suggest a right hemispheric dominance in gaze-triggered shifts of attention. The aim of this study was to clarify the dominant hemisphere in the gaze processing that mediates attentional shift. A target localization task, with preceding non-predicative gaze cues presented to each visual field, was undertaken by 44 healthy subjects,…

  4. Effects of methylphenidate on attentional set-shifting in a genetic model of attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Cao, Ai-hua; Yu, Lin; Wang, Yu-wei; Wang, Jun-mei; Yang, Le-jin; Lei, Ge-Fei

    2012-02-28

    Although deficits of attentional set-shifting have been reported in individuals with attention deficit/hyperactivity disorder (ADHD), it is rarely examined in animal models. This study compared spontaneously hypertensive rats (SHRs; a genetic animal model of ADHD) and Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats (normoactive control strains), on attentional set-shifting task (ASST) performance. Furthermore, the dose-effects of methylphenidate (MPH) on attentional set-shifting of SHR were investigated. In experiment 1, ASST procedures were conducted in SHR, WKY and SD rats of 8 each at the age of 5 weeks. Mean latencies at the initial phase, error types and numbers, and trials to criteria at each stage were recorded. In experiment 2, 24 SHR rats were randomly assigned to 3 groups of 8 each-- MPH-L (lower dose), MPH-H (higher dose), and SHR-vehicle groups. From 3 weeks, they were administered 2.5 mg/kg or 5 mg/kg MPH or saline respectively for 14 consecutive days. All rats were tested in the ASST at the age of 5 weeks. The SHRs generally exhibited poorer performance on ASST than the control WKY and SD rats. Significant strain effects on mean latency [F (2, 21) = 639.636, p attentional set-shifting. Our study provides evidence that MPH may improve the SHR's performance on attentional set-shifting and lower dose is more effective than higher dose.

  5. Are Categorical Spatial Relations Encoded by Shifting Visual Attention between Objects?

    Science.gov (United States)

    Uttal, David; Franconeri, Steven

    2016-01-01

    Perceiving not just values, but relations between values, is critical to human cognition. We tested the predictions of a proposed mechanism for processing categorical spatial relations between two objects—the shift account of relation processing—which states that relations such as ‘above’ or ‘below’ are extracted by shifting visual attention upward or downward in space. If so, then shifts of attention should improve the representation of spatial relations, compared to a control condition of identity memory. Participants viewed a pair of briefly flashed objects and were then tested on either the relative spatial relation or identity of one of those objects. Using eye tracking to reveal participants’ voluntary shifts of attention over time, we found that when initial fixation was on neither object, relational memory showed an absolute advantage for the object following an attention shift, while identity memory showed no advantage for either object. This result is consistent with the shift account of relation processing. When initial fixation began on one of the objects, identity memory strongly benefited this fixated object, while relational memory only showed a relative benefit for objects following an attention shift. This result is also consistent, although not as uniquely, with the shift account of relation processing. Taken together, we suggest that the attention shift account provides a mechanistic explanation for the overall results. This account can potentially serve as the common mechanism underlying both linguistic and perceptual representations of spatial relations. PMID:27695104

  6. Attention, Exposure Duration, and Gaze Shifting in Naming Performance

    Science.gov (United States)

    Roelofs, Ardi

    2011-01-01

    Two experiments are reported in which the role of attribute exposure duration in naming performance was examined by tracking eye movements. Participants were presented with color-word Stroop stimuli and left- or right-pointing arrows on different sides of a computer screen. They named the color attribute and shifted their gaze to the arrow to…

  7. Rapid ecosystem shifts in peatlands: linking plant physiology and succession.

    Science.gov (United States)

    Granath, Gustaf; Strengbom, Joachim; Rydin, Håkan

    2010-10-01

    Stratigraphic records from peatlands suggest that the shift from a rich fen (calcareous fen) to an ombrotrophic bog can occur rapidly. This shift constitutes a switch from a species-rich ecosystem to a species-poor one with greater carbon storage. In this process, the invasion and expansion of acidifying bog species of Sphagnum (peat mosses) play a key role. To test under what conditions an acidifying bog species could invade a rich fen, we conducted three experiments, contrasting the bog species S. fucsum with the rich-fen species S. warnstorfii and S. teres. We first tested the effect of calcareous water by growing the three species at different constant height above the water table (HWT; 2, 7, and 14 cm) in a rich-fen pool and measured maximum photosynthetic rate and production and difference in length growth as an indicator of competition. In none of the species was the photosynthetic capacity negatively affected when placed at low HWT, but S. fuscum was a weaker competitor at low HWT. In our second experiment we transplanted the three species into microhabitats with different and naturally varying HWT in a rich fen. Here, S. fuscum nearly ceased to photosynthesize when transplanted to low HWT (brown moss carpet), while it performed similarly to the two rich-fen species at the intermediate level (S. warnstorfii hummock level). In contrast to S. fuscum, the rich-fen sphagna performed equally well in both habitats. The brown moss carpet was seasonally flooded, and in our third experiment we found that S. fuscum, but not S. teres, was severely damaged when submerged in rich-fen water. Our results suggest two thresholds in HWT affecting the ecosystem switch: one level that reduces the risk of submergence and a higher one that makes bog sphagna competitive against the rich-fen species.

  8. Dynamic Pointing Triggers Shifts of Visual Attention in Young Infants

    Science.gov (United States)

    Rohlfing, Katharina J.; Longo, Matthew R.; Bertenthal, Bennett I.

    2012-01-01

    Pointing, like eye gaze, is a deictic gesture that can be used to orient the attention of another person towards an object or an event. Previous research suggests that infants first begin to follow a pointing gesture between 10 and 13 months of age. We investigated whether sensitivity to pointing could be seen at younger ages employing a technique…

  9. Attention Modulation by Proportion Congruency: The Asymmetrical List Shifting Effect

    Science.gov (United States)

    Abrahamse, Elger L.; Duthoo, Wout; Notebaert, Wim; Risko, Evan F.

    2013-01-01

    Proportion congruency effects represent hallmark phenomena in current theorizing about cognitive control. This is based on the notion that proportion congruency determines the relative levels of attention to relevant and irrelevant information in conflict tasks. However, little empirical evidence exists that uniquely supports such an attention…

  10. Attentional Shifts between Audition and Vision in Autism Spectrum Disorders

    Science.gov (United States)

    Occelli, Valeria; Esposito, Gianluca; Venuti, Paola; Arduino, Giuseppe Maurizio; Zampini, Massimiliano

    2013-01-01

    Previous evidence on neurotypical adults shows that the presentation of a stimulus allocates the attention to its modality, resulting in faster responses to a subsequent target presented in the same (vs. different) modality. People with Autism Spectrum Disorders (ASDs) often fail to detect a (visual or auditory) target in a stream of stimuli after…

  11. Pupillary correlates of covert shifts of attention during working memory maintenance.

    Science.gov (United States)

    Unsworth, Nash; Robison, Matthew K

    2017-04-01

    The pupillary light reflex (PLR) was used to track covert shifts of attention to items maintained in visual working memory (VWM). In three experiments, participants performed a change detection task in which rectangles appeared on either side of fixation and at test participants indicated if the cued rectangle changed its orientation. Prior to presentation or during the delay, participants were cued to the light or dark side of the screen. When cued to the light side, the pupil constricted, and when cued to the dark side, the pupil dilated, suggesting that the PLR tracked covert shifts of attention. Similar covert shifts of attention were seen when the target stimuli remained onscreen and during a blank delay period, suggesting similar effects for attention to perceptual stimuli and attention to stimuli maintained in VWM. Furthermore, similar effects were demonstrated when participants were pre-cued or retro-cued to the prioritized location, suggesting that shifts of covert attention can occur both before and after target presentation. These results are consistent with prior research, suggesting an important role of covert shifts of attention during VWM maintenance and that the PLR can be used to track these covert shifts of attention.

  12. Covert shift of attention modulates the value encoding in the orbitofrontal cortex.

    Science.gov (United States)

    Xie, Yang; Nie, Chechang; Yang, Tianming

    2018-03-13

    During value-based decision making, we often evaluate the value of each option sequentially by shifting our attention, even when the options are presented simultaneously. The orbitofrontal cortex (OFC) has been suggested to encode value during value-based decision making. Yet it is not known how its activity is modulated by attention shifts. We investigated this question by employing a passive viewing task that allowed us to disentangle effects of attention, value, choice and eye movement. We found that the attention modulated OFC activity through a winner-take-all mechanism. When we attracted the monkeys' attention covertly, the OFC neuronal activity reflected the reward value of the newly attended cue. The shift of attention could be explained by a normalization model. Our results strongly argue for the hypothesis that the OFC neuronal activity represents the value of the attended item. They provide important insights toward understanding the OFC's role in value-based decision making. © 2018, Xie et al.

  13. Effects of methylphenidate on attentional set-shifting in a genetic model of attention-deficit/hyperactivity disorder

    Directory of Open Access Journals (Sweden)

    Cao Ai-hua

    2012-02-01

    Full Text Available Abstract Background Although deficits of attentional set-shifting have been reported in individuals with attention deficit/hyperactivity disorder (ADHD, it is rarely examined in animal models. Methods This study compared spontaneously hypertensive rats (SHRs; a genetic animal model of ADHD and Wistar-Kyoto (WKY and Sprague-Dawley (SD rats (normoactive control strains, on attentional set-shifting task (ASST performance. Furthermore, the dose-effects of methylphenidate (MPH on attentional set-shifting of SHR were investigated. In experiment 1, ASST procedures were conducted in SHR, WKY and SD rats of 8 each at the age of 5 weeks. Mean latencies at the initial phase, error types and numbers, and trials to criteria at each stage were recorded. In experiment 2, 24 SHR rats were randomly assigned to 3 groups of 8 each-- MPH-L (lower dose, MPH-H (higher dose, and SHR-vehicle groups. From 3 weeks, they were administered 2.5 mg/kg or 5 mg/kg MPH or saline respectively for 14 consecutive days. All rats were tested in the ASST at the age of 5 weeks. Results The SHRs generally exhibited poorer performance on ASST than the control WKY and SD rats. Significant strain effects on mean latency [F (2, 21 = 639.636, p p p p p Conclusions The SHR may be impaired in discrimination learning, reversal learning and attentional set-shifting. Our study provides evidence that MPH may improve the SHR's performance on attentional set-shifting and lower dose is more effective than higher dose.

  14. Transient inactivation of the neonatal ventral hippocampus impairs attentional set-shifting behavior

    DEFF Research Database (Denmark)

    Brooks, Julie M; Pershing, Michelle L; Thomsen, Morten Skøtt

    2012-01-01

    as adults on an attentional set-shifting task. Performance in this task depends upon the integrity of the PFC and NAC. TTX infusions did not affect the initial acquisition or ability to learn an intra-dimensional shift. However, TTX rats required a greater number of trials than did controls to acquire...

  15. Age-Related Change in Shifting Attention between Global and Local Levels of Hierarchical Stimuli

    Science.gov (United States)

    Huizinga, Mariette; Burack, Jacob A.; Van der Molen, Maurits W.

    2010-01-01

    The focus of this study was the developmental pattern of the ability to shift attention between global and local levels of hierarchical stimuli. Children aged 7 years and 11 years and 21-year-old adults were administered a task (two experiments) that allowed for the examination of 1) the direction of attention to global or local stimulus levels;…

  16. Rapid Hydrogen Shift Reactions in Acyl Peroxy Radicals

    DEFF Research Database (Denmark)

    Knap, Hasse Christian; Jørgensen, Solvejg

    2017-01-01

    -shift with X = 6, 7, 8, or 9) in the hydroperoxy acyl peroxy radicals, this H-shift is a reversible reaction and it scrambles between two peroxides, hydroperoxy acyl peroxy and peroxy peroxoic acid radicals. The forward reaction rate constants of the 1,X-OOH H-shift reactions are estimated to be above 103 s–1...... with transition state theory corrected with Eckart quantum tunnelling correction. The ratio between the forward and reverse reaction rate constant of the 1,X-OOH H-shift reactions is around ∼105. Therefore, the equilibrium is pushed toward the production of peroxy peroxoic acid radicals. These very fast 1,X-OOH H......We have used quantum mechanical chemical calculations (CCSD(T)-F12a/cc-pVDZ-F12//M06-2X/aug-cc-pVTZ) to investigate the hydrogen shift (H-shift) reactions in acyl peroxy and hydroperoxy acyl peroxy radicals. We have focused on the H-shift reactions from a hydroperoxy group (OOH) (1,X-OOH H...

  17. How does reward compete with goal-directed and stimulus-driven shifts of attention?

    Science.gov (United States)

    Bourgeois, Alexia; Neveu, Rémi; Bayle, Dimitri J; Vuilleumier, Patrik

    2017-01-01

    In order to behave adaptively, attention can be directed in space either voluntarily (i.e. endogenously) according to strategic goals, or involuntarily (i.e. exogenously) through reflexive capture by salient or novel events. The emotional or motivational values of stimuli can also influence attentional orienting. However, little is known about how reward-related effects compete or interact with endogenous and exogenous attention mechanisms. Here we designed a visual search paradigm in which goal-driven and stimulus-driven shifts of attention were manipulated by classic spatial cueing procedures, while an irrelevant, but previously rewarded stimulus also appeared as a distractor and hence competed with both types of spatial attention during search. Our results demonstrated that stimuli previously associated with a high monetary reward received higher attentional priority in the subsequent visual search task, even though these stimuli and reward were no longer task-relevant, mitigating the attentional orienting induced by both endogenous and exogenous cues.

  18. Attention and alcohol cues: a role for medial parietal cortex and shifting away from alcohol features?

    Directory of Open Access Journals (Sweden)

    Thomas Edward Gladwin

    2013-12-01

    Full Text Available Attention plays a central role in theories of alcohol dependence; however, its precise role in alcohol-related biases is not yet clear. In the current study, social drinkers performed a spatial cueing task designed to evoke conflict between automatic processes due to incentive salience and control exerted to follow task-related goals. Such conflict is a potentially important task feature from the perspective of dual-process models of addiction. Subjects received instructions either to direct their attention towards pictures of alcoholic beverages, and away from non-alcohol beverages; or to direct their attention towards pictures of non-alcoholic beverages, and away from alcohol beverages. A probe stimulus was likely to appear at the attended location, so that both spatial and non-spatial interference was possible. Activation in medial parietal cortex was found during Approach Alcohol versus Avoid Alcohol blocks. This region is associated with the, possibly automatic, shifting of attention between stimulus features, suggesting that subjects may have shifted attention away from certain features of alcoholic cues when attention had to be directed towards an upcoming stimulus at their location. Further, activation in voxels close to this region was negatively correlated with riskier drinking behavior. A tentative interpretation of the results is that risky drinking may be associated with a reduced tendency to shift attention away from potentially distracting task-irrelevant alcohol cues. The results suggest novel hypotheses and directions for future study, in particular towards the potential therapeutic use of training the ability to shifting attention away from alcohol-related stimulus features.

  19. Cortical mechanisms of cognitive control for shifting attention in vision and working memory.

    Science.gov (United States)

    Tamber-Rosenau, Benjamin J; Esterman, Michael; Chiu, Yu-Chin; Yantis, Steven

    2011-10-01

    Organisms operate within both a perceptual domain of objects and events, and a mnemonic domain of past experiences and future goals. Each domain requires a deliberate selection of task-relevant information, through deployments of external (perceptual) and internal (mnemonic) attention, respectively. Little is known about the control of attention shifts in working memory, or whether voluntary control of attention in these two domains is subserved by a common or by distinct functional networks. We used human fMRI to examine the neural basis of cognitive control while participants shifted attention in vision and in working memory. We found that these acts of control recruit in common a subset of the dorsal fronto-parietal attentional control network, including the medial superior parietal lobule, intraparietal sulcus, and superior frontal sulcus/gyrus. Event-related multivoxel pattern classification reveals, however, that these regions exhibit distinct spatio-temporal patterns of neural activity during internal and external shifts of attention, respectively. These findings constrain theoretical accounts of selection in working memory and perception by showing that populations of neurons in dorsal fronto-parietal network regions exhibit selective tuning for acts of cognitive control in different cognitive domains.

  20. Rapid shift in substrate utilization driven by hypothalamic Agrp neurons

    OpenAIRE

    Cavalcanti-De-Albuquerque, Joao; Dietrich, Marcelo; Bober, Jeremy; Zimmer, Marcelo

    2016-01-01

    Agrp neurons drive feeding. To what extend these neurons participate in the regulation of other homeostatic processes is not well understood. We investigated the role of Agrp neurons in substrate utilization in mice. Activation of Agrp neurons was sufficient to rapidly increase RER and carbohydrate utilization, while decreasing fat utilization. These metabolic changes were linearly correlated with carbohydrates ingested, but not protein or fat ingestion. However, even in the absence of ingest...

  1. Learning in shifts of transient attention improves recognition of parts of ambiguous figure-ground displays.

    Science.gov (United States)

    Kristjánsson, Arni

    2009-04-24

    Previously demonstrated learning effects in shifts of transient attention have only been shown to result in beneficial effects upon secondary discrimination tasks and affect landing points of express saccades. Can such learning result in more direct effects upon perception than previously demonstrated? Observers performed a cued Vernier acuity discrimination task where the cue was one of a set of ambiguous figure-ground displays (with a black and white part). The critical measure was whether, if a target appeared consistently within a part of a cue of a certain brightness, this would result in learning effects and whether such learning would then affect recognition of the cue parts. Critically the target always appeared within the same part of each individual cue. Some cues were used in early parts of streaks of repetition of cue-part brightness, and others in latter parts of such streaks. All the observers showed learning in shifts of transient attention, with improved performance the more often the target appeared within the part of the cue of the same brightness. Subsequently the observers judged whether cue-parts had been parts of the cues used on the preceding discrimination task. Recognition of the figure parts, where the target had consistently appeared, improved strongly with increased length of streaks of repetition of cue-part brightness. Learning in shifts of transient attention leads not only to faster attention shifts but to direct effects upon perception, in this case recognition of parts of figure-ground ambiguous cues.

  2. Endogenous and Exogenous Attention Shifts are Mediated by the Same Large-Scale Neural Network.

    NARCIS (Netherlands)

    Peelen, M.V.; Heslenfeld, D.J.; Theeuwes, J.

    2004-01-01

    Event-related fMRI was used to examine the neural basis of endogenous (top-down) and exogenous (bottom-up) spatial orienting. Shifts of attention were induced by central (endogenous) or peripheral (exogenous) cues. Reaction times on subsequently presented targets showed the expected pattern of

  3. Rapid influences of cued visual memories on attentional guidance

    NARCIS (Netherlands)

    van Moorselaar, D.; Battistoni, E.; Theeuwes, J.; Olivers, C.N.L.

    2015-01-01

    There is evidence that the deployment of attention can be biased by the content of visual working memory. Recently, it has been shown that focusing internal attention to a specific item in memory not only increases the accessibility of that specific item for retrieval, but also results in increased

  4. Right prefrontal TMS disrupts interregional anticipatory EEG alpha activity during shifting of visuospatial attention

    Directory of Open Access Journals (Sweden)

    Paul eSauseng

    2011-10-01

    Full Text Available Visual attention can be shifted in space without moving the eyes. Amplitude decrease of rhythmical brain activity around 10 Hz (so called alpha activity at contralateral posterior sites has been reported during covert shifts of visuospatial attention to one visual hemifield. Alpha amplitude increase, on the other hand, can be found at ipsilateral visual cortex. There is some evidence suggesting an involvement of prefrontal brain areas during the control of attention-related anticipatory alpha amplitude asymmetry. However, the exact neural mechanism by which prefrontal cortex influences visual processing has not been completely clear yet. This open question has been studied in detail using a multimodal approach combining transcranial magnetic stimulation (TMS and multichannel electroencephalography (EEG in healthy humans. Slow (1 Hz repetitive TMS inducing an inhibitory effect at the stimulation site was delivered either to right frontal eye field or a control site (vertex. Subsequently, participants had to perform a spatial cueing task in which covert shifts of attention were required to either the left or the right visual hemi-field. After stimulation at the vertex (control condition a pattern of anticipatory, attention-related ipsilateral alpha increase / contralateral alpha decrease over posterior recording sites could be obtained. Additionally, there was pronounced coupling between (in particular right FEF and posterior brain sites. When, however, the right prefrontal cortex had been virtually lesioned preceding the task, these EEG correlates of visuospatial attention were attenuated. Notably, the effect of TMS at the right FEF on interregional fronto-parietal alpha coupling predicted the effect on response times. This suggests that visual attention processes associated with posterior EEG alpha activity are at least partly top-down controlled by the prefrontal cortex.

  5. High spatial validity is not sufficient to elicit voluntary shifts of attention.

    Science.gov (United States)

    Pauszek, Joseph R; Gibson, Bradley S

    2016-10-01

    Previous research suggests that the use of valid symbolic cues is sufficient to elicit voluntary shifts of attention. The present study interpreted this previous research within a broader theoretical context which contends that observers will voluntarily use symbolic cues to orient their attention in space when the temporal costs of using the cues are perceived to be less than the temporal costs of searching without the aid of the cues. In this view, previous research has not addressed the sufficiency of valid symbolic cues, because the temporal cost of using the cues is usually incurred before the target display appears. To address this concern, 70%-valid spatial word cues were presented simultaneously with a search display. In addition, other research suggests that opposing cue-dependent and cue-independent spatial biases may operate in these studies and alter standard measures of orienting. After identifying and controlling these opposing spatial biases, the results of two experiments showed that the word cues did not elicit voluntary shifts of attention when the search task was relatively easy but did when the search task was relatively difficult. Moreover, the findings also showed that voluntary use of the word cues changed over the course of the experiment when the task was difficult, presumably because the temporal cost of searching without the cue lessened as the task got easier with practice. Altogether, the present findings suggested that the factors underlying voluntary control are multifaceted and contextual, and that spatial validity alone is not sufficient to elicit voluntary shifts of attention.

  6. Physiological Measures of Dopaminergic and Noradrenergic Activity During Attentional Set Shifting and Reversal

    Directory of Open Access Journals (Sweden)

    Péter Pajkossy

    2018-04-01

    Full Text Available Dopamine (DA and noradrenaline (NA are important neurotransmitters, which are suggested to play a vital role in modulating the neural circuitry involved in the executive control of cognition. One way to investigate the functions of these neurotransmitter systems is to assess physiological indices of DA and NA transmission. Here we examined how variations of spontaneous eye-blink rate and pupil size, as indirect measures of DA and NA activity, respectively, are related to performance in a hallmark aspect of executive control: attentional set shifting. We used the Intra/Extradimensional Set Shifting Task, where participants have to choose between different compound stimuli while the stimulus-reward contingencies change periodically. During such rule shifts, participants have to refresh their attentional set while they reassess which stimulus-features are relevant. We found that both eye-blink rate (EBR and pupil size increased after rule shifts, when explorative processes are required to establish stimulus–reward contingencies. Furthermore, baseline pupil size was related to performance during the most difficult, extradimensional set shifting stage, whereas baseline EBR was associated with task performance prior to this stage. Our results support a range of neurobiological models suggesting that the activity of DA and NA neurotransmitter systems determines individual differences in executive functions (EF, possibly by regulating neurotransmission in prefrontal circuits. We also suggest that assessing specific, easily accessible indirect physiological markers, such as pupil size and blink rate, contributes to the comprehension of the relationship between neurotransmitter systems and EF.

  7. Experimental shift work studies of permanent night, and rapidly rotating, shift systems. Pt. 1. Behaviour of various characteristics of sleep

    Energy Technology Data Exchange (ETDEWEB)

    Knauth, P.; Rutenfranz, J.; Romberg, H.P.; Decoster, F.; Kiesswetter, E. (Dortmund Univ. (Germany, F.R.). Inst. fuer Arbeitsphysiologie); Schulz, H. (Max-Planck-Institut fuer Psychiatrie, Muenchen (Germany, F.R.). Klinisches Inst.)

    1980-06-01

    In connection with experimental shift work 20 volunteers were examined while working on different rapidly or slowly rotating shift systems. Sleep was analyzed over a total of 112 days. Sleep was disturbed by children's noise or traffic noise. Sleep duration and sleep quality were particularly badly affected by noise with a high information value (children's noise). The ultradian rhythmicity of sleep did not appear to be disrupted by the change from day to night work. There were no significant differences between morning sleep and afternoon sleep after night work. In the laboratory experiments with fixed sleep durations, no separate effects on sleep quality could be established for different shift systems.

  8. Division of attention as a function of the number of steps, visual shifts, and memory load

    Science.gov (United States)

    Chechile, R. A.; Butler, K.; Gutowski, W.; Palmer, E. A.

    1986-01-01

    The effects on divided attention of visual shifts and long-term memory retrieval during a monitoring task are considered. A concurrent vigilance task was standardized under all experimental conditions. The results show that subjects can perform nearly perfectly on all of the time-shared tasks if long-term memory retrieval is not required for monitoring. With the requirement of memory retrieval, however, there was a large decrease in accuracy for all of the time-shared activities. It was concluded that the attentional demand of longterm memory retrieval is appreciable (even for a well-learned motor sequence), and thus memory retrieval results in a sizable reduction in the capability of subjects to divide their attention. A selected bibliography on the divided attention literature is provided.

  9. Rotating night shifts too quickly may cause anxiety and decreased attentional performance, and impact prolactin levels during the subsequent day: a case control study.

    Science.gov (United States)

    Chang, Yu-San; Chen, Hsiang-Lan; Wu, Yu-Hsuan; Hsu, Chung-Yao; Liu, Ching-Kuan; Hsu, Chin

    2014-08-05

    We investigated circadian changes and effects on mood, sleep-related hormones and cognitive performance when nurses worked consecutive night shifts in a rapidly rotating shift system. Daytime cognitive function, sleep propensity and sleep-related hormones (growth hormone, cortisol, prolactin, thyrotropin) were compared after participants worked two and four consecutive night shifts. Twenty-three off-duty nurses, 20 nurses working two consecutive night shifts and 16 nurses working four consecutive night shifts were enrolled. All participants completed the Maintenance of Wakefulness Test, State-Trait Anxiety Inventory, Stanford Sleepiness Scale, visual attention tasks (VAT), Wisconsin Card Sorting Test, and modified Multiple Sleep Latency Test. Hormone levels were also measured four times throughout the day, at 2-h intervals. During the day, the participants in the night shift groups were less able to maintain wakefulness, had poor performance on VAT, and higher thyrotropin levels than did those in the off-duty group. Participants who worked two night shifts were better able to maintain wakefulness, had higher anxiety scale scores, poorer initial performance and lack of learning effect on VAT, and higher prolactin levels compared with those who worked four night shifts. There were no differences in cortisol levels between the two- and four- shift groups. Rotating night shifts too quickly may cause anxiety and decreased attentional performance, and may impact daytime prolactin levels after night shifts. It is possible that the two-shift group had a higher cortisol level than did the four-shift group, which would be consistent with the group's higher state anxiety scores. The negative findings may be due to the small sample size. Further studies on the effects of consecutive night shifts on mood and cortisol levels during the daytime after sleep restriction would be valuable.

  10. Reward learning and negative emotion during rapid attentional competition

    Directory of Open Access Journals (Sweden)

    Takemasa eYokoyama

    2015-03-01

    Full Text Available Learned stimulus-reward associations influence how attention is allocated, such that stimuli rewarded in the past are favored in situations involving limited resources and competition. At the same time, task-irrelevant, high-arousal negative stimuli capture attention and divert resources away from tasks resulting in poor behavioral performance. Yet, investigations of how reward learning and negative stimuli affect perceptual and attentional processing have been conducted in a largely independent fashion. We have recently reported that performance-based monetary rewards reduce negative stimuli interference during perception. The goal of the present study was to investigate how stimuli associated with past monetary rewards compete with negative stimuli during a subsequent attentional task when, critically, no performance-based rewards were at stake. Across two experiments, we found that target stimuli that were associated with high reward reduced the interference effect of potent, negative distractors. Similar to our recent findings with performance-based rewards, our results demonstrate that reward-associated stimuli reduce the deleterious impact of negative stimuli on behavior.

  11. Auditory Attention and Comprehension During a Simulated Night Shift: Effects of Task Characteristics.

    Science.gov (United States)

    Pilcher, June J; Jennings, Kristen S; Phillips, Ginger E; McCubbin, James A

    2016-11-01

    The current study investigated performance on a dual auditory task during a simulated night shift. Night shifts and sleep deprivation negatively affect performance on vigilance-based tasks, but less is known about the effects on complex tasks. Because language processing is necessary for successful work performance, it is important to understand how it is affected by night work and sleep deprivation. Sixty-two participants completed a simulated night shift resulting in 28 hr of total sleep deprivation. Performance on a vigilance task and a dual auditory language task was examined across four testing sessions. The results indicate that working at night negatively impacts vigilance, auditory attention, and comprehension. The effects on the auditory task varied based on the content of the auditory material. When the material was interesting and easy, the participants performed better. Night work had a greater negative effect when the auditory material was less interesting and more difficult. These findings support research that vigilance decreases during the night. The results suggest that auditory comprehension suffers when individuals are required to work at night. Maintaining attention and controlling effort especially on passages that are less interesting or more difficult could improve performance during night shifts. The results from the current study apply to many work environments where decision making is necessary in response to complex auditory information. Better predicting the effects of night work on language processing is important for developing improved means of coping with shiftwork. © 2016, Human Factors and Ergonomics Society.

  12. The shift to rapid job placement for people living with mental illness: an analysis of consequences.

    Science.gov (United States)

    Gewurtz, Rebecca E; Cott, Cheryl; Rush, Brian; Kirsh, Bonnie

    2012-12-01

    This article reports on the consequences of the revised policy for employment supports within the Ontario Disability Support Program, a disability benefit program administered by the provincial government in Ontario, Canada. The revised policy involves a change from a fee-for-service model to an outcome-based funding model. This revision has encouraged a shift from preemployment to job placement services, with a particular focus on rapid placement into available jobs. Using a qualitative case study approach, 25 key informant interviews were conducted with individuals involved in developing or implementing the policy, or delivering employment services for individuals living with mental illness under the policy. Policy documents were also reviewed in order to explore the intent of the policy. Analysis focused on exploring how the policy has been implemented in practice, and its impact on employment services for individuals living with mental illness. The findings highlight how employment support practices have evolved under the new policy. Although there is now an increased focus on employment rather than preemployment supports, the financial imperative to place individuals into jobs as quickly as possible has decreased attention to career development. Jobs are reported to be concentrated at the entry-level with low pay and little security or benefits. These findings raise questions about the quality of employment being achieved under the new policy, highlight problems with adopting selected components of evidence-based approaches, and begin to explicate the influence that funding structures can have on practice.

  13. The impact of social threat cues on a card sorting task with attentional-shifting demands.

    Science.gov (United States)

    Mohlman, Jan; DeVito, Alyssa

    2017-12-01

    The current study investigated social anxiety and attentional control using two versions of a task designed to tap intentional shifting of attention and set switching: the standard Wisconsin Card Sorting Test (WCST; Heaton, 1981) and a modified version that included emotionally salient pictorial stimuli, the Emotional Faces Card Sorting Test (EFCST). A Group (lower-, higher-SPS) by Condition (WCST, EFCST) by Sorting Rule (color, form, number) interaction was expected in which the higher-SPS EFCST group would have worse overall performance and make more perseverative errors than the other groups. No differences were predicted on nonperseverative errors, which are typically caused by brief attentional lapses. Participants were 80 undergraduate students who scored in the upper and lower quartile of the distribution on the Social Phobia Scale (SPS; Mattick & Clarke, 1998) were randomly assigned to complete either the WCST or EFCST. On the WCST, the higher-SPS group showed performance similar to that of the lower-SPS group. On the EFCST, the higher-SPS group evidenced more perseverative errors in the condition that depicted angry faces. Interpretations based on a non-clinical sample limit the generalisability of the conclusions. Reliability of this new measure has yet to be established. Successful completion of the WCST requires more than set-shifting processes. These results suggest that the higher-SPS group in the EFCST condition might have had trouble disengaging attention from threat-related cues, despite ongoing corrective feedback. Copyright © 2017. Published by Elsevier Ltd.

  14. Selective, sustained, and shift in attention in patients with diagnoses of schizophrenia.

    Science.gov (United States)

    Hagh-Shenas, H; Toobai, S; Makaremi, A

    2002-12-01

    Attentional deficits are a prominent aspect of cognitive dysfunction in schizophrenia. The present study was designed to investigate attention deficit in a group of patients with diagnosis of schizophrenia. According to the segmental set theory suggested by Hogarty and Flesher, three aspects of attention problems, selective, sustained, and shift in attention, were studied. The 30 patients hospitalized on three psychiatric wards at Shiraz and Isfahan and 30 normal healthy subjects matched for age, sex, and years of education were administered a computerized Continuous Performance Test, Stroop Color-word Test, and Wisconsin Card Sorting test. Analysis showed patients performed more poorly than control subjects on measured aspects of attention. The acute/chronic classification did not predict differences in attention scores between subtypes of schizophrenia, while the positive/negative classification did. Paranoid, undifferentiated, and residual groups by subtypes of schizophrenia showed similar performance on the Continuous Performance Test, but were significantly different on errors on the Wisconsin Card Sorting test and on reaction time to Stroop stimuli in the incongruent color-word condition. Patients with paranoid diagnosis performed better than other subtypes on these tasks. Present results suggest that the Continuous Performance Test is valuable for differentiating of schizophrenia spectrum disorder, while scores on Stroop and Wisconsin card sorting may have better diagnostic value for differentiating subtypes of the disorder.

  15. Dissociating location-specific inhibition and attention shifts: evidence against the disengagement account of contingent capture.

    Science.gov (United States)

    Anderson, Brian A; Folk, Charles L

    2012-08-01

    The study of attentional capture has provided a rich context for assessing the relative influence of top-down and bottom-up factors in visual perception. Some have argued that attentional capture by a salient, irrelevant stimulus is contingent on top-down attentional set (e.g., Folk, Remington, & Johnston, Journal of Experimental Psychology: Human Perception and Performance 18:1030-1044, 1992). Others, however, have argued that capture is driven entirely by bottom-up salience and that top-down factors influence the postallocation speed of disengagement from the irrelevant stimulus (e.g., Theeuwes, Acta Psychologica 135:77-99, 2010a). In support of this speed-of-disengagement hypothesis, recent findings from the modified spatial-cuing paradigm show that cues carrying a no-go target property produce reverse, or negative, cuing effects, consistent with inhibition of the cue location from which attention has been very quickly disengaged (Belopolsky, Schreij, & Theeuwes, Perception, & Psychophysics, 72, 326-341, 2010). Across six experiments, we show that this inhibitory process can be dissociated from shifts of spatial attention and is, thus, not a reliable marker of capture. We conclude that the data are inconsistent with the predictions of the disengagement hypothesis.

  16. Feature-Selective Attention Adaptively Shifts Noise Correlations in Primary Auditory Cortex.

    Science.gov (United States)

    Downer, Joshua D; Rapone, Brittany; Verhein, Jessica; O'Connor, Kevin N; Sutter, Mitchell L

    2017-05-24

    Sensory environments often contain an overwhelming amount of information, with both relevant and irrelevant information competing for neural resources. Feature attention mediates this competition by selecting the sensory features needed to form a coherent percept. How attention affects the activity of populations of neurons to support this process is poorly understood because population coding is typically studied through simulations in which one sensory feature is encoded without competition. Therefore, to study the effects of feature attention on population-based neural coding, investigations must be extended to include stimuli with both relevant and irrelevant features. We measured noise correlations ( r noise ) within small neural populations in primary auditory cortex while rhesus macaques performed a novel feature-selective attention task. We found that the effect of feature-selective attention on r noise depended not only on the population tuning to the attended feature, but also on the tuning to the distractor feature. To attempt to explain how these observed effects might support enhanced perceptual performance, we propose an extension of a simple and influential model in which shifts in r noise can simultaneously enhance the representation of the attended feature while suppressing the distractor. These findings present a novel mechanism by which attention modulates neural populations to support sensory processing in cluttered environments. SIGNIFICANCE STATEMENT Although feature-selective attention constitutes one of the building blocks of listening in natural environments, its neural bases remain obscure. To address this, we developed a novel auditory feature-selective attention task and measured noise correlations ( r noise ) in rhesus macaque A1 during task performance. Unlike previous studies showing that the effect of attention on r noise depends on population tuning to the attended feature, we show that the effect of attention depends on the tuning

  17. Evaluation of a neurodevelopmental model of schizophrenia - Early postnatal PCP treatment in attentional set-shifting

    DEFF Research Database (Denmark)

    Broberg, B.V.; Dias, R.; Olsen, C.K.

    2008-01-01

    Phencyclidine (PCP) was administered to male and female Lister hooded rats on postnatal days (PND) 7, 9 and 11. All PCP animals tested in adulthood (PND 53-93) showed deficits in cognitive flexibility, specifically in their ability to shift attentional set, compared to controls. This novel finding...... is reminiscent of the impairment observed in schizophrenia patients, and supports the validity of the early postnatal PCP regimen as a disease-like model. (c) 2008 Elsevier B.V. All rights reserved Udgivelsesdato: 2008...

  18. Attenuating the alcohol allure: attentional broadening reduces rapid motivational response to alcohol pictures.

    Science.gov (United States)

    Ryerson, Nicole C; Neal, Lauren B; Gable, Philip A

    2017-04-01

    Past research has found that exposure to alcohol cues causes a narrowing of attentional scope and enhances the neural responses associated with approach motivation. The current research sought to determine if a manipulated broadened (global) attentional scope would reduce approach-motivated neural reactivity to alcohol pictures. In the current study, participants (n = 82) were exposed to alcohol and neutral pictures following either a global or local attentional scope manipulation. Early motivated attentional processing was assessed using the N1 event-related potential (ERP), a neurophysiological marker of rapid motivated attention. A global attentional scope reduced N1 amplitudes to alcohol pictures as compared to a local attentional scope. Self-reported binge drinking related to larger N1 amplitudes to alcohol pictures, but not to neutral pictures. Individuals with greater binge drinking experience demonstrated increased rapid motivated attentional processing to alcohol pictures. These results suggest that enhancing a global (vs. local) attentional scope attenuates rapid motivated attentional processing of alcohol pictures in comparison to neutral pictures. Graphical abstract ᅟ.

  19. Expectation violations in sensorimotor sequences: shifting from LTM-based attentional selection to visual search.

    Science.gov (United States)

    Foerster, Rebecca M; Schneider, Werner X

    2015-03-01

    Long-term memory (LTM) delivers important control signals for attentional selection. LTM expectations have an important role in guiding the task-driven sequence of covert attention and gaze shifts, especially in well-practiced multistep sensorimotor actions. What happens when LTM expectations are disconfirmed? Does a sensory-based visual-search mode of attentional selection replace the LTM-based mode? What happens when prior LTM expectations become valid again? We investigated these questions in a computerized version of the number-connection test. Participants clicked on spatially distributed numbered shapes in ascending order while gaze was recorded. Sixty trials were performed with a constant spatial arrangement. In 20 consecutive trials, either numbers, shapes, both, or no features switched position. In 20 reversion trials, participants worked on the original arrangement. Only the sequence-affecting number switches elicited slower clicking, visual search-like scanning, and lower eye-hand synchrony. The effects were neither limited to the exchanged numbers nor to the corresponding actions. Thus, expectation violations in a well-learned sensorimotor sequence cause a regression from LTM-based attentional selection to visual search beyond deviant-related actions and locations. Effects lasted for several trials and reappeared during reversion. © 2015 New York Academy of Sciences.

  20. Behavioral performance follows the time course of neural facilitation and suppression during cued shifts of feature-selective attention

    OpenAIRE

    Andersen, S. K.; Müller, M. M.

    2010-01-01

    A central question in the field of attention is whether visual processing is a strictly limited resource, which must be allocated by selective attention. If this were the case, attentional enhancement of one stimulus should invariably lead to suppression of unattended distracter stimuli. Here we examine voluntary cued shifts of feature-selective attention to either one of two superimposed red or blue random dot kinematograms (RDKs) to test whether such a reciprocal relationship between enhanc...

  1. Behavioral inhibition and anxiety: The moderating roles of inhibitory control and attention shifting

    Science.gov (United States)

    White, Lauren K.; McDermott, Jennifer Martin; Degnan, Kathryn A.; Henderson, Heather A.; Fox, Nathan A.

    2013-01-01

    Behavioral inhibition (BI), a temperament identified in early childhood, is associated with social reticence in childhood and an increased risk for anxiety problems in adolescence and adulthood. However, not all behaviorally inhibited children remain reticent or develop an anxiety disorder. One possible mechanism accounting for the variability in the developmental trajectories of BI is a child’s ability to successfully recruit cognitive processes involved in the regulation of negative reactivity. However, separate cognitive processes may differentially moderate the association between BI and later anxiety problems. The goal of the current study was to examine how two cognitive processes - attention shifting and inhibitory control - laboratory assessed at 48 months of age moderated the association between 24-month BI and anxiety symptoms in the preschool years. Results revealed that high levels of attention shifting decreased the risk for anxiety symptoms in children with high levels of BI, whereas high levels of inhibitory control increased this risk for anxiety symptoms. These findings suggest that different cognitive processes may influence relative levels of risk or adaptation depending upon a child’s temperamental reactivity. PMID:21301953

  2. Right hemispheric dominance and interhemispheric cooperation in gaze-triggered reflexive shift of attention.

    Science.gov (United States)

    Okada, Takashi; Sato, Wataru; Kubota, Yasutaka; Toichi, Motomi; Murai, Toshiya

    2012-03-01

    The neural substrate for the processing of gaze remains unknown. The aim of the present study was to clarify which hemisphere dominantly processes and whether bilateral hemispheres cooperate with each other in gaze-triggered reflexive shift of attention. Twenty-eight normal subjects were tested. The non-predictive gaze cues were presented either in unilateral or bilateral visual fields. The subjects localized the target as soon as possible. Reaction times (RT) were shorter when gaze-cues were congruent toward than away from targets, whichever visual field they were presented in. RT were shorter in left than right visual field presentations. RT in mono-directional bilateral presentations were shorter than both of those in left and right presentations. When bi-directional bilateral cues were presented, RT were faster when valid cues were presented in the left than right visual fields. The right hemisphere appears to be dominant, and there is interhemispheric cooperation in gaze-triggered reflexive shift of attention. © 2012 The Authors. Psychiatry and Clinical Neurosciences © 2012 Japanese Society of Psychiatry and Neurology.

  3. Addition and Subtraction but Not Multiplication and Division Cause Shifts of Spatial Attention

    Directory of Open Access Journals (Sweden)

    Mengjin Li

    2018-05-01

    Full Text Available Many studies have shown that solving addition and subtraction problems can induce overt shifts of spatial attention. In particular, right-side targets are detected faster than left-side targets when preceded by an addition operation, while left-side targets are detected faster than right-side targets when preceded by a subtraction operation. However, the interaction between space and arithmetic in multiplication or division is hardly studied and remains controversial. In order to make a strong case for the interaction between space and mental arithmetic, we attempted to replicate the spatial-arithmetic association in addition and subtraction (Experiment 1, and at the same time investigated whether shift of spatial attention would also be induced by multiplication or division operations (Experiment 2. We found that solving addition problems facilitated the detection of right-side targets, whereas left-side targets were detected faster after solving subtraction problems. However, no interaction between space and arithmetic operation was observed in multiplication or division. The implication of these findings is discussed.

  4. Decoding the Charitable Brain: Empathy, Perspective Taking, and Attention Shifts Differentially Predict Altruistic Giving.

    Science.gov (United States)

    Tusche, Anita; Böckler, Anne; Kanske, Philipp; Trautwein, Fynn-Mathis; Singer, Tania

    2016-04-27

    Altruistic behavior varies considerably across people and decision contexts. The relevant computational and motivational mechanisms that underlie its heterogeneity, however, are poorly understood. Using a charitable giving task together with multivariate decoding techniques, we identified three distinct psychological mechanisms underlying altruistic decision-making (empathy, perspective taking, and attentional reorienting) and linked them to dissociable neural computations. Neural responses in the anterior insula (AI) (but not temporoparietal junction [TPJ]) encoded trial-wise empathy for beneficiaries, whereas the TPJ (but not AI) predicted the degree of perspective taking. Importantly, the relative influence of both socio-cognitive processes differed across individuals: participants whose donation behavior was heavily influenced by affective empathy exhibited higher predictive accuracies for generosity in AI, whereas those who strongly relied on cognitive perspective taking showed improved predictions of generous donations in TPJ. Furthermore, subject-specific contributions of both processes for donations were reflected in participants' empathy and perspective taking responses in a separate fMRI task (EmpaToM), suggesting that process-specific inputs into altruistic choices may reflect participants' general propensity to either empathize or mentalize. Finally, using independent attention task data, we identified shared neural codes for attentional reorienting and generous donations in the posterior superior temporal sulcus, suggesting that domain-general attention shifts also contribute to generous behavior (but not in TPJ or AI). Overall, our findings demonstrate highly specific roles of AI for affective empathy and TPJ for cognitive perspective taking as precursors of prosocial behavior and suggest that these discrete routes of social cognition differentially drive intraindividual and interindividual differences in altruistic behavior. Human societies depend on

  5. Attention and Related Factors in Tehran Night Shift Prehospital Emergency Personnel

    Directory of Open Access Journals (Sweden)

    Abbasali Ebrahimian

    2015-10-01

    Full Text Available Background:  Emergency  medical  services  (EMS  staff  can  play  an  important  role  in  the survival and prevention of serious injuries to patients if they are in good physical and mental health and focus on doing their jobs with sufficient attention. Therefore, a study was conducted to  investigate  attention  level  and  its  related  factors  in  night  shift  prehospital  emergency personnel. Materials and Methods: This research is a descriptive-analytic study. A total of 114 Tehran prehospital emergency staff participated in this study. Pen and paper Bonnardel test and a questionnaire was used to collect information. The attention of the participants was assessed around 10-11 PM and 4-5 AM. The data were analyzed by using the Spearman correlation coefficient and independent t test. Results:  Mean  attention  level  of  EMS  staff  was  0.490±0.237  around  10-11  PM  and 0.456±0.252  around 4-5 AM. There  was  no  statistically  significant  difference  between  the attention level of prehospital emergency staff around 10-11 PM and 4-5 AM (P˃0.01. Also, there was significant difference between age and the night attention (P<0.01. Conclusion: The mean level of night attention of EMS staff was moderate. Therefore, based on the average number of daily missions in different bases, we recommend increasing the number of ambulances in the base or the number of bases in the crowded emergency areas. It is also necessary to increase welfare and nutritional facilities in prehospital emergency bases so that those who are older and experienced carry out fewer missions.

  6. An online brain-computer interface based on shifting attention to concurrent streams of auditory stimuli

    Science.gov (United States)

    Hill, N. J.; Schölkopf, B.

    2012-04-01

    We report on the development and online testing of an electroencephalogram-based brain-computer interface (BCI) that aims to be usable by completely paralysed users—for whom visual or motor-system-based BCIs may not be suitable, and among whom reports of successful BCI use have so far been very rare. The current approach exploits covert shifts of attention to auditory stimuli in a dichotic-listening stimulus design. To compare the efficacy of event-related potentials (ERPs) and steady-state auditory evoked potentials (SSAEPs), the stimuli were designed such that they elicited both ERPs and SSAEPs simultaneously. Trial-by-trial feedback was provided online, based on subjects' modulation of N1 and P3 ERP components measured during single 5 s stimulation intervals. All 13 healthy subjects were able to use the BCI, with performance in a binary left/right choice task ranging from 75% to 96% correct across subjects (mean 85%). BCI classification was based on the contrast between stimuli in the attended stream and stimuli in the unattended stream, making use of every stimulus, rather than contrasting frequent standard and rare ‘oddball’ stimuli. SSAEPs were assessed offline: for all subjects, spectral components at the two exactly known modulation frequencies allowed discrimination of pre-stimulus from stimulus intervals, and of left-only stimuli from right-only stimuli when one side of the dichotic stimulus pair was muted. However, attention modulation of SSAEPs was not sufficient for single-trial BCI communication, even when the subject's attention was clearly focused well enough to allow classification of the same trials via ERPs. ERPs clearly provided a superior basis for BCI. The ERP results are a promising step towards the development of a simple-to-use, reliable yes/no communication system for users in the most severely paralysed states, as well as potential attention-monitoring and -training applications outside the context of assistive technology.

  7. Just a minute meditation: Rapid voluntary conscious state shifts in long term meditators.

    Science.gov (United States)

    Nair, Ajay Kumar; Sasidharan, Arun; John, John P; Mehrotra, Seema; Kutty, Bindu M

    2017-08-01

    Meditation induces a modified state of consciousness that remains under voluntary control. Can meditators rapidly and reversibly bring about mental state changes on demand? To check, we carried out 128 channel EEG recordings on Brahma Kumaris Rajayoga meditators (36 long term: median 14240h meditation; 25 short term: 1095h) and controls (25) while they tried to switch every minute between rest and meditation states in different conditions (eyes open and closed; before and after an engaging task). Long term meditators robustly shifted states with enhanced theta power (4-8Hz) during meditation. Short term meditators had limited ability to shift between states and showed increased lower alpha power (8-10Hz) during eyes closed meditation only when pre and post task data were combined. Controls could not shift states. Thus trained beginners can reliably meditate but it takes long term practice to exercise more refined control over meditative states. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Mazindol attenuates ketamine-induced cognitive deficit in the attentional set shifting task in rats.

    Science.gov (United States)

    Nikiforuk, Agnieszka; Gołembiowska, Krystyna; Popik, Piotr

    2010-01-01

    Cognitive impairments associated with schizophrenia await an effective treatment. In order to model schizophrenia-like cognitive deficits in rats, we evaluated the effects of ketamine, a dissociative anesthetic NMDA/glutamate receptor channel blocker in the attentional set-shifting task (ASST). Acute administration of ketamine (10 but not 3mg/kg) selectively impaired solving of the extradimensional (ED) set-shifting component. Next, we investigated whether the co-administration of mazindol, a dopamine and norepinephrine reuptake inhibitor would protect rats from ketamine-induced deficits. Mazindol dose-dependently and selectively alleviated ketamine-induced ED deficit with a minimal effective dose of 0.5mg/kg. The ED component improvement was noted primarily in ketamine - but not in vehicle co-treated rats, in which the drug facilitated ED shift solving at the dose as high as 5mg/kg. A "positive control", sertindole (2.5mg/kg) also ameliorated ketamine-induced ED deficit. Microdialysis of the prefrontal cortex in a separate group of animals revealed that 2-3h after the administration of 5mg/kg of mazindol and ketamine (i.e., at the time of ED component solving), the extracellular concentrations of dopamine were enhanced by ~300% as compared to the baseline and were intermediate between the mazindol- and ketamine-treated reference groups. However, at that time the levels of norepinephrine, serotonin and glutamate appeared unaffected. We conclude that ketamine may be useful in mimicking deficits specifically related to cognitive inflexibility observed in schizophrenia, and suggest that these anomalies could be ameliorated by mazindol. The beneficial effects of mazindol on ASST performance may have therapeutic implications for the treatment of schizophrenia.

  9. Comparison of shifting attention function in 7-13-years-old children with fluent speech and developmental stuttering

    Directory of Open Access Journals (Sweden)

    Kowsar Esfandeh

    2014-04-01

    Full Text Available Background and Aim: Attention has causal role in speech and language processing. Studies are limited about relation between attention and language development. As a result, the purpose of this study was to investigate the difference shifting attention function in children with developmental stuttering and fluent speech.Methods: Thirty children who stutter (21 boys and 9 girls and thirty children who did not stutter (21 boys and 9 girls were evaluated. Shifting attention function was investigated using Wisconsin card sorting test. The data were analyzed via Kolmogorov-Smirnov, independent t, and Mann-Whitney U-tests.Results: Between group analysis showed significant differences for all of the indexes in Wisconsin card sorting test . The number of categories completed in children who stutter was significantly less than that control group (p<0.05. But preservative errors, total errors, total tries, time of test performance and try for first pattern in children who stutter was more than in the control group and data differences were significant for all of the indexes (p<0.05.Conclusion: The findings of this study show that children with and without stuttering are different in shifting attention function and children who stutter have weaker function in shifting attention. The findings were linked to emerging theoretical frameworks of stuttering development and that were taken to suggest a possible role for attention processes in developmental stuttering.

  10. Theta–gamma coordination between anterior cingulate and prefrontal cortex indexes correct attention shifts

    Science.gov (United States)

    Voloh, Benjamin; Valiante, Taufik A.; Everling, Stefan; Womelsdorf, Thilo

    2015-01-01

    Anterior cingulate and lateral prefrontal cortex (ACC/PFC) are believed to coordinate activity to flexibly prioritize the processing of goal-relevant over irrelevant information. This between-area coordination may be realized by common low-frequency excitability changes synchronizing segregated high-frequency activations. We tested this coordination hypothesis by recording in macaque ACC/PFC during the covert utilization of attention cues. We found robust increases of 5–10 Hz (theta) to 35–55 Hz (gamma) phase–amplitude correlation between ACC and PFC during successful attention shifts but not before errors. Cortical sites providing theta phases (i) showed a prominent cue-induced phase reset, (ii) were more likely in ACC than PFC, and (iii) hosted neurons with burst firing events that synchronized to distant gamma activity. These findings suggest that interareal theta–gamma correlations could follow mechanistically from a cue-triggered reactivation of rule memory that synchronizes theta across ACC/PFC. PMID:26100868

  11. Acoustic noise induces attention shifts and reduces foraging performance in three-spined sticklebacks (Gasterosteus aculeatus.

    Directory of Open Access Journals (Sweden)

    Julia Purser

    2011-02-01

    Full Text Available Acoustic noise is known to have a variety of detrimental effects on many animals, including humans, but surprisingly little is known about its impacts on foraging behaviour, despite the obvious potential consequences for survival and reproductive success. We therefore exposed captive three-spined sticklebacks (Gasterosteus aculeatus to brief and prolonged noise to investigate how foraging performance is affected by the addition of acoustic noise to an otherwise quiet environment. The addition of noise induced only mild fear-related behaviours--there was an increase in startle responses, but no change in the time spent freezing or hiding compared to a silent control--and thus had no significant impact on the total amount of food eaten. However, there was strong evidence that the addition of noise increased food-handling errors and reduced discrimination between food and non-food items, results that are consistent with a shift in attention. Consequently, noise resulted in decreased foraging efficiency, with more attacks needed to consume the same number of prey items. Our results suggest that acoustic noise has the potential to influence a whole host of everyday activities through effects on attention, and that even very brief noise exposure can cause functionally significant impacts, emphasising the threat posed by ever-increasing levels of anthropogenic noise in the environment.

  12. Rapid tryptophan depletion improves decision-making cognition in healthy humans without affecting reversal learning or set shifting.

    Science.gov (United States)

    Talbot, Peter S; Watson, David R; Barrett, Suzanne L; Cooper, Stephen J

    2006-07-01

    Rapid tryptophan (Trp) depletion (RTD) has been reported to cause deterioration in the quality of decision making and impaired reversal learning, while leaving attentional set shifting relatively unimpaired. These findings have been attributed to a more powerful neuromodulatory effect of reduced 5-HT on ventral prefrontal cortex (PFC) than on dorsolateral PFC. In view of the limited number of reports, the aim of this study was to independently replicate these findings using the same test paradigms. Healthy human subjects without a personal or family history of affective disorder were assessed using a computerized decision making/gambling task and the CANTAB ID/ED attentional set-shifting task under Trp-depleted (n=17; nine males and eight females) or control (n=15; seven males and eight females) conditions, in a double-blind, randomized, parallel-group design. There was no significant effect of RTD on set shifting, reversal learning, risk taking, impulsivity, or subjective mood. However, RTD significantly altered decision making such that depleted subjects chose the more likely of two possible outcomes significantly more often than controls. This is in direct contrast to the previous report that subjects chose the more likely outcome significantly less often following RTD. In the terminology of that report, our result may be interpreted as improvement in the quality of decision making following RTD. This contrast between studies highlights the variability in the cognitive effects of RTD between apparently similar groups of healthy subjects, and suggests the need for future RTD studies to control for a range of personality, family history, and genetic factors that may be associated with 5-HT function.

  13. Attentional set-shifting deficit in Parkinson's disease is associated with prefrontal dysfunction: an FDG-PET study.

    Directory of Open Access Journals (Sweden)

    Yoichi Sawada

    Full Text Available The attentional set-shifting deficit that has been observed in Parkinson's disease (PD has long been considered neuropsychological evidence of the involvement of meso-prefrontal and prefrontal-striatal circuits in cognitive flexibility. However, recent studies have suggested that non-dopaminergic, posterior cortical pathologies may also contribute to this deficit. Although several neuroimaging studies have addressed this issue, the results of these studies were confounded by the use of tasks that required other cognitive processes in addition to set-shifting, such as rule learning and working memory. In this study, we attempted to identify the neural correlates of the attentional set-shifting deficit in PD using a compound letter task and 18F-fluoro-deoxy-glucose (FDG positron emission tomography during rest. Shift cost, which is a measure of attentional set-shifting ability, was significantly correlated with hypometabolism in the right dorsolateral prefrontal cortex, including the putative human frontal eye field. Our results provide direct evidence that dysfunction in the dorsolateral prefrontal cortex makes a primary contribution to the attentional set-shifting deficit that has been observed in PD patients.

  14. An online brain-computer interface based on shifting attention to concurrent streams of auditory stimuli

    Science.gov (United States)

    Hill, N J; Schölkopf, B

    2012-01-01

    We report on the development and online testing of an EEG-based brain-computer interface (BCI) that aims to be usable by completely paralysed users—for whom visual or motor-system-based BCIs may not be suitable, and among whom reports of successful BCI use have so far been very rare. The current approach exploits covert shifts of attention to auditory stimuli in a dichotic-listening stimulus design. To compare the efficacy of event-related potentials (ERPs) and steady-state auditory evoked potentials (SSAEPs), the stimuli were designed such that they elicited both ERPs and SSAEPs simultaneously. Trial-by-trial feedback was provided online, based on subjects’ modulation of N1 and P3 ERP components measured during single 5-second stimulation intervals. All 13 healthy subjects were able to use the BCI, with performance in a binary left/right choice task ranging from 75% to 96% correct across subjects (mean 85%). BCI classification was based on the contrast between stimuli in the attended stream and stimuli in the unattended stream, making use of every stimulus, rather than contrasting frequent standard and rare “oddball” stimuli. SSAEPs were assessed offline: for all subjects, spectral components at the two exactly-known modulation frequencies allowed discrimination of pre-stimulus from stimulus intervals, and of left-only stimuli from right-only stimuli when one side of the dichotic stimulus pair was muted. However, attention-modulation of SSAEPs was not sufficient for single-trial BCI communication, even when the subject’s attention was clearly focused well enough to allow classification of the same trials via ERPs. ERPs clearly provided a superior basis for BCI. The ERP results are a promising step towards the development of a simple-to-use, reliable yes/no communication system for users in the most severely paralysed states, as well as potential attention-monitoring and -training applications outside the context of assistive technology. PMID:22333135

  15. Evidence for rapid, tide-related shifts in the microbiome of the coral Coelastrea aspera

    Science.gov (United States)

    Sweet, M. J.; Brown, B. E.; Dunne, R. P.; Singleton, I.; Bulling, M.

    2017-09-01

    Shifts in the microbiome of the intertidal coral Coelastrea aspera (formally known as Goniastrea aspera) from Phuket, Thailand, were noted over the course of a 4-d period of spring tides. During this time, corals were naturally exposed to high temperatures, intense solar radiation, sub-aerial exposure and tidally induced water fluxes. Analysis of the 16S microbiome highlighted that the corals harbored both `core or stable' communities and those which appeared to be more `transient or sporadic.' Only relatively few microbial associates were classified as core microbes; the majority were transient or sporadic. Such transient associates were likely to have been governed by tidally induced variations in mucus thickness and water fluxes. Here we report strong shifts in the bacterial community of C. aspera over a short temporal scale. However, we also show significant differences in the timing of shifts between the two age groups of corals studied. More rapid changes (within 2 d of sub-aerial exposure) occurred within the 4-yr-old colonies, but a slightly delayed response was observed in the 10-yr-old colonies, whereby the microbial associates only changed after 4 d. We hypothesize that these shifts are age related and could be influenced by the observed baseline differences in the microbiome of the 4- and 10-yr-old corals, bacteria-bacteria interactions, and/or host energetics.

  16. Rapid resetting of human peripheral clocks by phototherapy during simulated night shift work.

    Science.gov (United States)

    Cuesta, Marc; Boudreau, Philippe; Cermakian, Nicolas; Boivin, Diane B

    2017-11-24

    A majority of night shift workers have their circadian rhythms misaligned to their atypical schedule. While bright light exposure at night is known to reset the human central circadian clock, the behavior of peripheral clocks under conditions of shift work is more elusive. The aim of the present study was to quantify the resetting effects of bright light exposure on both central (plasma cortisol and melatonin) and peripheral clocks markers (clock gene expression in peripheral blood mononuclear cells, PBMCs) in subjects living at night. Eighteen healthy subjects were enrolled to either a control (dim light) or a bright light group. Blood was sampled at baseline and on the 4 th day of simulated night shift. In response to a night-oriented schedule, the phase of PER1 and BMAL1 rhythms in PBMCs was delayed by ~2.5-3 h (P shift was observed for the other clock genes and the central markers. Three cycles of 8-h bright light induced significant phase delays (P night-oriented schedule and a rapid resetting effect of nocturnal bright light exposure on peripheral clocks.

  17. Tonic noradrenergic activity modulates explorative behavior and attentional set shifting: Evidence from pupillometry and gaze pattern analysis.

    Science.gov (United States)

    Pajkossy, Péter; Szőllősi, Ágnes; Demeter, Gyula; Racsmány, Mihály

    2017-12-01

    A constant task for every living organism is to decide whether to exploit rewards associated with current behavior or to explore the environment for more rewarding options. Current empirical evidence indicates that exploitation is related to phasic whereas exploration is related to tonic firing mode of noradrenergic neurons in the locus coeruleus. In humans, this exploration-exploitation trade-off is subserved by the ability to flexibly switch attention between task-related and task-irrelevant information. Here, we investigated whether this function, called attentional set shifting, is related to exploration and tonic noradrenergic discharge. We measured pretrial baseline pupil dilation, proved to be strongly correlated with the activity of the locus coeruleus, while human participants took part in well-known tasks of attentional set shifting. Study 1 used the Wisconsin Card Sorting Task, whereas in Study 2, the Intra/Extradimensional Set Shifting Task was used. Both tasks require participants to choose between different compound stimuli based on feedback provided for their previous decisions. During the task, stimulus-reward contingencies change periodically, thus participants are repeatedly required to reassess which stimulus features are relevant (i.e., they shift their attentional set). Our results showed that baseline pupil diameter steadily decreased when the stimulus-reward contingencies were stable, whereas they suddenly increased when these contingencies changed. Analysis of looking patterns also confirmed the presence of exploratory behavior during attentional set shifting. Thus, our results suggest that tonic firing mode of noradrenergic neurons in the locus coeruleus is implicated in attentional set shifting, as it regulates the amount of exploration. © 2017 Society for Psychophysiological Research.

  18. Avoiding math on a rapid timescale: Emotional responsivity and anxious attention in math anxiety.

    Science.gov (United States)

    Pizzie, Rachel G; Kraemer, David J M

    2017-11-01

    Math anxiety (MA) is characterized by negative feelings towards mathematics, resulting in avoidance of math classes and of careers that rely on mathematical skills. Focused on a long timescale, this research may miss important cognitive and affective processes that operate moment-to-moment, changing rapid reactions even when a student simply sees a math problem. Here, using fMRI with an attentional deployment paradigm, we show that MA influences rapid spontaneous emotional and attentional responses to mathematical stimuli upon brief presentation. Critically, participants viewed but did not attempt to solve the problems. Indicating increased threat reactivity to even brief presentations of math problems, increased MA was associated with increased amygdala response during math viewing trials. Functionally and anatomically defined amygdala ROIs yielded similar results, indicating robustness of the finding. Similar to the pattern of vigilance and avoidance observed in specific phobia, behavioral results of the attentional paradigm demonstrated that MA is associated with attentional disengagement for mathematical symbols. This attentional avoidance is specific to math stimuli; when viewing negatively-valenced images, MA is correlated with attentional engagement, similar to other forms of anxiety. These results indicate that even brief exposure to mathematics triggers a neural response related to threat avoidance in highly MA individuals. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Guanfacine enhances inhibitory control and attentional shifting in early abstinent cocaine-dependent individuals.

    Science.gov (United States)

    Fox, Helen; Sofuoglu, Mehmet; Sinha, Rajita

    2015-03-01

    Attenuation of adrenergic drive and cognitive enhancement, via stimulation of alpha2 pre- and post-synaptic receptors, may selectively enhance executive performance in early abstinent cocaine-dependent individuals. As these cognitive processes underpin important treatment-related behaviors, the alpha2 agonist, guanfacine HCl, may represent an effective pharmaco-therapeutic intervention. Twenty-five early abstinent cocaine-dependent individuals were administered a battery of neurocognitive tasks on entry into treatment (baseline) and again following 3 weeks of either placebo or guanfacine treatment (up to 3 mg). Tasks included: Stop Signal, Stroop, 3-Dimentional Intra-dimensional/Extra-dimensional (IDED) task, Spatial Working Memory (SWM), Paired Associates Learning (PAL), Verbal Fluency and the Rey Auditory Verbal Learning Test (RAVLT). Compared with placebo, the guanfacine group demonstrated attenuated anxiety and negative affect as well as improved performance on selective executive tests. This included fewer directional errors on the stop signal task, fewer errors on the extra-dimensional shift component of the IDED task and better attentional switching during verbal fluency. Guanfacine did not improve strategic working memory or peripheral memory. Guanfacine improves selective cognitive processes which may underlie salient treatment-related regulatory behaviors. Alpha2 agonists may therefore represent important agents for cocaine dependence. © The Author(s) 2015.

  20. Optical code division multiple access secure communications systems with rapid reconfigurable polarization shift key user code

    Science.gov (United States)

    Gao, Kaiqiang; Wu, Chongqing; Sheng, Xinzhi; Shang, Chao; Liu, Lanlan; Wang, Jian

    2015-09-01

    An optical code division multiple access (OCDMA) secure communications system scheme with rapid reconfigurable polarization shift key (Pol-SK) bipolar user code is proposed and demonstrated. Compared to fix code OCDMA, by constantly changing the user code, the performance of anti-eavesdropping is greatly improved. The Pol-SK OCDMA experiment with a 10 Gchip/s user code and a 1.25 Gb/s user data of payload has been realized, which means this scheme has better tolerance and could be easily realized.

  1. Neural evidence reveals the rapid effects of reward history on selective attention.

    Science.gov (United States)

    MacLean, Mary H; Giesbrecht, Barry

    2015-05-05

    Selective attention is often framed as being primarily driven by two factors: task-relevance and physical salience. However, factors like selection and reward history, which are neither currently task-relevant nor physically salient, can reliably and persistently influence visual selective attention. The current study investigated the nature of the persistent effects of irrelevant, physically non-salient, reward-associated features. These features affected one of the earliest reliable neural indicators of visual selective attention in humans, the P1 event-related potential, measured one week after the reward associations were learned. However, the effects of reward history were moderated by current task demands. The modulation of visually evoked activity supports the hypothesis that reward history influences the innate salience of reward associated features, such that even when no longer relevant, nor physically salient, these features have a rapid, persistent, and robust effect on early visual selective attention. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. The Role of Attention Shifting in Orthographic Competencies: Cross-Sectional Findings from 1st, 3rd, and 8th Grade Students

    Directory of Open Access Journals (Sweden)

    Antje von Suchodoletz

    2017-09-01

    Full Text Available Attention shifting refers to one core component of executive functions, a set of higher-order cognitive processes that predict different aspects of academic achievement. To date, few studies have investigated the role of attention shifting in orthographic competencies during middle childhood and early adolescence. In the present study, 69 first-grade, 121 third-grade, and 85 eighth-grade students' attention shifting was tested with a computer version of the Dimensional Change Card Sort (DCCS; Zelazo, 2006. General spelling skills and specific writing and spelling strategies were assessed with the Hamburger Writing Test (May, 2002. Results suggested associations between attention shifting and various orthographic competencies that differ across age groups and by sex. Across all age groups, better attention shifting was associated with less errors in applying alphabetical strategies. In third graders, better attention shifting was furthermore related to better general spelling skills and less errors in using orthographical strategies. In this age group, associations did not differ by sex. Among first graders, attention shifting was negatively related to general spelling skills, but only for boys. In contrast, attention shifting was positively related to general spelling skills in eighth graders, but only for girls. Finally, better attention shifting was associated with less case-related errors in eighth graders, independent of students' sex. In sum, the data provide insight into both variability and consistency in the pattern of relations between attention shifting and various orthographic competencies among elementary and middle school students.

  3. Rapid Detection of Glycogen Synthase Kinase-3 Activity in Mouse Sperm Using Fluorescent Gel Shift Electrophoresis

    Directory of Open Access Journals (Sweden)

    Hoseok Choi

    2016-04-01

    Full Text Available Assaying the glycogen synthase kinase-3 (GSK3 activity in sperm is of great importance because it is closely implicated in sperm motility and male infertility. While a number of studies on GSK3 activity have relied on labor-intensive immunoblotting to identify phosphorylated GSK3, here we report the simple and rapid detection of GSK3 activity in mouse sperm using conventional agarose gel electrophoresis and a fluorescent peptide substrate. When a dye-tethered and prephosphorylated (primed peptide substrate for GSK3 was employed, a distinct mobility shift in the fluorescent bands on the agarose was observed by GSK3-induced phosphorylation of the primed peptides. The GSK3 activity in mouse testes and sperm were quantifiable by gel shift assay with low sample consumption and were significantly correlated with the expression levels of GSK3 and p-GSK3. We suggest that our assay can be used for reliable and rapid detection of GSK3 activity in cells and tissue extracts.

  4. Rapid Detection of Glycogen Synthase Kinase-3 Activity in Mouse Sperm Using Fluorescent Gel Shift Electrophoresis

    Science.gov (United States)

    Choi, Hoseok; Choi, Bomi; Seo, Ju Tae; Lee, Kyung Jin; Gye, Myung Chan; Kim, Young-Pil

    2016-01-01

    Assaying the glycogen synthase kinase-3 (GSK3) activity in sperm is of great importance because it is closely implicated in sperm motility and male infertility. While a number of studies on GSK3 activity have relied on labor-intensive immunoblotting to identify phosphorylated GSK3, here we report the simple and rapid detection of GSK3 activity in mouse sperm using conventional agarose gel electrophoresis and a fluorescent peptide substrate. When a dye-tethered and prephosphorylated (primed) peptide substrate for GSK3 was employed, a distinct mobility shift in the fluorescent bands on the agarose was observed by GSK3-induced phosphorylation of the primed peptides. The GSK3 activity in mouse testes and sperm were quantifiable by gel shift assay with low sample consumption and were significantly correlated with the expression levels of GSK3 and p-GSK3. We suggest that our assay can be used for reliable and rapid detection of GSK3 activity in cells and tissue extracts. PMID:27092510

  5. Rapidly shifting environmental baselines among fishers of the Gulf of California

    Science.gov (United States)

    Sáenz-Arroyo, Andrea; Roberts, Callum M; Torre, Jorge; Cariño-Olvera, Micheline; Enríquez-Andrade, Roberto R

    2005-01-01

    Shifting environmental baselines are inter-generational changes in perception of the state of the environment. As one generation replaces another, people's perceptions of what is natural change even to the extent that they no longer believe historical anecdotes of past abundance or size of species. Although widely accepted, this phenomenon has yet to be quantitatively tested. Here we survey three generations of fishers from Mexico's Gulf of California (N=108), where fish populations have declined steeply over the last 60 years, to investigate how far and fast their environmental baselines are shifting. Compared to young fishers, old fishers named five times as many species and four times as many fishing sites as once being abundant/productive but now depleted (Kruskal–Wallis tests, both p<0.001) with no evidence of a slowdown in rates of loss experienced by younger compared to older generations (Kruskal–Wallis test, n.s. in both cases). Old fishers caught up to 25 times as many Gulf grouper Mycteroperca jordani as young fishers on their best ever fishing day (regression r2=0.62, p<0.001). Despite times of plentiful large fish still being within living memory, few young fishers appreciated that large species had ever been common or nearshore sites productive. Such rapid shifts in perception of what is natural help explain why society is tolerant of the creeping loss of biodiversity. They imply a large educational hurdle in efforts to reset expectations and targets for conservation. PMID:16191603

  6. Rapidly shifting baselines in Yangtze fishing communities and local memory of extinct species.

    Science.gov (United States)

    Turvey, Samuel T; Barrett, Leigh A; Yujiang, Hao; Lei, Zhang; Xinqiao, Zhang; Xianyan, Wang; Yadong, Huang; Kaiya, Zhou; Hart, Tom; Ding, Wang

    2010-06-01

    Local ecological knowledge can provide a unique source of data for conservation, especially in efforts to investigate the status of rare or possibly extinct species, but it is unlikely to remain constant over time. Loss of perspective about past ecological conditions caused by lack of communication between generations may create "shifting baseline syndrome," in which younger generations are less aware of local species diversity or abundance in the recent past. This phenomenon has been widely discussed, but has rarely been examined quantitatively. We present new evidence of shifting baselines in local perception of regional species declines and on the duration of "community memory" of extinct species on the basis of extensive interviews with fishers in communities across the middle-lower Yangtze basin. Many Yangtze species have experienced major declines in recent decades, and the Yangtze River dolphin or baiji (Lipotes vexillifer) and Yangtze paddlefish (Psephurus gladius) may have become extinct during the 21(st) century. Although informants across all age classes were strongly aware of the Yangtze ecosystem's escalating resource depletion and environmental degradation, older informants were more likely to recognize declines in two commercially important fish species, Reeves' shad (Tenualosa reevesii) and Yangtze pufferfish (Takifugu fasciatus), and to have encountered baiji and paddlefish in the past. Age was also a strong predictor of whether informants had even heard of baiji or paddlefish, with younger informants being substantially less likely to recognize either species. A marked decrease in local knowledge about the Yangtze freshwater megafauna matched the time of major population declines of these species from the 1970s onwards, and paddlefish were already unknown to over 70% of all informants below the age of 40 and to those who first started fishing after 1995. This rapid rate of cultural baseline shift suggests that once even megafaunal species cease to

  7. The effect of shift rotation on employee cortisol profile, sleep quality, fatigue, and attention level: a systematic review.

    Science.gov (United States)

    Niu, Shu-Fen; Chung, Min-Huey; Chen, Chiung-Hua; Hegney, Desley; O'Brien, Anthony; Chou, Kuei-Ru

    2011-03-01

    Disrupted circadian rhythm, especially working night duty together with irregular sleep patterns, sleep deprivation, and fatigue, creates an occupational health risk associated with diminished vigilance and work performance. This study reviewed the effect of shift rotations on employee cortisol profile, sleep quality, fatigue, and attention level. Researchers conducted a systematic review of relevant articles published between 1996 and 2008 that were listed on the following databases: SCOPUS, OVID, Blackwell Science, EBSCO Host, PsycINFO, Cochrane Controlled Trials Register, and CEPS. A total of 28 articles were included in the review. Previous research into the effects of shift work on cortisol profiles, sleep quality, fatigue, and attention used data assessed at evidence Levels II to IV. Our systematic review confirmed a conflict between sleep-wake cycle and light-dark cycle in night work. Consequences of circadian rhythm disturbance include disruption of sleep, decreased vigilance, general feeling of malaise, and decreased mental efficiency. Shift workers who sleep during the day (day sleepers) experience cortisol secretion increases, which diminish the healing power of sleep and enjoy 1 to 4 hours less sleep on average than night sleepers. Sleep debt accumulation results in chronic fatigue. Prolonged fatigue and inadequate recovery result in decreased work performance and more incidents. Rotation from day shift to night shift and its effect on shift workers was a special focus of the articles retained for review. Disturbed circadian rhythm in humans has been associated with a variety of mental and physical disorders and may negatively impact on work safety, performance, and productivity.

  8. A bottom-up model of spatial attention predicts human error patterns in rapid scene recognition.

    Science.gov (United States)

    Einhäuser, Wolfgang; Mundhenk, T Nathan; Baldi, Pierre; Koch, Christof; Itti, Laurent

    2007-07-20

    Humans demonstrate a peculiar ability to detect complex targets in rapidly presented natural scenes. Recent studies suggest that (nearly) no focal attention is required for overall performance in such tasks. Little is known, however, of how detection performance varies from trial to trial and which stages in the processing hierarchy limit performance: bottom-up visual processing (attentional selection and/or recognition) or top-down factors (e.g., decision-making, memory, or alertness fluctuations)? To investigate the relative contribution of these factors, eight human observers performed an animal detection task in natural scenes presented at 20 Hz. Trial-by-trial performance was highly consistent across observers, far exceeding the prediction of independent errors. This consistency demonstrates that performance is not primarily limited by idiosyncratic factors but by visual processing. Two statistical stimulus properties, contrast variation in the target image and the information-theoretical measure of "surprise" in adjacent images, predict performance on a trial-by-trial basis. These measures are tightly related to spatial attention, demonstrating that spatial attention and rapid target detection share common mechanisms. To isolate the causal contribution of the surprise measure, eight additional observers performed the animal detection task in sequences that were reordered versions of those all subjects had correctly recognized in the first experiment. Reordering increased surprise before and/or after the target while keeping the target and distractors themselves unchanged. Surprise enhancement impaired target detection in all observers. Consequently, and contrary to several previously published findings, our results demonstrate that attentional limitations, rather than target recognition alone, affect the detection of targets in rapidly presented visual sequences.

  9. How Does Awareness Modulate Goal-Directed and Stimulus-Driven Shifts of Attention Triggered by Value Learning?

    Directory of Open Access Journals (Sweden)

    Alexia Bourgeois

    Full Text Available In order to behave adaptively, attention can be directed in space either voluntarily (i.e., endogenously according to strategic goals, or involuntarily (i.e., exogenously through reflexive capture by salient or novel events. The emotional or motivational value of stimuli can also strongly influence attentional orienting. However, little is known about how reward-related effects compete or interact with endogenous and exogenous attention mechanisms, particularly outside of awareness. Here we developed a visual search paradigm to study subliminal value-based attentional orienting. We systematically manipulated goal-directed or stimulus-driven attentional orienting and examined whether an irrelevant, but previously rewarded stimulus could compete with both types of spatial attention during search. Critically, reward was learned without conscious awareness in a preceding phase where one among several visual symbols was consistently paired with a subliminal monetary reinforcement cue. Our results demonstrated that symbols previously associated with a monetary reward received higher attentional priority in the subsequent visual search task, even though these stimuli and reward were no longer task-relevant, and despite reward being unconsciously acquired. Thus, motivational processes operating independent of conscious awareness may provide powerful influences on mechanisms of attentional selection, which could mitigate both stimulus-driven and goal-directed shifts of attention.

  10. How Does Awareness Modulate Goal-Directed and Stimulus-Driven Shifts of Attention Triggered by Value Learning?

    Science.gov (United States)

    Bourgeois, Alexia; Neveu, Rémi; Vuilleumier, Patrik

    2016-01-01

    In order to behave adaptively, attention can be directed in space either voluntarily (i.e., endogenously) according to strategic goals, or involuntarily (i.e., exogenously) through reflexive capture by salient or novel events. The emotional or motivational value of stimuli can also strongly influence attentional orienting. However, little is known about how reward-related effects compete or interact with endogenous and exogenous attention mechanisms, particularly outside of awareness. Here we developed a visual search paradigm to study subliminal value-based attentional orienting. We systematically manipulated goal-directed or stimulus-driven attentional orienting and examined whether an irrelevant, but previously rewarded stimulus could compete with both types of spatial attention during search. Critically, reward was learned without conscious awareness in a preceding phase where one among several visual symbols was consistently paired with a subliminal monetary reinforcement cue. Our results demonstrated that symbols previously associated with a monetary reward received higher attentional priority in the subsequent visual search task, even though these stimuli and reward were no longer task-relevant, and despite reward being unconsciously acquired. Thus, motivational processes operating independent of conscious awareness may provide powerful influences on mechanisms of attentional selection, which could mitigate both stimulus-driven and goal-directed shifts of attention.

  11. Shifting the Spotlight of Attention: Evidence for Discrete Computations in Cognition

    OpenAIRE

    Buschman, Timothy J.; Miller, Earl K.

    2010-01-01

    Our thoughts have a limited bandwidth; we can only fully process a few items in mind simultaneously. To compensate, the brain developed attention, the ability to select information relevant to the current task, while filtering out the rest. Therefore, by understanding the neural mechanisms of attention we hope to understand a core component of cognition. Here, we review our recent investigations of the neural mechanisms underlying the control of visual attention in frontal and parietal cor...

  12. Multiple shifts to different pollinators fuelled rapid diversification in sexually deceptive Ophrys orchids.

    Science.gov (United States)

    Breitkopf, Hendrik; Onstein, Renske E; Cafasso, Donata; Schlüter, Philipp M; Cozzolino, Salvatore

    2015-07-01

    Episodes of rapid speciation provide unique insights into evolutionary processes underlying species radiations and patterns of biodiversity. Here we investigated the radiation of sexually deceptive bee orchids (Ophrys). Based on a time-calibrated phylogeny and by means of ancestral character reconstruction and divergence time estimation, we estimated the tempo and mode of this radiation within a state-dependent evolutionary framework. It appears that, in the Pleistocene, the evolution of Ophrys was marked by episodes of rapid diversification coinciding with shifts to different pollinator types: from wasps to Eucera bees to Andrena and other bees. An abrupt increase in net diversification rate was detected in three clades. Among these, two phylogenetically distant lineages switched from Eucera to Andrena and other bees in a parallel fashion and at about the same time in their evolutionary history. Lack of early radiation associated with the evolution of the key innovation of sexual deception suggests that Ophrys diversification was mainly driven by subsequent ecological opportunities provided by the exploitation of novel pollinator groups, encompassing many bee species slightly differing in their sex pheromone communication systems, and by spatiotemporal fluctuations in the pollinator mosaic. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  13. Evaluation of a neurodevelopmental model of schizophrenia--early postnatal PCP treatment in attentional set-shifting

    DEFF Research Database (Denmark)

    Broberg, Brian Villumsen; Dias, Rebecca; Glenthøj, Birte Yding

    2008-01-01

    Phencyclidine (PCP) was administered to male and female Lister hooded rats on postnatal days (PND) 7, 9 and 11. All PCP animals tested in adulthood (PND 53-93) showed deficits in cognitive flexibility, specifically in their ability to shift attentional set, compared to controls. This novel finding...... is reminiscent of the impairment observed in schizophrenia patients, and supports the validity of the early postnatal PCP regimen as a disease-like model....

  14. Using task effort and pupil size to track covert shifts of visual attention independently of a pupillary light reflex.

    Science.gov (United States)

    Brocher, Andreas; Harbecke, Raphael; Graf, Tim; Memmert, Daniel; Hüttermann, Stefanie

    2018-03-07

    We tested the link between pupil size and the task effort involved in covert shifts of visual attention. The goal of this study was to establish pupil size as a marker of attentional shifting in the absence of luminance manipulations. In three experiments, participants evaluated two stimuli that were presented peripherally, appearing equidistant from and on opposite sides of eye fixation. The angle between eye fixation and the peripherally presented target stimuli varied from 12.5° to 42.5°. The evaluation of more distant stimuli led to poorer performance than did the evaluation of more proximal stimuli throughout our study, confirming that the former required more effort than the latter. In addition, in Experiment 1 we found that pupil size increased with increasing angle and that this effect could not be reduced to the operation of low-level visual processes in the task. In Experiment 2 the pupil dilated more strongly overall when participants evaluated the target stimuli, which required shifts of attention, than when they merely reported on the target's presence versus absence. Both conditions yielded larger pupils for more distant than for more proximal stimuli, however. In Experiment 3, we manipulated task difficulty more directly, by changing the contrast at which the target stimuli were presented. We replicated the results from Experiment 1 only with the high-contrast stimuli. With stimuli of low contrast, ceiling effects in pupil size were observed. Our data show that the link between task effort and pupil size can be used to track the degree to which an observer covertly shifts attention to or detects stimuli in peripheral vision.

  15. [Allocation of attentional resource and monitoring processes under rapid serial visual presentation].

    Science.gov (United States)

    Nishiura, K

    1998-08-01

    With the use of rapid serial visual presentation (RSVP), the present study investigated the cause of target intrusion errors and functioning of monitoring processes. Eighteen students participated in Experiment 1, and 24 in Experiment 2. In Experiment 1, different target intrusion errors were found depending on different kinds of letters --romaji, hiragana, and kanji. In Experiment 2, stimulus set size and context information were manipulated in an attempt to explore the cause of post-target intrusion errors. Results showed that as stimulus set size increased, the post-target intrusion errors also increased, but contextual information did not affect the errors. Results concerning mean report probability indicated that increased allocation of attentional resource to response-defining dimension was the cause of the errors. In addition, results concerning confidence rating showed that monitoring of temporal and contextual information was extremely accurate, but it was not so for stimulus information. These results suggest that attentional resource is different from monitoring resource.

  16. Erratum to: The blocking effect in associative learning involves learned biases in rapid attentional capture.

    Science.gov (United States)

    2018-04-01

    Luque, D., Vadillo, M, A., Gutiérrez-Cobo, M, J., Le Pelley, M, E. (2018). The blocking effect in associative learning involves learned biases in rapid attentional capture. Quarterly Journal of Experimental Psychology, 71, 522-544. doi: 10.1080/17470218.2016.1262435. The above article is part of the Special Issue on Associative Learning (in honour of Nick Mackintosh) and was inadvertently published in the February 2018 issue of Quarterly Journal of Experimental Psychology. After publication of the Special Issue, an online collection on Associative Learning will be created on SAGE Journals and this paper will be included in that collection. The Publisher apologises for this error.

  17. Lorazepam induces multiple disturbances in selective attention: attentional overload, decrement in target processing efficiency, and shifts in perceptual discrimination and response bias.

    Science.gov (United States)

    Michael, George Andrew; Bacon, Elisabeth; Offerlin-Meyer, Isabelle

    2007-09-01

    There is a general consensus that benzodiazepines affect attentional processes, yet only few studies have tried to investigate these impairments in detail. The purpose of the present study was to investigate the effects of a single dose of Lorazepam on performance in a target cancellation task with important time constraints. We measured correct target detections and correct distractor rejections, misses and false positives. The results show that Lorazepam produces multiple kinds of shifts in performance, which suggests that it impairs multipLe processes: (a) the evolution of performance over time was not the same between the placebo and the Lorazepam groups, with the Lorazepam affecting performance quite early after the beginning of the test. This is suggestive of a depletion of attentional resources during sequential attentional processing; (b) Lorazepam affected differently target and distractor processing, with target detection being the most impaired; (c) misses were more frequent under Lorazepam than under placebo, but no such difference was observed as far as false positives were concerned. Signal detection analyses showed that Lorazepam (d) decreased perceptual discrimination, and (e) reliably increased response bias. Our results bring new insights on the multiple effects of Lorazepam on selective attention which, when combined, may have deleterious effects on human performance.

  18. Perceptual Shift in Bilingualism: Brain Potentials Reveal Plasticity in Pre-Attentive Colour Perception

    Science.gov (United States)

    Athanasopoulos, Panos; Dering, Benjamin; Wiggett, Alison; Kuipers, Jan-Rouke; Thierry, Guillaume

    2010-01-01

    The validity of the linguistic relativity principle continues to stimulate vigorous debate and research. The debate has recently shifted from the behavioural investigation arena to a more biologically grounded field, in which tangible physiological evidence for language effects on perception can be obtained. Using brain potentials in a colour…

  19. Are Categorical Spatial Relations Encoded by Shifting Visual Attention between Objects?

    Science.gov (United States)

    Yuan, Lei; Uttal, David; Franconeri, Steven

    2016-01-01

    Perceiving not just values, but relations between values, is critical to human cognition. We tested the predictions of a proposed mechanism for processing categorical spatial relations between two objects--the "shift account" of relation processing--which states that relations such as "above" or "below" are extracted…

  20. Shifts in attention during mental fatigue: Evidence from subjective, behavioral, physiological, and eye-tracking data

    NARCIS (Netherlands)

    Hopstaken, J.; Linden, D. van der; Bakker, A.B.; Kompier, M.A.J.; Leung, Y.K.

    2016-01-01

    There is an increasing amount of evidence that during mental fatigue, shifts in motivation drive performance rather than reductions in finite mental energy. So far, studies that investigated such an approach have mainly focused on cognitive indicators of task engagement that were measured during

  1. The rapid distraction of attentional resources toward the source of incongruent stimulus input during multisensory conflict.

    Science.gov (United States)

    Donohue, Sarah E; Todisco, Alexandra E; Woldorff, Marty G

    2013-04-01

    Neuroimaging work on multisensory conflict suggests that the relevant modality receives enhanced processing in the face of incongruency. However, the degree of stimulus processing in the irrelevant modality and the temporal cascade of the attentional modulations in either the relevant or irrelevant modalities are unknown. Here, we employed an audiovisual conflict paradigm with a sensory probe in the task-irrelevant modality (vision) to gauge the attentional allocation to that modality. ERPs were recorded as participants attended to and discriminated spoken auditory letters while ignoring simultaneous bilateral visual letter stimuli that were either fully congruent, fully incongruent, or partially incongruent (one side incongruent, one congruent) with the auditory stimulation. Half of the audiovisual letter stimuli were followed 500-700 msec later by a bilateral visual probe stimulus. As expected, ERPs to the audiovisual stimuli showed an incongruency ERP effect (fully incongruent versus fully congruent) of an enhanced, centrally distributed, negative-polarity wave starting ∼250 msec. More critically here, the sensory ERP components to the visual probes were larger when they followed fully incongruent versus fully congruent multisensory stimuli, with these enhancements greatest on fully incongruent trials with the slowest RTs. In addition, on the slowest-response partially incongruent trials, the P2 sensory component to the visual probes was larger contralateral to the preceding incongruent visual stimulus. These data suggest that, in response to conflicting multisensory stimulus input, the initial cognitive effect is a capture of attention by the incongruent irrelevant-modality input, pulling neural processing resources toward that modality, resulting in rapid enhancement, rather than rapid suppression, of that input.

  2. Exogenous vs. endogenous attention: Shifting the balance of fronto-parietal activity.

    Science.gov (United States)

    Meyer, Kristin N; Du, Feng; Parks, Emily; Hopfinger, Joseph B

    2018-03-01

    Despite behavioral and electrophysiological evidence for dissociations between endogenous (voluntary) and exogenous (reflexive) attention, fMRI results have yet to consistently and clearly differentiate neural activation patterns between these two types of attention. This study specifically aimed to determine whether activity in the dorsal fronto-parietal network differed between endogenous and exogenous conditions. Participants performed a visual discrimination task in endogenous and exogenous attention conditions while undergoing fMRI scanning. Analyses revealed robust and bilateral activation throughout the dorsal fronto-parietal network for each condition, in line with many previous results. In order to investigate possible differences in the balance of neural activity within this network with greater sensitivity, a priori regions of interest (ROIs) were selected for analysis, centered on the frontal eye fields (FEF) and intraparietal sulcus (IPS) regions identified in previous studies. The results revealed a significant interaction between region, condition, and hemisphere. Specifically, in the left hemisphere, frontal areas were more active than parietal areas, but only during endogenous attention. Activity in the right hemisphere, in contrast, remained relatively consistent for these regions across conditions. Analysis of this activity over time indicates that this left-hemispheric regional imbalance is present within the FEF early, at 3-6.5 s post-stimulus presentation, whereas a regional imbalance in the exogenous condition is not evident until 6.5-8 s post-stimulus presentation. Overall, our results provide new evidence that although the dorsal fronto-parietal network is indeed associated with both types of attentional orienting, regions of the network are differentially engaged over time and across hemispheres depending on the type of attention. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Attention, gaze shifting, and dual-task interference from phonological encoding in spoken word planning

    NARCIS (Netherlands)

    Roelofs, A.P.A.

    2008-01-01

    Controversy exists about whether dual-task interference from word planning reflects structural bottleneck or attentional control factors. Here, participants named pictures whose names could or could not be phonologically prepared. and they manually responded to arrows presented away from (Experiment

  4. Attention.

    Science.gov (United States)

    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.

  5. Time-resolved neuroimaging of visual short term memory consolidation by post-perceptual attention shifts.

    Science.gov (United States)

    Hecht, Marcus; Thiemann, Ulf; Freitag, Christine M; Bender, Stephan

    2016-01-15

    Post-perceptual cues can enhance visual short term memory encoding even after the offset of the visual stimulus. However, both the mechanisms by which the sensory stimulus characteristics are buffered as well as the mechanisms by which post-perceptual selective attention enhances short term memory encoding remain unclear. We analyzed late post-perceptual event-related potentials (ERPs) in visual change detection tasks (100ms stimulus duration) by high-resolution ERP analysis to elucidate these mechanisms. The effects of early and late auditory post-cues (300ms or 850ms after visual stimulus onset) as well as the effects of a visual interference stimulus were examined in 27 healthy right-handed adults. Focusing attention with post-perceptual cues at both latencies significantly improved memory performance, i.e. sensory stimulus characteristics were available for up to 850ms after stimulus presentation. Passive watching of the visual stimuli without auditory cue presentation evoked a slow negative wave (N700) over occipito-temporal visual areas. N700 was strongly reduced by a visual interference stimulus which impeded memory maintenance. In contrast, contralateral delay activity (CDA) still developed in this condition after the application of auditory post-cues and was thereby dissociated from N700. CDA and N700 seem to represent two different processes involved in short term memory encoding. While N700 could reflect visual post processing by automatic attention attraction, CDA may reflect the top-down process of searching selectively for the required information through post-perceptual attention. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Biased ART: a neural architecture that shifts attention toward previously disregarded features following an incorrect prediction.

    Science.gov (United States)

    Carpenter, Gail A; Gaddam, Sai Chaitanya

    2010-04-01

    Memories in Adaptive Resonance Theory (ART) networks are based on matched patterns that focus attention on those portions of bottom-up inputs that match active top-down expectations. While this learning strategy has proved successful for both brain models and applications, computational examples show that attention to early critical features may later distort memory representations during online fast learning. For supervised learning, biased ARTMAP (bARTMAP) solves the problem of over-emphasis on early critical features by directing attention away from previously attended features after the system makes a predictive error. Small-scale, hand-computed analog and binary examples illustrate key model dynamics. Two-dimensional simulation examples demonstrate the evolution of bARTMAP memories as they are learned online. Benchmark simulations show that featural biasing also improves performance on large-scale examples. One example, which predicts movie genres and is based, in part, on the Netflix Prize database, was developed for this project. Both first principles and consistent performance improvements on all simulation studies suggest that featural biasing should be incorporated by default in all ARTMAP systems. Benchmark datasets and bARTMAP code are available from the CNS Technology Lab Website: http://techlab.bu.edu/bART/. Copyright 2009 Elsevier Ltd. All rights reserved.

  7. Shifting attention among working memory representations: testing cue type, awareness, and strategic control.

    Science.gov (United States)

    Berryhill, Marian E; Richmond, Lauren L; Shay, Cara S; Olson, Ingrid R

    2012-01-01

    It is well known that visual working memory (VWM) performance is modulated by attentional cues presented during encoding. Interestingly, retrospective cues presented after encoding, but prior to the test phase also improve performance. This improvement in performance is termed the retro-cue benefit. We investigated whether the retro-cue benefit is sensitive to cue type, whether participants were aware of their improvement in performance due to the retro-cue, and whether the effect was under strategic control. Experiment 1 compared the potential cueing benefits of abrupt onset retro-cues relying on bottom-up attention, number retro-cues relying on top-down attention, and arrow retro-cues, relying on a mixture of both. We found a significant retro-cue effect only for arrow retro-cues. In Experiment 2, we tested participants' awareness of their use of the informative retro-cue and found that they were aware of their improved performance. In Experiment 3, we asked whether participants have strategic control over the retro-cue. The retro-cue was difficult to ignore, suggesting that strategic control is low. The retro-cue effect appears to be within conscious awareness but not under full strategic control.

  8. Behavioral performance follows the time course of neural facilitation and suppression during cued shifts of feature-selective attention.

    Science.gov (United States)

    Andersen, S K; Müller, M M

    2010-08-03

    A central question in the field of attention is whether visual processing is a strictly limited resource, which must be allocated by selective attention. If this were the case, attentional enhancement of one stimulus should invariably lead to suppression of unattended distracter stimuli. Here we examine voluntary cued shifts of feature-selective attention to either one of two superimposed red or blue random dot kinematograms (RDKs) to test whether such a reciprocal relationship between enhancement of an attended and suppression of an unattended stimulus can be observed. The steady-state visual evoked potential (SSVEP), an oscillatory brain response elicited by the flickering RDKs, was measured in human EEG. Supporting limited resources, we observed both an enhancement of the attended and a suppression of the unattended RDK, but this observed reciprocity did not occur concurrently: enhancement of the attended RDK started at 220 ms after cue onset and preceded suppression of the unattended RDK by about 130 ms. Furthermore, we found that behavior was significantly correlated with the SSVEP time course of a measure of selectivity (attended minus unattended) but not with a measure of total activity (attended plus unattended). The significant deviations from a temporally synchronized reciprocity between enhancement and suppression suggest that the enhancement of the attended stimulus may cause the suppression of the unattended stimulus in the present experiment.

  9. Visual attention shift to printed words during spoken word recognition in Chinese: The role of phonological information.

    Science.gov (United States)

    Shen, Wei; Qu, Qingqing; Tong, Xiuhong

    2018-05-01

    The aim of this study was to investigate the extent to which phonological information mediates the visual attention shift to printed Chinese words in spoken word recognition by using an eye-movement technique with a printed-word paradigm. In this paradigm, participants are visually presented with four printed words on a computer screen, which include a target word, a phonological competitor, and two distractors. Participants are then required to select the target word using a computer mouse, and the eye movements are recorded. In Experiment 1, phonological information was manipulated at the full-phonological overlap; in Experiment 2, phonological information at the partial-phonological overlap was manipulated; and in Experiment 3, the phonological competitors were manipulated to share either fulloverlap or partial-overlap with targets directly. Results of the three experiments showed that the phonological competitor effects were observed at both the full-phonological overlap and partial-phonological overlap conditions. That is, phonological competitors attracted more fixations than distractors, which suggested that phonological information mediates the visual attention shift during spoken word recognition. More importantly, we found that the mediating role of phonological information varies as a function of the phonological similarity between target words and phonological competitors.

  10. Shifting attention from objective risk factors to patients' self-assessed health resources: a clinical model for general practice.

    Science.gov (United States)

    Hollnagel, H; Malterud, K

    1995-12-01

    The study was designed to present and apply theoretical and empirical knowledge for the construction of a clinical model intended to shift the attention of the general practitioner from objective risk factors to self-assessed health resources in male and female patients. Review, discussion and analysis of selected theoretical models about personal health resources involving assessing existing theories according to their emphasis concerning self-assessed vs. doctor-assessed health resources, specific health resources vs. life and coping in general, abstract vs. clinically applicable theory, gender perspective explicitly included or not. Relevant theoretical models on health and coping (salutogenesis, coping and social support, control/demand, locus of control, health belief model, quality of life), and the perspective of the underprivileged Other (critical theory, feminist standpoint theory, the patient-centred clinical method) were presented and assessed. Components from Antonovsky's salutogenetic perspective and McWhinney's patient-centred clinical method, supported by gender perspectives, were integrated to a clinical model which is presented. General practitioners are recommended to shift their attention from objective risk factors to self-assessed health resources by means of the clinical model. The relevance and feasibility of the model should be explored in empirical research.

  11. Rapid changes in gene expression direct rapid shifts in intestinal form and function in the Burmese python after feeding

    OpenAIRE

    Andrew, Audra L.; Card, Daren C.; Ruggiero, Robert P.; Schield, Drew R.; Adams, Richard H.; Pollock, David D.; Secor, Stephen M.; Castoe, Todd A.

    2015-01-01

    Snakes provide a unique and valuable model system for studying the extremes of physiological remodeling because of the ability of some species to rapidly upregulate organ form and function upon feeding. The predominant model species used to study such extreme responses has been the Burmese python because of the extreme nature of postfeeding response in this species. We analyzed the Burmese python intestine across a time series, before, during, and after feeding to understand the patterns and ...

  12. Subchronic and chronic PCP treatment produces temporally distinct deficits in attentional set shifting and prepulse inhibition in rats.

    Science.gov (United States)

    Egerton, Alice; Reid, Lee; McGregor, Sandie; Cochran, Susan M; Morris, Brian J; Pratt, Judith A

    2008-05-01

    We have previously demonstrated that subchronic (five daily administrations of 2.6 mg/kg PCP) and chronic intermittent administration of 2.6 mg/kg PCP to rats produces hypofrontality and other neurochemical changes akin to schizophrenia pathology (Cochran et al., Neuropsychopharmacology, 28:265-275, 2003). We sought to determine whether behavioral alterations related to discrete aspects of schizophrenia are also induced by these PCP treatment regimes. Following administration of vehicle or PCP according to the protocols described above, rats were assessed for attentional set shifting ability, prepulse inhibition (PPI), or social interaction and the locomotor response to a challenge dose of amphetamine. Ability to shift attentional set was impaired 72 h after the last PCP administration following the subchronic and chronic intermittent treatment regimes. PPI was disrupted after each acute administration of PCP in animals under the subchronic treatment regime. However, PPI deficits were not sustained 72 h after the last of five daily administrations. In subchronic and chronic PCP treated animals, no change was found in social interaction behavior, and there was little change in baseline or amphetamine-stimulated locomotor activity, employed as an indicator of dopaminergic hyperfunction. The temporally distinct behavioral effects of these PCP treatment regimes suggest that PPI deficits relate directly to acute NMDA receptor antagonism, whereas the more enduring set shifting deficits relate to the longer term consequences of NMDA receptor blockade. Therefore, these subchronic and chronic PCP treatment regimes produce hypofrontality (Cochran et al., Neuropsychopharmacology, 28:265-275, 2003) and associated prefrontal cortex-dependent deficits in behavioral flexibility which mirror core deficits in schizophrenia.

  13. Consciousness wanted, attention found: Reasons for the advantage of the left visual field in identifying T2 among rapidly presented series.

    Science.gov (United States)

    Verleger, Rolf; Śmigasiewicz, Kamila

    2015-09-01

    Everyday experience suggests that people are equally aware of events in both hemi-fields. However, when two streams of stimuli are rapidly presented left and right containing two targets, the second target is better identified in the left than in the right visual field. This might be considered evidence for a right-hemisphere advantage in generating conscious percepts. However, this putative asymmetry of conscious perception cannot be measured independently of participants' access to their conscious percepts, and there is actually evidence from split-brain patients for the reverse, left-hemisphere advantage in having access to conscious percepts. Several other topics were studied in search of the responsible mechanism, among others: Mutual inhibition of hemispheres, cooperation of hemispheres in perceiving midline stimuli, and asymmetries in processing various perceptual inputs. Directing attention by salient cues turned out to be one of the few mechanisms capable of modifying the left visual-field advantage in this paradigm. Thus, this left visual-field advantage is best explained by the notion of a right-hemisphere advantage in directing attention to salient events. Dovetailing with the pathological asymmetries of attention after right-hemisphere lesions and with asymmetries of brain activation when healthy participants shift their attention, the present results extend that body of evidence by demonstrating unusually large and reliable behavioral asymmetries for attention-directing processes in healthy participants. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Visual processing in rapid-chase systems: Image processing, attention, and awareness

    Directory of Open Access Journals (Sweden)

    Thomas eSchmidt

    2011-07-01

    Full Text Available Visual stimuli can be classified so rapidly that their analysis may be based on a single sweep of feedforward processing through the visuomotor system. Behavioral criteria for feedforward processing can be evaluated in response priming tasks where speeded pointing or keypress responses are performed towards target stimuli which are preceded by prime stimuli. We apply this method to several classes of complex stimuli. 1 When participants classify natural images into animals or non-animals, the time course of their pointing responses indicates that prime and target signals remain strictly sequential throughout all processing stages, meeting stringent behavioral criteria for feedforward processing (rapid-chase criteria. 2 Such priming effects are boosted by selective visual attention for positions, shapes, and colors, in a way consistent with bottom-up enhancement of visuomotor processing, even when primes cannot be consciously identified. 3 Speeded processing of phobic images is observed in participants specifically fearful of spiders or snakes, suggesting enhancement of feedforward processing by long-term perceptual learning. 4 When the perceived brightness of primes in complex displays is altered by means of illumination or transparency illusions, priming effects in speeded keypress responses can systematically contradict subjective brightness judgments, such that one prime appears brighter than the other but activates motor responses as if it was darker. We propose that response priming captures the output of the first feedforward pass of visual signals through the visuomotor system, and that this output lacks some characteristic features of more elaborate, recurrent processing. This way, visuomotor measures may become dissociated from several aspects of conscious vision. We argue that "fast" visuomotor measures predominantly driven by feedforward processing should supplement "slow" psychophysical measures predominantly based on visual

  15. Rapid changes in gene expression direct rapid shifts in intestinal form and function in the Burmese python after feeding.

    Science.gov (United States)

    Andrew, Audra L; Card, Daren C; Ruggiero, Robert P; Schield, Drew R; Adams, Richard H; Pollock, David D; Secor, Stephen M; Castoe, Todd A

    2015-05-01

    Snakes provide a unique and valuable model system for studying the extremes of physiological remodeling because of the ability of some species to rapidly upregulate organ form and function upon feeding. The predominant model species used to study such extreme responses has been the Burmese python because of the extreme nature of postfeeding response in this species. We analyzed the Burmese python intestine across a time series, before, during, and after feeding to understand the patterns and timing of changes in gene expression and their relationship to changes in intestinal form and function upon feeding. Our results indicate that >2,000 genes show significant changes in expression in the small intestine following feeding, including genes involved in intestinal morphology and function (e.g., hydrolases, microvillus proteins, trafficking and transport proteins), as well as genes involved in cell division and apoptosis. Extensive changes in gene expression occur surprisingly rapidly, within the first 6 h of feeding, coincide with changes in intestinal morphology, and effectively return to prefeeding levels within 10 days. Collectively, our results provide an unprecedented portrait of parallel changes in gene expression and intestinal morphology and physiology on a scale that is extreme both in the magnitude of changes, as well as in the incredibly short time frame of these changes, with up- and downregulation of expression and function occurring in the span of 10 days. Our results also identify conserved vertebrate signaling pathways that modulate these responses, which may suggest pathways for therapeutic modulation of intestinal function in humans. Copyright © 2015 the American Physiological Society.

  16. Systemic range shift lags among a pollinator species assemblage following rapid climate change

    DEFF Research Database (Denmark)

    Bedford, Felicity E.; Whittaker, Robert J.; Kerr, Jeremy T.

    2012-01-01

    Contemporary climate change is driving widespread geographical range shifts among many species. If species are tracking changing climate successfully, then leading populations should experience similar climatic conditions through time as new populations establish beyond historical range margins....... Here, we investigate geographical range shifts relative to changing climatic conditions among a particularly well-sampled assemblage of butterflies in Canada. We assembled observations of 81 species and measured their latitudinal displacement between two periods: 1960–1975 (a period of little climate...... change) and 1990–2005 (a period with large climate change). We find an unexpected trend for species’ northern borders to shift progressively less relative to increasing minimum winter temperatures in northern Canada. This study demonstrates a novel, systemic latitudinal gradient in lags among a large...

  17. A rapid upward shift of a forest ecotone during 40 years of warming in the Green Mountains of Vermont.

    Science.gov (United States)

    Beckage, Brian; Osborne, Ben; Gavin, Daniel G; Pucko, Carolyn; Siccama, Thomas; Perkins, Timothy

    2008-03-18

    Detecting latitudinal range shifts of forest trees in response to recent climate change is difficult because of slow demographic rates and limited dispersal but may be facilitated by spatially compressed climatic zones along elevation gradients in montane environments. We resurveyed forest plots established in 1964 along elevation transects in the Green Mountains (Vermont) to examine whether a shift had occurred in the location of the northern hardwood-boreal forest ecotone (NBE) from 1964 to 2004. We found a 19% increase in dominance of northern hardwoods from 70% in 1964 to 89% in 2004 in the lower half of the NBE. This shift was driven by a decrease (up to 76%) in boreal and increase (up to 16%) in northern hardwood basal area within the lower portions of the ecotone. We used aerial photographs and satellite imagery to estimate a 91- to 119-m upslope shift in the upper limits of the NBE from 1962 to 2005. The upward shift is consistent with regional climatic change during the same period; interpolating climate data to the NBE showed a 1.1 degrees C increase in annual temperature, which would predict a 208-m upslope movement of the ecotone, along with a 34% increase in precipitation. The rapid upward movement of the NBE indicates little inertia to climatically induced range shifts in montane forests; the upslope shift may have been accelerated by high turnover in canopy trees that provided opportunities for ingrowth of lower elevation species. Our results indicate that high-elevation forests may be jeopardized by climate change sooner than anticipated.

  18. Rapid shifts in catch composition in the artisanal Red Sea reef fisheries of Eritrea

    NARCIS (Netherlands)

    Tsehaye, I.W.; Machiels, M.A.M.; Nagelkerke, L.A.J.

    2007-01-01

    Shifts in catch composition were registered in the Eritrean artisanal fisheries, which were launched into a renewed development after the end of the independence war in 1991. Our analysis of catch and effort data showed that total fishing effort as well as total annual catch increased more than

  19. Benefits of photobiological light exposure during rapidly rotating night-shift work

    NARCIS (Netherlands)

    Groot, E.H. de; Knoop, M.

    2007-01-01

    In the Netherlands, 76%o of the working population sometimes or regularly works between midnight and 6 a.m. This percentage is comparable to those of other countries. Two of the most common and harmful problems associated with shift work are reduced quality of sleep and a reduced alertness while at

  20. A Unique Role of Endogenous Visual-Spatial Attention in Rapid Processing of Multiple Targets

    Science.gov (United States)

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

    2011-01-01

    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).…

  1. Rapid shift in thermal resistance between generations through maternal heat exposure

    NARCIS (Netherlands)

    Zizzari, Z.V.; Ellers, J.

    2014-01-01

    Given the current rapid climate change, understanding the mechanisms underlying heat tolerance and its plasticity is an important goal of global change biology. Soil fauna communities are especially vulnerable because of their limited dispersal ability. It is generally recognized that

  2. The Effect of Orthographic Depth on Letter String Processing: The Case of Visual Attention Span and Rapid Automatized Naming

    Science.gov (United States)

    Antzaka, Alexia; Martin, Clara; Caffarra, Sendy; Schlöffel, Sophie; Carreiras, Manuel; Lallier, Marie

    2018-01-01

    The present study investigated whether orthographic depth can increase the bias towards multi-letter processing in two reading-related skills: visual attention span (VAS) and rapid automatized naming (RAN). VAS (i.e., the number of visual elements that can be processed at once in a multi-element array) was tested with a visual 1-back task and RAN…

  3. The effect of bright light on sleepiness among rapid-rotating 12-hour shift workers.

    Science.gov (United States)

    Sadeghniiat-Haghighi, Khosro; Yazdi, Zohreh; Jahanihashemi, Hassan; Aminian, Omid

    2011-01-01

    About 20% of workers in industrialized countries are shift workers and more than half of them work on night or rotating shifts. Most night workers complain of sleepiness due to lack of adjustment of the circadian rhythm. In simulated night-work experiments, scheduled exposure to bright light has been shown to reduce these complaints. Our study assessed the effects of bright light exposure on sleepiness during night work in an industrial setting. In a cross-over design, 94 workers at a ceramic factory were exposed to either bright (2500 lux) or normal light (300 lux) during breaks on night shifts. We initiated 20-minute breaks between 24.00 and 02.00 hours. Sleepiness ratings were determined using the Stanford Sleepiness Scale at 22.00, 24.00, 02.00 and 04.00 hours. Under normal light conditions, sleepiness peaked at 02:00 hours. A significant reduction (22% compared to normal light conditions) in sleepiness was observed after workers were exposed to bright light. Exposure to bright light may be effective in reducing sleepiness among night workers.

  4. Lateralization of spatial rather than temporal attention underlies the left hemifield advantage in rapid serial visual presentation.

    Science.gov (United States)

    Asanowicz, Dariusz; Kruse, Lena; Śmigasiewicz, Kamila; Verleger, Rolf

    2017-11-01

    In bilateral rapid serial visual presentation (RSVP), the second of two targets, T1 and T2, is better identified in the left visual field (LVF) than in the right visual field (RVF). This LVF advantage may reflect hemispheric asymmetry in temporal attention or/and in spatial orienting of attention. Participants performed two tasks: the "standard" bilateral RSVP task (Exp.1) and its unilateral variant (Exp.1 & 2). In the bilateral task, spatial location was uncertain, thus target identification involved stimulus-driven spatial orienting. In the unilateral task, the targets were presented block-wise in the LVF or RVF only, such that no spatial orienting was needed for target identification. Temporal attention was manipulated in both tasks by varying the T1-T2 lag. The results showed that the LVF advantage disappeared when involvement of stimulus-driven spatial orienting was eliminated, whereas the manipulation of temporal attention had no effect on the asymmetry. In conclusion, the results do not support the hypothesis of hemispheric asymmetry in temporal attention, and provide further evidence that the LVF advantage reflects right hemisphere predominance in stimulus-driven orienting of spatial attention. These conclusions fit evidence that temporal attention is implemented by bilateral parietal areas and spatial attention by the right-lateralized ventral frontoparietal network. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Molecular phylogeny of Pompilinae (Hymenoptera: Pompilidae): Evidence for rapid diversification and host shifts in spider wasps.

    Science.gov (United States)

    Rodriguez, Juanita; Pitts, James P; Florez, Jaime A; Bond, Jason E; von Dohlen, Carol D

    2016-01-01

    Pompilinae is one of the largest subfamilies of spider wasps (Pompilidae). Most pompilines are generalist spider predators at the family level, but some taxa exhibit ecological specificity (i.e., to spider-host guild). Here we present the first molecular phylogenetic analysis of Pompilinae, toward the aim of evaluating the monophyly of tribes and genera. We further test whether changes in the rate of diversification are associated with host-guild shifts. Molecular data were collected from five nuclear loci (28S, EF1-F2, LWRh, Wg, Pol2) for 76 taxa in 39 genera. Data were analyzed using maximum likelihood (ML) and Bayesian inference (BI). The phylogenetic results were compared with previous hypotheses of subfamilial and tribal classification, as well as generic relationships in the subfamily. The classification of Pompilus and Agenioideus is also discussed. A Bayesian relaxed molecular clock analysis was used to examine divergence times. Diversification rate-shift tests accounted for taxon-sampling bias using ML and BI approaches. Ancestral host family and host guild were reconstructed using MP and ML methods. Ancestral host guild for all Pompilinae, for the ancestor at the node where a diversification rate-shift was detected, and two more nodes back in time was inferred using BI. In the resulting phylogenies, Aporini was the only previously proposed monophyletic tribe. Several genera (e.g., Pompilus, Microphadnus and Schistonyx) are also not monophyletic. Dating analyses produced a well-supported chronogram consistent with topologies from BI and ML results. The BI ancestral host-use reconstruction inferred the use of spiders belonging to the guild "other hunters" (frequenting the ground and vegetation) as the ancestral state for Pompilinae. This guild had the highest probability for the ML reconstruction and was equivocal for the MP reconstruction; various switching events to other guilds occurred throughout the evolution of the group. The diversification of

  6. Use of task-shifting to rapidly scale-up HIV treatment services: experiences from Lusaka, Zambia

    Directory of Open Access Journals (Sweden)

    Chi Harmony F

    2009-01-01

    Full Text Available Abstract The World Health Organization advocates task-shifting, the process of delegating clinical care functions from more specialized to less specialized health workers, as a strategy to achieve the United Nations Millennium Development Goals. However, there is a dearth of literature describing task shifting in sub-Saharan Africa, where services for antiretroviral therapy (ART have scaled up rapidly in the face of generalized human resource crises. As part of ART services expansion in Lusaka, Zambia, we implemented a comprehensive task-shifting program among existing health providers and community-based workers. Training begins with didactic sessions targeting specialized skill sets. This is followed by an intensive period of practical mentorship, where providers are paired with trainers before working independently. We provide on-going quality assessment using key indicators of clinical care quality at each site. Program performance is reviewed with clinic-based staff quarterly. When problems are identified, clinic staff members design and implement specific interventions to address targeted areas. From 2005 to 2007, we trained 516 health providers in adult HIV treatment; 270 in pediatric HIV treatment; 341 in adherence counseling; 91 in a specialty nurse "triage" course, and 93 in an intensive clinical mentorship program. On-going quality assessment demonstrated improvement across clinical care quality indicators, despite rapidly growing patient volumes. Our task-shifting strategy was designed to address current health care worker needs and to sustain ART scale-up activities. While this approach has been successful, long-term solutions to the human resource crisis are also urgently needed to expand the number of providers and to slow staff migration out of the region.

  7. Learned Predictiveness Influences Rapid Attentional Capture: Evidence from the Dot Probe Task

    Science.gov (United States)

    Le Pelley, Mike E.; Vadillo, Miguel; Luque, David

    2013-01-01

    Attentional theories of associative learning and categorization propose that learning about the predictiveness of a stimulus influences the amount of attention that is paid to that stimulus. Three experiments tested this idea by looking at the extent to which stimuli that had previously been experienced as predictive or nonpredictive in a…

  8. Rapid shifts in Atta cephalotes fungus-garden enzyme activity after a change in fungal substrate (Attini, Formicidae)

    DEFF Research Database (Denmark)

    Kooij, P W; Schiøtt, M; Boomsma, J J

    2011-01-01

    Fungus gardens of the basidiomycete Leucocoprinus gongylophorus sustain large colonies of leaf-cutting ants by degrading the plant material collected by the ants. Recent studies have shown that enzyme activity in these gardens is primarily targeted toward starch, proteins and the pectin matrix......, we measured the changes in enzyme activity after a controlled shift in fungal substrate offered to six laboratory colonies of Atta cephalotes. An ant diet consisting exclusively of grains of parboiled rice rapidly increased the activity of endo-proteinases and some of the pectinases attacking...... from the rice diet, relative to the leaf diet controls. Enzyme activity in the older, bottom sections of fungus gardens decreased, indicating a faster processing of the rice substrate compared to the leaf diet. These results suggest that leaf-cutting ant fungus gardens can rapidly adjust enzyme...

  9. Carbon and nitrogen isotopes from top predator amino acids reveal rapidly shifting ocean biochemistry in the outer California Current.

    Directory of Open Access Journals (Sweden)

    Rocio I Ruiz-Cooley

    Full Text Available Climatic variation alters biochemical and ecological processes, but it is difficult both to quantify the magnitude of such changes, and to differentiate long-term shifts from inter-annual variability. Here, we simultaneously quantify decade-scale isotopic variability at the lowest and highest trophic positions in the offshore California Current System (CCS by measuring δ15N and δ13C values of amino acids in a top predator, the sperm whale (Physeter macrocephalus. Using a time series of skin tissue samples as a biological archive, isotopic records from individual amino acids (AAs can reveal the proximate factors driving a temporal decline we observed in bulk isotope values (a decline of ≥1 ‰ by decoupling changes in primary producer isotope values from those linked to the trophic position of this toothed whale. A continuous decline in baseline (i.e., primary producer δ15N and δ13C values was observed from 1993 to 2005 (a decrease of ∼4‰ for δ15N source-AAs and 3‰ for δ13C essential-AAs, while the trophic position of whales was variable over time and it did not exhibit directional trends. The baseline δ15N and δ13C shifts suggest rapid ongoing changes in the carbon and nitrogen biogeochemical cycling in the offshore CCS, potentially occurring at faster rates than long-term shifts observed elsewhere in the Pacific. While the mechanisms forcing these biogeochemical shifts remain to be determined, our data suggest possible links to natural climate variability, and also corresponding shifts in surface nutrient availability. Our study demonstrates that isotopic analysis of individual amino acids from a top marine mammal predator can be a powerful new approach to reconstructing temporal variation in both biochemical cycling and trophic structure.

  10. Carbon and nitrogen isotopes from top predator amino acids reveal rapidly shifting ocean biochemistry in the outer California Current.

    Science.gov (United States)

    Ruiz-Cooley, Rocio I; Koch, Paul L; Fiedler, Paul C; McCarthy, Matthew D

    2014-01-01

    Climatic variation alters biochemical and ecological processes, but it is difficult both to quantify the magnitude of such changes, and to differentiate long-term shifts from inter-annual variability. Here, we simultaneously quantify decade-scale isotopic variability at the lowest and highest trophic positions in the offshore California Current System (CCS) by measuring δ15N and δ13C values of amino acids in a top predator, the sperm whale (Physeter macrocephalus). Using a time series of skin tissue samples as a biological archive, isotopic records from individual amino acids (AAs) can reveal the proximate factors driving a temporal decline we observed in bulk isotope values (a decline of ≥1 ‰) by decoupling changes in primary producer isotope values from those linked to the trophic position of this toothed whale. A continuous decline in baseline (i.e., primary producer) δ15N and δ13C values was observed from 1993 to 2005 (a decrease of ∼4‰ for δ15N source-AAs and 3‰ for δ13C essential-AAs), while the trophic position of whales was variable over time and it did not exhibit directional trends. The baseline δ15N and δ13C shifts suggest rapid ongoing changes in the carbon and nitrogen biogeochemical cycling in the offshore CCS, potentially occurring at faster rates than long-term shifts observed elsewhere in the Pacific. While the mechanisms forcing these biogeochemical shifts remain to be determined, our data suggest possible links to natural climate variability, and also corresponding shifts in surface nutrient availability. Our study demonstrates that isotopic analysis of individual amino acids from a top marine mammal predator can be a powerful new approach to reconstructing temporal variation in both biochemical cycling and trophic structure.

  11. Rapid yet accurate measurement of mass diffusion coefficients by phase shifting interferometer

    CERN Document Server

    Guo Zhi Xiong; Komiya, A

    1999-01-01

    The technique of using a phase-shifting interferometer is applied to the study of diffusion in transparent liquid mixtures. A quick method is proposed for determining the diffusion coefficient from the measurements of the location of fringes on a grey level picture. The measurement time is very short (within 100 s) and a very small transient diffusion field can be observed and recorded accurately with a rate of 30 frames per second. The measurement can be completed using less than 0.12 cc of solutions. The influence of gravity on the measurement of the diffusion coefficient is eliminated in the present method. Results on NaCl-water diffusion systems are presented and compared with the reference data. (author)

  12. Saccade generation by the frontal eye fields in rhesus monkeys is separable from visual detection and bottom-up attention shift.

    Science.gov (United States)

    Lee, Kyoung-Min; Ahn, Kyung-Ha; Keller, Edward L

    2012-01-01

    The frontal eye fields (FEF), originally identified as an oculomotor cortex, have also been implicated in perceptual functions, such as constructing a visual saliency map and shifting visual attention. Further dissecting the area's role in the transformation from visual input to oculomotor command has been difficult because of spatial confounding between stimuli and responses and consequently between intermediate cognitive processes, such as attention shift and saccade preparation. Here we developed two tasks in which the visual stimulus and the saccade response were dissociated in space (the extended memory-guided saccade task), and bottom-up attention shift and saccade target selection were independent (the four-alternative delayed saccade task). Reversible inactivation of the FEF in rhesus monkeys disrupted, as expected, contralateral memory-guided saccades, but visual detection was demonstrated to be intact at the same field. Moreover, saccade behavior was impaired when a bottom-up shift of attention was not a prerequisite for saccade target selection, indicating that the inactivation effect was independent of the previously reported dysfunctions in bottom-up attention control. These findings underscore the motor aspect of the area's functions, especially in situations where saccades are generated by internal cognitive processes, including visual short-term memory and long-term associative memory.

  13. Saccade generation by the frontal eye fields in rhesus monkeys is separable from visual detection and bottom-up attention shift.

    Directory of Open Access Journals (Sweden)

    Kyoung-Min Lee

    Full Text Available The frontal eye fields (FEF, originally identified as an oculomotor cortex, have also been implicated in perceptual functions, such as constructing a visual saliency map and shifting visual attention. Further dissecting the area's role in the transformation from visual input to oculomotor command has been difficult because of spatial confounding between stimuli and responses and consequently between intermediate cognitive processes, such as attention shift and saccade preparation. Here we developed two tasks in which the visual stimulus and the saccade response were dissociated in space (the extended memory-guided saccade task, and bottom-up attention shift and saccade target selection were independent (the four-alternative delayed saccade task. Reversible inactivation of the FEF in rhesus monkeys disrupted, as expected, contralateral memory-guided saccades, but visual detection was demonstrated to be intact at the same field. Moreover, saccade behavior was impaired when a bottom-up shift of attention was not a prerequisite for saccade target selection, indicating that the inactivation effect was independent of the previously reported dysfunctions in bottom-up attention control. These findings underscore the motor aspect of the area's functions, especially in situations where saccades are generated by internal cognitive processes, including visual short-term memory and long-term associative memory.

  14. Progress in Rapidly-Tunable External Cavity Quantum Cascade Lasers with a Frequency-Shifted Feedback

    Directory of Open Access Journals (Sweden)

    Arkadiy Lyakh

    2016-04-01

    Full Text Available The recent demonstration of external cavity quantum cascade lasers with optical feedback, controlled by an acousto-optic modulator, paves the way to ruggedized infrared laser systems with the capability of tuning the emission wavelength on a microsecond scale. Such systems are of great importance for various critical applications requiring ultra-rapid wavelength tuning, including combustion and explosion diagnostics and standoff detection. In this paper, recent research results on these devices are summarized and the advantages of the new configuration are analyzed in the context of practical applications.

  15. Rapid shift and millennial-scale variations in Holocene North Pacific Intermediate Water ventilation.

    Science.gov (United States)

    Lembke-Jene, Lester; Tiedemann, Ralf; Nürnberg, Dirk; Gong, Xun; Lohmann, Gerrit

    2018-05-22

    The Pacific hosts the largest oxygen minimum zones (OMZs) in the world ocean, which are thought to intensify and expand under future climate change, with significant consequences for marine ecosystems, biogeochemical cycles, and fisheries. At present, no deep ventilation occurs in the North Pacific due to a persistent halocline, but relatively better-oxygenated subsurface North Pacific Intermediate Water (NPIW) mitigates OMZ development in lower latitudes. Over the past decades, instrumental data show decreasing oxygenation in NPIW; however, long-term variations in middepth ventilation are potentially large, obscuring anthropogenic influences against millennial-scale natural background shifts. Here, we use paleoceanographic proxy evidence from the Okhotsk Sea, the foremost North Pacific ventilation region, to show that its modern oxygenated pattern is a relatively recent feature, with little to no ventilation before six thousand years ago, constituting an apparent Early-Middle Holocene (EMH) threshold or "tipping point." Complementary paleomodeling results likewise indicate a warmer, saltier EMH NPIW, different from its modern conditions. During the EMH, the Okhotsk Sea switched from a modern oxygenation source to a sink, through a combination of sea ice loss, higher water temperatures, and remineralization rates, inhibiting ventilation. We estimate a strongly decreased EMH NPIW oxygenation of ∼30 to 50%, and increased middepth Pacific nutrient concentrations and carbon storage. Our results ( i ) imply that under past or future warmer-than-present conditions, oceanic biogeochemical feedback mechanisms may change or even switch direction, and ( ii ) provide constraints on the high-latitude North Pacific's influence on mesopelagic ventilation dynamics, with consequences for large oceanic regions. Copyright © 2018 the Author(s). Published by PNAS.

  16. Unbounded boundaries and shifting baselines: Estuaries and coastal seas in a rapidly changing world

    Science.gov (United States)

    Little, S.; Spencer, K. L.; Schuttelaars, H. M.; Millward, G. E.; Elliott, M.

    2017-11-01

    future modelling studies and; (4) the importance of shifting baselines on ecosystem functioning and the future provision of ecosystem services.

  17. Coastal regime shifts: rapid responses of coastal wetlands to changes in mangrove cover.

    Science.gov (United States)

    Guo, Hongyu; Weaver, Carolyn; Charles, Sean P; Whitt, Ashley; Dastidar, Sayantani; D'Odorico, Paolo; Fuentes, Jose D; Kominoski, John S; Armitage, Anna R; Pennings, Steven C

    2017-03-01

    Global changes are causing broad-scale shifts in vegetation communities worldwide, including coastal habitats where the borders between mangroves and salt marsh are in flux. Coastal habitats provide numerous ecosystem services of high economic value, but the consequences of variation in mangrove cover are poorly known. We experimentally manipulated mangrove cover in large plots to test a set of linked hypotheses regarding the effects of changes in mangrove cover. We found that changes in mangrove cover had strong effects on microclimate, plant community, sediment accretion, soil organic content, and bird abundance within 2 yr. At higher mangrove cover, wind speed declined and light interception by vegetation increased. Air and soil temperatures had hump-shaped relationships with mangrove cover. The cover of salt marsh plants decreased at higher mangrove cover. Wrack cover, the distance that wrack was distributed from the water's edge, and sediment accretion decreased at higher mangrove cover. Soil organic content increased with mangrove cover. Wading bird abundance decreased at higher mangrove cover. Many of these relationships were non-linear, with the greatest effects when mangrove cover varied from zero to intermediate values, and lesser effects when mangrove cover varied from intermediate to high values. Temporal and spatial variation in measured variables often peaked at intermediate mangrove cover, with ecological consequences that are largely unexplored. Because different processes varied in different ways with mangrove cover, the "optimum" cover of mangroves from a societal point of view will depend on which ecosystem services are most desired. © 2016 by the Ecological Society of America.

  18. Asymmetrical effects of adaptation to left- and right-shifting prisms depends on pre-existing attentional biases.

    Science.gov (United States)

    Goedert, Kelly M; Leblanc, Andrew; Tsai, Sen-Wei; Barrett, Anna M

    2010-09-01

    Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal individuals rely on a dissociation between the postadaptation performance of individuals trained with left- versus right-shifting prisms (e.g., Colent, Pisella, & Rossetti, 2000). A potential problem with this evidence is that normal young adults have an a priori leftward bias (e.g., Jewell & McCourt, 2000). In Experiment 1, we compared the line bisection performance of young adults to that of aged adults, who as a group may lack a leftward bias in line bisection. Participants trained with both left- and right-shifting prisms. Consistent with our hypothesis, while young adults demonstrated aftereffects for left, but not right prisms, aged adults demonstrated reliable aftereffects for both prisms. In Experiment 2, we recruited a larger sample of young adults, some of whom were right-biased at baseline. We observed an interaction between baseline bias and prism-shift, consistent with the results of Experiment 1: Left-biased individuals showed a reduced aftereffect when training with right-shifting prisms and right-biased individuals showed a reduced aftereffect when training with left-shifting prisms. These results suggest that previous failures to find generalizable aftereffects with right-shifting prisms may be driven by participants' baseline biases rather than specific effects of the prism itself.

  19. Attention to local and global levels of hierarchical Navon figures affects rapid scene categorization.

    Science.gov (United States)

    Brand, John; Johnson, Aaron P

    2014-01-01

    In four experiments, we investigated how attention to local and global levels of hierarchical Navon figures affected the selection of diagnostic spatial scale information used in scene categorization. We explored this issue by asking observers to classify hybrid images (i.e., images that contain low spatial frequency (LSF) content of one image, and high spatial frequency (HSF) content from a second image) immediately following global and local Navon tasks. Hybrid images can be classified according to either their LSF, or HSF content; thus, making them ideal for investigating diagnostic spatial scale preference. Although observers were sensitive to both spatial scales (Experiment 1), they overwhelmingly preferred to classify hybrids based on LSF content (Experiment 2). In Experiment 3, we demonstrated that LSF based hybrid categorization was faster following global Navon tasks, suggesting that LSF processing associated with global Navon tasks primed the selection of LSFs in hybrid images. In Experiment 4, replicating Experiment 3 but suppressing the LSF information in Navon letters by contrast balancing the stimuli examined this hypothesis. Similar to Experiment 3, observers preferred to classify hybrids based on LSF content; however and in contrast, LSF based hybrid categorization was slower following global than local Navon tasks.

  20. Rapid Improvement in Visual Selective Attention Related to Action Video Gaming Experience

    Directory of Open Access Journals (Sweden)

    Nan Qiu

    2018-02-01

    Full Text Available A central issue in cognitive science is understanding how learning induces cognitive and neural plasticity, which helps illuminate the biological basis of learning. Research in the past few decades showed that action video gaming (AVG offered new, important perspectives on learning-related cognitive and neural plasticity. However, it is still unclear whether cognitive and neural plasticity is observable after a brief AVG session. Using behavioral and electrophysiological measures, this study examined the plasticity of visual selective attention (VSA associated with a 1 h AVG session. Both AVG experts and non-experts participated in this study. Their VSA was assessed prior to and after the AVG session. Within-group comparisons on the participants' performance before and after the AVG session showed improvements in response time in both groups and modulations of electrophysiological measures in the non-experts. Furthermore, between-group comparisons showed that the experts had superior VSA, relative to the non-experts, prior to the AVG session. These findings suggested an association between the plasticity of VSA and AVG. Most importantly, this study showed that the plasticity of VSA was observable after even a 1 h AVG session.

  1. Rapid Improvement in Visual Selective Attention Related to Action Video Gaming Experience.

    Science.gov (United States)

    Qiu, Nan; Ma, Weiyi; Fan, Xin; Zhang, Youjin; Li, Yi; Yan, Yuening; Zhou, Zhongliang; Li, Fali; Gong, Diankun; Yao, Dezhong

    2018-01-01

    A central issue in cognitive science is understanding how learning induces cognitive and neural plasticity, which helps illuminate the biological basis of learning. Research in the past few decades showed that action video gaming (AVG) offered new, important perspectives on learning-related cognitive and neural plasticity. However, it is still unclear whether cognitive and neural plasticity is observable after a brief AVG session. Using behavioral and electrophysiological measures, this study examined the plasticity of visual selective attention (VSA) associated with a 1 h AVG session. Both AVG experts and non-experts participated in this study. Their VSA was assessed prior to and after the AVG session. Within-group comparisons on the participants' performance before and after the AVG session showed improvements in response time in both groups and modulations of electrophysiological measures in the non-experts. Furthermore, between-group comparisons showed that the experts had superior VSA, relative to the non-experts, prior to the AVG session. These findings suggested an association between the plasticity of VSA and AVG. Most importantly, this study showed that the plasticity of VSA was observable after even a 1 h AVG session.

  2. Attention to local and global levels of hierarchical Navon figures affects rapid scene categorization

    Science.gov (United States)

    Brand, John; Johnson, Aaron P.

    2014-01-01

    In four experiments, we investigated how attention to local and global levels of hierarchical Navon figures affected the selection of diagnostic spatial scale information used in scene categorization. We explored this issue by asking observers to classify hybrid images (i.e., images that contain low spatial frequency (LSF) content of one image, and high spatial frequency (HSF) content from a second image) immediately following global and local Navon tasks. Hybrid images can be classified according to either their LSF, or HSF content; thus, making them ideal for investigating diagnostic spatial scale preference. Although observers were sensitive to both spatial scales (Experiment 1), they overwhelmingly preferred to classify hybrids based on LSF content (Experiment 2). In Experiment 3, we demonstrated that LSF based hybrid categorization was faster following global Navon tasks, suggesting that LSF processing associated with global Navon tasks primed the selection of LSFs in hybrid images. In Experiment 4, replicating Experiment 3 but suppressing the LSF information in Navon letters by contrast balancing the stimuli examined this hypothesis. Similar to Experiment 3, observers preferred to classify hybrids based on LSF content; however and in contrast, LSF based hybrid categorization was slower following global than local Navon tasks. PMID:25520675

  3. Performance on a strategy set shifting task during adolescence in a genetic model of attention deficit/hyperactivity disorder: Methylphenidate vs. atomoxetine treatments

    Science.gov (United States)

    Harvey, Roxann C; Jordan, Chloe J; Tassin, David H; Moody, Kayla R; Dwoskin, Linda P; Kantak, Kathleen M

    2013-01-01

    Research examining medication effects on set shifting in teens with attention deficit/hyperactivity disorder (ADHD) is lacking. An animal model of ADHD may be useful for exploring this gap. The Spontaneously Hypertensive Rat (SHR) is a commonly used animal model of ADHD. SHR and two comparator strains, Wistar-Kyoto (WKY) and Wistar (WIS), were evaluated during adolescence in a strategy set shifting task under conditions of a 0-sec or 15-sec delay to reinforcer delivery. The task had three phases: initial discrimination, set shift and reversal learning. Under 0-sec delays, SHR performed as well as or better than WKY and WIS. Treatment with 0.3 mg/kg/day atomoxetine had little effect, other than to modestly increase trials to criterion during set shifting in all strains. Under 15-sec delays, SHR had longer lever press reaction times, longer latencies to criterion and more trial omissions than WKY during set shifting and reversal learning. These deficits were not reduced systematically by 1.5 mg/kg/day methylphenidate or 0.3 mg/kg/day atomoxetine. Regarding learning in SHR, methylphenidate improved initial discrimination, whereas atomoxetine improved set shifting but disrupted initial discrimination. During reversal learning, both drugs were ineffective in SHR, and atomoxetine made reaction time and trial omissions greater in WKY. Overall, WIS performance differed from SHR or WKY, depending on phase. Collectively, a genetic model of ADHD in adolescent rats revealed that neither methylphenidate nor atomoxetine mitigated all deficits in SHR during the set shifting task. Thus, methylphenidate or atomoxetine monotherapy may not mitigate all set shift task-related deficits in teens with ADHD. PMID:23376704

  4. Timing divided attention.

    Science.gov (United States)

    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.

  5. Attention and gaze shifting in dual-task and go/no-go performance with vocal responding

    NARCIS (Netherlands)

    Lamers, M.J.M.; Roelofs, A.P.A.

    2011-01-01

    Evidence from go/no-go performance on the Eriksen flanker task with manual responding suggests that individuals gaze at stimuli just as long as needed to identify them (e.g.. Sanders, 1998). In contrast, evidence from dual-task performance with vocal responding suggests that gaze shifts occur after

  6. Shifts of visuospatial attention to invisible (metacontrast-masked singletons: Clues from reaction times and event-related potential

    Directory of Open Access Journals (Sweden)

    Manfred Heumann

    2006-01-01

    Full Text Available In the current study, we tested whether a masked and, thus, invisible singleton-cue captures atten-tion in a stimulus-driven manner or in a top-down contingent manner. The manual RT (Reaction Time capture effect with the invisible singleton--cue decreased substantially when a match between the singleton-cue and the top-down controlled set of searched-for target features was also decreased. By contrast, with the PCN (Posterior Contralateral Negativity, an electrophysiological measure of the capture of visuospatial attention by the invisible singleton-cue, no significant decrement was observed. Taken together, the results support the assumption that an invisible singleton-cue can capture attention in a stimulus-driven manner, and that different delays in the deallocation of attention (i.e., attention is deallocated more efficiently from acue that does not match the top-down controlled set than from a cue that does match the same set account for the weaker manual RT capture effect with a set- -nonmatching invisible singleton-cue.

  7. Effects of acamprosate on attentional set-shifting and cellular function in the prefrontal cortex of chronic alcohol-exposed mice

    Science.gov (United States)

    Hu, Wei

    Background: The medial prefrontal cortex (mPFC) inhibits impulsive and compulsive behaviors that characterize drug abuse and dependence. Acamprosate is the leading medication approved for the maintenance of abstinence, shown to reduce craving and relapse in animal models and human alcoholics. Whether acamprosate can modulate executive functions that are impaired by chronic ethanol exposure is unknown. Here we explored the effects of acamprosate on an attentional set-shifting task, and tested whether these behavioral effects are correlated with modulation of glutamatergic synaptic transmission and intrinsic excitability of mPFC neurons. Methods: We induced alcohol dependence in mice via chronic intermittent ethanol (CIE) exposure in vapor chambers and measured changes in alcohol consumption in a limited access 2-bottle choice paradigm. Impairments of executive function were assessed in an attentional set-shifting task. Acamprosate was applied subchronically for 2 days during withdrawal before the final behavioral test. Alcohol-induced changes in cellular function of layer 5/6 pyramidal neurons, and the potential modulation of these changes by acamprosate, were measured using patch clamp recordings in brain slices. Results: Chronic ethanol exposure impaired cognitive flexibility in the attentional set-shifting task. Acamprosate improved overall performance and reduced perseveration. Recordings of mPFC neurons showed that chronic ethanol exposure increased use-dependent presynaptic transmitter release and enhanced postsynaptic N-methyl-D-aspartate receptor (NMDAR) function. Moreover, CIE-treatment lowered input resistance, and decreased the threshold and the afterhyperpolarization (AHP) of action potentials, suggesting chronic ethanol exposure also impacted membrane excitability of mPFC neurons. However, acamprosate treatment did not reverse these ethanol-induced changes cellular function. Conclusion: Acamprosate improved attentional control of ethanol exposed animals

  8. Age-related grey matter volume correlates of response inhibition and shifting in Attention Deficit Hyperactivity Disorder

    NARCIS (Netherlands)

    McAlonan, G. M.; Cheung, V.; Chua, S. E.; Oosterlaan, J.; Hung, S.; Tang, C.; Lee, C.; Kwong, S.; Ho, T.; Cheung, C.; Suckling, J.; Leung, P. W. L.

    2009-01-01

    Background Children with attention-deficit hyperactivity disorder (ADHD) have difficulties with executive function and impulse control which may improve with age. Aims To map the brain correlates of executive function in ADHD and determine age-related changes in reaction times and brain volumes.

  9. Mental rotation impairs attention shifting and short-term memory encoding: neurophysiological evidence against the response-selection bottleneck model of dual-task performance.

    Science.gov (United States)

    Pannebakker, Merel M; Jolicœur, Pierre; van Dam, Wessel O; Band, Guido P H; Ridderinkhof, K Richard; Hommel, Bernhard

    2011-09-01

    Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial attention to a second stimulus (S2). Visual-spatial attention was monitored by using the N2pc component of the ERP. In addition, we examined the sustained posterior contralateral negativity (SPCN) believed to index the retention of information in visual short-term memory. We found modulations of both the N2pc and the SPCN, suggesting that engaging mechanisms of mental rotation impairs the deployment of visual-spatial attention and delays the passage of a representation of S2 into visual short-term memory. Both results suggest interactions between mental rotation and visual-spatial attention in capacity-limited processing mechanisms indicating that response selection is not pivotal in dual-task delays and all three processes are likely to share a common resource like executive control. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Shifts of visuospatial attention to invisible (metacontrast-masked) singletons: Clues from reaction times and event-related potential

    OpenAIRE

    Manfred Heumann; Ulrich Ansorge

    2006-01-01

    In the current study, we tested whether a masked and, thus, invisible singleton-cue captures atten-tion in a stimulus-driven manner or in a top-down contingent manner. The manual RT (Reaction Time) capture effect with the invisible singleton--cue decreased substantially when a match between the singleton-cue and the top-down controlled set of searched-for target features was also decreased. By contrast, with the PCN (Posterior Contralateral Negativity), an electrophysiological measure of the ...

  11. The Memory Trace Supporting Lose-Shift Responding Decays Rapidly after Reward Omission and Is Distinct from Other Learning Mechanisms in Rats.

    Science.gov (United States)

    Gruber, Aaron J; Thapa, Rajat

    2016-01-01

    The propensity of animals to shift choices immediately after unexpectedly poor reinforcement outcomes is a pervasive strategy across species and tasks. We report here that the memory supporting such lose-shift responding in rats rapidly decays during the intertrial interval and persists throughout training and testing on a binary choice task, despite being a suboptimal strategy. Lose-shift responding is not positively correlated with the prevalence and temporal dependence of win-stay responding, and it is inconsistent with predictions of reinforcement learning on the task. These data provide further evidence that win-stay and lose-shift are mediated by dissociated neural mechanisms and indicate that lose-shift responding presents a potential confound for the study of choice in the many operant choice tasks with short intertrial intervals. We propose that this immediate lose-shift responding is an intrinsic feature of the brain's choice mechanisms that is engaged as a choice reflex and works in parallel with reinforcement learning and other control mechanisms to guide action selection.

  12. Attention Gating in Short-Term Visual Memory.

    Science.gov (United States)

    Reeves, Adam; Sperling, George

    1986-01-01

    An experiment is conducted showing that an attention shift to a stream of numerals presented in rapid serial visual presentation mode produces not a total loss, but a systematic distortion of order. An attention gating model (AGM) is developed from a more general attention model. (Author/LMO)

  13. Rapid upslope shifts in New Guinean birds illustrate strong distributional responses of tropical montane species to global warming

    Science.gov (United States)

    Freeman, Benjamin G.; Class Freeman, Alexandra M.

    2014-01-01

    Temperate-zone species have responded to warming temperatures by shifting their distributions poleward and upslope. Thermal tolerance data suggests that tropical species may respond to warming temperatures even more strongly than temperate-zone species, but this prediction has yet to be tested. We addressed this data gap by conducting resurveys to measure distributional responses to temperature increases in the elevational limits of the avifaunas of two geographically and faunally independent New Guinean mountains, Mt. Karimui and Karkar Island, 47 and 44 y after they were originally surveyed. Although species richness is roughly five times greater on mainland Mt. Karimui than oceanic Karkar Island, distributional shifts at both sites were similar: upslope shifts averaged 113 m (Mt. Karimui) and 152 m (Karkar Island) for upper limits and 95 m (Mt. Karimui) and 123 m (Karkar Island) for lower limits. We incorporated these results into a metaanalysis to compare distributional responses of tropical species with those of temperate-zone species, finding that average upslope shifts in tropical montane species match local temperature increases significantly more closely than in temperate-zone montane species. That tropical species appear to be strong responders has global conservation implications and provides empirical support to hitherto untested models that predict widespread extinctions in upper-elevation tropical endemics with small ranges. PMID:24550460

  14. Performance of an attention-demanding task during treadmill walking shifts the noise qualities of step-to-step variation in step width.

    Science.gov (United States)

    Grabiner, Mark D; Marone, Jane R; Wyatt, Marilynn; Sessoms, Pinata; Kaufman, Kenton R

    2018-06-01

    The fractal scaling evident in the step-to-step fluctuations of stepping-related time series reflects, to some degree, neuromotor noise. The primary purpose of this study was to determine the extent to which the fractal scaling of step width, step width and step width variability are affected by performance of an attention-demanding task. We hypothesized that the attention-demanding task would shift the structure of the step width time series toward white, uncorrelated noise. Subjects performed two 10-min treadmill walking trials, a control trial of undisturbed walking and a trial during which they performed a mental arithmetic/texting task. Motion capture data was converted to step width time series, the fractal scaling of which were determined from their power spectra. Fractal scaling decreased by 22% during the texting condition (p Step width and step width variability increased 19% and five percent, respectively (p step width fractal scaling. The change of the fractal scaling of step width is consistent with increased cognitive demand and suggests a transition in the characteristics of the signal noise. This may reflect an important advance toward the understanding of the manner in which neuromotor noise contributes to some types of falls. However, further investigation of the repeatability of the results, the sensitivity of the results to progressive increases in cognitive load imposed by attention-demanding tasks, and the extent to which the results can be generalized to the gait of older adults seems warranted. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. A computer vision system for rapid search inspired by surface-based attention mechanisms from human perception.

    Science.gov (United States)

    Mohr, Johannes; Park, Jong-Han; Obermayer, Klaus

    2014-12-01

    Humans are highly efficient at visual search tasks by focusing selective attention on a small but relevant region of a visual scene. Recent results from biological vision suggest that surfaces of distinct physical objects form the basic units of this attentional process. The aim of this paper is to demonstrate how such surface-based attention mechanisms can speed up a computer vision system for visual search. The system uses fast perceptual grouping of depth cues to represent the visual world at the level of surfaces. This representation is stored in short-term memory and updated over time. A top-down guided attention mechanism sequentially selects one of the surfaces for detailed inspection by a recognition module. We show that the proposed attention framework requires little computational overhead (about 11 ms), but enables the system to operate in real-time and leads to a substantial increase in search efficiency. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Factors associated with shift work disorder in nurses working with rapid-rotation schedules in Japan: the nurses' sleep health project.

    Science.gov (United States)

    Asaoka, Shoichi; Aritake, Sayaka; Komada, Yoko; Ozaki, Akiko; Odagiri, Yuko; Inoue, Shigeru; Shimomitsu, Teruichi; Inoue, Yuichi

    2013-05-01

    Workers who meet the criteria for shift work disorder (SWD) have elevated levels of risk for various health and behavioral problems. However, the impact of having SWD on shiftworkers engaged in rapid-rotation schedules is unknown. Moreover, the risk factors for the occurrence of SWD remain unclear. To clarify these issues, we conducted a questionnaire-based, cross-sectional survey on a sample of shiftworking nurses. Responses were obtained from 1202 nurses working at university hospitals in Tokyo, Japan, including 727 two-shift workers and 315 three-shift workers. The questionnaire included items relevant to age, gender, family structure, work environment, health-related quality of life (QOL), diurnal type, depressive symptoms, and SWD. Participants who reported insomnia and/or excessive sleepiness for at least 1 mo that was subjectively relevant to their shiftwork schedules were categorized as having SWD. The prevalence of SWD in the sampled shiftworking nurses was 24.4%; shiftworking nurses with SWD showed lower health-related QOL and more severe depressive symptoms, with greater rates of both actual accidents/errors and near misses, than those without SWD. The results of logistic regression analyses showed that more time spent working at night, frequent missing of nap opportunities during night work, and having an eveningness-oriented chronotype were significantly associated with SWD. The present study indicated that SWD might be associated with reduced health-related QOL and decreased work performance in shiftworking nurses on rapid-rotation schedules. The results also suggested that missing napping opportunities during night work, long nighttime working hours, and the delay of circadian rhythms are associated with the occurrence of SWD among shiftworking nurses on rapid-rotation schedules.

  17. Shift in room-temperature photoluminescence of low-fluence Si+-implanted SiO2 films subjected to rapid thermal annealing

    International Nuclear Information System (INIS)

    Fu Mingyue; Tsai, J.-H.; Yang, C.-F.; Liao, C.-H.

    2008-01-01

    We experimentally demonstrate the effect of the rapid thermal annealing (RTA) in nitrogen flow on photoluminescence (PL) of SiO 2 films implanted by different doses of Si + ions. Room-temperature PL from 400-nm-thick SiO 2 films implanted to a dose of 3x10 16 cm -2 shifted from 2.1 to 1.7 eV upon increasing RTA temperature (950-1150 deg. C) and duration (5-20 s). The reported approach of implanting silicon into SiO 2 films followed by RTA may be effective for tuning Si-based photonic devices.

  18. EEG-guided transcranial magnetic stimulation reveals rapid shifts in motor cortical excitability during the human sleep slow oscillation

    DEFF Research Database (Denmark)

    Bergmann, Til O; Mölle, Matthias; Schmidt, Marlit A

    2012-01-01

    Evoked cortical responses do not follow a rigid input–output function but are dynamically shaped by intrinsic neural properties at the time of stimulation. Recent research has emphasized the role of oscillatory activity in determining cortical excitability. Here we employed EEG-guided transcranial......, closely resembling a spontaneous SO. However, both MEPs and TEPs were consistently larger when evoked during SO up-states than during down-states, and ampliudes within each SO state depended on the actual EEG potential at the time and site of stimulation. These results provide first-time evidence...... magnetic stimulation (TMS) during non-rapid eye movement sleep to examine whether the spontaneous

  19. Reversal of cognitive deficits by an ampakine (CX516) and sertindole in two animal models of schizophrenia--sub-chronic and early postnatal PCP treatment in attentional set-shifting

    DEFF Research Database (Denmark)

    Broberg, Brian Villumsen; Glenthøj, Birte Yding; Dias, Rebecca

    2009-01-01

    RATIONALE: Therapies treating cognitive impairments in schizophrenia especially deficits in executive functioning are not available at present. OBJECTIVE: The current study evaluated the effect of ampakine CX516 in reversing deficits in executive functioning as represented in two animal models of...... that direct glutamatergic interventions could improve these, when assessed in the ID-ED attentional set-shifting task....... of schizophrenia and assessed by a rodent analog of the intradimensional-extradimensional (ID-ED) attentional set-shifting task. The second generation antipsychotic, sertindole, provided further validation of the schizophrenia-like disease models. METHODS: Animals were subjected to (a) sub-chronic or (b) early...

  20. Interocular Shift of Visual Attention Enhances Stereopsis and Visual Acuities of Anisometropic Amblyopes beyond the Critical Period of Visual Development: A Novel Approach

    Directory of Open Access Journals (Sweden)

    Liwen Huang

    2014-01-01

    Full Text Available Aims. Increasing evidence shows that imbalanced suppressive drive prior to binocular combination may be the key factor in amblyopia. We described a novel binocular approach, interocular shift of visual attention (ISVA, for treatment of amblyopia in adult patients. Methods. Visual stimuli were presented anaglyphically on a computer screen. A square target resembling Landolt C had 2 openings, one in red and one in cyan color. Through blue-red goggles, each eye could only see one of the two openings. The patient was required to report the location of the opening presented to the amblyopic eye. It started at an opening size of 800 sec of arc, went up and down in 160 sec of arc step, and stopped when reaching the 5th reversals. Ten patients with anisometropic amblyopia older than age 14 (average age: 26.7 were recruited and received ISVA treatment for 6 weeks, with 2 training sessions per day. Results. Both Titmus stereopsis (z=-2.809, P=0.005 and Random-dot stereopsis (z=-2.317, P=0.018 were significantly improved. Average improvement in best corrected visual acuity (BCVA was 0.74 line (t=5.842, P<0.001. Conclusions. The ISVA treatment may be effective in treating amblyopia and restoring stereoscopic function.

  1. Rapid ecological shift following piscivorous fish introduction to increasingly eutrophic and warmer Lake Furnas (Azores Archipelago, Portugal): A paleoecological approach

    DEFF Research Database (Denmark)

    Buchaca, Teresa; Skov, Tue; Amsinck, Susanne Lildal

    2011-01-01

    Lake ecosystems are nowadays often subjected to multi-stressors, such as eutrophication, climate change, and fish manipulations, the effects of which can be difficult to disentangle, not least from the usual short-term limnological time-series that are available. However, multi-proxy paleoecologi......Lake ecosystems are nowadays often subjected to multi-stressors, such as eutrophication, climate change, and fish manipulations, the effects of which can be difficult to disentangle, not least from the usual short-term limnological time-series that are available. However, multi......, meteorological forcing, and fish species introduction for recent lake ecosystem development in Lake Furnas on the island of Sa˜o Miguel, the Azores. The lake was stocked with cyprinids in the late nineteenth century and recently also with piscivorous fish, and has been affected by increasing agricultural......, and cryptophytes. The composition of microbial and algal assemblages changed rapidly after Daphnia appearance, and the covariance between fish stocking, nutrient loading, and enhanced temperatures captured most of the variability in algae accumulation, and thus likely in lake primary production as well. Thus, lake...

  2. Catastrophic shifts in vegetation-soil systems may unfold rapidly or slowly independent of the rate of change in the system driver

    Science.gov (United States)

    Karssenberg, Derek; Bierkens, Marc

    2014-05-01

    Complex systems may switch between contrasting stable states under gradual change of a driver. Such critical transitions often result in considerable long-term damage because strong hysteresis impedes reversion, and the transition becomes catastrophic. Critical transitions largely reduce our capability of forecasting future system states because it is hard to predict the timing of their occurrence [2]. Moreover, for many systems it is unknown how rapidly the critical transition unfolds when the tipping point has been reached. The rate of change during collapse, however, is important information because it determines the time available to take action to reverse a shift [1]. In this study we explore the rate of change during the degradation of a vegetation-soil system on a hillslope from a state with considerable vegetation cover and large soil depths, to a state with sparse vegetation and a bare rock or negligible soil depths. Using a distributed, stochastic model coupling hydrology, vegetation, weathering and water erosion, we derive two differential equations describing the vegetation and the soil system, and their interaction. Two stable states - vegetated and bare - are identified by means of analytical investigation, and it is shown that the change between these two states is a critical transition as indicated by hysteresis. Surprisingly, when the tipping point is reached under a very slow increase of grazing pressure, the transition between the vegetated and the bare state can either unfold rapidly, over a few years, or gradually, occurring over decennia up to millennia. These differences in the rate of change during the transient state are explained by differences in bedrock weathering rates. This finding emphasizes the considerable uncertainty associated with forecasting catastrophic shifts in ecosystems, which is due to both difficulties in forecasting the timing of the tipping point and the rate of change when the transition unfolds. References [1] Hughes

  3. Shift in room-temperature photoluminescence of low-fluence Si{sup +}-implanted SiO{sub 2} films subjected to rapid thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Mingyue, Fu [Department of Avionics Engineering, Air Force Academy, Kangshan, Kaohsiung 820, Taiwan (China); Tsai, J -H [Department of Mathematics and Physics, Air Force Academy, Kangshan, Kaohsiung 820, Taiwan (China); Yang, C -F [Department of Chemical and Materials Engineering, National Kaohsiung University, Nan-Tzu District, Kaohsiung 811, Taiwan (China); Liao, C.-H. [Department of Physics, Chinese Military Academy, Fengshan, Kaohsiung 830, Taiwan (China)], E-mail: fumy@cc.cafa.edu.tw

    2008-12-15

    We experimentally demonstrate the effect of the rapid thermal annealing (RTA) in nitrogen flow on photoluminescence (PL) of SiO{sub 2} films implanted by different doses of Si{sup +} ions. Room-temperature PL from 400-nm-thick SiO{sub 2} films implanted to a dose of 3x10{sup 16} cm{sup -2} shifted from 2.1 to 1.7 eV upon increasing RTA temperature (950-1150 deg. C) and duration (5-20 s). The reported approach of implanting silicon into SiO{sub 2} films followed by RTA may be effective for tuning Si-based photonic devices.

  4. Rapid and Simple Detection of Hot Spot Point Mutations of Epidermal Growth Factor Receptor, BRAF, and NRAS in Cancers Using the Loop-Hybrid Mobility Shift Assay

    Science.gov (United States)

    Matsukuma, Shoichi; Yoshihara, Mitsuyo; Kasai, Fumio; Kato, Akinori; Yoshida, Akira; Akaike, Makoto; Kobayashi, Osamu; Nakayama, Haruhiko; Sakuma, Yuji; Yoshida, Tsutomu; Kameda, Yoichi; Tsuchiya, Eiju; Miyagi, Yohei

    2006-01-01

    A simple and rapid method to detect the epidermal growth factor receptor hot spot mutation L858R in lung adenocarcinoma was developed based on principles similar to the universal heteroduplex generator technology. A single-stranded oligonucleotide with an internal deletion was used to generate heteroduplexes (loop-hybrids) bearing a loop in the complementary strand derived from the polymerase chain reaction product of the normal or mutant allele. By placing deletion in the oligonucleotide adjacent to the mutational site, difference in electrophoretic mobility between loop-hybrids with normal and mutated DNA was distinguishable in a native polyacrylamide gel. The method was also modified to detect in-frame deletion mutations of epidermal growth factor receptor in lung adenocarcinomas. In addition, the method was adapted to detect hot spot mutations in the B-type Raf kinase (BRAF) at V600 and in a Ras-oncogene (NRAS) at Q61, the mutations commonly found in thyroid carcinomas. Our mutation detection system, designated the loop-hybrid mobility shift assay was sensitive enough to detect mutant DNA comprising 7.5% of the total DNA. As a simple and straightforward mutation detection technique, loop-hybrid mobility shift assay may be useful for the molecular diagnosis of certain types of clinical cancers. Other applications are also discussed. PMID:16931592

  5. Capturing Attention When Attention "Blinks"

    Science.gov (United States)

    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…

  6. Forced-Attention Dichotic Listening with University Students with Dyslexia: Search for a Core Deficit

    Science.gov (United States)

    Kershner, John R.

    2016-01-01

    Rapidly changing environments in day-to-day activities, enriched with stimuli competing for attention, require a cognitive control mechanism to select relevant stimuli, ignore irrelevant stimuli, and shift attention between alternative features of the environment. Such attentional orchestration is essential to the acquisition of reading skills. In…

  7. The Attention Cascade Model and Attentional Blink

    Science.gov (United States)

    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,…

  8. Shifts in frog size and phenology: Testing predictions of climate change on a widespread anuran using data from prior to rapid climate warming.

    Science.gov (United States)

    Sheridan, Jennifer A; Caruso, Nicholas M; Apodaca, Joseph J; Rissler, Leslie J

    2018-01-01

    Changes in body size and breeding phenology have been identified as two major ecological consequences of climate change, yet it remains unclear whether climate acts directly or indirectly on these variables. To better understand the relationship between climate and ecological changes, it is necessary to determine environmental predictors of both size and phenology using data from prior to the onset of rapid climate warming, and then to examine spatially explicit changes in climate, size, and phenology, not just general spatial and temporal trends. We used 100 years of natural history collection data for the wood frog, Lithobates sylvaticus with a range >9 million km 2 , and spatially explicit environmental data to determine the best predictors of size and phenology prior to rapid climate warming (1901-1960). We then tested how closely size and phenology changes predicted by those environmental variables reflected actual changes from 1961 to 2000. Size, phenology, and climate all changed as expected (smaller, earlier, and warmer, respectively) at broad spatial scales across the entire study range. However, while spatially explicit changes in climate variables accurately predicted changes in phenology, they did not accurately predict size changes during recent climate change (1961-2000), contrary to expectations from numerous recent studies. Our results suggest that changes in climate are directly linked to observed phenological shifts. However, the mechanisms driving observed body size changes are yet to be determined, given the less straightforward relationship between size and climate factors examined in this study. We recommend that caution be used in "space-for-time" studies where measures of a species' traits at lower latitudes or elevations are considered representative of those under future projected climate conditions. Future studies should aim to determine mechanisms driving trends in phenology and body size, as well as the impact of climate on population

  9. Phobic spider fear is associated with enhanced attentional capture by spider pictures: a rapid serial presentation event-related potential study.

    Science.gov (United States)

    Van Strien, Jan W; Franken, Ingmar H A; Huijding, Jorg

    2009-03-04

    The early posterior negativity (EPN) reflects early selective visual processing of emotionally significant information. This study explored the association between fear of spiders and the EPN for spider pictures. Fifty women completed a Spider Phobia Questionnaire and watched the random rapid serial presentation of 600 neutral, 600 negatively valenced emotional, and 600 spider pictures (three pictures per second). The EPN was scored as the mean activity in the 225-300-ms time window at lateral occipital electrodes. Participants with higher scores on the phobia questionnaire showed larger (i.e. more negative) EPN amplitudes in response to spider pictures. The results suggest that the attentional capture of spider-related stimuli is an automatic response, which is modulated by the extent of spider fear.

  10. Visuospatial selective attention in chickens.

    Science.gov (United States)

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

    2014-05-13

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

  11. Mental rotation impairs attention shifting and short-term memory encoding: neurophysiological evidence against the response-selection bottleneck model of dual-task performance

    NARCIS (Netherlands)

    Pannebakker, M.M.; van Dam, W.O.; Band, G.P.H.; Ridderinkhof, K.R.; Hommel, B.

    2011-01-01

    Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial

  12. Proteomics indicators of the rapidly shifting physiology from whole mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae, adults during early host colonization.

    Directory of Open Access Journals (Sweden)

    Caitlin Pitt

    Full Text Available We developed proteome profiles for host colonizing mountain pine beetle adults, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae. Adult insects were fed in pairs on fresh host lodgepole pine, Pinus contorta Dougl. ex Loud, phloem tissue. The proteomes of fed individuals were monitored using iTRAQ and compared to those of starved beetles, revealing 757 and 739 expressed proteins in females and males, respectively, for which quantitative information was obtained. Overall functional category distributions were similar for males and females, with the majority of proteins falling under carbohydrate metabolism (glycolysis, gluconeogenesis, citric acid cycle, structure (cuticle, muscle, cytoskeleton, and protein and amino acid metabolism. Females had 23 proteins with levels that changed significantly with feeding (p<0.05, FDR<0.20, including chaperones and enzymes required for vitellogenesis. In males, levels of 29 proteins changed significantly with feeding (p<0.05, FDR<0.20, including chaperones as well as motor proteins. Only two proteins, both chaperones, exhibited a significant change in both females and males with feeding. Proteins with differential accumulation patterns in females exhibited higher fold changes with feeding than did those in males. This difference may be due to major and rapid physiological changes occurring in females upon finding a host tree during the physiological shift from dispersal to reproduction. The significant accumulation of chaperone proteins, a cytochrome P450, and a glutathione S-transferase, indicate secondary metabolite-induced stress physiology related to chemical detoxification during early host colonization. The females' activation of vitellogenin only after encountering a host indicates deliberate partitioning of resources and a balancing of the needs of dispersal and reproduction.

  13. Attention and Representational Momentum

    OpenAIRE

    Hayes, Amy; Freyd, Jennifer J

    1995-01-01

    Representational momentum, the tendency for memory to be distorted in the direction of an implied transformation, suggests that dynamics are an intrinsic part of perceptual representations. We examined the effect of attention on dynamic representation by testing for representational momentum under conditions of distraction. Forward memory shifts increase when attention is divided. Attention may be involved in halting but not in maintaining dynamic representations.

  14. Shift Colors

    Science.gov (United States)

    Publications & News Shift Colors Pages default Sign In NPC Logo Banner : Shift Colors Search Navy Personnel Command > Reference Library > Publications & News > Shift Colors Top Link Bar Navy Personnel Library Expand Reference Library Quick Launch Shift Colors Shift Colors Archives Mailing Address How to

  15. Slow oscillating transcranial direct current stimulation during non-rapid eye movement sleep improves behavioral inhibition in attention-deficit/ hyperactivity disorder

    Directory of Open Access Journals (Sweden)

    Manuel Tobias Munz

    2015-08-01

    Full Text Available Background: Behavioral inhibition, which is a later-developing executive function (EF and anatomically located in prefrontal areas, is impaired in attention-deficit and hyperactivity disorder (ADHD. While optimal EFs have been shown to depend on efficient sleep in healthy subjects, the impact of sleep problems, frequently reported in ADHD, remains elusive. Findings of macroscopic sleep changes in ADHD are inconsistent, but there is emerging evidence for distinct microscopic changes with a focus on prefrontal cortical regions and non-rapid eye movement (non-REM slow-wave sleep. Recently, slow oscillations (SO during non-REM sleep were found to be less functional and, as such, may be involved in sleep-dependent memory impairments in ADHD. Objective: By augmenting slow-wave power through bilateral, slow oscillating transcranial direct current stimulation (so-tDCS, frequency = 0.75 Hz during non-REM sleep, we aimed to improve daytime behavioral inhibition in children with ADHD. Methods: 14 boys (10-14 yrs diagnosed with ADHD were included. In a randomized, double-blind, cross-over design, patients received so-tDCS either in the first or in the second experimental sleep night. Inhibition control was assessed with a visuomotor go/no-go task. Intrinsic alertness was assessed with a simple stimulus response task. To control for visuomotor performance, motor memory was assessed with a finger sequence tapping task. Results: SO-power was enhanced during early non-REM sleep, accompanied by slowed reaction times and decreased standard deviations of reaction times, in the go/no-go task after so-tDCS. In contrast, intrinsic alertness and motor memory performance were not improved by so-tDCS. Conclusion: Since behavioral inhibition but not intrinsic alertness or motor memory was improved by so-tDCS, our results suggest that lateral prefrontal slow oscillations during sleep might play a specific role for executive functioning in ADHD.

  16. Rapid protein fold determination using secondary chemical shifts and cross-hydrogen bond 15N-13C’ scalar couplings (3hbJNC’)

    NARCIS (Netherlands)

    Bonvin, A.M.J.J.; Houben, K.; Guenneugues, M.N.L.; Kaptein, R.; Boelens, R.

    2001-01-01

    The possibility of generating protein folds at the stage of backbone assignment using structural restraints derived from experimentally measured cross-hydrogen bond scalar couplings and secondary chemical shift information is investigated using as a test case the small alpha/beta protein

  17. Shifts in hatch dates do not provide pied flycatchers with a rapid ontogenetic route to adjust offspring time schedules to climate change

    NARCIS (Netherlands)

    Ouwehand, Janne; Burger, Claudia; Both, Christiaan

    1. Environments change rapidly, and it is unclear whether organisms with complex life-styles, such as avian migrants, are able to adjust sufficiently. For understanding human impacts on ecosystem functioning, it is crucial to understand how well, and by which mechanisms species are able to adapt. 2.

  18. Rapid protein fold determination using secondary chemical shifts and cross-hydrogen bond 15N-13C' scalar couplings (3hbJNC')

    Energy Technology Data Exchange (ETDEWEB)

    Bonvin, Alexandre M.J.J.; Houben, Klaartje; Guenneugues, Marc; Kaptein, Robert; Boelens, Rolf [Utrecht University, Bijvoet Center for Biomolecular Research, NMR Spectroscopy (Netherlands)

    2001-11-15

    The possibility of generating protein folds at the stage of backbone assignment using structural restraints derived from experimentally measured cross-hydrogen bond scalar couplings and secondary chemical shift information is investigated using as a test case the small {alpha}/{beta} protein chymotrypsin inhibitor 2. Dihedral angle restraints for the {phi} and {psi} angles of 32 out of 64 residues could be obtained from secondary chemical shift analysis with the TALOS program (Corneliscu et al., 1999a). This information was supplemented by 18 hydrogen-bond restraints derived from experimentally measured cross-hydrogen bond {sup 3hb}J{sub NC'} coupling constants. These experimental data were sufficient to generate structures that are as close as 1.0 A backbone rmsd from the crystal structure. The fold is, however, not uniquely defined and several solutions are generated that cannot be distinguished on the basis of violations or energetic considerations. Correct folds could be identified by combining clustering methods with knowledge-based potentials derived from structural databases.

  19. Attention to Attention

    DEFF Research Database (Denmark)

    Tække, Jesper; Paulsen, Michael Eric

    In these years digital media and wireless networks are introduced in upper secondary schools in Denmark. This implies new “attentional objects” like updates on Facebook or tweets on Twitter within instant reach of the pupils and teachers. Also it implies new kinds of attention (awareness) like when...... pupils try to listen to the teacher and simultaneously participate in online games. To this new social setting the teachers has reacted with either prohibition or unconcern. What has not been realised is that the introduction of new media profoundly challenges the way attention hitherto has functioned...... as a psychic prerequisite for the social interaction between pupils and teachers. New kinds of “split attention” arise and new kinds of social mediation (regulation and “use”) of psychic attention become necessary if teaching in the new digital medium milieu shall be beneficial. In this paper we qualify...

  20. Paradigm shift for golden times. Change on energy requires a rapid grid expansion; Paradigmenwechsel fuer goldene Zeiten. Energiewende erfordert raschen Netzausbau

    Energy Technology Data Exchange (ETDEWEB)

    Kamphues, Stephan [Open Grid Europe GmbH, Essen (Germany)

    2011-07-01

    In the recently published report, the International Energy Agency (Paris, France) resumes that the global gas consumption can increase by more than 50 % up to 2035. The reasons for this rapid increase include: flexible use, best CO{sub 2} emissions from fossil fuels and long-term availability. The final report of the Ethics Commission 'Energy security' comes to the conclusion that natural gas energy will have a supporting function in Germany. Nationally and internationally, it is assumed that gas is an essential part of the energy supply of the next decades.

  1. Toxoplasma gondii infection shifts dendritic cells into an amoeboid rapid migration mode encompassing podosome dissolution, secretion of TIMP-1, and reduced proteolysis of extracellular matrix.

    Science.gov (United States)

    Ólafsson, Einar B; Varas-Godoy, Manuel; Barragan, Antonio

    2018-03-01

    Dendritic cells (DCs) infected by Toxoplasma gondii rapidly acquire a hypermigratory phenotype that promotes systemic parasite dissemination by a "Trojan horse" mechanism in mice. Recent paradigms of leukocyte migration have identified the amoeboid migration mode of DCs as particularly suited for rapid locomotion in extracellular matrix and tissues. Here, we have developed a microscopy-based high-throughput approach to assess motility and matrix degradation by Toxoplasma-challenged murine and human DCs. DCs challenged with T. gondii exhibited dependency on metalloproteinase activity for hypermotility and transmigration but, strikingly, also dramatically reduced pericellular proteolysis. Toxoplasma-challenged DCs up-regulated expression and secretion of tissue inhibitor of metalloproteinases-1 (TIMP-1) and their supernatants impaired matrix degradation by naïve DCs and by-stander DCs dose dependently. Gene silencing of TIMP-1 by short hairpin RNA restored matrix degradation activity in Toxoplasma-infected DCs. Additionally, dissolution of podosome structures in parasitised DCs coincided with abrogated matrix degradation. Toxoplasma lysates inhibited pericellular proteolysis in a MyD88-dependent fashion whereas abrogated proteolysis persevered in Toxoplasma-infected MyD88-deficient DCs. This indicated that both TLR/MyD88-dependent and TLR/MyD88-independent signalling pathways mediated podosome dissolution and the abrogated matrix degradation. We report that increased TIMP-1 secretion and cytoskeletal rearrangements encompassing podosome dissolution are features of Toxoplasma-induced hypermigration of DCs with an impact on matrix degradation. Jointly, the data highlight how an obligate intracellular parasite orchestrates key regulatory cellular processes consistent with non-proteolytic amoeboid migration of the vehicle cells that facilitate its dissemination. © 2017 John Wiley & Sons Ltd.

  2. Potential reversal of a phase shift: the rapid decrease in the cover of the invasive green macroalga Dictyosphaeria cavernosa Forsskål on coral reefs in Kāne`ohe Bay, Oahu, Hawai`i

    Science.gov (United States)

    Stimson, J.; Conklin, E.

    2008-12-01

    The native green macroalga Dictyosphaeria cavernosa dominated most of the reef slope habitat in Kāne‘ohe Bay, Hawai‘i for 40 years prior to 2006 and had displaced corals from the habitats they created. This has been one of the most oft-cited examples of a phase shift occurring on a coral reef. After decades of relatively constant, high abundance of the alga, percent cover declined dramatically throughout the bay between February and June 2006. The sudden decrease in cover of this alga appears to be the result of an unusually protracted cloudy, rainy period in March 2006, which may have reduced irradiance and caused the alga to lose weight. Corals and red macroalgae living at the same depths and in some of the same habitats were apparently not affected by this 42-day period of rain and overcast skies. Competition between corals and D. cavernosa for space on reef slopes has been virtually eliminated by the death of this alga, but the unstable rubble formations, which remain in much of the area formerly covered by D. cavernosa may not be conducive to rapid increase in cover by the remaining corals or to establishment by coral recruits. Two years later, there was still no recovery of D. cavernosa. This represents a rare example of decline in macroalgal dominance on a reef and a partial reversal, possibly only temporary, of a phase shift.

  3. Bullet trains and steam engines: exogenous attention zips but endogenous attention chugs along.

    Science.gov (United States)

    Chakravarthi, Ramakrishna; VanRullen, Rufin

    2011-04-20

    Analyzing a scene requires shifting attention from object to object. Although several studies have attempted to determine the speed of these attentional shifts, there are large discrepancies in their estimates. Here, we adapt a method pioneered by T. A. Carlson, H. Hogendoorn, and F. A. J. Verstraten (2006) that directly measures pure attentional shift times. We also test if attentional shifts can be handled in parallel by the independent resources available in the two cortical hemispheres. We present 10 "clocks," with single revolving hands, in a ring around fixation. Observers are asked to report the hand position on one of the clocks at the onset of a transient cue. The delay between the reported time and the veridical time at cue onset can be used to infer processing and attentional shift times. With this setup, we use a novel subtraction method that utilizes different combinations of exogenous and endogenous cues to determine shift times for both types of attention. In one experiment, subjects shift attention to an exogenously cued clock (baseline condition) in one block, and in other blocks, subjects perform one further endogenous shift to a nearby clock (test condition). In another experiment, attention is endogenously cued to one clock (baseline condition), and on other trials, an exogenous cue further shifts attention to a nearby clock (test condition). Subtracting report delays in the baseline condition from those obtained in the test condition allows us to isolate genuine attentional shift times. In agreement with previous studies, our results reveal that endogenous attention is much slower than exogenous attention (endogenous: 250 ms; exogenous: 100 ms). Surprisingly, the dependence of shift time on distance is minimal for exogenous attention, whereas it is steep for endogenous attention. In the final experiment, we find that endogenous shifts are faster across hemifields than within a hemifield suggesting that the two hemispheres can simultaneously

  4. Market shifting

    Energy Technology Data Exchange (ETDEWEB)

    Forst, Michael

    2013-11-01

    After years of oversupply and artificially low module pricing, market analysts believe that the solar industry will begin to stabilize by 2017. While the market activities are shifting from Europe to the Asia Pacific region and the United States, the solar shakeout continues to be in full swing including solar cell and module manufacturing. (orig.)

  5. Tough Shift

    DEFF Research Database (Denmark)

    Brewer, Robert S.; Verdezoto, Nervo; Holst, Thomas

    2015-01-01

    people to change their behavior at home. Leveraging prior research on encouraging reductions in residential energy use through game play, we introduce ShareBuddy: a casual mobile game intended to encourage players not only to reduce, but also to shift their electricity use. We conducted two field studies...... real-world resource use into a game....

  6. Selective attention within the foveola.

    Science.gov (United States)

    Poletti, Martina; Rucci, Michele; Carrasco, Marisa

    2017-10-01

    Efficient control of attentional resources and high-acuity vision are both fundamental for survival. Shifts in visual attention are known to covertly enhance processing at locations away from the center of gaze, where visual resolution is low. It is unknown, however, whether selective spatial attention operates where the observer is already looking-that is, within the high-acuity foveola, the small yet disproportionally important rod-free region of the retina. Using new methods for precisely controlling retinal stimulation, here we show that covert attention flexibly improves and speeds up both detection and discrimination at loci only a fraction of a degree apart within the foveola. These findings reveal a surprisingly precise control of attention and its involvement in fine spatial vision. They show that the commonly studied covert shifts of attention away from the fovea are the expression of a global mechanism that exerts its action across the entire visual field.

  7. Fluid Shifts

    Science.gov (United States)

    Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.; hide

    2017-01-01

    Introduction. NASA's Human Research Program is focused on addressing health risks associated with long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but now more than 50 percent of ISS astronauts have experienced more profound, chronic changes with objective structural findings such as optic disc edema, globe flattening and choroidal folds. These structural and functional changes are referred to as the visual impairment and intracranial pressure (VIIP) syndrome. Development of VIIP symptoms may be related to elevated intracranial pressure (ICP) secondary to spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight and to determine if a relation exists with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as any VIIP-related effects of those shifts, are predicted by the crewmember's pre-flight status and responses to acute hemodynamic manipulations, specifically posture changes and lower body negative pressure. Methods. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, and calcaneus tissue thickness (by ultrasound); (3) vascular dimensions by ultrasound (jugular veins, cerebral and carotid arteries, vertebral arteries and veins, portal vein); (4) vascular dynamics by MRI (head/neck blood flow, cerebrospinal fluid

  8. Coupling age-structured stock assessment and fish bioenergetics models: a system of time-varying models for quantifying piscivory patterns during the rapid trophic shift in the main basin of Lake Huron

    Science.gov (United States)

    He, Ji X.; Bence, James R.; Madenjian, Charles P.; Pothoven, Steven A.; Dobiesz, Norine E.; Fielder, David G.; Johnson, James E.; Ebener, Mark P.; Cottrill, Adam R.; Mohr, Lloyd C.; Koproski, Scott R.

    2015-01-01

    We quantified piscivory patterns in the main basin of Lake Huron during 1984–2010 and found that the biomass transfer from prey fish to piscivores remained consistently high despite the rapid major trophic shift in the food webs. We coupled age-structured stock assessment models and fish bioenergetics models for lake trout (Salvelinus namaycush), Chinook salmon (Oncorhynchus tshawytscha), walleye (Sander vitreus), and lake whitefish (Coregonus clupeaformis). The model system also included time-varying parameters or variables of growth, length–mass relations, maturity schedules, energy density, and diets. These time-varying models reflected the dynamic connections that a fish cohort responded to year-to-year ecosystem changes at different ages and body sizes. We found that the ratio of annual predation by lake trout, Chinook salmon, and walleye combined with the biomass indices of age-1 and older alewives (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) increased more than tenfold during 1987–2010, and such increases in predation pressure were structured by relatively stable biomass of the three piscivores and stepwise declines in the biomass of alewives and rainbow smelt. The piscivore stability was supported by the use of alternative energy pathways and changes in relative composition of the three piscivores. In addition, lake whitefish became a new piscivore by feeding on round goby (Neogobius melanostomus). Their total fish consumption rivaled that of the other piscivores combined, although fish were still a modest proportion of their diet. Overall, the use of alternative energy pathways by piscivores allowed the increases in predation pressure on dominant diet species.

  9. Shifting Sugars and Shifting Paradigms

    Science.gov (United States)

    Siegal, Mark L.

    2015-01-01

    No organism lives in a constant environment. Based on classical studies in molecular biology, many have viewed microbes as following strict rules for shifting their metabolic activities when prevailing conditions change. For example, students learn that the bacterium Escherichia coli makes proteins for digesting lactose only when lactose is available and glucose, a better sugar, is not. However, recent studies, including three PLOS Biology papers examining sugar utilization in the budding yeast Saccharomyces cerevisiae, show that considerable heterogeneity in response to complex environments exists within and between populations. These results join similar recent results in other organisms that suggest that microbial populations anticipate predictable environmental changes and hedge their bets against unpredictable ones. The classical view therefore represents but one special case in a range of evolutionary adaptations to environmental changes that all organisms face. PMID:25688600

  10. Shifting sugars and shifting paradigms.

    Directory of Open Access Journals (Sweden)

    Mark L Siegal

    2015-02-01

    Full Text Available No organism lives in a constant environment. Based on classical studies in molecular biology, many have viewed microbes as following strict rules for shifting their metabolic activities when prevailing conditions change. For example, students learn that the bacterium Escherichia coli makes proteins for digesting lactose only when lactose is available and glucose, a better sugar, is not. However, recent studies, including three PLOS Biology papers examining sugar utilization in the budding yeast Saccharomyces cerevisiae, show that considerable heterogeneity in response to complex environments exists within and between populations. These results join similar recent results in other organisms that suggest that microbial populations anticipate predictable environmental changes and hedge their bets against unpredictable ones. The classical view therefore represents but one special case in a range of evolutionary adaptations to environmental changes that all organisms face.

  11. Visual attention.

    Science.gov (United States)

    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.

  12. Attention in Urban Foraging

    Directory of Open Access Journals (Sweden)

    Malcolm McCullough

    2013-05-01

    Full Text Available This position paper argues how there has to be much more to smart city learning than just wayshowing, and something better as augmented reality than covering the world with instructions. Attention has become something for many people to know better in an age of information superabundance. Embodied cognition explains how the work-ings of attention are not solely a foreground task, as if attention is something to pay. As digital media appear in ever more formats and contexts, their hybrids with physical form increasing influence how habitual engagement with persistent situations creates learning. Ambient information can just add to the distraction by multitasking, or it can support more favorable processes of shifting among different kinds of information with a particular intent. As one word for this latter process, foraging deserves more consideration in smart city learning

  13. Attentional blink in children with attention deficit hyperactivity disorder

    OpenAIRE

    Amador-Campos,Juan A.; Aznar-Casanova,J. Antonio; Bezerra,Izabela; Torro-Alves,Nelson; Sánchez,Manuel M.

    2015-01-01

    Objective: To explore the temporal mechanism of attention in children with attention deficit hyperactivity disorder (ADHD) and controls using a rapid serial visual presentation (RSVP) task in which two letters (T1 and T2) were presented in close temporal proximity among distractors (attentional blink [AB]). Method: Thirty children aged between 9 and 13 years (12 with ADHD combined type and 18 controls) took part in the study. Both groups performed two kinds of RSVP task. In the single task, p...

  14. The temporal relationship between reduction of early imitative responses and the development of attention mechanisms

    Directory of Open Access Journals (Sweden)

    Benga Oana

    2003-12-01

    Full Text Available Abstract Background To determine whether early imitative responses fade out following the maturation of attentional mechanisms, the relationship between primitive imitation behaviors and the development of attention was examined in 4-month-old infants. They were divided into high and low imitators, based on an index of imitation. The status of attention was assessed by studying inhibition of return (IOR. Nine-month-old infants were also tested to confirm the hypothesis. Results The IOR latency data replicate previous results that infants get faster to produce a covert shift of attention with increasing age. However, those 4-month-olds who showed less imitation had more rapid saccades to the cue before target presentation. Conclusion The cortical control of saccade planning appears to be related to an apparent drop in early imitation. We interpret the results as suggesting a relationship between the status of imitation and the neural development of attention-related eye movement.

  15. Neural dynamics of object-based multifocal visual spatial attention and priming: object cueing, useful-field-of-view, and crowding.

    Science.gov (United States)

    Foley, Nicholas C; Grossberg, Stephen; Mingolla, Ennio

    2012-08-01

    How are spatial and object attention coordinated to achieve rapid object learning and recognition during eye movement search? How do prefrontal priming and parietal spatial mechanisms interact to determine the reaction time costs of intra-object attention shifts, inter-object attention shifts, and shifts between visible objects and covertly cued locations? What factors underlie individual differences in the timing and frequency of such attentional shifts? How do transient and sustained spatial attentional mechanisms work and interact? How can volition, mediated via the basal ganglia, influence the span of spatial attention? A neural model is developed of how spatial attention in the where cortical stream coordinates view-invariant object category learning in the what cortical stream under free viewing conditions. The model simulates psychological data about the dynamics of covert attention priming and switching requiring multifocal attention without eye movements. The model predicts how "attentional shrouds" are formed when surface representations in cortical area V4 resonate with spatial attention in posterior parietal cortex (PPC) and prefrontal cortex (PFC), while shrouds compete among themselves for dominance. Winning shrouds support invariant object category learning, and active surface-shroud resonances support conscious surface perception and recognition. Attentive competition between multiple objects and cues simulates reaction-time data from the two-object cueing paradigm. The relative strength of sustained surface-driven and fast-transient motion-driven spatial attention controls individual differences in reaction time for invalid cues. Competition between surface-driven attentional shrouds controls individual differences in detection rate of peripheral targets in useful-field-of-view tasks. The model proposes how the strength of competition can be mediated, though learning or momentary changes in volition, by the basal ganglia. A new explanation of

  16. Assessment of Attention in Preschoolers

    Science.gov (United States)

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

    2012-01-01

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

  17. Visual attention

    NARCIS (Netherlands)

    Evans, K.K.; Horowitz, T.S.; Howe, P.; Pedersini, R.; Reijnen, E.; Pinto, Y.; Wolfe, J.M.

    2011-01-01

    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

  18. Attention Sensor

    NARCIS (Netherlands)

    Börner, Dirk; Kalz, Marco; Specht, Marcus

    2014-01-01

    This software sketch was used in the context of an experiment for the PhD project “Ambient Learning Displays”. The sketch comprises a custom-built attention sensor. The sensor measured (during the experiment) whether a participant looked at and thus attended a public display. The sensor was built

  19. Attracting the attention of a fly

    OpenAIRE

    Sareen, Preeti; Wolf, Reinhard; Heisenberg, Martin

    2011-01-01

    Organisms with complex visual systems rarely respond to just the sum of all visual stimuli impinging on their eyes. Often, they restrict their responses to stimuli in a temporarily selected region of the visual field (selective visual attention). Here, we investigate visual attention in the fly Drosophila during tethered flight at a torque meter. Flies can actively shift their attention; however, their attention can be guided to a certain location by external cues. Using visual cues, we can d...

  20. [THE INFLUENCE OF SHIFT WORK ON WORKER'S HEALTH STATUS (REVIEW)].

    Science.gov (United States)

    Chernikova, E F

    2015-01-01

    The article provides an overview of domestic and foreign works on the impact of the replaceable labor on the efficiency, general state of health, the health and the dream of workers. Many hours shifts and overtime work were found to disturb likely familiar rhythms (sleep, wakefulness, performance), change the metabolic and hormonal metabolisms, reducing the recovery period between duties, contribute to more rapid development of fatigue. The consequence of circadian dyschrony may be the development of diseases of the cardiovascular system and cancer incidence. Studies have shown that sleep disorders are associated with metabolic changes, and particularly, obesity. In persons working in shifts, there are more often registered as individual features of the metabolic syndrome and the whole syndrome. It is noted that persons forming this group are at higher risk of developing diseases of the gastrointestinal tract. Thus, the problem of shift work is presented to be very important. Knowledge of ways and mechanisms that explain the impact of shift work on health is necessary to evaluate the professional risk. In the system of health measures the attention should be given to the rationalization of work and rest regimens, prevention of fatigue, struggle with sleep disorders and obesity.

  1. Thinking of God Moves Attention

    Science.gov (United States)

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

    2010-01-01

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

  2. Saccade Preparation Is Required for Exogenous Attention but Not Endogenous Attention or IOR

    Science.gov (United States)

    Smith, Daniel T.; Schenk, Thomas; Rorden, Chris

    2012-01-01

    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…

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

    Science.gov (United States)

    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).

  4. Time course of spatial and feature selective attention for partly-occluded objects.

    Science.gov (United States)

    Kasai, Tetsuko; Takeya, Ryuji

    2012-07-01

    Attention selects objects/groups as the most fundamental units, and this may be achieved by an attention-spreading mechanism. Previous event-related potential (ERP) studies have found that attention-spreading is reflected by a decrease in the N1 spatial attention effect. The present study tested whether the electrophysiological attention effect is associated with the perception of object unity or amodal completion through the use of partly-occluded objects. ERPs were recorded in 14 participants who were required to pay attention to their left or right visual field and to press a button for a target shape in the attended field. Bilateral stimuli were presented rapidly, and were separated, connected, or connected behind an occluder. Behavioral performance in the connected and occluded conditions was worse than that in the separated condition, indicating that attention spread over perceptual object representations after amodal completion. Consistently, the late N1 spatial attention effect (180-220 ms post-stimulus) and the early phase (230-280 ms) of feature selection effects (target N2) at contralateral sites decreased, equally for the occluded and connected conditions, while the attention effect in the early N1 latency (140-180 ms) shifted most positively for the occluded condition. These results suggest that perceptual organization processes for object recognition transiently modulate spatial and feature selection processes in the visual cortex. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Impaired Visual Attention in Children with Dyslexia.

    Science.gov (United States)

    Heiervang, Einar; Hugdahl, Kenneth

    2003-01-01

    A cue-target visual attention task was administered to 25 children (ages 10-12) with dyslexia. Results showed a general pattern of slower responses in the children with dyslexia compared to controls. Subjects also had longer reaction times in the short and long cue-target interval conditions (covert and overt shift of attention). (Contains…

  6. Contingent Attentional Capture by Conceptually Relevant Images

    Science.gov (United States)

    Wyble, Brad; Folk, Charles; Potter, Mary C.

    2013-01-01

    Attentional capture is an unintentional shift of visuospatial attention to the location of a distractor that is either highly salient, or relevant to the current task set. The latter situation is referred to as contingent capture, in that the effect is contingent on a match between characteristics of the stimuli and the task-defined…

  7. The Chinese experience of rapid modernization: sociocultural changes, psychological consequences?

    Directory of Open Access Journals (Sweden)

    Jiahong eSun

    2016-04-01

    Full Text Available Mainland China has undergone profound changes dating back to the nineteenth century, including a contemporary period of rapid modernization that began in the 1980s. The result has been dramatic social, cultural, and economic shifts impacting the daily lives of Chinese people. In this paper, we explore the psychological implications of sociocultural transformation in China, emphasizing two central themes. First, rising individualism: findings from social and developmental psychology suggest that China’s rapid development has been accompanied by ever-increasing adherence to individualistic values. Second, rising rates of depression: findings from psychiatric epidemiology point to increasing prevalence of depression over this same time period, particularly in rural settings. We argue that links between sociocultural and psychological shifts in China can be usefully studied through a cultural psychology lens, emphasizing the mutual constitution of culture, mind, and brain. In particular, we note that the link between social change, individualism, and rising mental illness deserves careful attention. Our review suggests that shifting values and socialization practices shape emotion norms of concealment and display, with implications for depressive symptom presentation. The challenge comes with interpretation. Increasing prevalence rates of depression may indeed be a general response to the rapidity of sociocultural change, or a specific consequence of rising individualism—but may also result from increasingly ‘Western’ patterns of symptom presentation, or improvements in diagnostic practice. We conclude by considering the challenges posed to standard universal models of psychological phenomena.

  8. The Chinese Experience of Rapid Modernization: Sociocultural Changes, Psychological Consequences?

    Science.gov (United States)

    Sun, Jiahong; Ryder, Andrew G.

    2016-01-01

    Mainland China has undergone profound changes dating back to the nineteenth century, including a contemporary period of rapid modernization that began in the 1980s. The result has been dramatic social, cultural, and economic shifts impacting the daily lives of Chinese people. In this paper, we explore the psychological implications of sociocultural transformation in China, emphasizing two central themes. First, rising individualism: findings from social and developmental psychology suggest that China’s rapid development has been accompanied by ever-increasing adherence to individualistic values. Second, rising rates of depression: findings from psychiatric epidemiology point to increasing prevalence of depression over this same time period, particularly in rural settings. We argue that links between sociocultural and psychological shifts in China can be usefully studied through a cultural psychology lens, emphasizing the mutual constitution of culture, mind, and brain. In particular, we note that the link between social change, individualism, and rising mental illness deserves careful attention. Our review suggests that shifting values and socialization practices shape emotion norms of concealment and display, with implications for depressive symptom presentation. The challenge comes with interpretation. Increasing prevalence rates of depression may indeed be a general response to the rapidity of sociocultural change, or a specific consequence of rising individualism—but may also result from increasingly ‘Western’ patterns of symptom presentation, or improvements in diagnostic practice. We conclude by considering the challenges posed to standard universal models of psychological phenomena. PMID:27092093

  9. Effects of Psychological Attention on Pronoun Comprehension

    Science.gov (United States)

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

    2015-01-01

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

  10. The attention habit: how reward learning shapes attentional selection.

    Science.gov (United States)

    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.

  11. Vision in Flies: Measuring the Attention Span.

    Science.gov (United States)

    Koenig, Sebastian; Wolf, Reinhard; Heisenberg, Martin

    2016-01-01

    A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA). The animal is said to have a focus of attention (FoA) which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

  12. Vision in Flies: Measuring the Attention Span.

    Directory of Open Access Journals (Sweden)

    Sebastian Koenig

    Full Text Available A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA. The animal is said to have a focus of attention (FoA which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

  13. Fixation not required: characterizing oculomotor attention capture for looming stimuli.

    Science.gov (United States)

    Lewis, Joanna E; Neider, Mark B

    2015-10-01

    A stimulus moving toward us, such as a ball being thrown in our direction or a vehicle braking suddenly in front of ours, often represents a stimulus that requires a rapid response. Using a visual search task in which target and distractor items were systematically associated with a looming object, we explored whether this sort of looming motion captures attention, the nature of such capture using eye movement measures (overt/covert), and the extent to which such capture effects are more closely tied to motion onset or the motion itself. We replicated previous findings indicating that looming motion induces response time benefits and costs during visual search Lin, Franconeri, & Enns(Psychological Science 19(7): 686-693, 2008). These differences in response times were independent of fixation, indicating that these capture effects did not necessitate overt attentional shifts to a looming object for search benefits or costs to occur. Interestingly, we found no differences in capture benefits and costs associated with differences in looming motion type. Combined, our results suggest that capture effects associated with looming motion are more likely subserved by covert attentional mechanisms rather than overt mechanisms, and attention capture for looming motion is likely related to motion itself rather than the onset of motion.

  14. Micropatch Antenna Phase Shifting

    National Research Council Canada - National Science Library

    Thursby, Michael

    2000-01-01

    .... We have been looking at the ability of embedded element to adjust the phase shift seen by the element with the goal of being able to remove the phase shifting devices from the antenna and replace...

  15. Micropatch Antenna Phase Shifting

    National Research Council Canada - National Science Library

    Thursby, Michael

    1999-01-01

    .... We have been looking at the ability of embedded element to adjust the phase shift seen by the element wit the goal of being able to remove the phase shifting devices from the antenna and replace...

  16. Decreased visual attention further from the perceived direction of gaze for equidistant retinal targets

    DEFF Research Database (Denmark)

    Balslev, Daniela; Gowen, Emma; Miall, R Chris

    2011-01-01

    The oculomotor and spatial attention systems are interconnected. Whereas a link between motor commands and spatial shifts in visual attention is demonstrated, it is still unknown whether the recently discovered proprioceptive signal in somatosensory cortex impacts on visual attention, too...

  17. OpenShift Workshop

    CERN Multimedia

    CERN. Geneva; Rodriguez Peon, Alberto

    2017-01-01

    Workshop to introduce developers to the OpenShift platform available at CERN. Several use cases will be shown, including deploying an existing application into OpenShift. We expect attendees to realize about OpenShift features and general architecture of the service.

  18. Capture of exogenous attention modulates the attentional blink

    DEFF Research Database (Denmark)

    Nielsen, Simon; Andersen, Tobias

    2011-01-01

    When two targets (T1 & T2) are presented in rapid succession, observers often fail to report T2 if they attend to T1. Bottleneck theories propose that this attentional blink (AB) is due to T1 occupying a slow processing stage when T2 is presented. Accordingly, if increasing T1 difficulty increases...... T1 processing time, this should cause a greater AB. Attention capture hypotheses suggest that T1 captures attention, which cannot be reallocated to T2 in time. Accordingly, if increasing T1 difficulty, decreases saliency, this should cause a smaller AB. Studies examining how T1 difficulty affects...... with T1 contrast energy. Our results indicate that T1 capture modulates the AB. We suggest that this effect has confounded previous studies on the effect of T1 difficulty. In an electrophysiological version of the study we will further examine the implied relation between attention capture and the AB....

  19. Costs of switching auditory spatial attention in following conversational turn-taking

    Directory of Open Access Journals (Sweden)

    Gaven eLin

    2015-04-01

    Full Text Available Following a multi-talker conversation relies on the ability to rapidly and efficiently shift the focus of spatial attention from one talker to another. The current study investigated the listening costs associated with shifts in spatial attention during conversational turn-taking in 16 normally-hearing listeners using a novel sentence recall task. Three pairs of syntactically fixed but semantically unpredictable matrix sentences, recorded from a single male talker, were presented concurrently through an array of three loudspeakers (directly ahead and +/-30° azimuth. Subjects attended to one spatial location, cued by a tone, and followed the target conversation from one sentence to the next using the call-sign at the beginning of each sentence. Subjects were required to report the last three words of each sentence (speech recall task or answer multiple choice questions related to the target material (speech comprehension task. The reading span test, attention network test, and trail making test were also administered to assess working memory, attentional control, and executive function. There was a 10.7 ± 1.3% decrease in word recall, a pronounced primacy effect, and a rise in masker confusion errors and word omissions when the target switched location between sentences. Switching costs were independent of the location, direction, and angular size of the spatial shift but did appear to be load dependent and only significant for complex questions requiring multiple cognitive operations. Reading span scores were positively correlated with total words recalled, and negatively correlated with switching costs and word omissions. Task switching speed (Trail-B time was also significantly correlated with recall accuracy. Overall, this study highlights i the listening costs associated with shifts in spatial attention and ii the important role of working memory in maintaining goal relevant information and extracting meaning from dynamic multi

  20. Attention, Joint Attention, and Social Cognition

    OpenAIRE

    Mundy, Peter; Newell, Lisa

    2007-01-01

    Before social cognition there is joint processing of information about the attention of self and others. This joint attention requires the integrated activation of a distributed cortical network involving the anterior and posterior attention systems. In infancy, practice with the integrated activation of this distributed attention network is a major contributor to the development of social cognition. Thus, the functional neuroanatomies of social cognition and the anterior–posterior attention ...

  1. Updating the premotor theory: the allocation of attention is not always accompanied by saccade preparation.

    Science.gov (United States)

    Belopolsky, Artem V; Theeuwes, Jan

    2012-08-01

    There is an ongoing controversy regarding the relationship between covert attention and saccadic eye movements. While there is quite some evidence that the preparation of a saccade is obligatory preceded by a shift of covert attention, the reverse is not clear: Is allocation of attention always accompanied by saccade preparation? Recently, a shifting and maintenance account was proposed suggesting that shifting and maintenance components of covert attention differ in their relation to the oculomotor system. Specifically, it was argued that a shift of covert attention is always accompanied by activation of the oculomotor program, while maintaining covert attention at a location can be accompanied either by activation or suppression of oculomotor program, depending on the probability of executing an eye movement to the attended location. In the present study we tested whether there is such an obligatory coupling between shifting of attention and saccade preparation and how quickly saccade preparation gets suppressed. The results showed that attention shifting was always accompanied by saccade preparation whenever covert attention had to be shifted during visual search, as well as in response to exogenous or endogenous cues. However, for the endogenous cues the saccade program to the attended location was suppressed very soon after the attention shift was completed. The current findings support the shifting and maintenance account and indicate that the premotor theory needs to be updated to include a shifting and maintenance component for the cases in which covert shifts of attention are made without the intention to execute a saccade. (c) 2012 APA, all rights reserved.

  2. No Effect of Featural Attention on Body Size Aftereffects

    OpenAIRE

    Stephen, Ian D.; Bickersteth, Chloe; Mond, Jonathan; Stevenson, Richard J.; Brooks, Kevin R.

    2016-01-01

    Prolonged exposure to images of narrow bodies has been shown to induce a perceptual aftereffect, such that observers’ point of subjective normality (PSN) for bodies shifts toward narrower bodies. The converse effect is shown for adaptation to wide bodies. In low-level stimuli, object attention (attention directed to the object) and spatial attention (attention directed to the location of the object) have been shown to increase the magnitude of visual aftereffects, while object-based attention...

  3. Memory-guided attention during active viewing of edited dynamic scenes.

    Science.gov (United States)

    Valuch, Christian; König, Peter; Ansorge, Ulrich

    2017-01-01

    Films, TV shows, and other edited dynamic scenes contain many cuts, which are abrupt transitions from one video shot to the next. Cuts occur within or between scenes, and often join together visually and semantically related shots. Here, we tested to which degree memory for the visual features of the precut shot facilitates shifting attention to the postcut shot. We manipulated visual similarity across cuts, and measured how this affected covert attention (Experiment 1) and overt attention (Experiments 2 and 3). In Experiments 1 and 2, participants actively viewed a target movie that randomly switched locations with a second, distractor movie at the time of the cuts. In Experiments 1 and 2, participants were able to deploy attention more rapidly and accurately to the target movie's continuation when visual similarity was high than when it was low. Experiment 3 tested whether this could be explained by stimulus-driven (bottom-up) priming by feature similarity, using one clip at screen center that was followed by two alternative continuations to the left and right. Here, even the highest similarity across cuts did not capture attention. We conclude that following cuts of high visual similarity, memory-guided attention facilitates the deployment of attention, but this effect is (top-down) dependent on the viewer's active matching of scene content across cuts.

  4. Doppler interpretation of quasar red shifts.

    Science.gov (United States)

    Zapolsky, H S

    1966-08-05

    The hypothesis that the quasistellar sources (quasars) are local objects moving with velocities close to the speed of light is examined. Provided there is no observational cutoff on apparent bolometric magnitude for the quasars, the transverse Doppler effect leads to the expectation of fewer blue shifts than red shifts for an isotropic distribution of velocities. Such a distribution also yields a function N(z), the number of objects with red shift less than z which is not inconsistent with the present data. On the basis of two extreme assumptions concerning the origin of such rapidly moving sources, we computed curves of red shift plotted against magnitude. In particular, the curve obtained on the assumption that the quasars originated from an explosion in or nearby our own galaxy is in as good agreement with the observations as the curve of cosmological red shift plotted against magnitude.

  5. Attentional ability among survivors of leukaemia.

    Science.gov (United States)

    Rodgers, J; Horrocks, J; Britton, P G; Kernahan, J

    1999-04-01

    Attentional ability in 19 survivors of acute lymphoblastic leukaemia and 19 sibling controls was assessed using a neuropsychological model of attention. Analysis revealed that children who had received treatment for leukaemia exhibited significantly poorer performance on measures of the "focus encode" and "focus execute" elements of attention and on measures of the ability to respond to external cues and feedback. No significant differences in performance were found for measures of sustained attention and the ability to shift attention. These results indicate that children who have received treatment for leukaemia may experience highly specific attentional deficits that could have an impact on academic performance, particularly mathematical and reading skills. It is suggested that this underlying attentional deficit might be the source of the neuropsychological sequelae associated with the disease. Future attempts at remediation should incorporate activities specifically designed to ameliorate focusing difficulties.

  6. Dividing Attention Increases Operational Momentum

    Directory of Open Access Journals (Sweden)

    Koleen McCrink

    2017-12-01

    Full Text Available When adding or subtracting two quantities, adults often compute an estimated outcome that is larger or smaller, respectively, than the actual outcome, a bias referred to as “operational momentum”. The effects of attention on operational momentum were investigated. Participants viewed a display in which two arrays of objects were added, or one array was subtracted from another array, and judged whether a subsequent outcome (probe array contained the correct or incorrect number of objects. In a baseline condition, only the arrays to be added or subtracted were viewed. In divided attention conditions, participants simultaneously viewed a sequence of colors or shapes, and judged which color (a non-spatial judgment or shape (a spatial judgment was repeated. Operational momentum occurred in all conditions, but was higher in divided attention conditions than in the baseline condition, primarily for addition problems. This pattern suggests that dividing attention, rather than decreasing operational momentum by decreasing attentional shifts, actually increased operational momentum. These results are consistent with a heightened use of arithmetic heuristics under conditions of divided attention.

  7. An effective attentional set for a specific colour does not prevent capture by infrequently presented motion distractors.

    Science.gov (United States)

    Retell, James D; Becker, Stefanie I; Remington, Roger W

    2016-01-01

    An organism's survival depends on the ability to rapidly orient attention to unanticipated events in the world. Yet, the conditions needed to elicit such involuntary capture remain in doubt. Especially puzzling are spatial cueing experiments, which have consistently shown that involuntary shifts of attention to highly salient distractors are not determined by stimulus properties, but instead are contingent on attentional control settings induced by task demands. Do we always need to be set for an event to be captured by it, or is there a class of events that draw attention involuntarily even when unconnected to task goals? Recent results suggest that a task-irrelevant event will capture attention on first presentation, suggesting that salient stimuli that violate contextual expectations might automatically capture attention. Here, we investigated the role of contextual expectation by examining whether an irrelevant motion cue that was presented only rarely (∼3-6% of trials) would capture attention when observers had an active set for a specific target colour. The motion cue had no effect when presented frequently, but when rare produced a pattern of interference consistent with attentional capture. The critical dependence on the frequency with which the irrelevant motion singleton was presented is consistent with early theories of involuntary orienting to novel stimuli. We suggest that attention will be captured by salient stimuli that violate expectations, whereas top-down goals appear to modulate capture by stimuli that broadly conform to contextual expectations.

  8. Attentional Capture by Emotional Stimuli Is Modulated by Semantic Processing

    Science.gov (United States)

    Huang, Yang-Ming; Baddeley, Alan; Young, Andrew W.

    2008-01-01

    The attentional blink paradigm was used to examine whether emotional stimuli always capture attention. The processing requirement for emotional stimuli in a rapid sequential visual presentation stream was manipulated to investigate the circumstances under which emotional distractors capture attention, as reflected in an enhanced attentional blink…

  9. Attention Deficit Hyperactivity Disorder

    Science.gov (United States)

    Matthews, Marguerite; Nigg, Joel T.

    2014-01-01

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

  10. Evidence that emotion mediates social attention in rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Emily J Bethell

    Full Text Available BACKGROUND: Recent work on non-human primates indicates that the allocation of social attention is mediated by characteristics of the attending animal, such as social status and genotype, as well as by the value of the target to which attention is directed. Studies of humans indicate that an individual's emotion state also plays a crucial role in mediating their social attention; for example, individuals look for longer towards aggressive faces when they are feeling more anxious, and this bias leads to increased negative arousal and distraction from other ongoing tasks. To our knowledge, no studies have tested for an effect of emotion state on allocation of social attention in any non-human species. METHODOLOGY: We presented captive adult male rhesus macaques with pairs of adult male conspecific face images - one with an aggressive expression, one with a neutral expression - and recorded gaze towards these images. Each animal was tested twice, once during a putatively stressful condition (i.e. following a veterinary health check, and once during a neutral (or potentially positive condition (i.e. a period of environmental enrichment. Initial analyses revealed that behavioural indicators of anxiety and stress were significantly higher after the health check than during enrichment, indicating that the former caused a negative shift in emotional state. PRINCIPLE FINDINGS: The macaques showed initial vigilance for aggressive faces across both conditions, but subsequent responses differed between conditions. Following the health check, initial vigilance was followed by rapid and sustained avoidance of aggressive faces. By contrast, during the period of enrichment, the macaques showed sustained attention towards the same aggressive faces. CONCLUSIONS/SIGNIFICANCE: These data provide, to our knowledge, the first evidence that shifts in emotion state mediate social attention towards and away from facial cues of emotion in a non-human animal. This work

  11. Choice Shifts in Groups

    OpenAIRE

    Kfir Eliaz; Debraj Ray

    2004-01-01

    The phenomenon of "choice shifts" in group decision-making is fairly ubiquitous in the social psychology literature. Faced with a choice between a ``safe" and ``risky" decision, group members appear to move to one extreme or the other, relative to the choices each member might have made on her own. Both risky and cautious shifts have been identified in different situations. This paper demonstrates that from an individual decision-making perspective, choice shifts may be viewed as a systematic...

  12. Implementing OpenShift

    CERN Document Server

    Miller, Adam

    2013-01-01

    A standard tutorial-based approach to using OpenShift and deploying custom or pre-built web applications to the OpenShift Online cloud.This book is for software developers and DevOps alike who are interested in learning how to use the OpenShift Platform-as-a-Service for developing and deploying applications, how the environment works on the back end, and how to deploy their very own open source Platform-as-a-Service based on the upstream OpenShift Origin project.

  13. Insomnia in shift work.

    Science.gov (United States)

    Vallières, Annie; Azaiez, Aïda; Moreau, Vincent; LeBlanc, Mélanie; Morin, Charles M

    2014-12-01

    Shift work disorder involves insomnia and/or excessive sleepiness associated with the work schedule. The present study examined the impact of insomnia on the perceived physical and psychological health of adults working on night and rotating shift schedules compared to day workers. A total of 418 adults (51% women, mean age 41.4 years), including 51 night workers, 158 rotating shift workers, and 209 day workers were selected from an epidemiological study. An algorithm was used to classify each participant of the two groups (working night or rotating shifts) according to the presence or absence of insomnia symptoms. Each of these individuals was paired with a day worker according to gender, age, and income. Participants completed several questionnaires measuring sleep, health, and psychological variables. Night and rotating shift workers with insomnia presented a sleep profile similar to that of day workers with insomnia. Sleep time was more strongly related to insomnia than to shift work per se. Participants with insomnia in the three groups complained of anxiety, depression, and fatigue, and reported consuming equal amounts of sleep-aid medication. Insomnia also contributed to chronic pain and otorhinolaryngology problems, especially among rotating shift workers. Work productivity and absenteeism were more strongly related to insomnia. The present study highlights insomnia as an important component of the sleep difficulties experienced by shift workers. Insomnia may exacerbate certain physical and mental health problems of shift workers, and impair their quality of life. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Cueing spatial attention through timing and probability.

    Science.gov (United States)

    Girardi, Giovanna; Antonucci, Gabriella; Nico, Daniele

    2013-01-01

    Even when focused on an effortful task we retain the ability to detect salient environmental information, and even irrelevant visual stimuli can be automatically detected. However, to which extent unattended information affects attentional control is not fully understood. Here we provide evidences of how the brain spontaneously organizes its cognitive resources by shifting attention between a selective-attending and a stimulus-driven modality within a single task. Using a spatial cueing paradigm we investigated the effect of cue-target asynchronies as a function of their probabilities of occurrence (i.e., relative frequency). Results show that this accessory information modulates attentional shifts. A valid spatial cue improved participants' performance as compared to an invalid one only in trials in which target onset was highly predictable because of its more robust occurrence. Conversely, cuing proved ineffective when spatial cue and target were associated according to a less frequent asynchrony. These patterns of response depended on asynchronies' probability and not on their duration. Our findings clearly demonstrate that through a fine decision-making, performed trial-by-trial, the brain utilizes implicit information to decide whether or not voluntarily shifting spatial attention. As if according to a cost-planning strategy, the cognitive effort of shifting attention depending on the cue is performed only when the expected advantages are higher. In a trade-off competition for cognitive resources, voluntary/automatic attending may thus be a more complex process than expected. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Shifted Independent Component Analysis

    DEFF Research Database (Denmark)

    Mørup, Morten; Madsen, Kristoffer Hougaard; Hansen, Lars Kai

    2007-01-01

    Delayed mixing is a problem of theoretical interest and practical importance, e.g., in speech processing, bio-medical signal analysis and financial data modelling. Most previous analyses have been based on models with integer shifts, i.e., shifts by a number of samples, and have often been carried...

  16. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    Douglas class were classified in [3]; they are unilateral block shifts of arbitrary block size (i.e. dim H(n) can be anything). However, no examples of irreducible homogeneous bilateral block shifts of block size larger than 1 were known until now.

  17. OpenShift cookbook

    CERN Document Server

    Gulati, Shekhar

    2014-01-01

    If you are a web application developer who wants to use the OpenShift platform to host your next big idea but are looking for guidance on how to achieve this, then this book is the first step you need to take. This is a very accessible cookbook where no previous knowledge of OpenShift is needed.

  18. Josephson shift registers

    International Nuclear Information System (INIS)

    Przybysz, J.X.

    1989-01-01

    This paper gives a review of Josephson shift register circuits that were designed, fabricated, or tested, with emphasis on work in the 1980s. Operating speed is most important, since it often limits system performance. Older designs used square-wave clocks, but most modern designs use offset sine waves, with either two or three phases. Operating margins and gate bias uniformity are key concerns. The fastest measured Josephson shift register operated at 2.3 GHz, which compares well with a GaAs shift register that consumes 250 times more power. The difficulties of high-speed testing have prevented many Josephson shift registers from being operated at their highest speeds. Computer simulations suggest that 30-GHz operation is possible with current Nb/Al 2 O 3 /Nb technology. Junctions with critical current densities near 10 kA/cm 2 would make 100-GHz shift registers feasible

  19. Attention and Olfactory Consciousness

    OpenAIRE

    Keller, Andreas

    2011-01-01

    Understanding the relation between attention and consciousness is an important part of our understanding of consciousness. Attention, unlike consciousness, can be systematically manipulated in psychophysical experiments and a law-like relation between attention and consciousness is waiting to be discovered. Most attempts to discover the nature of this relation are focused on a special type of attention: spatial visual attention. In this review I want to introduce another type of attention to ...

  20. Shift Performance Test and Analysis of Multipurpose Vehicle

    Directory of Open Access Journals (Sweden)

    Can Yang

    2014-08-01

    Full Text Available This paper presented an analysis of the gear shifting performances of a multipurpose vehicle transmission in driving condition by Ricardo's Gear Shift Quality Assessment (GSQA system. The performances of the transmission included the travel and effort of the gear shift lever and synchronizing time. The mathematic models of the transmission including the gear shift mechanism and synchronizer were developed in MATLAB. The model of the gear shift mechanism was developed to analyze the travel map of the gear shift lever and the model of the synchronizer was developed to obtain the force-time curve of the synchronizer during the slipping time. The model of the synchronizer was used to investigate the relationship between the performances of the transmission and the variation of parameters during gear shifting. The mathematic models of the gear shift mechanism and the synchronizer provided a rapid design and verification method for the transmission with ring spring.

  1. Selective and divided attention modulates auditory-vocal integration in the processing of pitch feedback errors.

    Science.gov (United States)

    Liu, Ying; Hu, Huijing; Jones, Jeffery A; Guo, Zhiqiang; Li, Weifeng; Chen, Xi; Liu, Peng; Liu, Hanjun

    2015-08-01

    Speakers rapidly adjust their ongoing vocal productions to compensate for errors they hear in their auditory feedback. It is currently unclear what role attention plays in these vocal compensations. This event-related potential (ERP) study examined the influence of selective and divided attention on the vocal and cortical responses to pitch errors heard in auditory feedback regarding ongoing vocalisations. During the production of a sustained vowel, participants briefly heard their vocal pitch shifted up two semitones while they actively attended to auditory or visual events (selective attention), or both auditory and visual events (divided attention), or were not told to attend to either modality (control condition). The behavioral results showed that attending to the pitch perturbations elicited larger vocal compensations than attending to the visual stimuli. Moreover, ERPs were likewise sensitive to the attentional manipulations: P2 responses to pitch perturbations were larger when participants attended to the auditory stimuli compared to when they attended to the visual stimuli, and compared to when they were not explicitly told to attend to either the visual or auditory stimuli. By contrast, dividing attention between the auditory and visual modalities caused suppressed P2 responses relative to all the other conditions and caused enhanced N1 responses relative to the control condition. These findings provide strong evidence for the influence of attention on the mechanisms underlying the auditory-vocal integration in the processing of pitch feedback errors. In addition, selective attention and divided attention appear to modulate the neurobehavioral processing of pitch feedback errors in different ways. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  2. Nurses' shift reports

    DEFF Research Database (Denmark)

    Buus, Niels; Hoeck, Bente; Hamilton, Bridget Elizabeth

    2017-01-01

    AIMS AND OBJECTIVES: To identify reporting practices that feature in studies of nurses' shift reports across diverse nursing specialities. The objectives were to perform an exhaustive systematic literature search and to critically review the quality and findings of qualitative field studies...... of nurses' shift reports. BACKGROUND: Nurses' shift reports are routine occurrences in healthcare organisations that are viewed as crucial for patient outcomes, patient safety and continuity of care. Studies of communication between nurses attend primarily to 1:1 communication and analyse the adequacy...... and accuracy of patient information and feature handovers at the bedside. Still, verbal reports between groups of nurses about patients are commonplace. Shift reports are obvious sites for studying the situated accomplishment of professional nursing at the group level. This review is focused exclusively...

  3. Shift Verification and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Pandya, Tara M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Evans, Thomas M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Davidson, Gregory G [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Seth R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Godfrey, Andrew T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-07

    This documentation outlines the verification and validation of Shift for the Consortium for Advanced Simulation of Light Water Reactors (CASL). Five main types of problems were used for validation: small criticality benchmark problems; full-core reactor benchmarks for light water reactors; fixed-source coupled neutron-photon dosimetry benchmarks; depletion/burnup benchmarks; and full-core reactor performance benchmarks. We compared Shift results to measured data and other simulated Monte Carlo radiation transport code results, and found very good agreement in a variety of comparison measures. These include prediction of critical eigenvalue, radial and axial pin power distributions, rod worth, leakage spectra, and nuclide inventories over a burn cycle. Based on this validation of Shift, we are confident in Shift to provide reference results for CASL benchmarking.

  4. Molecular Electronic Shift Registers

    Science.gov (United States)

    Beratan, David N.; Onuchic, Jose N.

    1990-01-01

    Molecular-scale shift registers eventually constructed as parts of high-density integrated memory circuits. In principle, variety of organic molecules makes possible large number of different configurations and modes of operation for such shift-register devices. Several classes of devices and implementations in some specific types of molecules proposed. All based on transfer of electrons or holes along chains of repeating molecular units.

  5. Age differences in strategy shift: retrieval avoidance or general shift reluctance?

    Science.gov (United States)

    Frank, David J; Touron, Dayna R; Hertzog, Christopher

    2013-09-01

    Previous studies of metacognitive age differences in skill acquisition strategies have relied exclusively on tasks with a processing shift from an algorithm to retrieval strategy. Older adults' demonstrated reluctance to shift strategies in such tasks could reflect either a specific aversion to a memory retrieval strategy or a general, inertial resistance to strategy change. Haider and Frensch's (1999) alphabet verification task (AVT) affords a non-retrieval-based strategy shift. Participants verify the continuation of alphabet strings such as D E F G [4] L, with the bracketed digit indicating a number of letters to be skipped. When all deviations are restricted to the letter-digit-letter portion, participants can speed their responses by selectively attending to only that part of the stimulus. We adapted the AVT to include conditions that promoted shift to a retrieval strategy, a selective attention strategy, or both strategies. Item-level strategy reports were validated by eye movement data. Older adults shifted more slowly to the retrieval strategy but more quickly to the selective attention strategy than young adults, indicating a retrieval-strategy avoidance. Strategy confidence and perceived strategy difficulty correlated with shift to the two strategies in both age groups. Perceived speed of responses with each strategy specifically correlated with older adults' strategy choices, suggesting that some older adults avoid retrieval because they do not appreciate its efficiency benefits.

  6. Age Differences in Strategy Shift: Retrieval Avoidance or General Shift Reluctance?

    Science.gov (United States)

    Frank, David J.; Touron, Dayna R.; Hertzog, Christopher

    2013-01-01

    Previous studies of metacognitive age differences in skill acquisition strategies have relied exclusively on tasks with a processing shift from an algorithm to retrieval strategy. Older adults’ demonstrated reluctance to shift strategies in such tasks could reflect either a specific aversion to a memory retrieval strategy or a general, inertial resistance to strategy change. Haider and Frensch’s (1999) alphabet verification task (AVT) affords a non-retrieval-based strategy shift. Participants verify the continuation of alphabet strings such as D E F G [4] L, with the bracketed digit indicating a number of letters to be skipped. When all deviations are restricted to the letter-digit-letter portion, participants can speed their responses by selectively attend only to that part of the stimulus. We adapted the AVT to include conditions which promoted shift to a retrieval strategy, a selective attention strategy, or both strategies. Item-level strategy reports were validated by eye movement data. Older adults shifted more slowly to the retrieval strategy but more quickly to the selective attention strategy than young adults, indicating a retrieval-strategy avoidance. Strategy confidence and perceived strategy difficulty correlated with shift to the two strategies in both age groups. Perceived speed of responses with each strategy specifically correlated with older adults’ strategy choices, suggesting that some older adults avoid retrieval because they do not appreciate its efficiency benefits. PMID:23088195

  7. Is ostension any more than attention?

    Science.gov (United States)

    Szufnarowska, Joanna; Rohlfing, Katharina J; Fawcett, Christine; Gredebäck, Gustaf

    2014-06-16

    According to natural pedagogy theory, infants are sensitive to particular ostensive cues that communicate to them that they are being addressed and that they can expect to learn referential information. We demonstrate that 6-month-old infants follow others' gaze direction in situations that are highly attention-grabbing. This occurs irrespective of whether these situations include communicative intent and ostensive cues (a model looks directly into the child's eyes prior to shifting gaze to an object) or not (a model shivers while looking down prior to shifting gaze to an object). In contrast, in less attention-grabbing contexts in which the model simply looks down prior to shifting gaze to an object, no effect is found. These findings demonstrate that one of the central pillars of natural pedagogy is false. Sensitivity to gaze following in infancy is not restricted to contexts in which ostensive cues are conveyed.

  8. Contributors to shift work tolerance in South Korean nurses working rotating shift.

    Science.gov (United States)

    Jung, Hye-Sun; Lee, Bokim

    2015-05-01

    Shift workers have rapidly increased in South Korea; however, there is no published research exploring shift work tolerance among South Korean workers. This study aimed to investigate factors related to shift work tolerance in South Korean nurses. The sample comprised of 660 nurses who worked shifts in a large hospital in South Korea. A structured questionnaire included following comprehensive variables: demographic (age and number of children), individual (morningness and self-esteem), psychosocial (social support and job stress), lifestyle (alcohol consumption, physical activity, and BMI), and working condition factors (number of night shifts and working hours). Shift work tolerance was measured in terms of insomnia, fatigue, and depression. The results of hierarchical regressions indicate that all variables, except for three, number of children, BMI, and working hours, were related to at least one of the symptoms associated with shift work tolerance. Based on these results, we offer some practical implications to help improve shift work tolerance of workers. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Object-based attention in chimpanzees (Pan troglodytes).

    Science.gov (United States)

    Ushitani, Tomokazu; Imura, Tomoko; Tomonaga, Masaki

    2010-03-17

    We conducted three experiments to investigate how object-based components contribute to the attentional processes of chimpanzees and to examine how such processes operate with regard to perceptually structured objects. In Experiment 1, chimpanzees responded to a spatial cueing task that required them to touch a target appearing at either end of two parallel rectangles. We compared the time involved in shifting attention (cost of attentional shift) when the locations of targets were cued and non cued. Results showed that the cost of the attentional shift within one rectangle was smaller than that beyond the object's boundary, demonstrating object-based attention in chimpanzees. The results of Experiment 2, conducted with different stimulus configurations, replicated the results of Experiment 1, supporting that object-based attention operates in chimpanzees. In Experiment 3, the cost of attentional shift within a cued but partly occluded rectangle was shorter than that within a rectangle that was cued but divided in the middle. The results suggest that the attention of chimpanzees is activated not only by an explicit object but also by fragmented patches represented as an object at a higher-order perceptual level. Chimpanzees' object-based attention may be similar to that of humans. Copyright 2010 Elsevier Ltd. All rights reserved.

  10. Content-specific working memory modulation of the attentional blink

    NARCIS (Netherlands)

    Akyürek, Elkan G.; Abedian-Amiri, Ali; Ostermeier, Sonja M.

    2011-01-01

    Three experiments were conducted to investigate the effects of working memory content on temporal attention in a rapid serial visual presentation attentional blink paradigm. It was shown that categorical similarity between working memory content and the target stimuli pertaining to the attentional

  11. Attentional blink in children with attention deficit hyperactivity disorder.

    Science.gov (United States)

    Amador-Campos, Juan A; Aznar-Casanova, J Antonio; Bezerra, Izabela; Torro-Alves, Nelson; Sánchez, Manuel M

    2015-01-01

    To explore the temporal mechanism of attention in children with attention deficit hyperactivity disorder (ADHD) and controls using a rapid serial visual presentation (RSVP) task in which two letters (T1 and T2) were presented in close temporal proximity among distractors (attentional blink [AB]). Thirty children aged between 9 and 13 years (12 with ADHD combined type and 18 controls) took part in the study. Both groups performed two kinds of RSVP task. In the single task, participants simply had to identify a target letter (T1), whereas in the dual task, they had to identify a target letter (T1) and a probe letter (T2). The ADHD and control groups were equivalent in their single-task performance. However, in the dual-task condition, there were significant between-group differences in the rate of detection of the probe letter (T2) at lag + 1 and lag + 4. The ADHD group exhibited a larger overall AB compared with controls. Our findings provide support for a link between ADHD and attentional blink.

  12. Attentional blink in children with attention deficit hyperactivity disorder

    Directory of Open Access Journals (Sweden)

    Juan A. Amador-Campos

    2015-06-01

    Full Text Available Objective:To explore the temporal mechanism of attention in children with attention deficit hyperactivity disorder (ADHD and controls using a rapid serial visual presentation (RSVP task in which two letters (T1 and T2 were presented in close temporal proximity among distractors (attentional blink [AB].Method:Thirty children aged between 9 and 13 years (12 with ADHD combined type and 18 controls took part in the study. Both groups performed two kinds of RSVP task. In the single task, participants simply had to identify a target letter (T1, whereas in the dual task, they had to identify a target letter (T1 and a probe letter (T2.Results:The ADHD and control groups were equivalent in their single-task performance. However, in the dual-task condition, there were significant between-group differences in the rate of detection of the probe letter (T2 at lag + 1 and lag + 4. The ADHD group exhibited a larger overall AB compared with controls.Conclusion:Our findings provide support for a link between ADHD and attentional blink.

  13. Mechanism of Perceptual Attention

    National Research Council Canada - National Science Library

    Lu, Zhong-Lin

    2000-01-01

    .... Attention may affect the perceived clarity of visual displays and improve performance. In this project, a powerful external noise method was developed to identify and characterize the effect of attention on perceptual performance in visual tasks...

  14. Mechanisms of Perceptual Attention

    National Research Council Canada - National Science Library

    Dosher, Barbara

    2000-01-01

    .... Attention may affect the perceived clarity of visual displays and improve performance. In this project, a powerful external noise method was developed to identify and characterize the effect of attention on perceptual performance in visual tasks...

  15. Comparison of sleep disturbances in shift workers and people working with a fixed shift

    Directory of Open Access Journals (Sweden)

    Zohreh Yazdi

    2013-11-01

    Full Text Available Background: Different types of sleep disturbances can have a serious negative effect on a person’s ability, function and overall well-being. One of the most important issues that can result in sleep disturbances are occupational causes, the most important among them is shift work. The objective of this study was to compare the prevalence of sleep disturbances between shift work and non-shift workers. Material and Methods: This study was designed as a case-control study in 196 shift workers and 204 non-shift workers in a textile factory. The data were collected by using a comprehensive questionnaire including Pittsburg Sleep Quality Index questionnaire, Berlin Questionnaire, Epworth Sleepiness Scale, Insomnia Severity Index and Restless Leg Syndrome Questionnaire. Data analyses were carried out using the SPSS software version 13 by student's t-test, Chi square and multiple logistic regressions. Results: The duration of night sleep in shift workers was less than day workers (p<0.001. Prevalence of poor sleep quality and insomnia were higher in shift workers significantly than non shift workers (p<0.001, OR=2.3 95% CI: 1.7-2.9. The most prevalent type of insomnia was problems in initiating sleep (P=0.022, OR=2.2 95% CI: 1.5-3.2. There was no difference in the prevalence of excessive day-time sleepiness, restless leg syndrome, snoring, obstructive sleep apnea and different types of parasomnias between two groups. Conclusion: Reduced length of sleep and higher prevalence of poor sleep quality and insomnia in shift workers emphasizes the importance of serious attention to sleep disorders in shift workers.

  16. Mechanical spectral shift reactor

    International Nuclear Information System (INIS)

    Sherwood, D.G.; Wilson, J.F.; Salton, R.B.; Fensterer, H.F.

    1981-01-01

    A mechanical spectral shift reactor comprises apparatus for inserting and withdrawing water displacer elements from the reactor core for selectively changing the water-moderator volume in the core thereby changing the reactivity of the core. The apparatus includes drivemechanisms for moving the displacer elements relative to the core and guide mechanisms for guiding the displayer rods through the reactor vessel

  17. Mechanical spectral shift reactor

    International Nuclear Information System (INIS)

    Sherwood, D.G.; Wilson, J.F.; Salton, R.B.; Fensterer, H.F.

    1982-01-01

    A mechanical spectral shift reactor comprises apparatus for inserting and withdrawing water displacer elements from the reactor core for selectively changing the water-moderator volume in the core thereby changing the reactivity of the core. The apparatus includes drive mechanisms for moving the displacer elements relative to the core and guide mechanisms for guiding the displacer rods through the reactor vessel. (author)

  18. Dynamics of Media Attention

    NARCIS (Netherlands)

    Traag, V.A.; Reinanda, R.; Hicks, J.; van Klinken, G.; Aziz-Alaoui, M.A.; Bertelle, C.; Liu, X.; Olivier, D.

    2014-01-01

    Studies of human attention dynamics analyses how attention is focused on specific topics, issues or people. In online social media, there are clear signs of exogenous shocks, bursty dynamics, and an exponential or powerlaw lifetime distribution. We here analyse the attention dynamics of traditional

  19. [Shift and night work and mental health].

    Science.gov (United States)

    Sancini, Angela; Ciarrocca, Manuela; Capozzella, Assunta; Corbosiero, Paola; Fiaschetti, Maria; Caciari, Tiziana; Cetica, Carlotta; Scimitto, Lara; Ponticiello, Barnaba Giuseppina; Tasciotti, Zaira; Schifano, Maria Pia; Andreozzit, Giorgia; Tomei, Francesco; Tomei, Gianfranco

    2012-01-01

    Aim of our study was to evaluate the influence that shift work and night work could have on mental health. A review of literary articles from 1990 to 2011 on shift work and night work was carried out. The results of this review confirmed that the shift work and night work affect mental health with the onset of neuropsychological disorders such as mood disorders, anxiety, nervousness, depressive anxiety syndromes, chronic fatigue and chronic insomnia irritability, sleep disturbances, reduction in levels of attention, cognitive impairments, alteration of circadian rhythm. Night work and shift work cause severe desynchronization of the cronobiological rhythms and a disruption of social life with negative effects on performance at work, on health and on social relationships. In the light of these results and recognizing shift work and night work as risk factors for the health of workers is necessary to implement preventive and periodic health checks by the occupational doctor to ensure the health and safety of workers taking account of the different environmental and individual factors.

  20. The Premotor theory of attention: time to move on?

    Science.gov (United States)

    Smith, Daniel T; Schenk, Thomas

    2012-05-01

    Spatial attention and eye-movements are tightly coupled, but the precise nature of this coupling is controversial. The influential but controversial Premotor theory of attention makes four specific predictions about the relationship between motor preparation and spatial attention. Firstly, spatial attention and motor preparation use the same neural substrates. Secondly, spatial attention is functionally equivalent to planning goal directed actions such as eye-movements (i.e. planning an action is both necessary and sufficient for a shift of spatial attention). Thirdly, planning a goal directed action with any effector system is sufficient to trigger a shift of spatial attention. Fourthly, the eye-movement system has a privileged role in orienting visual spatial attention. This article reviews empirical studies that have tested these predictions. Contrary to predictions one and two there is evidence of anatomical and functional dissociations between endogenous spatial attention and motor preparation. However, there is compelling evidence that exogenous attention is reliant on activation of the oculomotor system. With respect to the third prediction, there is correlational evidence that spatial attention is directed to the endpoint of goal-directed actions but no direct evidence that this attention shift is dependent on motor preparation. The few studies to have directly tested the fourth prediction have produced conflicting results, so the extent to which the oculomotor system has a privileged role in spatial attention remains unclear. Overall, the evidence is not consistent with the view that spatial attention is functionally equivalent to motor preparation so the Premotor theory should be rejected, although a limited version of the Premotor theory in which only exogenous attention is dependent on motor preparation may still be tenable. A plausible alternative account is that activity in the motor system contributes to biased competition between different sensory

  1. Attention competition with advertisement

    Science.gov (United States)

    Cetin, Uzay; Bingol, Haluk O.

    2014-09-01

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

  2. Attention to spoken word planning: Chronometric and neuroimaging evidence

    NARCIS (Netherlands)

    Roelofs, A.P.A.

    2008-01-01

    This article reviews chronometric and neuroimaging evidence on attention to spoken word planning, using the WEAVER++ model as theoretical framework. First, chronometric studies on the time to initiate vocal responding and gaze shifting suggest that spoken word planning may require some attention,

  3. The spatial and temporal deployment of voluntary attention across the visual field.

    Directory of Open Access Journals (Sweden)

    Guilhem Ibos

    Full Text Available Several studies have addressed the question of the time it takes for attention to shift from one position in space to another. Here we present a behavioural paradigm which offers a direct access to an estimate of voluntary shift time by comparing, in the same task, a situation in which subjects are required to re-engage their attention at the same spatial location with a situation in which they need to shift their attention to another location, all other sensory, cognitive and motor parameters being equal. We show that spatial attention takes on average 55 ms to voluntarily shift from one hemifield to the other and 38 ms to shift within the same hemifield. In addition, we show that across and within hemifields attentional processes are different. In particular, attentional spotlight division appears to be more difficult to operate within than across hemifields.

  4. Principles of visual attention

    DEFF Research Database (Denmark)

    Bundesen, Claus; Habekost, Thomas

    research as a field that is fundamentally fragmented. This book takes a different perspective and presents a unified theory of visual attention: the TVA model. The TVA model explains the many aspects of visual attention by just two mechanisms for selection of information: filtering and pigeonholing......The nature of attention is one of the oldest and most central problems in psychology. A huge amount of research has been produced on this subject in the last half century, especially on attention in the visual modality, but a general explanation has remained elusive. Many still view attention....... These mechanisms are described in a set of simple equations, which allow TVA to mathematically model a large number of classical results in the attention literature. The theory explains psychological and neuroscientific findings by the same equations; TVA is a complete theory of visual attention, linking mind...

  5. Race Guides Attention in Visual Search.

    Directory of Open Access Journals (Sweden)

    Marte Otten

    Full Text Available It is known that faces are rapidly and even unconsciously categorized into social groups (black vs. white, male vs. female. Here, I test whether preferences for specific social groups guide attention, using a visual search paradigm. In Experiment 1 participants searched displays of neutral faces for an angry or frightened target face. Black target faces were detected more efficiently than white targets, indicating that black faces attracted more attention. Experiment 2 showed that attention differences between black and white faces were correlated with individual differences in automatic race preference. In Experiment 3, using happy target faces, the attentional preference for black over white faces was eliminated. Taken together, these results suggest that automatic preferences for social groups guide attention to individuals from negatively valenced groups, when people are searching for a negative emotion such as anger or fear.

  6. Mechanical spectral shift reactor

    International Nuclear Information System (INIS)

    Wilson, J.F.; Sherwood, D.G.

    1982-01-01

    A mechanical spectral shift reactor comprises a reactive core having fuel assemblies accommodating both water displacer elements and neutron absorbing control rods for selectively changing the volume of water-moderator in the core. The fuel assemblies with displacer and control rods are arranged in alternating fashion so that one displacer element drive mechanism may move displacer elements in more than one fuel assembly without interfering with the movement of control rods of a corresponding control rod drive mechanisms. (author)

  7. Serotonergic and dopaminergic modulation of attentional processes.

    Science.gov (United States)

    Boulougouris, Vasileios; Tsaltas, Eleftheria

    2008-01-01

    Disturbances in attentional processes are a common feature of several psychiatric disorders such as schizophrenia, attention deficit/hyperactivity disorder and Huntington's disease. The use of animal models has been useful in defining various candidate neural systems thus enabling us to translate basic laboratory science to the clinic and vice-versa. In this chapter, a comparative and integrated account is provided on the neuroanatomical and neurochemical modulation of basic behavioural operations such as selective attention, vigilance, set-shifting and executive control focusing on the comparative functions of the serotonin and dopamine systems in the cognitive control exerted by the prefrontal cortex. Specifically, we have reviewed evidence emerging from several behavioural paradigms in experimental animals and humans each of which centres on a different aspect of the attentional function. These paradigms offering both human and animal variants include the five-choice serial reaction time task (5CSRTT), attentional set-shifting and stop-signal reaction time task. In each case, the types of operation that are measured by the given paradigm and their neural correlates are defined. Then, the role of the ascending dopaminergic and serotonergic systems in the neurochemical modulation of its behavioural output are examined, and reference is made to clinical implications for neurological and neuropsychiatric disorders which exhibit deficits in these cognitive tests.

  8. Attention Mosaics: Studies of Organizational Attention

    NARCIS (Netherlands)

    L. Carvalho de Mesquita Ferreira (Luciana)

    2010-01-01

    textabstractOrganizational studies emphasizing the role of attention in organizational behavior depart from the idea that organizations, like individuals, have limited capacity to attend to environmental stimuli. The bounded capacity of the organizations to respond to stimuli is conditioned by the

  9. Attention in schizophrenia and in epileptic psychosis

    Directory of Open Access Journals (Sweden)

    I.C.J Kairalla

    2008-01-01

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

  10. The attentional blink in amblyopia.

    Science.gov (United States)

    Popple, Ariella V; Levi, Dennis M

    2008-10-31

    Amblyopia is a disorder of visual acuity in one eye, thought to arise from suppression by the other eye during development of the visual cortex. In the attentional blink, the second of two targets (T2) in a Rapid Serial Visual Presentation (RSVP) stream is difficult to detect and identify when it appears shortly but not immediately after the first target (T1). We investigated the attentional blink seen through amblyopic eyes and found that it was less finely tuned in time than when the 12 amblyopic observers viewed the stimuli with their preferred eyes. T2 performance was slightly better through amblyopic eyes two frames after T1 but worse one frame after T1. Previously (A. V. Popple & D. M. Levi, 2007), we showed that when the targets were red letters in a stream of gray letters (or vice versa), normal observers frequently confused T2 with the letters before and after it (neighbor errors). Observers viewing through their amblyopic eyes made significantly fewer neighbor errors and more T2 responses consisting of letters that were never presented. In normal observers, T1 (on the rare occasions when it was reported incorrectly) was often confused with the letter immediately after it. Viewing through their amblyopic eyes, observers with amblyopia made more responses to the letter immediately before T1. These results suggest that childhood suppression of the input from amblyopic eyes disrupts attentive processing. We hypothesize reduced connectivity between monocularly tuned lower visual areas, subcortical structures that drive foveal attention, and more frontal regions of the brain responsible for letter recognition and working memory. Perhaps when viewing through their amblyopic eyes, the observers were still processing the letter identity of a prior distractor when the color flash associated with the target was detected. After T1, unfocused temporal attention may have bound together erroneously the features of succeeding letters, resulting in the appearance of

  11. Announcements to Attentive Agents

    DEFF Research Database (Denmark)

    Bolander, Thomas; van Ditmarsch, Hans; Herzig, Andreas

    2016-01-01

    -based announcement can also be described as an action model. We extend our logic by integrating attention change. Finally, we add the notion of common belief to the language, we exploit this to formalize the concept of joint attention, that has been widely discussed in the philosophical and cognitive science...... literature, and we provide a corresponding axiomatization. This axiomatization also employs the auxiliary notion of attention-based relativized common belief....

  12. Eye Movements Blink the Attentional Blink

    Science.gov (United States)

    Kamienkowski, Juan E.; Navajas, Joaquin; Sigman, Mariano

    2012-01-01

    When presented with a sequence of visual stimuli in rapid succession, participants often fail to detect a second salient target, a phenomenon referred as the attentional blink (AB; Raymond, Shapiro, & Arnell, 1992; Shapiro, Raymond, & Arnell, 1997). On the basis of a vast corpus of experiments, several cognitive theories suggest that the blink…

  13. Choice Shifts in Groups: A Decision-Theoretic Basis

    OpenAIRE

    Kfir Eliaz; Debraj Ray; Ronny Razin

    2006-01-01

    The phenomenon of choice shifts in group decision-making has received attention in the social psychology literature. Faced with a risky group decision, individuals appear to support more extreme choices relative to those they would make on their own. This paper demonstrates that from a decision-theoretic perspective, choice shifts are intimately connected to failures of expected utility theory. In the model studied here, the Allais paradox is equivalent to a well-studied configuration of choi...

  14. Attention modulates trans-saccadic integration.

    Science.gov (United States)

    Stewart, Emma E M; Schütz, Alexander C

    2018-01-01

    With every saccade, humans must reconcile the low resolution peripheral information available before a saccade, with the high resolution foveal information acquired after the saccade. While research has shown that we are able to integrate peripheral and foveal vision in a near-optimal manner, it is still unclear which mechanisms may underpin this important perceptual process. One potential mechanism that may moderate this integration process is visual attention. Pre-saccadic attention is a well documented phenomenon, whereby visual attention shifts to the location of an upcoming saccade before the saccade is executed. While it plays an important role in other peri-saccadic processes such as predictive remapping, the role of attention in the integration process is as yet unknown. This study aimed to determine whether the presentation of an attentional distractor during a saccade impaired trans-saccadic integration, and to measure the time-course of this impairment. Results showed that presenting an attentional distractor impaired integration performance both before saccade onset, and during the saccade, in selected subjects who showed integration in the absence of a distractor. This suggests that visual attention may be a mechanism that facilitates trans-saccadic integration. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  15. S-ketamine influences strategic allocation of attention but not exogenous capture of attention.

    Science.gov (United States)

    Fuchs, Isabella; Ansorge, Ulrich; Huber-Huber, Christoph; Höflich, Anna; Lanzenberger, Rupert

    2015-09-01

    We investigated whether s-ketamine differentially affects strategic allocation of attention. In Experiment 1, (1) a less visible cue was weakly masked by the onsets of competing placeholders or (2) a better visible cue was not masked because it was presented in isolation. Both types of cue appeared more often opposite of the target (75%) than at target position (25%). With this setup, we tested for strategic attention shifts to the opposite side of the cues and for exogenous attentional capture toward the cue's side in a short cue-target interval, as well as for (reverse) cueing effects in a long cue-target interval after s-ketamine and after placebo treatment in a double-blind within-participant design. We found reduced strategic attention shifts after cues presented without placeholders for the s-ketamine compared to the placebo treatment in the short interval, indicating an early effect on the strategic allocation of attention. No differences between the two treatments were found for exogenous attentional capture by less visible cues, suggesting that s-ketamine does not affect exogenous attentional capture in the presence of competing distractors. Experiment 2 confirmed that the competing onsets of the placeholders prevented the strategic cueing effect. Taken together, the results indicate that s-ketamine affects strategic attentional capture, but not exogenous attentional capture. The findings point to a more prominent role of s-ketamine during top-down controlled forms of attention that require suppression of automatic capture than during automatic capture itself. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Attention lapses in children with spina bifida and hydrocephalus and children with attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    De la Torre, Gabriel G; Martin, Alba; Cervantes, Elizabeth; Guil, Rocio; Mestre, Jose M

    2017-08-01

    Attentional lapses are usually defined as temporary and often brief shifts of attention away from some primary task to unrelated internal information processing. This study addressed the incidence of attention lapses and differences in attentional functioning in 30 children with attention-deficit/hyperactivity disorder (ADHD), 26 healthy children, and 29 children with spina bifida myelomeningocele and hydrocephalus (SBH). Assessments were conducted using computerized tonic and phasic attention tests, the Symbol Digit Modalities Test (SDMT), and the Trail Making Test Form B (TMT-B). The group with SBH differed from normal controls on cognitive measures of attention and executive functions. The ADHD group obtained lower scores than the SBH group and healthy children. ANOVA results showed that there was an effect of shunt revisions and shunt-related infections on neuropsychological performance. Lapses of attention together with reaction time may thus represent important factors for the understanding of cognitive deficits in SBH.

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

    Science.gov (United States)

    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…

  18. The shifting beverage landscape.

    Science.gov (United States)

    Storey, Maureen

    2010-04-26

    STOREY, M.L. The shifting beverage landscape. PHYSIOL BEHAV, 2010. - Simultaneous lifestyle changes have occurred in the last few decades, creating an imbalance in energy intake and energy expenditure that has led to overweight and obesity. Trends in the food supply show that total daily calories available per capita increased 28% since 1970. Total energy intake among men and women has also increased dramatically since that time. Some have suggested that intake of beverages has had a disproportional impact on obesity. Data collected by the Beverage Marketing Corporation between 1988-2008 demonstrate that, in reality, fewer calories per ounce are being produced by the beverage industry. Moreover, data from the National Cancer Institute show that soft drink intake represents 5.5% of daily calories. Data from NHANES 1999-2003 vs. 2003-06 may demonstrate a shift in beverage consumption for age/gender groups, ages 6 to>60years. The beverages provided in schools have significantly changed since 2006 when the beverage industry implemented School Beverage Guidelines. This voluntary action has removed full-calorie soft drinks from participating schools across the country. This shift to lower-calorie and smaller-portion beverages in school has led to a significant decrease in total beverage calories in schools. These data support the concept that to prevent and treat obesity, public health efforts should focus on energy balance and that a narrow focus on sweetened beverages is unlikely to have any meaningful impact on this complex problem. Copyright 2010 Elsevier Inc. All rights reserved.

  19. Mechanical spectral shift reactor

    International Nuclear Information System (INIS)

    Doshi, P.K.; George, R.A.; Dollard, W.J.

    1982-01-01

    A mechanical spectral shift arrangement for controlling a nuclear reactor includes a plurality of reactor coolant displacer members which are inserted into a reactor core at the beginning of the core life to reduce the volume of reactor coolant-moderator in the core at start-up. However, as the reactivity of the core declines with fuel depletion, selected displacer members are withdrawn from the core at selected time intervals to increase core moderation at a time when fuel reactivity is declining. (author)

  20. Spectral shift reactor

    International Nuclear Information System (INIS)

    Carlson, W.R.; Piplica, E.J.

    1982-01-01

    A spectral shift pressurized water reactor comprising apparatus for inserting and withdrawing water displacer elements having differing neutron absorbing capabilities for selectively changing the water-moderator volume in the core thereby changing the reactivity of the core. The displacer elements comprise substantially hollow cylindrical low neutron absorbing rods and substantially hollow cylindrical thick walled stainless rods. Since the stainless steel displacer rods have greater neutron absorbing capability, they can effect greater reactivity change per rod. However, by arranging fewer stainless steel displacer rods in a cluster, the reactivity worth of the stainless steel displacer rod cluster can be less than a low neutron absorbing displacer rod cluster. (author)

  1. Doppler Shift Compensation Schemes in VANETs

    Directory of Open Access Journals (Sweden)

    F. Nyongesa

    2015-01-01

    Full Text Available Over the last decade vehicle-to-vehicle (V2V communication has received a lot of attention as it is a crucial issue in intravehicle communication as well as in Intelligent Transportation System (ITS. In ITS the focus is placed on integration of communication between mobile and fixed infrastructure to execute road safety as well as nonsafety information dissemination. The safety application such as emergence alerts lays emphasis on low-latency packet delivery rate (PDR, whereas multimedia and infotainment call for high data rates at low bit error rate (BER. The nonsafety information includes multimedia streaming for traffic information and infotainment applications such as playing audio content, utilizing navigation for driving, and accessing Internet. A lot of vehicular ad hoc network (VANET research has focused on specific areas including channel multiplexing, antenna diversity, and Doppler shift compensation schemes in an attempt to optimize BER performance. Despite this effort few surveys have been conducted to highlight the state-of-the-art collection on Doppler shift compensation schemes. Driven by this cause we survey some of the recent research activities in Doppler shift compensation schemes and highlight challenges and solutions as a stock-taking exercise. Moreover, we present open issues to be further investigated in order to address the challenges of Doppler shift in VANETs.

  2. Repetition and Translation Shifts

    Directory of Open Access Journals (Sweden)

    Simon Zupan

    2006-06-01

    Full Text Available Repetition manifests itself in different ways and at different levels of the text. The first basic type of repetition involves complete recurrences; in which a particular textual feature repeats in its entirety. The second type involves partial recurrences; in which the second repetition of the same textual feature includes certain modifications to the first occurrence. In the article; repetitive patterns in Edgar Allan Poe’s short story “The Fall of the House of Usher” and its Slovene translation; “Konec Usherjeve hiše”; are compared. The author examines different kinds of repetitive patterns. Repetitions are compared at both the micro- and macrostructural levels. As detailed analyses have shown; considerable microstructural translation shifts occur in certain types of repetitive patterns. Since these are not only occasional; sporadic phenomena; but are of a relatively high frequency; they reduce the translated text’s potential for achieving some of the gothic effects. The macrostructural textual property particularly affected by these shifts is the narrator’s experience as described by the narrative; which suffers a reduction in intensity.

  3. Attention and choice

    DEFF Research Database (Denmark)

    Orquin, Jacob Lund; Mueller Loose, Simone

    2013-01-01

    satisfaction models. Although most theories were confirmed with regard to certain predictions, none of the theories adequately accounted for the role of attention during decision making. Several observations emerged concerning the drivers and down-stream effects of attention on choice, suggesting......This paper reviews studies on eye movements in decision making, and compares their observations to theoretical predictions concerning the role of attention in decision making. Four decision theories are examined: rational models, bounded rationality, evidence accumulation, and parallel constraint...... that attention processes plays an active role in constructing decisions. So far, decision theories have largely ignored the constructive role of attention by assuming that it is entirely determined by heuristics, or that it consists of stochastic information sampling. The empirical observations reveal...

  4. The impact of shift work on the psychological and physical health of nurses in a general hospital: a comparison between rotating night shifts and day shifts.

    Science.gov (United States)

    Ferri, Paola; Guadi, Matteo; Marcheselli, Luigi; Balduzzi, Sara; Magnani, Daniela; Di Lorenzo, Rosaria

    2016-01-01

    Shift work is considered necessary to ensure continuity of care in hospitals and residential facilities. In particular, the night shift is one of the most frequent reasons for the disruption of circadian rhythms, causing significant alterations of sleep and biological functions that can affect physical and psychological well-being and negatively impact work performance. The aim of this study was to highlight if shift work with nights, as compared with day work only, is associated with risk factors predisposing nurses to poorer health conditions and lower job satisfaction. This cross-sectional study was conducted from June 1, 2015 to July 31, 2015 in 17 wards of a general hospital and a residential facility of a northern Italian city. This study involved 213 nurses working in rotating night shifts and 65 in day shifts. The instrument used for data collection was the "Standard Shift Work Index," validated in Italian. Data were statistically analyzed. The response rate was 86%. The nurses engaged in rotating night shifts were statistically significantly younger, more frequently single, and had Bachelors and Masters degrees in nursing. They reported the lowest mean score in the items of job satisfaction, quality and quantity of sleep, with more frequent chronic fatigue, psychological, and cardiovascular symptoms in comparison with the day shift workers, in a statistically significant way. Our results suggest that nurses with rotating night schedule need special attention due to the higher risk for both job dissatisfaction and undesirable health effects.

  5. Shift Work: Improving Daytime Sleep

    Science.gov (United States)

    ... night. Good daytime sleep is possible, though, if shift work is a necessary part of your work life. ... mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/shift-work/faq-20057991 . Mayo Clinic Footer Legal Conditions and ...

  6. Automatic Mechanisms for Social Attention Are Culturally Penetrable.

    Science.gov (United States)

    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.

  7. Sleep and satisfaction in 8- and 12-h forward-rotating shift systems: Industrial employees prefer 12-h shifts.

    Science.gov (United States)

    Karhula, Kati; Härmä, Mikko; Ropponen, Annina; Hakola, Tarja; Sallinen, Mikael; Puttonen, Sampsa

    2016-01-01

    Twelve-hour shift systems have become more popular in industry. Survey data of shift length, shift rotation speed, self-rated sleep, satisfaction and perceived health were investigated for the associations among 599 predominantly male Finnish industrial employees. The studied forward-rotating shift systems were 12-h fast (12fast, DDNN------, n = 268), 8-h fast (8fast, MMEENN----, n = 161) and 8-h slow (8slow, MMMM-EEEE-NNNN, n = 170). Satisfaction with shift system differed between the groups (p effects on sleep and alertness were rare (8%) in the 12fast group (53% 8fast, 66% 8 slow, p effects of the current shift system on general health (12fast 4%, 8fast 30%, 8slow 41%, p work-life balance (12fast 8%, 8fast 52%, 8slow 63%, p effects of shift work were dependent on both shift length and shift rotation speed: employees in the 12-h rapidly forward-rotating shift system were most satisfied, perceived better work-life balance and slept better than the employees in the 8fast or especially the employees in the 8-h slowly rotating systems.

  8. Lanthanide shift reagents, binding, shift mechanisms and exchange

    International Nuclear Information System (INIS)

    Boer, J.W.M. de

    1977-01-01

    Paramagnetic lanthanide shift reagents, when added to a solution of a substrate, induce shifts in the nuclear magnetic resonance (NMR) spectrum of the substrate molecules. The induced shifts contain information about the structure of the shift reagent substrate complex. The structural information, however, may be difficult to extract because of the following effects: (1) different complexes between shift reagent and substrate may be present in solution, e.g. 1:1 and 1:2 complexes, and the shift observed is a weighed average of the shifts of the substrate nuclei in the different complexes; (2) the Fermi contact interaction, arising from the spin density at the nucleus, contributes to the induced shift; (3) chemical exchange effects may complicate the NMR spectrum. In this thesis, the results of an investigation into the influence of these effects on the NMR spectra of solutions containing a substrate and LSR are presented. The equations describing the pseudo contact and the Fermi contact shift are derived. In addition, it is shown how the modified Bloch equations describing the effect of the chemical exchange processes occurring in the systems studied can be reduced to the familiar equations for a two-site exchange case. The binding of mono- and bifunctional ethers to the shift reagent are reported. An analysis of the induced shifts is given. Finally, the results of the experiments performed to study the exchange behavior of dimethoxyethane and heptafluorodimethyloctanedionato ligands are presented

  9. Faktor Dan Penjadualan Shift Kerja

    OpenAIRE

    Maurits, Lientje Setyawati; Widodo, Imam Djati

    2008-01-01

    Work shift has negative effect in physical and mental health, work performance and job accident. Disturbance of circadian rhythms is indicated as source of the problems. This article explores some researches related to the impacts of work shift and establishes basic principles of work shift scheduling that considers human need and limitation.

  10. Isotope shifting capacity of rock

    International Nuclear Information System (INIS)

    Blattner, P.; Department of Scientific and Industrial Research, Lower Hutt

    1980-01-01

    Any oxygen isotope shifted rock volume exactly defines a past throughput of water. An expression is derived that relates the throughput of an open system to the isotope shift of reservoir rock and present-day output. The small isotope shift of Ngawha reservoir rock and the small, high delta oxygen-18 output are best accounted for by a magmatic water source

  11. Attractive faces temporally modulate visual attention

    Science.gov (United States)

    Nakamura, Koyo; Kawabata, Hideaki

    2014-01-01

    Facial attractiveness is an important biological and social signal on social interaction. Recent research has demonstrated that an attractive face captures greater spatial attention than an unattractive face does. Little is known, however, about the temporal characteristics of visual attention for facial attractiveness. In this study, we investigated the temporal modulation of visual attention induced by facial attractiveness by using a rapid serial visual presentation. Fourteen male faces and two female faces were successively presented for 160 ms, respectively, and participants were asked to identify two female faces embedded among a series of multiple male distractor faces. Identification of a second female target (T2) was impaired when a first target (T1) was attractive compared to neutral or unattractive faces, at 320 ms stimulus onset asynchrony (SOA); identification was improved when T1 was attractive compared to unattractive faces at 640 ms SOA. These findings suggest that the spontaneous appraisal of facial attractiveness modulates temporal attention. PMID:24994994

  12. Attractive faces temporally modulate visual attention

    Directory of Open Access Journals (Sweden)

    Koyo eNakamura

    2014-06-01

    Full Text Available Facial attractiveness is an important biological and social signal on social interaction. Recent research has demonstrated that an attractive face captures greater spatial attention than an unattractive face does. Little is known, however, about the temporal characteristics of visual attention for facial attractiveness. In this study, we investigated the temporal modulation of visual attention induced by facial attractiveness by using a rapid serial visual presentation (RSVP. Fourteen male faces and two female faces were successively presented for 160 ms respectively, and participants were asked to identify two female faces embedded among a series of multiple male distractor faces. Identification of a second female target (T2 was impaired when a first target (T1 was attractive compared to neutral or unattractive faces, at 320 ms SOA; identification was improved when T1 was attractive compared to unattractive faces at 640 ms SOA. These findings suggest that the spontaneous appraisal of facial attractiveness modulates temporal attention.

  13. [Thalamus and Attention].

    Science.gov (United States)

    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.

  14. The shift in windpower

    International Nuclear Information System (INIS)

    Gipe, P.

    1992-01-01

    Despite new production records, the near-term market for new windpower projects in the US remains bleak. Congressional incentives and project proposals in the mid-1990s offer promise, but for now most development has shifted to Europe. During 1992 and 1993 the largest wind projects developed by US companies will not be in the US, but in the United Kingdom and Spain. Indeed, most of the US's windpower industry is going abroad, establishing offices overseas. This move toward Europe comes as little surprise. New project development for US firms has faltered at home while the European market has burgeoned. The topics of the article include the move to Europe, a reduction in California's share of producing wind power plants, a rise in Europe's share of producing wind power plants, the future market for wind power in the US, and reawakening California's market

  15. Enhanced facilitation of spatial attention in schizophrenia.

    Science.gov (United States)

    Spencer, Kevin M; Nestor, Paul G; Valdman, Olga; Niznikiewicz, Margaret A; Shenton, Martha E; McCarley, Robert W

    2011-01-01

    While attentional functions are usually found to be impaired in schizophrenia, a review of the literature on the orienting of spatial attention in schizophrenia suggested that voluntary attentional orienting in response to a valid cue might be paradoxically enhanced. We tested this hypothesis with orienting tasks involving the cued detection of a laterally presented target stimulus. Subjects were chronic schizophrenia patients (SZ) and matched healthy control subjects (HC). In Experiment 1 (15 SZ, 16 HC), cues were endogenous (arrows) and could be valid (100% predictive) or neutral with respect to the subsequent target position. In Experiment 2 (16 SZ, 16 HC), subjects performed a standard orienting task with unpredictive exogenous cues (brightening of the target boxes). In Experiment 1, SZ showed a larger attentional facilitation effect on reaction time than HC. In Experiment 2, no clear sign of enhanced attentional facilitation was found in SZ. The voluntary, facilitatory shifting of spatial attention may be relatively enhanced in individuals with schizophrenia in comparison to healthy individuals. This effect bears resemblance to other relative enhancements of information processing in schizophrenia such as saccade speed and semantic priming. (c) 2010 APA, all rights reserved.

  16. Review: Attention and Memory in Autism

    Directory of Open Access Journals (Sweden)

    Arash Mirab-Zadeh

    2001-12-01

    Full Text Available Many investigations have documented about attentional and memorial abnormality in individuals with autism. This study is summary of recent researches about alternations of attention and memory in autism. The most important changes of attention in autism are: 1 Arousal modulatory system dysfunction, leading to fluctuations between states over and under arousal. 2 Reduction of orienting and processing of novel stimuli. 3 Over focused attention, responding to only a subset of environmental cues. 4 Deficit in shifting attention, leading to difficulty moving their attention from one special location to another. The most important changes of memory in autism are: 1 Good rote memory 2 Cued recall is significantly better than free recall 3 Deficit in working memory 4 Deficit in implicit and explicit memory 5 Deficit in verbal memory about material that requires further encoding, organization or use of meaning or semantic cues for recalling 6 High functioning memory in some of the patients for example ability to read well, singing or recognizing musical pieces

  17. Shape-shifting colloids via stimulated dewetting

    Science.gov (United States)

    Youssef, Mena; Hueckel, Theodore; Yi, Gi-Ra; Sacanna, Stefano

    2016-01-01

    The ability to reconfigure elementary building blocks from one structure to another is key to many biological systems. Bringing the intrinsic adaptability of biological systems to traditional synthetic materials is currently one of the biggest scientific challenges in material engineering. Here we introduce a new design concept for the experimental realization of self-assembling systems with built-in shape-shifting elements. We demonstrate that dewetting forces between an oil phase and solid colloidal substrates can be exploited to engineer shape-shifting particles whose geometry can be changed on demand by a chemical or optical signal. We find this approach to be quite general and applicable to a broad spectrum of materials, including polymers, semiconductors and magnetic materials. This synthetic methodology can be further adopted as a new experimental platform for designing and rapidly prototyping functional colloids, such as reconfigurable micro swimmers, colloidal surfactants and switchable building blocks for self-assembly. PMID:27426418

  18. Attentional and Contextual Priors in Sound Perception.

    Science.gov (United States)

    Wolmetz, Michael; Elhilali, Mounya

    2016-01-01

    Behavioral and neural studies of selective attention have consistently demonstrated that explicit attentional cues to particular perceptual features profoundly alter perception and performance. The statistics of the sensory environment can also provide cues about what perceptual features to expect, but the extent to which these more implicit contextual cues impact perception and performance, as well as their relationship to explicit attentional cues, is not well understood. In this study, the explicit cues, or attentional prior probabilities, and the implicit cues, or contextual prior probabilities, associated with different acoustic frequencies in a detection task were simultaneously manipulated. Both attentional and contextual priors had similarly large but independent impacts on sound detectability, with evidence that listeners tracked and used contextual priors for a variety of sound classes (pure tones, harmonic complexes, and vowels). Further analyses showed that listeners updated their contextual priors rapidly and optimally, given the changing acoustic frequency statistics inherent in the paradigm. A Bayesian Observer model accounted for both attentional and contextual adaptations found with listeners. These results bolster the interpretation of perception as Bayesian inference, and suggest that some effects attributed to selective attention may be a special case of contextual prior integration along a feature axis.

  19. Iconic memory requires attention.

    Science.gov (United States)

    Persuh, Marjan; Genzer, Boris; Melara, Robert D

    2012-01-01

    Two experiments investigated whether attention plays a role in iconic memory, employing either a change detection paradigm (Experiment 1) or a partial-report paradigm (Experiment 2). In each experiment, attention was taxed during initial display presentation, focusing the manipulation on consolidation of information into iconic memory, prior to transfer into working memory. Observers were able to maintain high levels of performance (accuracy of change detection or categorization) even when concurrently performing an easy visual search task (low load). However, when the concurrent search was made difficult (high load), observers' performance dropped to almost chance levels, while search accuracy held at single-task levels. The effects of attentional load remained the same across paradigms. The results suggest that, without attention, participants consolidate in iconic memory only gross representations of the visual scene, information too impoverished for successful detection of perceptual change or categorization of features.

  20. Iconic memory requires attention

    Directory of Open Access Journals (Sweden)

    Marjan ePersuh

    2012-05-01

    Full Text Available Two experiments investigated whether attention plays a role in iconic memory, employing either a change-detection paradigm (Experiment 1 or a partial-report paradigm (Experiment 2. In each experiment, attention was taxed during initial display presentation, focusing the manipulation on consolidation of information into iconic memory, prior to transfer into working memory. Observers were able to maintain high levels of performance (accuracy of change detection or categorization even when concurrently performing an easy visual search task (low load. However, when the concurrent search was made difficult (high load, observers’ performance dropped to almost chance levels, while search accuracy held at single-task levels. The effects of attentional load remained the same across paradigms. The results suggest that, without attention, participants consolidate in iconic memory only gross representations of the visual scene, information too impoverished for successful detection of perceptual change or categorization of features.

  1. Iconic memory requires attention

    OpenAIRE

    Persuh, Marjan; Genzer, Boris; Melara, Robert D.

    2012-01-01

    Two experiments investigated whether attention plays a role in iconic memory, employing either a change detection paradigm (Experiment 1) or a partial-report paradigm (Experiment 2). In each experiment, attention was taxed during initial display presentation, focusing the manipulation on consolidation of information into iconic memory, prior to transfer into working memory. Observers were able to maintain high levels of performance (accuracy of change detection or categorization) even when co...

  2. Attention deficits and divorce.

    Science.gov (United States)

    Bouchard, Geneviève; Saint-Aubin, Jean

    2014-09-01

    Building on previous work on the role of attention deficits associated with the regulation of executive control in psychiatric disorders, we examine whether these attention deficits are related to an interpersonal disturbance, the experience of divorce. Attentional capacities of 95 randomly selected couples from the general population were measured with a well-established task, the Attentional Network Task, which assesses the efficiency of 3 attention networks (that is, alerting, orienting, and executive control). Among the 190 participants, 32 had experienced a divorce in the past. ANCOVAs were used to compare divorced people in marital or cohabiting unions with people in first unions in their performance on this purely cognitive task. Our findings indicate that divorced people who are currently living in a cohabiting relationship show significantly lower executive control than other adults living as couples, after controlling for sex, age, income, and education. This subgroup of divorced people not only exhibit greater difficulty in responding to some stimuli while ignoring irrelevant ones but also manifest cognitive deficits in conflict resolution. This study highlights the links between attention and the long-term maintenance of intimate relationships. Our results may have important implications for the identification of people at risk for divorce.

  3. Cognition, emotion, and attention.

    Science.gov (United States)

    Müller-Oehring, Eva M; Schulte, Tilman

    2014-01-01

    Deficits of attention, emotion, and cognition occur in individuals with alcohol abuse and addiction. This review elucidates the concepts of attention, emotion, and cognition and references research on the underlying neural networks and their compromise in alcohol use disorder. Neuroimaging research on adolescents with family history of alcoholism contributes to the understanding of pre-existing brain structural conditions and characterization of cognition and attention processes in high-risk individuals. Attention and cognition interact with other brain functions, including perceptual selection, salience, emotion, reward, and memory, through interconnected neural networks. Recent research reports compromised microstructural and functional network connectivity in alcoholism, which can have an effect on the dynamic tuning between brain systems, e.g., the frontally based executive control system, the limbic emotion system, and the midbrain-striatal reward system, thereby impeding cognitive flexibility and behavioral adaptation to changing environments. Finally, we introduce concepts of functional compensation, the capacity to generate attentional resources for performance enhancement, and brain structure recovery with abstinence. An understanding of the neural mechanisms of attention, emotion, and cognition will likely provide the basis for better treatment strategies for developing skills that enhance alcoholism therapy adherence and quality of life, and reduce the propensity for relapse. © 2014 Elsevier B.V. All rights reserved.

  4. Interaction of hypertension and age in visual selective attention performance.

    Science.gov (United States)

    Madden, D J; Blumenthal, J A

    1998-01-01

    Previous research suggests that some aspects of cognitive performance decline as a joint function of age and hypertension. In this experiment, 51 unmedicated individuals with mild essential hypertension and 48 normotensive individuals, 18-78 years of age, performed a visual search task. The estimated time required to identify a display character and shift attention between display positions increased with age. This attention shift time did not differ significantly between hypertensive and normotensive participants, but regression analyses indicated some mediation of the age effect by blood pressure. For individuals less than 60 years of age, the error rate was greater for hypertensive than for normotensive participants. Although the present design could detect effects of only moderate to large size, the results suggest that effects of hypertension may be more evident in a relatively general measure of performance (mean error rate) than in the speed of shifting visual attention.

  5. Exogenous (automatic) attention to emotional stimuli: a review

    OpenAIRE

    Carretié, Luis

    2014-01-01

    Current knowledge on the architecture of exogenous attention (also called automatic, bottom-up, or stimulus-driven attention, among other terms) has been mainly obtained from studies employing neutral, anodyne stimuli. Since, from an evolutionary perspective, exogenous attention can be understood as an adaptive tool for rapidly detecting salient events, reorienting processing resources to them, and enhancing processing mechanisms, emotional events (which are, by definition, salient for the in...

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

    Science.gov (United States)

    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…

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

    Directory of Open Access Journals (Sweden)

    Anita D. Barber

    2015-01-01

    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 hand, greater DMN–occipital anti-correlation supported better attentional control in TD children.

  8. Chemical shift imaging: a review

    International Nuclear Information System (INIS)

    Brateman, L.

    1986-01-01

    Chemical shift is the phenomenon that is seen when an isotope possessing a nuclear magnetic dipole moment resonates at a spectrum of resonance frequencies in a given magnetic field. These resonance frequencies, or chemical shifts, depend on the chemical environments of particular nuclei. Mapping the spatial distribution of nuclei associated with a particular chemical shift (e.g., hydrogen nuclei associated with water molecules or with lipid groups) is called chemical shift imaging. Several techniques of proton chemical shift imaging that have been applied in vivo are presented, and their clinical findings are reported and summarized. Acquiring high-resolution spectra for large numbers of volume elements in two or three dimensions may be prohibitive because of time constraints, but other methods of imaging lipid of water distributions (i.e., selective excitation, selective saturation, or variations in conventional magnetic resonance imaging pulse sequences) can provide chemical shift information. These techniques require less time, but they lack spectral information. Since fat deposition seen by chemical shift imaging may not be demonstrated by conventional magnetic resonance imaging, certain applications of chemical shift imaging, such as in the determination of fatty liver disease, have greater diagnostic utility than conventional magnetic resonance imaging. Furthermore, edge artifacts caused by chemical shift effects can be eliminated by certain selective methods of data acquisition employed in chemical shift imaging

  9. Infants' Selective Attention to Reliable Visual Cues in the Presence of Salient Distractors

    Science.gov (United States)

    Tummeltshammer, Kristen Swan; Mareschal, Denis; Kirkham, Natasha Z.

    2014-01-01

    With many features competing for attention in their visual environment, infants must learn to deploy attention toward informative cues while ignoring distractions. Three eye tracking experiments were conducted to investigate whether 6- and 8-month-olds (total N = 102) would shift attention away from a distractor stimulus to learn a cue-reward…

  10. Chemical shift homology in proteins

    International Nuclear Information System (INIS)

    Potts, Barbara C.M.; Chazin, Walter J.

    1998-01-01

    The degree of chemical shift similarity for homologous proteins has been determined from a chemical shift database of over 50 proteins representing a variety of families and folds, and spanning a wide range of sequence homologies. After sequence alignment, the similarity of the secondary chemical shifts of C α protons was examined as a function of amino acid sequence identity for 37 pairs of structurally homologous proteins. A correlation between sequence identity and secondary chemical shift rmsd was observed. Important insights are provided by examining the sequence identity of homologous proteins versus percentage of secondary chemical shifts that fall within 0.1 and 0.3 ppm thresholds. These results begin to establish practical guidelines for the extent of chemical shift similarity to expect among structurally homologous proteins

  11. Shifted-modified Chebyshev filters

    OpenAIRE

    ŞENGÜL, Metin

    2013-01-01

    This paper introduces a new type of filter approximation method that utilizes shifted-modified Chebyshev filters. Construction of the new filters involves the use of shifted-modified Chebyshev polynomials that are formed using the roots of conventional Chebyshev polynomials. The study also includes 2 tables containing the shifted-modified Chebyshev polynomials and the normalized element values for the low-pass prototype filters up to degree 6. The transducer power gain, group dela...

  12. Portable shift register

    International Nuclear Information System (INIS)

    Halbig, J.K.; Bourret, S.C.; Hansen, W.J.; Hicks, D.V.; Klosterbuer, S.F.; Krick, M.S.

    1994-01-01

    An electronics package for a small, battery-operated, self-contained, neutron coincidence counter based on a portable shift-register (PSR) has been developed. The counter was developed for applications not adequately addressed by commercial packages, including in-plant measurements to demonstrate compliance with regulations (domestic and international), in-plant process control, and in-field measurements (environmental monitoring or safeguards). Our package's features, which address these applications, include the following: Small size for portability and ease of installation;battery or mains operation; a built-in battery to power the unit and a typical detector such as a small sample counter, for over 6 h if power lines are bad or noisy, if there is a temporary absence of power, or if portability is desired; complete support, including bias, for standard neutron detectors; a powerful communications package to easily facilitate robust external control over a serial port; and a C-library to simplify creating external control programs in computers or other controllers. Whereas the PSR specifically addresses the applications mentioned above, it also performs all the measurements made by previous electronics packages for neutron coincidence counters developed at Los Alamos and commercialized. The PSR electronics package, exclusive of carrying handle, is 8 by 10 by 20 cm; it contains the circuit boards, battery, and bias supply and weighs less than 2 kg. This instrument package is the second in an emerging family of portable measurement instruments being developed; the first was the Miniature and Modular Multichannel Analyzer (M 3 CA). The PSR makes extensive use of hardware and software developed for the M 3 CA; like the M 3 CA, it is intended primarily for use with an external controller interfaced over a serial channel

  13. Quantized beam shifts in graphene

    Energy Technology Data Exchange (ETDEWEB)

    de Melo Kort-Kamp, Wilton Junior [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinitsyn, Nikolai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dalvit, Diego Alejandro Roberto [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-08

    We predict the existence of quantized Imbert-Fedorov, Goos-Hanchen, and photonic spin Hall shifts for light beams impinging on a graphene-on-substrate system in an external magnetic field. In the quantum Hall regime the Imbert-Fedorov and photonic spin Hall shifts are quantized in integer multiples of the fine structure constant α, while the Goos-Hanchen ones in multiples of α2. We investigate the influence on these shifts of magnetic field, temperature, and material dispersion and dissipation. An experimental demonstration of quantized beam shifts could be achieved at terahertz frequencies for moderate values of the magnetic field.

  14. Does oculomotor readiness mediate exogenous capture of visual attention?

    Science.gov (United States)

    MacLean, Gregory H; Klein, Raymond M; Hilchey, Matthew D

    2015-10-01

    The oculomotor readiness hypothesis makes 2 predictions: Shifts in covert attention are accompanied by preparedness to move one's eyes to the attended region, and preparedness to move one's eyes to a region in space is accompanied by a shift in covert attention to the prepared location. Both predictions have been disconfirmed using an endogenous attention task. In the 2 experiments presented here, the same 2 predictions were tested using an exogenous attention task. It was found that participants experienced covert capture without accompanying oculomotor activation and experienced oculomotor activation without accompanying covert capture. While under everyday conditions the overt and covert orienting systems may be strongly linked, apparently they can nonetheless operate with a high degree of independence from one another. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  15. Divided spatial attention and feature-mixing errors.

    Science.gov (United States)

    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.

  16. Emotional attention for erotic stimuli: Cognitive and brain mechanisms.

    Science.gov (United States)

    Sennwald, Vanessa; Pool, Eva; Brosch, Tobias; Delplanque, Sylvain; Bianchi-Demicheli, Francesco; Sander, David

    2016-06-01

    It has long been posited that among emotional stimuli, only negative threatening information modulates early shifts of attention. However, in the last few decades there has been an increase in research showing that attention is also involuntarily oriented toward positive rewarding stimuli such as babies, food, and erotic information. Because reproduction-related stimuli have some of the largest effects among positive stimuli on emotional attention, the present work reviews recent literature and proposes that the cognitive and cerebral mechanisms underlying the involuntarily attentional orientation toward threat-related information are also sensitive to erotic information. More specifically, the recent research suggests that both types of information involuntarily orient attention due to their concern relevance and that the amygdala plays an important role in detecting concern-relevant stimuli, thereby enhancing perceptual processing and influencing emotional attentional processes. © 2015 Wiley Periodicals, Inc.

  17. Attentional bias for craving-related (chocolate) food cues.

    Science.gov (United States)

    Kemps, Eva; Tiggemann, Marika

    2009-12-01

    In this study, we investigated attentional biases for craving-related food cues. A pictorial dot probe task was used to assess selective attentional processing of one particular highly desired food, namely chocolate, relative to that of other highly desired foods. In Experiment 1, we examined biased processing of chocolate cues in habitual (trait) chocolate cravers, whereas in Experiment 2 we investigated the effect of experimentally induced (state) chocolate cravings on such processing. As predicted, habitual chocolate cravers (Experiment 1) and individuals in whom a craving for chocolate was temporarily induced (Experiment 2) showed speeded detection of probes replacing chocolate-related pictures, demonstrating an attentional bias for chocolate cues. Subsequent examination indicated that in both experiments the observed attentional biases stemmed from difficulty in disengaging attention from chocolate cues rather than from a shift of attention toward such cues. The findings have important theoretical and practical implications.

  18. Managerial Attention in International SMEs

    NARCIS (Netherlands)

    Fan, Jiasi

    2017-01-01

    Managerial attention affects organizational strategies and the resulting consequences. In the international business context, it is noted that how much attention managers give to the international marketplace, i.e., international attention, has profound implications for large global companies’

  19. Attention: Moral-Cognitive Geography.

    Science.gov (United States)

    Tuan, Yi-Fu

    1987-01-01

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

  20. Rapid shallow breathing

    Science.gov (United States)

    Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Shallow, rapid breathing has many possible medical causes, including: Asthma Blood clot in an artery in the ...

  1. An overview of attention deficits after paediatric traumatic brain injury.

    Science.gov (United States)

    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.

  2. Are You Paying Attention?

    DEFF Research Database (Denmark)

    Ørmen, Jacob

    2016-01-01

    and sustained. To study such attention practices, 16 semi-structured interviews with adult Danes are carried out. Through a thematic analysis of these interviews, the chapter explores how ways of attending relate to individual media and how patterns of daily life enable some practices and constrain others...

  3. Visual attention and stability

    NARCIS (Netherlands)

    Mathot, Sebastiaan; Theeuwes, Jan

    2011-01-01

    In the present review, we address the relationship between attention and visual stability. Even though with each eye, head and body movement the retinal image changes dramatically, we perceive the world as stable and are able to perform visually guided actions. However, visual stability is not as

  4. Deep Visual Attention Prediction

    Science.gov (United States)

    Wang, Wenguan; Shen, Jianbing

    2018-05-01

    In this work, we aim to predict human eye fixation with view-free scenes based on an end-to-end deep learning architecture. Although Convolutional Neural Networks (CNNs) have made substantial improvement on human attention prediction, it is still needed to improve CNN based attention models by efficiently leveraging multi-scale features. Our visual attention network is proposed to capture hierarchical saliency information from deep, coarse layers with global saliency information to shallow, fine layers with local saliency response. Our model is based on a skip-layer network structure, which predicts human attention from multiple convolutional layers with various reception fields. Final saliency prediction is achieved via the cooperation of those global and local predictions. Our model is learned in a deep supervision manner, where supervision is directly fed into multi-level layers, instead of previous approaches of providing supervision only at the output layer and propagating this supervision back to earlier layers. Our model thus incorporates multi-level saliency predictions within a single network, which significantly decreases the redundancy of previous approaches of learning multiple network streams with different input scales. Extensive experimental analysis on various challenging benchmark datasets demonstrate our method yields state-of-the-art performance with competitive inference time.

  5. Automated visual attention manipulation

    NARCIS (Netherlands)

    Bosse, T.; Lambalgen, R. van; Maanen, P.P. van; Treur, J.

    2009-01-01

    In this paper a system for visual attention manipulation is introduced and formally described. This system is part of the design of a software agent that supports naval crew in her task to compile a tactical picture of the situation in the field. A case study is described in hich the system is used

  6. Laughter catches attention!

    Science.gov (United States)

    Pinheiro, Ana P; Barros, Carla; Dias, Marcelo; Kotz, Sonja A

    2017-12-01

    In social interactions, emotionally salient and sudden changes in vocal expressions attract attention. However, only a few studies examined how emotion and attention interact in voice processing. We investigated neutral, happy (laughs) and angry (growls) vocalizations in a modified oddball task. Participants silently counted the targets in each block and rated the valence and arousal of the vocalizations. A combined event-related potential and time-frequency analysis focused on the P3 and pre-stimulus alpha power to capture attention effects in response to unexpected events. Whereas an early differentiation between emotionally salient and neutral vocalizations was reflected in the P3a response, the P3b was selectively enhanced for happy voices. The P3b modulation was predicted by pre-stimulus frontal alpha desynchronization, and by the perceived pleasantness of the targets. These findings indicate that vocal emotions may be differently processed based on task relevance and valence. Increased anticipation and attention to positive vocal cues (laughter) may reflect their high social relevance. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Attention: oscillations and neuropharmacology.

    Science.gov (United States)

    Deco, Gustavo; Thiele, Alexander

    2009-08-01

    Attention is a rich psychological and neurobiological construct that influences almost all aspects of cognitive behaviour. It enables enhanced processing of behaviourally relevant stimuli at the expense of irrelevant stimuli. At the cellular level, rhythmic synchronization at local and long-range spatial scales complements the attention-induced firing rate changes of neurons. The former is hypothesized to enable efficient communication between neuronal ensembles tuned to spatial and featural aspects of the attended stimulus. Recent modelling studies suggest that the rhythmic synchronization in the gamma range may be mediated by a fine balance between N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate postsynaptic currents, whereas other studies have highlighted the possible contribution of the neuromodulator acetylcholine. This review summarizes some recent modelling and experimental studies investigating mechanisms of attention in sensory areas and discusses possibilities of how glutamatergic and cholinergic systems could contribute to increased processing abilities at the cellular and network level during states of top-down attention.

  8. Attention Capture by Faces

    Science.gov (United States)

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

    2008-01-01

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

  9. Work shifts in Emergency Medicine

    Directory of Open Access Journals (Sweden)

    Roberto Recupero

    2007-06-01

    Full Text Available Emergency Medicine is known as a high stress specialty. The adverse effect of constantly rotating shifts is the single most important reason given for premature attrition from the field. In this work problems tied with night shift work will be taken into account and some solutions to reduce the impact of night work on the emergency physicians will be proposed.

  10. Flexible Schedules and Shift Work.

    Science.gov (United States)

    Beers, Thomas M.

    2000-01-01

    Flexible work hours have gained prominence, as more than 25 million workers (27.6% of all full-time workers) can now vary their schedules. However, there has been little change since the mid-1980s in the proportion who work a shift other than a regular daytime shift. (JOW)

  11. A new model for the mental health nursing change of shift report.

    Science.gov (United States)

    Priest, C S; Holmberg, S K

    2000-08-01

    Nursing shift reports are intended to enhance the continuity and quality of nursing care delivered by providing results of nursing assessments, summarizing medical information, and drawing attention to specific nursing interventions and goals anticipated during the upcoming shift. In this article, contemporary literature on shift reports is reviewed with specific attention to the unique characteristics and problems that commonly occur in change of shift reports in a mental health setting. The framework proposed is Gordon's functional health patterns because it provides a holistic structure for organizing patient data in a clear, objective manner. Additional methods for enhancing shift reports are recommended, including the use of specific behavioral descriptions, the inclusion of data from targeted nursing assessments, and the discussion of alternative care approaches that support the development of consistent, collaborative nursing interventions across shifts. A case example is used for demonstration.

  12. Neural correlates of endogenous attention, exogenous attention and inhibition of return in touch.

    Science.gov (United States)

    Jones, Alexander; Forster, Bettina

    2014-07-01

    Selective attention helps process the myriad of information constantly touching our body. Both endogenous and exogenous mechanisms are relied upon to effectively process this information; however, it is unclear how they relate in the sense of touch. In three tasks we contrasted endogenous and exogenous event-related potential (ERP) and behavioural effects. Unilateral tactile cues were followed by a tactile target at the same or opposite hand. Clear behavioural effects showed facilitation of expected targets both when the cue predicted targets at the same (endogenous predictive task) and opposite hand (endogenous counter-predictive task), and these effects also correlated with ERP effects of endogenous attention. In an exogenous task, where the cue was non-informative, inhibition of return (IOR) was observed. The electrophysiological results demonstrated early effects of exogenous attention followed by later endogenous attention modulations. These effects were independent in both the endogenous predictive and exogenous tasks. However, voluntarily directing attention away from a cued body part influenced the early exogenous marker (N80). This suggests that the two mechanisms are interdependent, at least when the task requires more demanding shifts of attention. The early marker of exogenous tactile attention, the N80, was not directly related to IOR, which may suggest that exogenous attention and IOR are not necessarily two sides of the same coin. This study adds valuable new insight into how we process and select information presented to our body, showing both independent and interdependent effects of endogenous and exogenous attention in touch. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  13. What Do We Know About Base Erosion and Profit Shifting? A Review of the Empirical Literature

    OpenAIRE

    Dhammika Dharmapala

    2014-01-01

    The issue of tax-motivated income shifting within multinational firms has attracted increasing global attention in recent years. It is of central importance to many current policy debates, including those related to recent initiatives by the OECD on base erosion and profit shifting (BEPS) and to proposals for US tax reform in a territorial direction. This paper provides a survey of the empirical literature on tax-motivated income-shifting within multinational firms. Its emphasis is on clarify...

  14. Changes in forest productivity across Alaska consistent with biome shift.

    Science.gov (United States)

    Beck, Pieter S A; Juday, Glenn P; Alix, Claire; Barber, Valerie A; Winslow, Stephen E; Sousa, Emily E; Heiser, Patricia; Herriges, James D; Goetz, Scott J

    2011-04-01

    Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biome's margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biome's southern edge. We evaluated changes in forest productivity since 1982 across boreal Alaska by linking satellite estimates of primary productivity and a large tree-ring data set. Trends in both records show consistent growth increases at the boreal-tundra ecotones that contrast with drought-induced productivity declines throughout interior Alaska. These patterns support the hypothesized effects of an initiating biome shift. Ultimately, tree dispersal rates, habitat availability and the rate of future climate change, and how it changes disturbance regimes, are expected to determine where the boreal biome will undergo a gradual geographic range shift, and where a more rapid decline. © 2011 Blackwell Publishing Ltd/CNRS.

  15. Selective Attention and Attention Switching: Toward a Unified Developmental Approach

    OpenAIRE

    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 during the preschool years. The second literature encompasses a large and robust set of phenomena for the same developmental period that indicate a ...

  16. Visual attention capacity

    DEFF Research Database (Denmark)

    Habekost, Thomas; Starrfelt, Randi

    2009-01-01

    Psychophysical studies have identified two distinct limitations of visual attention capacity: processing speed and apprehension span. Using a simple test, these cognitive factors can be analyzed by Bundesen's Theory of Visual Attention (TVA). The method has strong specificity and sensitivity......, and measurements are highly reliable. As the method is theoretically founded, it also has high validity. TVA-based assessment has recently been used to investigate a broad range of neuropsychological and neurological conditions. We present the method, including the experimental paradigm and practical guidelines...... to patient testing, and review existing TVA-based patient studies organized by lesion anatomy. Lesions in three anatomical regions affect visual capacity: The parietal lobes, frontal cortex and basal ganglia, and extrastriate cortex. Visual capacity thus depends on large, bilaterally distributed anatomical...

  17. Scene incongruity and attention.

    Science.gov (United States)

    Mack, Arien; Clarke, Jason; Erol, Muge; Bert, John

    2017-02-01

    Does scene incongruity, (a mismatch between scene gist and a semantically incongruent object), capture attention and lead to conscious perception? We explored this question using 4 different procedures: Inattention (Experiment 1), Scene description (Experiment 2), Change detection (Experiment 3), and Iconic Memory (Experiment 4). We found no differences between scene incongruity and scene congruity in Experiments 1, 2, and 4, although in Experiment 3 change detection was faster for scenes containing an incongruent object. We offer an explanation for why the change detection results differ from the results of the other three experiments. In all four experiments, participants invariably failed to report the incongruity and routinely mis-described it by normalizing the incongruent object. None of the results supports the claim that semantic incongruity within a scene invariably captures attention and provide strong evidence of the dominant role of scene gist in determining what is perceived. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. No Effect of Featural Attention on Body Size Aftereffects

    Directory of Open Access Journals (Sweden)

    Ian David Stephen

    2016-08-01

    Full Text Available Prolonged exposure to images of narrow bodies has been shown to induce a perceptual aftereffect, such that observers’ point of subjective normality (PSN for bodies shifts towards narrower bodies. The converse effect is shown for adaptation to wide bodies. In low-level stimuli, object attention (attention directed to the object and spatial attention (attention directed to the location of the object have been shown to increase the magnitude of visual aftereffects, while object-based attention enhances the adaptation effect in faces. It is not known whether featural attention (attention directed to a specific aspect of the object affects the magnitude of adaptation effects in body stimuli. Here, we manipulate the attention of Caucasian observers to different featural information in body images, by asking them to rate the fatness or sex typicality of male and female bodies manipulated to appear fatter or thinner than average. PSNs for body fatness were taken at baseline and after adaptation, and a change in PSN (ΔPSN was calculated. A body size adaptation effect was found, with observers who viewed fat bodies showing an increased PSN, and those exposed to thin bodies showing a reduced PSN. However, manipulations of featural attention to body fatness or sex typicality produced equivalent results, suggesting that featural attention may not affect the strength of the body size aftereffect.

  19. No Effect of Featural Attention on Body Size Aftereffects.

    Science.gov (United States)

    Stephen, Ian D; Bickersteth, Chloe; Mond, Jonathan; Stevenson, Richard J; Brooks, Kevin R

    2016-01-01

    Prolonged exposure to images of narrow bodies has been shown to induce a perceptual aftereffect, such that observers' point of subjective normality (PSN) for bodies shifts toward narrower bodies. The converse effect is shown for adaptation to wide bodies. In low-level stimuli, object attention (attention directed to the object) and spatial attention (attention directed to the location of the object) have been shown to increase the magnitude of visual aftereffects, while object-based attention enhances the adaptation effect in faces. It is not known whether featural attention (attention directed to a specific aspect of the object) affects the magnitude of adaptation effects in body stimuli. Here, we manipulate the attention of Caucasian observers to different featural information in body images, by asking them to rate the fatness or sex typicality of male and female bodies manipulated to appear fatter or thinner than average. PSNs for body fatness were taken at baseline and after adaptation, and a change in PSN (ΔPSN) was calculated. A body size adaptation effect was found, with observers who viewed fat bodies showing an increased PSN, and those exposed to thin bodies showing a reduced PSN. However, manipulations of featural attention to body fatness or sex typicality produced equivalent results, suggesting that featural attention may not affect the strength of the body size aftereffect.

  20. Reversing the attention effect in figure-ground perception.

    Science.gov (United States)

    Huang, Liqiang; Pashler, Harold

    2009-10-01

    Human visual perception is sometimes ambiguous, switching between different perceptual structures, and shifts of attention sometimes favor one perceptual structure over another. It has been proposed that, in figure-ground segmentation, attention to certain regions tends to cause those regions to be perceived as closer to the observer. Here, we show that this attention effect can be reversed under certain conditions. To account for these phenomena, we propose an alternative principle: The visual system chooses the interpretation that maximizes simplicity of the attended regions.

  1. Attention Deficit Hyperactivity Disorder

    OpenAIRE

    Jaime O. Oliver

    2017-01-01

    Attention Deficit Hyperactivity Disorder (ADHD) is considered as among the most common yet serious brain disorders significant number of children are subjected to; the seriousness of which manifests in the ability of the disorder to continue to show up even after the childhood years, during the period of adolescence as well as adulthood. Considering the findings delivered by Brain Imaging Studies conducted on youth, it is revealed that people suffering from ADHD experiences del...

  2. Attention and Distraction

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2010-01-01

    This article aims to examine the interrelationship between attention and distraction in the reception of video installation art, a genre which is commonly associated with "immersion" and an intensified feeling of presence in the discourses on new media art and installation art. This tends to veil......, on the other hand, the cultural formations of television, film and computers have fundamentally re-configured "aesthetic experience."...

  3. Gaming the Attention Economy

    OpenAIRE

    Estrada, Daniel; Lawhead, Jonathan

    2013-01-01

    The future of human computation (HC) benefits from examining tasks that agents already perform and designing environments to give those tasks computational significance. We call this natural human computation (NHC). We consider the possible future of NHC through the lens of Swarm!, an application under development for Google Glass. Swarm! motivates users to compute the solutions to a class of economic optimization problems by engaging the attention dynamics of crowds. We argue that anticipati...

  4. Survey of methods for rapid spin reversal

    International Nuclear Information System (INIS)

    McKibben, J.L.

    1980-01-01

    The need for rapid spin reversal technique in polarization experiments is discussed. The ground-state atomic-beam source equipped with two rf transitions for hydrogen can be reversed rapidly, and is now in use on several accelerators. It is the optimum choice provided the accelerator can accept H + ions. At present all rapid reversal experiments using H - ions are done with Lamb-shift sources; however, this is not a unique choice. Three methods for the reversal of the spin of the atomic beam within the Lamb-shift source are discussed in order of development. Coherent intensity and perhaps focus modulation seem to be the biggest problems in both types of sources. Methods for reducing these modulations in the Lamb-shift source are discussed. The same Lamb-shift apparatus is easily modified to provide information on the atomic physics of quenching of the 2S/sub 1/2/ states versus spin orientation, and this is also discussed. 2 figures

  5. Role of Oculoproprioception in Coding the Locus of Attention.

    Science.gov (United States)

    Odoj, Bartholomaeus; Balslev, Daniela

    2016-03-01

    The most common neural representations for spatial attention encode locations retinotopically, relative to center of gaze. To keep track of visual objects across saccades or to orient toward sounds, retinotopic representations must be combined with information about the rotation of one's own eyes in the orbits. Although gaze input is critical for a correct allocation of attention, the source of this input has so far remained unidentified. Two main signals are available: corollary discharge (copy of oculomotor command) and oculoproprioception (feedback from extraocular muscles). Here we asked whether the oculoproprioceptive signal relayed from the somatosensory cortex contributes to coding the locus of attention. We used continuous theta burst stimulation (cTBS) over a human oculoproprioceptive area in the postcentral gyrus (S1EYE). S1EYE-cTBS reduces proprioceptive processing, causing ∼1° underestimation of gaze angle. Participants discriminated visual targets whose location was cued in a nonvisual modality. Throughout the visual space, S1EYE-cTBS shifted the locus of attention away from the cue by ∼1°, in the same direction and by the same magnitude as the oculoproprioceptive bias. This systematic shift cannot be attributed to visual mislocalization. Accuracy of open-loop pointing to the same visual targets, a function thought to rely mainly on the corollary discharge, was unchanged. We argue that oculoproprioception is selective for attention maps. By identifying a potential substrate for the coupling between eye and attention, this study contributes to the theoretical models for spatial attention.

  6. Scheduled evening sleep and enhanced lighting improve adaptation to night shift work in older adults.

    Science.gov (United States)

    Chinoy, Evan D; Harris, Michael P; Kim, Min Ju; Wang, Wei; Duffy, Jeanne F

    2016-12-01

    We tested whether a sleep and circadian-based treatment shown to improve circadian adaptation to night shifts and attenuate negative effects on alertness, performance and sleep in young adults would also be effective in older adults. We assessed subjective alertness, sustained attention (psychomotor vigilance task, PVT), sleep duration (actigraphy) and circadian timing (salivary dim-light melatonin onset, DLMO) in 18 older adults (57.2±3.8 years; mean±SD) in a simulated shift work protocol. 4 day shifts were followed by 3 night shifts in the laboratory. Participants slept at home and were randomised to either the treatment group (scheduled evening sleep and enhanced lighting during the latter half of night shifts) or control group (ad-lib sleep and typical lighting during night shifts). Compared with day shifts, alertness and sustained attention declined on the first night shift in both groups, and was worse in the latter half of the night shifts. Alertness and attention improved on nights 2 and 3 for the treatment group but remained lower for the control group. Sleep duration in the treatment group remained similar to baseline (6-7 hours) following night shifts, but was shorter (3-5 hours) following night shifts in the control group. Treatment group circadian timing advanced by 169.3±16.1 min (mean±SEM) but did not shift (-9.7±9.9 min) in the control group. The combined treatment of scheduled evening sleep and enhanced lighting increased sleep duration and partially aligned circadian phase with sleep and work timing, resulting in improved night shift alertness and performance. 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/.

  7. Scheduled Evening Sleep and Enhanced Lighting Improve Adaptation to Night Shift Work in Older Adults

    Science.gov (United States)

    Chinoy, Evan D.; Harris, Michael P.; Kim, Min Ju; Wang, Wei; Duffy, Jeanne F.

    2017-01-01

    Objectives We tested whether a sleep and circadian-based treatment shown to improve circadian adaptation to night shifts and attenuate negative effects on alertness, performance, and sleep in young adults would also be effective in older adults. Methods We assessed subjective alertness, sustained attention (psychomotor vigilance task, PVT), sleep duration (actigraphy), and circadian timing (salivary dim-light melatonin onset, DLMO) in eighteen older adults (57.2±3.8 y; mean±SD) in a simulated shift work protocol. Four day shifts were followed by three night shifts in the laboratory. Participants slept at home and were randomized to either the Treatment Group (scheduled evening sleep and enhanced lighting during the latter half of night shifts), or Control Group (ad lib sleep and typical lighting during night shifts). Results Compared to day shifts, alertness and sustained attention declined on the first night shift in both groups, and was worse in the latter half of the night shifts. Alertness and attention improved on nights 2 and 3 for the Treatment Group but remained lower for the Control Group. Sleep duration in the Treatment Group remained similar to baseline (6–7 h) following night shifts, but was shorter (3–5 h) following night shifts in the Control Group. Treatment Group circadian timing advanced by 169.3±16.1 min (mean±SEM) but did not shift (−9.7±9.9 min) in the Control Group. Conclusions The combined treatment of scheduled evening sleep and enhanced lighting increased sleep duration and partially aligned circadian phase with sleep and work timing, resulting in improved night shift alertness and performance. PMID:27566781

  8. The influence of attention on value integration.

    Science.gov (United States)

    Kunar, Melina A; Watson, Derrick G; Tsetsos, Konstantinos; Chater, Nick

    2017-08-01

    People often have to make decisions based on many pieces of information. Previous work has found that people are able to integrate values presented in a rapid serial visual presentation (RSVP) stream to make informed judgements on the overall stream value (Tsetsos et al. Proceedings of the National Academy of Sciences of the United States of America, 109(24), 9659-9664, 2012). It is also well known that attentional mechanisms influence how people process information. However, it is unknown how attentional factors impact value judgements of integrated material. The current study is the first of its kind to investigate whether value judgements are influenced by attentional processes when assimilating information. Experiments 1-3 examined whether the attentional salience of an item within an RSVP stream affected judgements of overall stream value. The results showed that the presence of an irrelevant high or low value salient item biased people to judge the stream as having a higher or lower overall mean value, respectively. Experiments 4-7 directly tested Tsetsos et al.'s (Proceedings of the National Academy of Sciences of the United States of America, 109(24), 9659-9664, 2012) theory examining whether extreme values in an RSVP stream become over-weighted, thereby capturing attention more than other values in the stream. The results showed that the presence of both a high (Experiments 4, 6 and 7) and a low (Experiment 5) value outlier captures attention leading to less accurate report of subsequent items in the stream. Taken together, the results showed that valuations can be influenced by attentional processes, and can lead to less accurate subjective judgements.

  9. Quantifying collective attention from tweet stream.

    Directory of Open Access Journals (Sweden)

    Kazutoshi Sasahara

    Full Text Available Online social media are increasingly facilitating our social interactions, thereby making available a massive "digital fossil" of human behavior. Discovering and quantifying distinct patterns using these data is important for studying social behavior, although the rapid time-variant nature and large volumes of these data make this task difficult and challenging. In this study, we focused on the emergence of "collective attention" on Twitter, a popular social networking service. We propose a simple method for detecting and measuring the collective attention evoked by various types of events. This method exploits the fact that tweeting activity exhibits a burst-like increase and an irregular oscillation when a particular real-world event occurs; otherwise, it follows regular circadian rhythms. The difference between regular and irregular states in the tweet stream was measured using the Jensen-Shannon divergence, which corresponds to the intensity of collective attention. We then associated irregular incidents with their corresponding events that attracted the attention and elicited responses from large numbers of people, based on the popularity and the enhancement of key terms in posted messages or "tweets." Next, we demonstrate the effectiveness of this method using a large dataset that contained approximately 490 million Japanese tweets by over 400,000 users, in which we identified 60 cases of collective attentions, including one related to the Tohoku-oki earthquake. "Retweet" networks were also investigated to understand collective attention in terms of social interactions. This simple method provides a retrospective summary of collective attention, thereby contributing to the fundamental understanding of social behavior in the digital era.

  10. Brief Report: High and Low Level Initiations of Joint Attention, and Response to Joint Attention--Differential Relationships with Language and Imitation

    Science.gov (United States)

    Pickard, Katherine E.; Ingersoll, Brooke R.

    2015-01-01

    Frequency of high-level (showing/pointing) and low-level (coordinated gaze shifts) behaviors on the Early Social Communication Scales are often used as a measure of joint attention initiations (IJA). This study examined the degree to which these skills and response to joint attention (RJA; e.g. gaze following) were differentially related to…

  11. Structural and geographic shifts in the Washington warehousing industry : transportation impacts for the Green River Valley.

    Science.gov (United States)

    2009-07-01

    Establishment level employment data indicate that the warehousing industry has experienced rapid growth and : restructuring since 1998. This restructuring has resulted in geographic shifts at the national, regional, and local scales. : Uneven growth ...

  12. Inequalities for scattering phase shifts

    International Nuclear Information System (INIS)

    Baumgartner, B.; Grosse, H.

    1985-01-01

    A recently developed method, which was used to derive bounds on energy levels, is applied to continuous spectra and gives relations between scattering phase shifts of various angular momenta. (Author)

  13. Isotope shifts in unstable nuclei

    International Nuclear Information System (INIS)

    Rebel, H.

    1980-05-01

    Current experimental investigations of isotope shifts in atomic spectra of unstable nuclei and the resulting information about size and shape of nuclei far off stability are discussed with reference to some representative examples. (orig.)

  14. Field of attention for instantaneous object recognition.

    Directory of Open Access Journals (Sweden)

    Jian-Gao Yao

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

  15. Pole shifting with constrained output feedback

    International Nuclear Information System (INIS)

    Hamel, D.; Mensah, S.; Boisvert, J.

    1984-03-01

    The concept of pole placement plays an important role in linear, multi-variable, control theory. It has received much attention since its introduction, and several pole shifting algorithms are now available. This work presents a new method which allows practical and engineering constraints such as gain limitation and controller structure to be introduced right into the pole shifting design strategy. This is achieved by formulating the pole placement problem as a constrained optimization problem. Explicit constraints (controller structure and gain limits) are defined to identify an admissible region for the feedback gain matrix. The desired pole configuration is translated into an appropriate cost function which must be closed-loop minimized. The resulting constrained optimization problem can thus be solved with optimization algorithms. The method has been implemented as an algorithmic interactive module in a computer-aided control system design package, MVPACK. The application of the method is illustrated to design controllers for an aircraft and an evaporator. The results illustrate the importance of controller structure on overall performance of a control system

  16. Attention, Predation, Counterintuition

    DEFF Research Database (Denmark)

    Clasen, Mathias

    2012-01-01

    Bram Stoker’s seminal horror novel Dracula (1897) has been subjected to a vast number of different critical readings, many of which are deeply flawed, e.g. by proceeding from defunct psychological theories. Incorporating recent advances in evolutionary social science, I offer a biocultural reading...... of Dracula to account for the novel’s impact and resilience. Dracula connected squarely with late-Victorian anxieties, but the novel also appeals to trans-historical adaptive dispositions. I analyze Stoker’s use of narrative strategies to grab and sustain attention, and Count Dracula as a supercharged...

  17. Attention: the claustrum.

    Science.gov (United States)

    Goll, Yael; Atlan, Gal; Citri, Ami

    2015-08-01

    The claustrum is a mysterious thin sheet of neurons lying between the insular cortex and the striatum. It is reciprocally connected with almost all cortical areas, including motor, somatosensory, visual, auditory, limbic, associative, and prefrontal cortices. In addition, it receives neuromodulatory input from subcortical structures. A decade ago, Sir Francis Crick and Christof Koch published an influential review proposing the claustrum as the 'seat of consciousness', spurring a revival of interest in the claustrum. We review the literature on the claustrum, emphasizing recent discoveries, and develop a detailed hypothesis describing a role for the claustrum in the segregation of attention. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  19. Attention to memory: orienting attention to sound object representations.

    Science.gov (United States)

    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.

  20. Anxiety about starting three-shift work among female workers: findings from the Female Shift Workers' Health Study.

    Science.gov (United States)

    Kubo, Tatsuhiko; Maruyama, Takashi; Shirane, Kiyoyumi; Otomo, Hajime; Matsumoto, Tetsuro; Oyama, Ichiro

    2008-03-01

    In 1999, the Japanese Law on Equal Employment Opportunity and Conditions was amended and the previous prohibition of the assignment of female workers to night work was abolished. Subsequently, the number of female shift workers has been increasing in Japan, necessitating greater attention to the health care of this population. The aim of the current study is to evaluate the relationship between anxiety expressed about starting three-shift work and background characteristics among female workers who were being assigned to three-shift work for the first time. The subjects were 38 middle-aged female workers (age range: 44 to 59 years) who were working at a chemical plant. The women completed a self-administered questionnaire before starting three-shift work. Levels of anxiety about starting three-shift work were assessed by the question 'Do you feel anxious about starting three-shift work?' The available responses were: 'Very agree', 'Considerably agree', 'Rather agree', 'Slightly agree' and 'Not agree at all', and 63% of the subjects gave one of the first two answers, which were defined as indicating anxiety. We also acquired information regarding lifestyle and occupation for each subject, including the following factors: frequency of breakfast consumption, subjective sleep insufficiency, previous experience of similar work before beginning shift work, previous experience of two-shift work, and responsibility for household duties. In the study, we found a marginally statistically significant trend association between frequent breakfast consumption and anxiety about starting three-shift work (P(trend) = 0.09). Anxiety was also high among subjects with sleep disorders, especially those suffering from subjective sleep insufficiency (P = 0.08). Due to the small study population, these results should be interpreted with caution and confirmed by future studies.

  1. Attention switching after dietary brain 5-HT challenge in high impulsive subjects.

    Science.gov (United States)

    Markus, C Rob; Jonkman, Lisa M

    2007-09-01

    High levels of impulsivity have adverse effects on performance in cognitive tasks, particularLy in those tasks that require high attention investment. Furthermore, both animal and human research has indicated that reduced brain serotonin (5-HT) function is associated with increases in impulsive behaviour or decreased inhibition ability, but the effects of 5-HT challenge have not yet been investigated in subjects vulnerable to impulsivity. The present study aimed to investigate whether subjects with high trait impulsivity perform worse than low impulsive subjects in a task switching paradigm in which they have to rapidly shift their attention between two response rules, and to investigate the influence of a 5-HT enhancing diet. Healthy subjects with high ( n = 19) and low (n = 18) trait impulsivity scores participated in a double-blind placebo-controlled study. All subjects performed the attention switch task in the morning following breakfast containing either tryptophan-rich alpha-lactalbumin (4.8 g/100 g TRP) or placebo protein (1.4 g/100 g TRP). Whereas there were no baseline differences between high and low impulsive subjects in task switching abilities, high impulsive subjects made significantly more switch errors and responded slower after dietary 5-HT stimulation, whereas no dietary effects were found on task switching performance in low-impulsive subjects. The deterioration in task switching performance induced by the 5-HT enhancing diet in high impulsive subjects was suggested to be established by general arousal/attention-reducing effects of 5-HT, which might have a larger impact in high impulsive subjects due to either different brain circuitry involved in task switching in this group or lower baseline arousal levels.

  2. Retro-cue benefits in working memory without sustained focal attention.

    Science.gov (United States)

    Rerko, Laura; Souza, Alessandra S; Oberauer, Klaus

    2014-07-01

    In working memory (WM) tasks, performance can be boosted by directing attention to one memory object: When a retro-cue in the retention interval indicates which object will be tested, responding is faster and more accurate (the retro-cue benefit). We tested whether the retro-cue benefit in WM depends on sustained attention to the cued object by inserting an attention-demanding interruption task between the retro-cue and the memory test. In the first experiment, the interruption task required participants to shift their visual attention away from the cued representation and to a visual classification task on colors. In the second and third experiments, the interruption task required participants to shift their focal attention within WM: Attention was directed away from the cued representation by probing another representation from the memory array prior to probing the cued object. The retro-cue benefit was not attenuated by shifts of perceptual attention or by shifts of attention within WM. We concluded that sustained attention is not needed to maintain the cued representation in a state of heightened accessibility.

  3. The contribution of attention in virtual moped riding training of teenagers.

    Science.gov (United States)

    Tagliabue, Mariaelena; Da Pos, Osvaldo; Spoto, Andrea; Vidotto, Giulio

    2013-08-01

    Riding a moped, like many other everyday activities, is a complex behavior in which attention plays a crucial role. This study aims to investigate the role of attention in enhancing the skills required to ride a moped simulator. Two experiments were conducted with 207 and 60 students (14-15 years old), respectively, using a moped simulator to ride on 12 different tracks. The assignment was to ride safely and avoid hazards. In experiment 1, we divided the hazard scenes of the tracks on the basis of the fact that a shift in attention was required to escape the danger. We showed that during the riding training, when no attentional shift was required, the ability to avoid hazards was constantly higher. In experiment 2, participants were asked to cope with the same basic experimental setting but with an additional attentive task. The results showed that they performed in such a way that not only did the attentive task not impair their performance, but it also produced an improvement in the ability to shift attentional focus, preserving performance efficiency. On the basis of these data, it can be claimed that, primarily, attentional shift plays a prominent role in accounting for accident circumstances. Secondarily, it can be claimed that attentional training contributes to improved processing efficiency so as to prevent mishaps. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    NARCIS (Netherlands)

    Martens, Sander; Johnson, Addie

    The attentional blink (AB) is a well-established phenomenon in the study of attention. This deficit in reporting the second of two targets presented in rapid serial visual presentation when it occurs 200-500 ms after the first is considered to reflect a fundamental limitation in attentional

  5. Decision Making under Ecological Regime Shift: An Experimental Economic Approach

    OpenAIRE

    Kawata, Yukichika

    2011-01-01

    Environmental economics postulates the assumption of homo economicus and presumes that externality occurs as a result of the rational economic activities of economic agents. This paper examines this assumption using an experimental economic approach in the context of regime shift, which has been receiving increasing attention. We observe that when externality does not exist, economic agents (subjects of experimemt) act economically rationally, but when externality exists, economic agents avoi...

  6. Shifting schedules: the health effects of reorganizing shift work.

    Science.gov (United States)

    Bambra, Clare L; Whitehead, Margaret M; Sowden, Amanda J; Akers, Joanne; Petticrew, Mark P

    2008-05-01

    Approximately one fifth of workers are engaged in some kind of shift work. The harmful effects of shift work on the health and work-life balance of employees are well known. A range of organizational interventions has been suggested to address these negative effects. This study undertook the systematic review (following Quality Of Reporting Of Meta [QUORUM] analyses guidelines) of experimental and quasi-experimental studies, from any country (in any language) that evaluated the effects on health and work-life balance of organizational-level interventions that redesign shift work schedules. Twenty-seven electronic databases (medical, social science, economic) were searched. Data extraction and quality appraisal were carried out by two independent reviewers. Narrative synthesis was performed. The review was conducted between October 2005 and November 2006. Twenty-six studies were found relating to a variety of organizational interventions. No one type of intervention was found to be consistently harmful to workers. However, three types were found to have beneficial effects on health and work-life balance: (1) switching from slow to fast rotation, (2) changing from backward to forward rotation, and (3) self-scheduling of shifts. Improvements were usually at little or no direct organizational cost. However, there were concerns about the generalizability of the evidence, and no studies reported on impacts on health inequalities. This review reinforces the findings of epidemiologic and laboratory-based research by suggesting that certain organizational-level interventions can improve the health of shift workers, their work-life balance, or both. This evidence could be useful when designing interventions to improve the experience of shift work.

  7. Does attention redirection contribute to the effectiveness of attention bias modification on social anxiety?

    Science.gov (United States)

    Yao, Nisha; Yu, Hongyu; Qian, Mingyi; Li, Songwei

    2015-12-01

    Attention bias modification (ABM) is designed to modify threat-related attention bias and thus alleviate anxiety. The current research examined whether consistently directing attention towards targeted goals per se contributes to ABM efficacy. We randomly assigned 68 non-clinical college students with elevated social anxiety to non-valence-specific attend-to-geometrics (AGC), attention modification (AMC), or attention control (ACC) conditions. We assessed subjective, behavioral, and physiological reactivity to a speech task and self-reported social anxiety symptoms. After training, participants in the AMC exhibited an attention avoidance from threat, and those in the AGC responded more rapidly toward targeted geometrics. There was a significant pre- to post-reduction in subjective speech distress across groups, but behavioral and physiological reactivity to speech, as well as self-report social anxiety symptoms, remained unchanged. These results lead to questions concerning effectiveness of ABM training for reducing social anxiety. Further examination of the current ABM protocol is required. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Selective attentional deficit in essential tremor: Evidence from the attention network test.

    Science.gov (United States)

    Pauletti, Caterina; Mannarelli, Daniela; De Lucia, Maria Caterina; Locuratolo, Nicoletta; Currà, Antonio; Missori, Paolo; Marinelli, Lucio; Fattapposta, Francesco

    2015-11-01

    The traditional view of essential tremor (ET) as a monosymptomatic and benign disorder has been reconsidered after patients with ET have been shown to experience cognitive deficits that are also related to attention. The Attention Network Test (ANT) is a rapid, widely used test to measure the efficiency of three attentional networks, i.e. alerting, orienting and executive, by evaluating reaction times (RTs) in response to visual stimuli. The aim of this study was to investigate attentional functioning in ET patients by means of the ANT. 21 non-demented patients with ET and 21 age- and sex-matched healthy controls performed the ANT. RT was significantly longer in ET patients than in controls (p attention in ET patients, probably owing to a dysfunction in the cerebello-thalamo-cortical loop. These selective attentional deficits are not related to clinical motor symptoms, contributing to shed further light on the clinical picture of ET. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Fearful, but not angry, expressions diffuse attention to peripheral targets in an attentional blink paradigm.

    Science.gov (United States)

    Taylor, James M; Whalen, Paul J

    2014-06-01

    We previously demonstrated that fearful facial expressions implicitly facilitate memory for contextual events whereas angry facial expressions do not. The current study sought to more directly address the implicit effect of fearful expressions on attention for contextual events within a classic attentional paradigm (i.e., the attentional blink) in which memory is tested on a trial-by-trial basis, thereby providing subjects with a clear, explicit attentional strategy. Neutral faces of a single gender were presented via rapid serial visual presentation (RSVP) while bordered by four gray pound signs. Participants were told to watch for a gender change within the sequence (T1). It is critical to note that the T1 face displayed a neutral, fearful, or angry expression. Subjects were then told to detect a color change (i.e., gray to green; T2) at one of the four peripheral pound sign locations appearing after T1. This T2 color change could appear at one of six temporal positions. Complementing previous attentional blink paradigms, participants were told to respond via button press immediately when a T2 target was detected. We found that, compared with the neutral T1 faces, fearful faces significantly increased target detection ability at four of the six temporal locations (all ps enhance environmental monitoring above and beyond explicit attentional effects related to task instructions.

  10. What does Attention in Neural Machine Translation Pay Attention to?

    NARCIS (Netherlands)

    Ghader, H.; Monz, C.; Kondrak, G.; Watanabe, T.

    2017-01-01

    Attention in neural machine translation provides the possibility to encode relevant parts of the source sentence at each translation step. As a result, attention is considered to be an alignment model as well. However, there is no work that specifically studies attention and provides analysis of

  11. Altering attentional control settings causes persistent biases of visual attention.

    Science.gov (United States)

    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.

  12. SAT in shift manager training

    International Nuclear Information System (INIS)

    Lecuyer, F.

    1995-01-01

    EDF has improved the organization of the operation shift teams with the replacement of shift supervisor in shift manager function. The shift manager is not only responsible for tasks associated to plant operation (production), but he is also responsible for safety of these tasks and for management of shift team members. A job analysis of this new job position has been performed in order to design the training programme. It resulted in a 10-month training programme that includes 8 weeks in safety-related topics and 12 weeks in soft-skills related topics. The safety related training courses are mandatory, the other courses are optional courses depending on individual trainee needs. The training also includes the development of management competencies. During the 10 month period, each trainee develops an individual project that is evaluated by NPP manager. As well, as group project is undertaken by the trainees and overseen by a steering committee. The steering committee participates in the evaluation process and provides operational experience feedback to the trainee groups and to the overall programme

  13. Attentional performance in children and adolescents with tic disorder and co-occurring attention-deficit/hyperactivity disorder: new insights from a 2 × 2 factorial design study.

    Science.gov (United States)

    Greimel, Ellen; Wanderer, Sina; Rothenberger, Aribert; Herpertz-Dahlmann, Beate; Konrad, Kerstin; Roessner, Veit

    2011-08-01

    The aim of the present study was to investigate the effect of both tic disorder (TD) and attention-deficit/hyperactivity disorder (ADHD) on attentional functions. N=96 children and adolescents participated in the study, including n=21 subjects with TD, n=23 subjects with ADHD, n=25 subjects with TD+ADHD, and n=27 controls. Attentional performance was tested based on four computerized attention tasks (sustained attention, divided attention, go/nogo and set shifting). The effect of TD as well as ADHD on attentional performance was tested using a 2 × 2 factorial approach. A diagnosis of TD had no negative impact on attentional functions but was associated with improved performance in the set shifting task. By contrast, regardless of a diagnosis of TD, subjects with ADHD were found to perform worse in the sustained attention, divided attention and go/nogo task. No interaction effect between the factors TD and ADHD was revealed for any of the attention measures. Our results add to findings from other areas of research, showing that in subjects with TD and ADHD, ADHD psychopathology is often the main source of impairment, whereas a diagnosis of TD has little or no impact on neuropsychological performance in most cases and even seems to be associated with adaptive mechanisms.

  14. How to detect the gravitationally induced phase shift of electromagnetic waves by optical-fiber interferometry

    International Nuclear Information System (INIS)

    Tanaka, K.

    1983-01-01

    Attention is called to a laboratory experiment of an optical-fiber interferometer which can show the gravitationally induced phase shift of optical waves. A phase shift of approx.10 -6 rad is anticipated for the Earth's gravitational potential difference of 1 m when a He-Ne laser and two multiple-turn optical-fiber loops of length 5 km are used. The phase shift can be varied by rotating the loops about an axis parallel to the Earth's surface. This order of phase shifts can be detected by current optical-fiber interferometric techniques

  15. Attention deficit hyperactivity disorder (ADHD)

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001551.htm Attention deficit hyperactivity disorder To use the sharing features on this page, please enable JavaScript. Attention deficit hyperactivity disorder (ADHD) is a problem caused by ...

  16. Finding Flicker: Critical Differences in Temporal Frequency Capture Attention

    OpenAIRE

    Cass, John; Van der Burg, Erik; Alais, David

    2011-01-01

    Rapid visual flicker is known to capture attention. Here we show slow flicker can also capture attention under reciprocal temporal conditions. Observers searched for a target line (vertical or horizontal) among tilted distractors. Distractor lines were surrounded by luminance modulating annuli, all flickering sinusoidally at 1.3 or 12.1 Hz, while the target’s annulus flickered at frequencies within this range. Search times improved with increasing target/distractor frequency differences. For ...

  17. Culture, attention, and emotion.

    Science.gov (United States)

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

    2012-02-01

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

  18. Attention and apparent motion.

    Science.gov (United States)

    Horowitz, T; Treisman, A

    1994-01-01

    Two dissociations between short- and long-range motion in visual search are reported. Previous research has shown parallel processing for short-range motion and apparently serial processing for long-range motion. This finding has been replicated and it has also been found that search for short-range targets can be impaired both by using bicontrast stimuli, and by prior adaptation to the target direction of motion. Neither factor impaired search in long-range motion displays. Adaptation actually facilitated search with long-range displays, which is attributed to response-level effects. A feature-integration account of apparent motion is proposed. In this theory, short-range motion depends on specialized motion feature detectors operating in parallel across the display, but subject to selective adaptation, whereas attention is needed to link successive elements when they appear at greater separations, or across opposite contrasts.

  19. Attentional Push: Augmenting Salience with Shared Attention Modeling

    OpenAIRE

    Gorji, Siavash; Clark, James J.

    2016-01-01

    We present a novel visual attention tracking technique based on Shared Attention modeling. Our proposed method models the viewer as a participant in the activity occurring in the scene. We go beyond image salience and instead of only computing the power of an image region to pull attention to it, we also consider the strength with which other regions of the image push attention to the region in question. We use the term Attentional Push to refer to the power of image regions to direct and man...

  20. Attention, biological motion, and action recognition.

    Science.gov (United States)

    Thompson, James; Parasuraman, Raja

    2012-01-02

    Interacting with others in the environment requires that we perceive and recognize their movements and actions. Neuroimaging and neuropsychological studies have indicated that a number of brain regions, particularly the superior temporal sulcus, are involved in a number of processes essential for action recognition, including the processing of biological motion and processing the intentions of actions. We review the behavioral and neuroimaging evidence suggesting that while some aspects of action recognition might be rapid and effective, they are not necessarily automatic. Attention is particularly important when visual information about actions is degraded or ambiguous, or if competing information is present. We present evidence indicating that neural responses associated with the processing of biological motion are strongly modulated by attention. In addition, behavioral and neuroimaging evidence shows that drawing inferences from the actions of others is attentionally demanding. The role of attention in action observation has implications for everyday social interactions and workplace applications that depend on observing, understanding and interpreting actions. Published by Elsevier Inc.

  1. Selective attention in normal and impaired hearing.

    Science.gov (United States)

    Shinn-Cunningham, Barbara G; Best, Virginia

    2008-12-01

    A common complaint among listeners with hearing loss (HL) is that they have difficulty communicating in common social settings. This article reviews how normal-hearing listeners cope in such settings, especially how they focus attention on a source of interest. Results of experiments with normal-hearing listeners suggest that the ability to selectively attend depends on the ability to analyze the acoustic scene and to form perceptual auditory objects properly. Unfortunately, sound features important for auditory object formation may not be robustly encoded in the auditory periphery of HL listeners. In turn, impaired auditory object formation may interfere with the ability to filter out competing sound sources. Peripheral degradations are also likely to reduce the salience of higher-order auditory cues such as location, pitch, and timbre, which enable normal-hearing listeners to select a desired sound source out of a sound mixture. Degraded peripheral processing is also likely to increase the time required to form auditory objects and focus selective attention so that listeners with HL lose the ability to switch attention rapidly (a skill that is particularly important when trying to participate in a lively conversation). Finally, peripheral deficits may interfere with strategies that normal-hearing listeners employ in complex acoustic settings, including the use of memory to fill in bits of the conversation that are missed. Thus, peripheral hearing deficits are likely to cause a number of interrelated problems that challenge the ability of HL listeners to communicate in social settings requiring selective attention.

  2. Does the ARFIMA really shift?

    DEFF Research Database (Denmark)

    Monache, Davide Delle; Grassi, Stefano; Santucci de Magistris, Paolo

    Short memory models contaminated by level shifts have long-memory features similar to those associated to processes generated under fractional integration. In this paper, we propose a robust testing procedure, based on an encompassing parametric specification, that allows to disentangle the level...... the highest power compared to other existing tests for spurious long-memory. Finally, we illustrate the usefulness of the proposed approach on the daily series of bipower variation and share turnover and on the monthly inflation series of G7 countries....... shift term from the ARFIMA component. The estimation is carried out via a state-space methodology and it leads to a robust estimate of the fractional integration parameter also in presence of level shifts.The Monte Carlo simulations show that this approach produces unbiased estimates of the fractional...

  3. Attentional mechanisms of social perception are biased in social phobia.

    Science.gov (United States)

    Boll, Sabrina; Bartholomaeus, Marie; Peter, Ulrike; Lupke, Ulrike; Gamer, Matthias

    2016-05-01

    Previous studies of social phobia have reported an increased vigilance to social threat cues but also an avoidance of socially relevant stimuli such as eye gaze. The primary aim of this study was to examine attentional mechanisms relevant for perceiving social cues by means of abnormalities in scanning of facial features in patients with social phobia. In two novel experimental paradigms, patients with social phobia and healthy controls matched on age, gender and education were compared regarding their gazing behavior towards facial cues. The first experiment was an emotion classification paradigm which allowed for differentiating reflexive attentional shifts from sustained attention towards diagnostically relevant facial features. In the second experiment, attentional orienting by gaze direction was assessed in a gaze-cueing paradigm in which non-predictive gaze cues shifted attention towards or away from subsequently presented targets. We found that patients as compared to controls reflexively oriented their attention more frequently towards the eyes of emotional faces in the emotion classification paradigm. This initial hypervigilance for the eye region was observed at very early attentional stages when faces were presented for 150ms, and persisted when facial stimuli were shown for 3s. Moreover, a delayed attentional orienting into the direction of eye gaze was observed in individuals with social phobia suggesting a differential time course of eye gaze processing in patients and controls. Our findings suggest that basic mechanisms of early attentional exploration of social cues are biased in social phobia and might contribute to the development and maintenance of the disorder. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Self-face Captures, Holds, and Biases Attention.

    Science.gov (United States)

    Wójcik, Michał J; Nowicka, Maria M; Kotlewska, Ilona; Nowicka, Anna

    2017-01-01

    The implicit self-recognition process may take place already in the pre-attentive stages of perception. After a silent stimulus has captured attention, it is passed on to the attentive stage where it can affect decision making and responding. Numerous studies show that the presence of self-referential information affects almost every cognitive level. These effects may share a common and fundamental basis in an attentional mechanism, conceptualized as attentional bias: the exaggerated deployment of attentional resources to a salient stimulus. A gold standard in attentional bias research is the dot-probe paradigm. In this task, a prominent stimulus (cue) and a neutral stimulus are presented in different spatial locations, followed by the presentation of a target. In the current study we aimed at investigating whether the self-face captures, holds and biases attention when presented as a task-irrelevant stimulus. In two dot-probe experiments coupled with the event-related potential (ERP) technique we analyzed the following relevant ERPs components: N2pc and SPCN which reflect attentional shifts and the maintenance of attention, respectively. An inter-stimulus interval separating face-cues and probes (800 ms) was introduced only in the first experiment. In line with our predictions, in Experiment 1 the self-face elicited the N2pc and the SPCN component. In Experiment 2 in addition to N2pc, an attentional bias was observed. Our results indicate that unintentional self-face processing disables the top-down control setting to filter out distractors, thus leading to the engagement of attentional resources and visual short-term memory.

  5. Self-face Captures, Holds, and Biases Attention

    Directory of Open Access Journals (Sweden)

    Michał J. Wójcik

    2018-01-01

    Full Text Available The implicit self-recognition process may take place already in the pre-attentive stages of perception. After a silent stimulus has captured attention, it is passed on to the attentive stage where it can affect decision making and responding. Numerous studies show that the presence of self-referential information affects almost every cognitive level. These effects may share a common and fundamental basis in an attentional mechanism, conceptualized as attentional bias: the exaggerated deployment of attentional resources to a salient stimulus. A gold standard in attentional bias research is the dot-probe paradigm. In this task, a prominent stimulus (cue and a neutral stimulus are presented in different spatial locations, followed by the presentation of a target. In the current study we aimed at investigating whether the self-face captures, holds and biases attention when presented as a task-irrelevant stimulus. In two dot-probe experiments coupled with the event-related potential (ERP technique we analyzed the following relevant ERPs components: N2pc and SPCN which reflect attentional shifts and the maintenance of attention, respectively. An inter-stimulus interval separating face-cues and probes (800 ms was introduced only in the first experiment. In line with our predictions, in Experiment 1 the self-face elicited the N2pc and the SPCN component. In Experiment 2 in addition to N2pc, an attentional bias was observed. Our results indicate that unintentional self-face processing disables the top-down control setting to filter out distractors, thus leading to the engagement of attentional resources and visual short-term memory.

  6. Fragmented perception: slower space-based but faster object-based attention in recent-onset psychosis with and without Schizophrenia.

    Directory of Open Access Journals (Sweden)

    Henderikus G O M Smid

    Full Text Available BACKGROUND: Schizophrenia is associated with impairments of the perception of objects, but how this affects higher cognitive functions, whether this impairment is already present after recent onset of psychosis, and whether it is specific for schizophrenia related psychosis, is not clear. We therefore tested the hypothesis that because schizophrenia is associated with impaired object perception, schizophrenia patients should differ in shifting attention between objects compared to healthy controls. To test this hypothesis, a task was used that allowed us to separately observe space-based and object-based covert orienting of attention. To examine whether impairment of object-based visual attention is related to higher order cognitive functions, standard neuropsychological tests were also administered. METHOD: Patients with recent onset psychosis and normal controls performed the attention task, in which space- and object-based attention shifts were induced by cue-target sequences that required reorienting of attention within an object, or reorienting attention between objects. RESULTS: Patients with and without schizophrenia showed slower than normal spatial attention shifts, but the object-based component of attention shifts in patients was smaller than normal. Schizophrenia was specifically associated with slowed right-to-left attention shifts. Reorienting speed was significantly correlated with verbal memory scores in controls, and with visual attention scores in patients, but not with speed-of-processing scores in either group. CONCLUSIONS: deficits of object-perception and spatial attention shifting are not only associated with schizophrenia, but are common to all psychosis patients. Schizophrenia patients only differed by having abnormally slow right-to-left visual field reorienting. Deficits of object-perception and spatial attention shifting are already present after recent onset of psychosis. Studies investigating visual spatial

  7. Paradigm Shifts in Ophthalmic Diagnostics.

    Science.gov (United States)

    Sebag, J; Sadun, Alfredo A; Pierce, Eric A

    2016-08-01

    Future advances in ophthalmology will see a paradigm shift in diagnostics from a focus on dysfunction and disease to better measures of psychophysical function and health. Practical methods to define genotypes will be increasingly important and non-invasive nanotechnologies are needed to detect molecular changes that predate histopathology. This is not a review nor meant to be comprehensive. Specific topics have been selected to illustrate the principles of important paradigm shifts that will influence the future of ophthalmic diagnostics. It is our impression that future evaluation of vision will go beyond visual acuity to assess ocular health in terms of psychophysical function. The definition of disease will incorporate genotype into what has historically been a phenotype-centric discipline. Non-invasive nanotechnologies will enable a paradigm shift from disease detection on a cellular level to a sub-cellular molecular level. Vision can be evaluated beyond visual acuity by measuring contrast sensitivity, color vision, and macular function, as these provide better insights into the impact of aging and disease. Distortions can be quantified and the psychophysical basis of vision can be better evaluated than in the past by designing tests that assess particular macular cell function(s). Advances in our understanding of the genetic basis of eye diseases will enable better characterization of ocular health and disease. Non-invasive nanotechnologies can assess molecular changes in the lens, vitreous, and macula that predate visible pathology. Oxygen metabolism and circulatory physiology are measurable indices of ocular health that can detect variations of physiology and early disease. This overview of paradigm shifts in ophthalmology suggests that the future will see significant improvements in ophthalmic diagnostics. The selected topics illustrate the principles of these paradigm shifts and should serve as a guide to further research and development. Indeed

  8. Chewing and Attention: A Positive Effect on Sustained Attention

    Science.gov (United States)

    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

  9. Chewing and Attention: A Positive Effect on Sustained Attention

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Hirano

    2015-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    Hirano, Yoshiyuki; Onozuka, Minoru

    2015-01-01

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

  11. Social Image Captioning: Exploring Visual Attention and User Attention.

    Science.gov (United States)

    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.

  12. Social Image Captioning: Exploring Visual Attention and User Attention

    Directory of Open Access Journals (Sweden)

    Leiquan Wang

    2018-02-01

    Full Text Available 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.

  13. Preparatory attention in visual cortex

    NARCIS (Netherlands)

    Battistoni, E.; Stein, T.; Peelen, M.V.

    Top-down attention is the mechanism that allows us to selectively process goal-relevant aspects of a scene while ignoring irrelevant aspects. A large body of research has characterized the effects of attention on neural activity evoked by a visual stimulus. However, attention also includes a

  14. Morphisms Between Sofic Shift Spaces

    DEFF Research Database (Denmark)

    Nielsen, Jan Agentoft

    The lower entropy factor problem asks for necessary and sufficient conditions for the existence of a factor map from a (mixing) sofic shift space onto another (mixing) sofic subshift of lower entropy. The problem was posed by Mike Boyle in 1984. It remains an open problem, but the present thesis...... gives a re-formulation which can be used to effectively decide the question for a larger class of sofic shifts than all previous results. In addition, the methods are used to make progress on the corresponding embedding problem which asks for necessary and sufficient conditions for the existence...

  15. Shift-Variant Multidimensional Systems.

    Science.gov (United States)

    1985-05-29

    x,y;u,v) is the system response at (x,y) to an unit impulse applied at (u,v). The presence of additive noise in the preceding input-output model of a...space model developed works very effi- ciently to deblur images affected by 2-D linear shift- varying blurs, its use, in presence of noise needs to be...causal linear shift-variant (LSV) system, whose impulse res- ponse is a K-th order degenerate sequence, a K-th order state-space model was obtained

  16. Explaining (Missing) Regulator Paradigm Shifts

    DEFF Research Database (Denmark)

    Wigger, Angela; Buch-Hansen, Hubert

    2014-01-01

    The global financial and economic crisis has prompted some scholars to suggest that a fundamental regulatory shift away from neoliberalism will take place – both in general and in the field of EU competition regulation. This paper shows that so far no radical break with the neoliberal type...... regulation after the crisis in the 1970s, the paper argues that the preconditions for a fundamental shift in this issue area are not present this time around. Several reasons account for this: the current crisis has been construed by economic and political elites as a crisis within and not of neoliberal...

  17. Attention and generalization during a conditional discrimination.

    Science.gov (United States)

    Reynolds, G S; Limpo, A J

    1969-11-01

    A conditional discrimination was established and analyzed, using four pigeons. The discrimination was among four compound stimuli projected on the response key-a white circle or triangle on a red or green background-during two conditions of illumination in the chamber, no illumination or flashing illumination. The two lighting conditions indicated whether the stimuli on the key containing triangles or those containing red would be the occasion for reinforcement. After the discrimination formed, generalization to intermediate and extreme values of the conditional stimulus and the attention of the birds to separate aspects of the stimulus on the key under each of the conditional stimuli were studied. All subjects generalized across values of the conditional stimulus, the lighting of the chamber. But subjects differed in the manner in which they treated the compound stimuli: two tended to attend to one or the other aspect of the stimulus on the key depending on the conditional stimulus, and two offered no evidence of such selective attention. Thus, the differential control of responding by the conditional stimuli cannot be attributed to a shift in attention between the figure and ground aspects of the compound stimuli.

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

    Science.gov (United States)

    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

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

    NARCIS (Netherlands)

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

    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

  20. Detecting communicative intent in a computerised test of joint attention

    Directory of Open Access Journals (Sweden)

    Nathan Caruana

    2017-01-01

    Full Text Available The successful navigation of social interactions depends on a range of cognitive faculties—including the ability to achieve joint attention with others to share information and experiences. We investigated the influence that intention monitoring processes have on gaze-following response times during joint attention. We employed a virtual reality task in which 16 healthy adults engaged in a collaborative game with a virtual partner to locate a target in a visual array. In the Search task, the virtual partner was programmed to engage in non-communicative gaze shifts in search of the target, establish eye contact, and then display a communicative gaze shift to guide the participant to the target. In the NoSearch task, the virtual partner simply established eye contact and then made a single communicative gaze shift towards the target (i.e., there were no non-communicative gaze shifts in search of the target. Thus, only the Search task required participants to monitor their partner’s communicative intent before responding to joint attention bids. We found that gaze following was significantly slower in the Search task than the NoSearch task. However, the same effect on response times was not observed when participants completed non-social control versions of the Search and NoSearch tasks, in which the avatar’s gaze was replaced by arrow cues. These data demonstrate that the intention monitoring processes involved in differentiating communicative and non-communicative gaze shifts during the Search task had a measurable influence on subsequent joint attention behaviour. The empirical and methodological implications of these findings for the fields of autism and social neuroscience will be discussed.

  1. Attention, media and fuel efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Thoenes, Stefan [Koeln Univ. (Germany). Energiewirtschaftliches Inst.; Koeln Univ. (Germany). Cologne Graduate School; Gores, Timo [Koeln Univ. (Germany). Cologne Graduate School

    2012-08-15

    This study examines attention effects in the market for hybrid vehicles. We show that local media coverage, gasoline price changes and unprecedented record gasoline prices have a significant causal impact on the consumers' attention. As attention is not directly observable, we analyze online search behavior as a proxy for the revealed consumer attention. Our study is based on weekly panel data of local newspaper coverage, gasoline prices and Google search trends for 19 metropolitan areas in the US. Additionally, we use monthly state-level panel data to show that the adoption rate of the hybrid vehicle technology is robustly related to our measure of attention.

  2. Characterizing recovery of sleep after four successive night shifts.

    Science.gov (United States)

    Kubo, Tomohide; Takahashi, Masaya; Tachi, Norihide; Takeyama, Hidemaro; Ebara, Takeshi; Inoue, Tatsuki; Takanishi, Toshimasa; Murasaki, Gen-i; Itani, Toru

    2009-10-01

    The purpose of this study was to characterize the recovery pattern of sleep following simulated, four successive night shifts in ten healthy men (22.9 + or - 3.2 yr). Poor sleep was defined as sleep efficiency of 80% or lower as determined actigraphically. The results showed that four (rapid, slow, pseudo, and incomplete) patterns of sleep recovery were observed over three recovery sleep periods. The rapid and slow recovery pattern represented immediate and slow return to baseline level prior to the nightshifts, respectively. The pseudo recovery pattern demonstrated poor sleep at the 3rd recovery sleep period, despite transient recovery at the 2nd sleep period. The incomplete recovery pattern was characterized by consistently poorer sleep during the entire recovery period. The correlation analysis indicated that sleep habits (bed time and variation of wake time) prior to the experiment were significantly related to the recovery patterns, rather than performance and alertness during the night shifts.

  3. Investigating Hemispheric Lateralization of Reflexive Attention to Gaze and Arrow Cues

    Science.gov (United States)

    Marotta, Andrea; Lupianez, Juan; Casagrande, Maria

    2012-01-01

    Recent studies have demonstrated that central cues, such as eyes and arrows, reflexively trigger attentional shifts. However, it is not clear whether the attentional mechanisms induced by these two cues are similar or rather differ in some important way. We investigated hemispheric lateralization of the orienting effects induced by the two cue…

  4. Selective Attention to a Talker's Mouth in Infancy: Role of Audiovisual Temporal Synchrony and Linguistic Experience

    Science.gov (United States)

    Hillairet de Boisferon, Anne; Tift, Amy H.; Minar, Nicholas J.; Lewkowicz, David J.

    2017-01-01

    Previous studies have found that infants shift their attention from the eyes to the mouth of a talker when they enter the canonical babbling phase after 6 months of age. Here, we investigated whether this increased attentional focus on the mouth is mediated by audio-visual synchrony and linguistic experience. To do so, we tracked eye gaze in 4-,…

  5. Leadership Shifts in Changing Field

    Science.gov (United States)

    Zubrzycki, Jaclyn

    2013-01-01

    As groups representing local and state education players struggle to remain relevant in a policy conversation often dominated by foundations, think tanks, new advocacy groups, and political and business figures, a shift in leadership has been under way at major associations. Most of the changes have come as part of the natural churn; former…

  6. Crichton's phase-shift ambiguity

    NARCIS (Netherlands)

    Atkinson, D.; Johnson, P.W.; Mehta, N.; Roo, M. de

    1973-01-01

    A re-examination of the SPD phase-shift ambiguity is made with a view to understanding certain singular features of the elastic unitarity constraint. An explicit solution of Crichton's equations is presented, and certain features of this solution are displayed graphically. In particular, it is shown

  7. Environmental Protection: a shifting focus

    NARCIS (Netherlands)

    Dr. ir. Jan Venselaar

    2004-01-01

    The last two decades have seen a fundamental change in the way chemistry handles environmental issues. A shift in focus has occurred from 'end-of-pipe' to prevention and process integration. Presently an even more fundamental change is brought about by the need for sustainable development. It is

  8. Anthropometric changes and fluid shifts

    Science.gov (United States)

    Thornton, W. E.; Hoffler, G. W.; Rummel, J. A.

    1974-01-01

    Several observations of body size, shape, posture, and configuration were made to document changes resulting from direct effects of weightlessness during the Skylab 4 mission. After the crewmen were placed in orbit, a number of anatomical and anthropometric changes occurred including a straightening of the thoracolumbar spine, a general decrease in truncal girth, and an increase in height. By the time of the earliest in-flight measurement on mission day 3, all crewmen had lost more than two liters of extravascular fluid from the calf and thigh. The puffy facies, the bird legs effect, the engorgement of upper body veins, and the reduced volume of lower body veins were all documented with photographs. Center-of-mass measurements confirmed a fluid shift cephalad. This shift remained throughout the mission until recovery, when a sharp reversal occurred; a major portion of the reversal was completed in a few hours. The anatomical changes are of considerable scientific interest and of import to the human factors design engineer, but the shifts of blood and extravascular fluid are of more consequence. It is hypothesized that the driving force for the fluid shift is the intrinsic and unopposed lower limb elasticity that forces venous blood and then other fluid cephalad.

  9. Perceptual organization and visual attention.

    Science.gov (United States)

    Kimchi, Ruth

    2009-01-01

    Perceptual organization--the processes structuring visual information into coherent units--and visual attention--the processes by which some visual information in a scene is selected--are crucial for the perception of our visual environment and to visuomotor behavior. Recent research points to important relations between attentional and organizational processes. Several studies demonstrated that perceptual organization constrains attentional selectivity, and other studies suggest that attention can also constrain perceptual organization. In this chapter I focus on two aspects of the relationship between perceptual organization and attention. The first addresses the question of whether or not perceptual organization can take place without attention. I present findings demonstrating that some forms of grouping and figure-ground segmentation can occur without attention, whereas others require controlled attentional processing, depending on the processes involved and the conditions prevailing for each process. These findings challenge the traditional view, which assumes that perceptual organization is a unitary entity that operates preattentively. The second issue addresses the question of whether perceptual organization can affect the automatic deployment of attention. I present findings showing that the mere organization of some elements in the visual field by Gestalt factors into a coherent perceptual unit (an "object"), with no abrupt onset or any other unique transient, can capture attention automatically in a stimulus-driven manner. Taken together, the findings discussed in this chapter demonstrate the multifaceted, interactive relations between perceptual organization and visual attention.

  10. The where and how of attention-based rehearsal in spatial working memory.

    Science.gov (United States)

    Postle, B R; Awh, E; Jonides, J; Smith, E E; D'Esposito, M

    2004-07-01

    Rehearsal in human spatial working memory is accomplished, in part, via covert shifts of spatial selective attention to memorized locations ("attention-based rehearsal"). We addressed two outstanding questions about attention-based rehearsal: the topography of the attention-based rehearsal effect, and the mechanism by which it operates. Using event-related fMRI and a procedure that randomized the presentation of trials with delay epochs that were either filled with a flickering checkerboard or unfilled, we localized the effect to extrastriate areas 18 and 19, and confirmed its absence in striate cortex. Delay-epoch activity in these extrastriate regions, as well as in superior parietal lobule and intraparietal sulcus, was also lateralized on unfilled trials, suggesting that attention-based rehearsal produces a baseline shift in areas representing the to-be-remembered location in space. No frontal regions (including frontal eye fields) demonstrated lateralized activity consistent with a role in attention-based rehearsal.

  11. Cognitive maps and attention.

    Science.gov (United States)

    Hardt, Oliver; Nadel, Lynn

    2009-01-01

    Cognitive map theory suggested that exploring an environment and attending to a stimulus should lead to its integration into an allocentric environmental representation. We here report that directed attention in the form of exploration serves to gather information needed to determine an optimal spatial strategy, given task demands and characteristics of the environment. Attended environmental features may integrate into spatial representations if they meet the requirements of the optimal spatial strategy: when learning involves a cognitive mapping strategy, cues with high codability (e.g., concrete objects) will be incorporated into a map, but cues with low codability (e.g., abstract paintings) will not. However, instructions encouraging map learning can lead to the incorporation of cues with low codability. On the other hand, if spatial learning is not map-based, abstract cues can and will be used to encode locations. Since exploration appears to determine what strategy to apply and whether or not to encode a cue, recognition memory for environmental features is independent of whether or not a cue is part of a spatial representation. In fact, when abstract cues were used in a way that was not map-based, or when they were not used for spatial navigation at all, they were nevertheless recognized as familiar. Thus, the relation between exploratory activity on the one hand and spatial strategy and memory on the other appears more complex than initially suggested by cognitive map theory.

  12. Attention Networks and Consciousness

    Directory of Open Access Journals (Sweden)

    Michael ePosner

    2012-03-01

    Full Text Available The term consciousness is an important one in the vernacular of the western literature in many fields. It is no wonder that scientists have assumed that consciousness will be found as a component of the human brain and that we will come to understand its neural basis. However, there is rather little in common between consciousness as the neurologist would use it to diagnose the vegetative state, how the feminist would use it to support raising male consciousness of the economic plight of women and as the philosopher would use it when defining the really hard question of the subjective state of awareness induced by sensory qualities. When faced with this kind of problem it is usual to subdivide the term into more manageable perhaps partly operational definitions. Three meanings that capture aspects of consciousness are: (1 the neurology of the state of mind allowing coherent orientation to time and place (2 the selection of sensory or memorial information for awareness and (3 the voluntary control over overt responses. In each of these cases the mechanisms of consciousness overlap with one or more of the attentional networks that have been studied with the methods of cognitive neuroscience. In this paper we explore t

  13. Dissociation of face-selective cortical responses by attention.

    Science.gov (United States)

    Furey, Maura L; Tanskanen, Topi; Beauchamp, Michael S; Avikainen, Sari; Uutela, Kimmo; Hari, Riitta; Haxby, James V

    2006-01-24

    We studied attentional modulation of cortical processing of faces and houses with functional MRI and magnetoencephalography (MEG). MEG detected an early, transient face-selective response. Directing attention to houses in "double-exposure" pictures of superimposed faces and houses strongly suppressed the characteristic, face-selective functional MRI response in the fusiform gyrus. By contrast, attention had no effect on the M170, the early, face-selective response detected with MEG. Late (>190 ms) category-related MEG responses elicited by faces and houses, however, were strongly modulated by attention. These results indicate that hemodynamic and electrophysiological measures of face-selective cortical processing complement each other. The hemodynamic signals reflect primarily late responses that can be modulated by feedback connections. By contrast, the early, face-specific M170 that was not modulated by attention likely reflects a rapid, feed-forward phase of face-selective processing.

  14. Effects of spatial and selective attention on basic multisensory integration

    DEFF Research Database (Denmark)

    Gondan, Matthias; Blurton, Steven Paul; Hughes, F.

    2011-01-01

    underlying the RSE. We investigated the role of spatial and selective attention on the RSE in audiovisual redundant signals tasks. In Experiment 1, stimuli were presented either centrally (narrow attentional focus) or at 1 of 3 unpredictable locations (wide focus). The RSE was accurately described...... task) or to central stimuli only (selective attention task). The RSE was consistent with task-specific coactivation models; accumulation of evidence, however, differed between the 2 tasks....... by a coactivation model assuming linear superposition of modality-specific activation. Effects of spatial attention were explained by a shift of the evidence criterion. In Experiment 2, stimuli were presented at 3 locations; participants had to respond either to all signals regardless of location (simple response...

  15. Attention biases visual activity in visual short-term memory.

    Science.gov (United States)

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

    2014-07-01

    In the current study, we tested whether representations in visual STM (VSTM) can be biased via top-down attentional modulation of visual activity in retinotopically specific locations. We manipulated attention using retrospective cues presented during the retention interval of a VSTM task. Retrospective cues triggered activity in a large-scale network implicated in attentional control and led to retinotopically specific modulation of activity in early visual areas V1-V4. Importantly, shifts of attention during VSTM maintenance were associated with changes in functional connectivity between pFC and retinotopic regions within V4. Our findings provide new insights into top-down control mechanisms that modulate VSTM representations for flexible and goal-directed maintenance of the most relevant memoranda.

  16. Peak load shifting control using different cold thermal energy storage facilities in commercial buildings: A review

    International Nuclear Information System (INIS)

    Sun, Yongjun; Wang, Shengwei; Xiao, Fu; Gao, Diance

    2013-01-01

    Highlights: • Little study reviews the load shifting control using different facilities. • This study reviews load shifting control using building thermal mass. • This study reviews load shifting control using thermal energy storage systems. • This study reviews load shifting control using phase change material. • Efforts for developing more applicable load shifting control are addressed. - Abstract: For decades, load shifting control, one of most effective peak demand management methods, has attracted increasing attentions from both researchers and engineers. Different load shifting control strategies have been developed when diverse cold thermal energy storage facilities are used in commercial buildings. The facilities include building thermal mass (BTM), thermal energy storage system (TES) and phase change material (PCM). Little study has systematically reviewed these load shifting control strategies and therefore this study presents a comprehensive review of peak load shifting control strategies using these thermal energy storage facilities in commercial buildings. The research and applications of the load shifting control strategies are presented and discussed. The further efforts needed for developing more applicable load shifting control strategies using the facilities are also addressed

  17. Chewing and Attention: A Positive Effect on Sustained Attention

    OpenAIRE

    Hirano, Yoshiyuki; Onozuka, Minoru

    2015-01-01

    Chewing is crushing food not only to aid swallowing and digestion, but also to help stress relief and regulate cognitive function, especially in attention. It is well known that chewing gum is used for sleepiness prevention during work, learning, and driving, suggesting a link between chewing and sustained attention. We hypothesized that chewing elevates attention and/or alertness, leading to improvements in cognitive performance. We carried out a systematic review of the PubMed database. We ...

  18. Experimental investigation of zero phase shift effects for Coriolis flowmeters due to pipe imperfections

    DEFF Research Database (Denmark)

    Enz, Stephanie; Thomsen, Jon Juel; Neumeyer, Stefan

    2011-01-01

    mass as well as temperature changes could be causes contributing to a time-varying measured zero shift, as observed with some commercial CFMs. The conducted experimental tests of the theoretically based hypotheses have shown that simple mathematical models and approximate analysis allow general......, the flexural vibrations of two bent, parallel, non-fluid-conveying pipes are studied experimentally, employing an industrial CFM. Special attention has been paid on the phase shift in the case of zero mass flow, i.e. the zero shift, caused by various imperfections to the ‘‘perfect’’ CFM, i.e. non-uniform pipe...... damping and mass, and on ambient temperature changes. Experimental observations confirm the hypothesis that asymmetry in the axial distribution of damping will induce zero shifts similar to the phase shifts due to fluid flow. Axially symmetrically distributed damping was observed to influence phase shift...

  19. Neural evidence for a distinction between short-term memory and the focus of attention

    OpenAIRE

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

    2012-01-01

    It is widely assumed that the short-term retention of information is accomplished via maintenance of an active neural trace. However, we demonstrate that memory can be preserved across a brief delay despite the apparent loss of sustained representations. Delay-period activity may in fact reflect the focus of attention, rather than short-term memory. We unconfounded attention and memory by causing external and internal shifts of attention away from items that were being actively retained. Mult...

  20. Contingent capture of involuntary visual attention interferes with detection of auditory stimuli

    OpenAIRE

    Kamke, Marc R.; Harris, Jill

    2014-01-01

    The involuntary capture of attention by salient visual stimuli can be influenced by the behavioral goals of an observer. For example, when searching for a target item, irrelevant items that possess the target-defining characteristic capture attention more strongly than items not possessing that feature. Such contingent capture involves a shift of spatial attention toward the item with the target-defining characteristic. It is not clear, however, if the associated decrements in performance for...

  1. Overnight shift work: factors contributing to diagnostic discrepancies.

    Science.gov (United States)

    Hanna, Tarek N; Loehfelm, Thomas; Khosa, Faisal; Rohatgi, Saurabh; Johnson, Jamlik-Omari

    2016-02-01

    The aims of the study are to identify factors contributing to preliminary interpretive discrepancies on overnight radiology resident shifts and apply this data in the context of known literature to draw parallels to attending overnight shift work schedules. Residents in one university-based training program provided preliminary interpretations of 18,488 overnight (11 pm–8 am) studies at a level 1 trauma center between July 1, 2013 and December 31, 2014. As part of their normal workflow and feedback, attendings scored the reports as major discrepancy, minor discrepancy, agree, and agree--good job. We retrospectively obtained the preliminary interpretation scores for each study. Total relative value units (RVUs) per shift were calculated as an indicator of overnight workload. The dataset was supplemented with information on trainee level, number of consecutive nights on night float, hour, modality, and per-shift RVU. The data were analyzed with proportional logistic regression and Fisher's exact test. There were 233 major discrepancies (1.26 %). Trainee level (senior vs. junior residents; 1.08 vs. 1.38 %; p performance. Increased workload affected more junior residents' performance, with R3 residents performing significantly worse on busier nights. Hour of the night was not significantly associated with performance, but there was a trend toward best performance at 2 am, with subsequent decreased accuracy throughout the remaining shift hours. Improved performance occurred after the first six night float shifts, presumably as residents acclimated to a night schedule. As overnight shift work schedules increase in popularity for residents and attendings, focused attention to factors impacting interpretative accuracy is warranted.

  2. Neural correlates of attention and arousal: insights from electrophysiology, functional neuroimaging and psychopharmacology.

    Science.gov (United States)

    Coull, J T

    1998-07-01

    Attention and arousal are multi-dimensional psychological processes, which interact closely with one another. The neural substrates of attention, as well as the interaction between arousal and attention, are discussed in this review. After a brief discussion of psychological and neuropsychological theories of attention, event-related potential correlates of attention are discussed. Essentially, attention acts to modulate stimulus-induced electrical potentials (N100/P100, P300, N400), rather than generating any unique potentials of its own. Functional neuroimaging studies of attentional orienting, selective attention, divided attention and sustained attention (and its inter-dependence on underlying levels of arousal) are then reviewed. A distinction is drawn between the brain areas which are crucially involved in the top-down modulation of attention (the 'sources' of attention) and those sensory-association areas whose activity is modulated by attention (the 'sites' of attentional expression). Frontal and parietal (usually right-lateralised) cortices and thalamus are most often associated with the source of attentional modulation. Also, the use of functional neuroimaging to test explicit hypotheses about psychological theories of attention is emphasised. These experimental paradigms form the basis for a 'new generation' of functional imaging studies which exploit the dynamic aspect of imaging and demonstrate how it can be used as more than just a 'brain mapping' device. Finally, a review of psychopharmacological studies in healthy human volunteers outlines the contributions of the noradrenergic, cholinergic and dopaminergic neurotransmitter systems to the neurochemical modulation of human attention and arousal. While, noradrenergic and cholinergic systems are involved in 'low-level' aspects of attention (e.g. attentional orienting), the dopaminergic system is associated with more 'executive' aspects of attention such as attentional set-shifting or working memory.

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

    Science.gov (United States)

    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.

  4. Right hemisphere dominance during spatial selective attention and target detection occurs outside the dorsal fronto-parietal network

    Science.gov (United States)

    Shulman, Gordon L.; Pope, Daniel L. W.; Astafiev, Serguei V.; McAvoy, Mark P.; Snyder, Abraham Z.; Corbetta, Maurizio

    2010-01-01

    Spatial selective attention is widely considered to be right hemisphere dominant. Previous functional magnetic resonance imaging (fMRI) studies, however, have reported bilateral blood-oxygenation-level-dependent (BOLD) responses in dorsal fronto-parietal regions during anticipatory shifts of attention to a location (Kastner et al., 1999; Corbetta et al., 2000; Hopfinger et al., 2000). Right-lateralized activity has mainly been reported in ventral fronto-parietal regions for shifts of attention to an unattended target stimulus (Arrington et al., 2000; Corbetta et al., 2000). However, clear conclusions cannot be drawn from these studies because hemispheric asymmetries were not assessed using direct voxel-wise comparisons of activity in left and right hemispheres. Here, we used this technique to measure hemispheric asymmetries during shifts of spatial attention evoked by a peripheral cue stimulus and during target detection at the cued location. Stimulus-driven shifts of spatial attention in both visual fields evoked right-hemisphere dominant activity in temporo-parietal junction (TPJ). Target detection at the attended location produced a more widespread right hemisphere dominance in frontal, parietal, and temporal cortex, including the TPJ region asymmetrically activated during shifts of spatial attention. However, hemispheric asymmetries were not observed during either shifts of attention or target detection in the dorsal fronto-parietal regions (anterior precuneus, medial intraparietal sulcus, frontal eye fields) that showed the most robust activations for shifts of attention. Therefore, right hemisphere dominance during stimulus-driven shifts of spatial attention and target detection reflects asymmetries in cortical regions that are largely distinct from the dorsal fronto-parietal network involved in the control of selective attention. PMID:20219998

  5. Rapid Prototyping Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The ARDEC Rapid Prototyping (RP) Laboratory was established in December 1992 to provide low cost RP capabilities to the ARDEC engineering community. The Stratasys,...

  6. [Burden and health effects of shift work].

    Science.gov (United States)

    Heitmann, Jörg

    2010-10-01

    In Germany aprox. 15% of all employees have irregular or flexible working hours. Disturbed sleep and/or hypersomnia are direct consequences of shift work and therefore described as shift work disorder. Beyond this, shift work can also be associated with specific pathological disorders. There are individual differences in tolerance to shift work. Optimization of both shift schedules and sleep to "non-physiological" times of the day are measures to counteract the negative effects of shift work. There is still not enough evidence to recommend drugs for routine use in shift workers. © Georg Thieme Verlag Stuttgart · New York.

  7. Attention in a bayesian framework

    DEFF Research Database (Denmark)

    Whiteley, Louise Emma; Sahani, Maneesh

    2012-01-01

    , and include both selective phenomena, where attention is invoked by cues that point to particular stimuli, and integrative phenomena, where attention is invoked dynamically by endogenous processing. However, most previous Bayesian accounts of attention have focused on describing relatively simple experimental...... selective and integrative roles, and thus cannot be easily extended to complex environments. We suggest that the resource bottleneck stems from the computational intractability of exact perceptual inference in complex settings, and that attention reflects an evolved mechanism for approximate inference which...... can be shaped to refine the local accuracy of perception. We show that this approach extends the simple picture of attention as prior, so as to provide a unified and computationally driven account of both selective and integrative attentional phenomena....

  8. Special training of shift personnel

    International Nuclear Information System (INIS)

    Martin, H.D.

    1981-01-01

    The first step of on-the-job training is practical observation phase in an operating Nuclear Plant, where the participants are assigned to shift work. The simulator training for operating personnel, for key personnel and, to some extent, also for maintenance personnel and specialists give the practical feeling for Nuclear Power Plant behaviour during normal and abnormal conditions. During the commissioning phase of the own Nuclear Power Plant, which is the most important practical training, the participants are integrated into the commissioning staff and assisted during their process of practical learning by special instructors. The preparation for the licensing exams is vitally important for shift personnel and special courses are provided after the first non-nuclear trial operation of the plant. Personnel training also includes performance of programmes and material for retraining, training of instructors and assistance in building up special training programmes and material as well as training centers. (orig./RW)

  9. Shift work as an oxidative stressor

    OpenAIRE

    Pasalar Parvin; Farahani Saeed; Sharifian Akbar; Gharavi Marjan; Aminian Omid

    2005-01-01

    Abstract Background Some medical disorders have higher prevalence in shift workers than others. This study was designed to evaluate the effect of night-shift-working on total plasma antioxidant capacity, with respect to the causative role of oxidative stress in induction of some of these disorders. Methods Two blood samples were taken from 44 workers with a rotational shift schedule, one after their day shift and one after their night shift. The total plasma antioxidant capacity of each worke...

  10. Perihelium shifts in central potentials

    International Nuclear Information System (INIS)

    Amorim, A.E.A.; Ferreira, P.L.

    1987-01-01

    Motivated by the rigorous results on level ordering for arbitrary central potentials recently derived in the literature a classical treatment of the perihelium shifts is presented, based on the consideration of those orbits which lie in the vicinity of a circular orbit. The role played by the Laplacian of the potential is emphasized. By the same approach Bertrand's theorem is also discussed, in connection with Arnold's proof. (Author) [pt

  11. Multicolor Holography With Phase Shifting

    Science.gov (United States)

    Vikram, Chandra S.

    1996-01-01

    Prototype apparatus constructed to test feasibility of two-color holographic interferometric scheme in which data for reconstructing holographic wavefront obtained with help of phase-shifting technique. Provides two sets of data needed to solve equations for effects of temperature and concentration. Concept extended to holography at three or more wavelengths to measure three or more phenomena associated with significant variations in index of refraction

  12. Advertising, Attention, and Financial Markets

    OpenAIRE

    Focke, Florens; Ruenzi, Stefan; Ungeheuer, Michael

    2015-01-01

    We investigate the impact of product market advertising on investor attention and financial market outcomes. Using daily advertising data allows us to identify short-term effects of advertising. We measure daily investor attention based the company's number of Wikipedia page views. We show that TV and newspaper advertising positively impacts short-term investor attention. It also positively impacts turnover and liquidity, but the effects are not economically significant. Most importantly, ass...

  13. Measuring the amplification of attention

    OpenAIRE

    Blaser, Erik; Sperling, George; Lu, Zhong-Lin

    1999-01-01

    An ambiguous motion paradigm, in which the direction of apparent motion is determined by salience (i.e., the extent to which an area is perceived as figure versus ground), is used to assay the amplification of color by attention to color. In the red–green colored gratings used in these experiments, without attention instructions, salience depends on the chromaticity difference between colored stripes embedded in the motion sequence and the yellow background. Selective attention to red (or to ...

  14. Shift Work and Endocrine Disorders

    Directory of Open Access Journals (Sweden)

    M. A. Ulhôa

    2015-01-01

    Full Text Available The objective of this review was to investigate the impact of shift and night work on metabolic processes and the role of alterations in the sleep-wake cycle and feeding times and environmental changes in the occurrence of metabolic disorders. The literature review was performed by searching three electronic databases for relevant studies published in the last 10 years. The methodological quality of each study was assessed, and best-evidence synthesis was applied to draw conclusions. The literature has shown changes in concentrations of melatonin, cortisol, ghrelin, and leptin among shift workers. Melatonin has been implicated for its role in the synthesis and action of insulin. The action of this hormone also regulates the expression of transporter glucose type 4 or triggers phosphorylation of the insulin receptor. Therefore, a reduction in melatonin can be associated with an increase in insulin resistance and a propensity for the development of diabetes. Moreover, shift work can negatively affect sleep and contribute to sedentarism, unhealthy eating habits, and stress. Recent studies on metabolic processes have increasingly revealed their complexity. Physiological changes induced in workers who invert their activity-rest cycle to fulfill work hours include disruptions in metabolic processes.

  15. PSYCHE Pure Shift NMR Spectroscopy.

    Science.gov (United States)

    Foroozandeh, Mohammadali; Morris, Gareth; Nilsson, Mathias

    2018-03-13

    Broadband homodecoupling techniques in NMR, also known as "pure shift" methods, aim to enhance spectral resolution by suppressing the effects of homonuclear coupling interactions to turn multiplet signals into singlets. Such techniques typically work by selecting a subset of "active" nuclear spins to observe, and selectively inverting the remaining, "passive", spins to reverse the effects of coupling. Pure Shift Yielded by Chirp Excitation (PSYCHE) is one such method; it is relatively recent, but has already been successfully implemented in a range of different NMR experiments. Paradoxically, PSYCHE is one of the trickiest of pure shift NMR techniques to understand but one of the easiest to use. Here we offer some insights into theoretical and practical aspects of the method, and into the effects and importance of the experimental parameters. Some recent improvements that enhance the spectral purity of PSYCHE spectra will be presented, and some experimental frameworks including examples in 1D and 2D NMR spectroscopy, for the implementation of PSYCHE will be introduced. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Preparatory attention in visual cortex.

    Science.gov (United States)

    Battistoni, Elisa; Stein, Timo; Peelen, Marius V

    2017-05-01

    Top-down attention is the mechanism that allows us to selectively process goal-relevant aspects of a scene while ignoring irrelevant aspects. A large body of research has characterized the effects of attention on neural activity evoked by a visual stimulus. However, attention also includes a preparatory phase before stimulus onset in which the attended dimension is internally represented. Here, we review neurophysiological, functional magnetic resonance imaging, magnetoencephalography, electroencephalography, and transcranial magnetic stimulation (TMS) studies investigating the neural basis of preparatory attention, both when attention is directed to a location in space and when it is directed to nonspatial stimulus attributes (content-based attention) ranging from low-level features to object categories. Results show that both spatial and content-based attention lead to increased baseline activity in neural populations that selectively code for the attended attribute. TMS studies provide evidence that this preparatory activity is causally related to subsequent attentional selection and behavioral performance. Attention thus acts by preactivating selective neurons in the visual cortex before stimulus onset. This appears to be a general mechanism that can operate on multiple levels of representation. We discuss the functional relevance of this mechanism, its limitations, and its relation to working memory, imagery, and expectation. We conclude by outlining open questions and future directions. © 2017 New York Academy of Sciences.

  17. Attentional networks in developmental dyscalculia

    Directory of Open Access Journals (Sweden)

    Henik Avishai

    2010-01-01

    Full Text Available Abstract Background Very little is known about attention deficits in developmental dyscalculia, hence, this study was designed to provide the missing information. We examined attention abilities of participants suffering from developmental dyscalculia using the attention networks test - interactions. This test was designed to examine three different attention networks--executive function, orienting and alerting--and the interactions between them. Methods Fourteen university students that were diagnosed as suffering from developmental dyscalculia--intelligence and reading abilities in the normal range and no indication of attention-deficit hyperactivity disorder--and 14 matched controls were tested using the attention networks test - interactions. All participants were given preliminary tests to measure mathematical abilities, reading, attention and intelligence. Results The results revealed deficits in the alerting network--a larger alerting effect--and in the executive function networks--a larger congruity effect in developmental dyscalculia participants. The interaction between the alerting and executive function networks was also modulated by group. In addition, developmental dyscalculia participants were slower to respond in the non-cued conditions. Conclusions These results imply specific attentional deficits in pure developmental dyscalculia. Namely, those with developmental dyscalculia seem to be deficient in the executive function and alertness networks. They suffer from difficulty in recruiting attention, in addition to the deficits in numerical processing.

  18. Attentional networks in developmental dyscalculia.

    Science.gov (United States)

    Askenazi, Sarit; Henik, Avishai

    2010-01-07

    Very little is known about attention deficits in developmental dyscalculia, hence, this study was designed to provide the missing information. We examined attention abilities of participants suffering from developmental dyscalculia using the attention networks test - interactions. This test was designed to examine three different attention networks--executive function, orienting and alerting--and the interactions between them. Fourteen university students that were diagnosed as suffering from developmental dyscalculia--intelligence and reading abilities in the normal range and no indication of attention-deficit hyperactivity disorder--and 14 matched controls were tested using the attention networks test-interactions. All participants were given preliminary tests to measure mathematical abilities, reading, attention and intelligence. The results revealed deficits in the alerting network--a larger alerting effect--and in the executive function networks--a larger congruity effect in developmental dyscalculia participants. The interaction between the alerting and executive function networks was also modulated by group. In addition, developmental dyscalculia participants were slower to respond in the non-cued conditions. These results imply specific attentional deficits in pure developmental dyscalculia. Namely, those with developmental dyscalculia seem to be deficient in the executive function and alertness networks. They suffer from difficulty in recruiting attention, in addition to the deficits in numerical processing.

  19. Laparoscopic Skills and Cognitive Function are not Affected in Surgeons During a Night Shift

    DEFF Research Database (Denmark)

    Amirian, Ilda; Andersen, Lærke T; Rosenberg, Jacob

    2014-01-01

    OBJECTIVE: To monitor surgeons' performance and cognition during night shifts. DESIGN: Surgeons were monitored before call and on call (17-hour shift). Psychomotor performance was assessed by laparoscopic simulation and cognition by the d2 test of attention. The surgeons performed the laparoscopi...... compared with on-call values. The d2 test of attention showed significantly improved values on call compared with before call. CONCLUSION: Sleep deprivation during a 17-hour night shift did not impair surgeons' psychomotor or cognitive performance....... simulation and the d2 test of attention at 8 a.m. before call and at 4 a.m. on call. Sleep was measured by wrist actigraphy and sleepiness by the Karolinska sleepiness scale. SETTING: Department of Surgery at Herlev Hospital, Denmark. PARTICIPANTS: Overall, 30 interns, residents, and attending surgeons were...

  20. Prevalence of myopic shifts among patients seeking cataract surgery

    Directory of Open Access Journals (Sweden)

    Rafael Iribarren

    2013-06-01

    Full Text Available Modern cataract surgery by phacoemulsification is a widely accepted procedure with a rapid recovery time. The prescription of specific intraocular lens, implanted during surgery, makes it possible to anticipate whether the patient will need reading glasses after the procedure. The present study analyses a sample of cataract surgery patients to show the frequency of myopic shifts related to nuclear opacity, which can result in clear near vision before surgery. A non-selected sample of consecutive patients who underwent elective cataract surgery in a private clinic was studied retrospectively. The myopic shift in refraction was assessed by comparing the old prescription with the spectacle correction at the time of interviewing.The mean age of the 229 subjects studied was 71.5 ± 10.4 years (109, 47.6%, males. A myopic shift in refraction, defined as at least - 0.5 diopters, was present in 37.1% of subjects (95% CI: 30.8%-43.4%. The mean change in refraction in these subjects was -2.52 ± 1.52 diopters. The percentage of subjects who had developed a myopic shift was significantly greater in those who presented greater nuclear opalescence. There were also differences in the mean myopic shift by refractive group, with the emmetropes having the greatest myopic shift. In this study of patients seeking cataract surgery in a clinical setting, more than one third had myopic shifts in refraction. This must be taken into account in order that patients maintain the benefit of clear near vision after surgery.

  1. Changes in nurses' decision making during a 12-h day shift.

    Science.gov (United States)

    McClelland, L E; Switzer, F S; Pilcher, J J

    2013-01-01

    Although shift work is necessary in many health-care settings, research suggests that it can have detrimental effects on performance in health-care providers. To determine if a change in decision-making occurred across a 12-h day shift in a sample of registered nurses. The participants were nurses working a 12-h day shift (7 a.m.-7 p.m.) at a large hospital in the south-eastern USA. Participants completed a policy-capturing questionnaire, examining their likelihood of calling a physician in response to specific patient symptoms, at the beginning and end of the shift. They also completed self-report surveys on alertness, stress and sleepiness. Sixty-five nurses completed the study, an overall response rate of 41%. Participants significantly changed their decision-making policies from the beginning to the end of the work shift and also became significantly less alert and more stressed. However, there was no correlation between decision-making and reported alertness and stress. These results suggest that medical judgment in registered nurses changed from the beginning to the end of a 12-h day shift. One possible underlying mechanism responsible for the changes seen across the shift could be the ability to maintain attention, as suggested by the Controlled Attention Model. The current results expand upon previous research, indicating there are a variety of negative outcomes associated with shift work.

  2. Perisaccadic Updating of Visual Representations and Attentional States: Linking Behavior and Neurophysiology

    Science.gov (United States)

    Marino, Alexandria C.; Mazer, James A.

    2016-01-01

    During natural vision, saccadic eye movements lead to frequent retinal image changes that result in different neuronal subpopulations representing the same visual feature across fixations. Despite these potentially disruptive changes to the neural representation, our visual percept is remarkably stable. Visual receptive field remapping, characterized as an anticipatory shift in the position of a neuron’s spatial receptive field immediately before saccades, has been proposed as one possible neural substrate for visual stability. Many of the specific properties of remapping, e.g., the exact direction of remapping relative to the saccade vector and the precise mechanisms by which remapping could instantiate stability, remain a matter of debate. Recent studies have also shown that visual attention, like perception itself, can be sustained across saccades, suggesting that the attentional control system can also compensate for eye movements. Classical remapping could have an attentional component, or there could be a distinct attentional analog of visual remapping. At this time we do not yet fully understand how the stability of attentional representations relates to perisaccadic receptive field shifts. In this review, we develop a vocabulary for discussing perisaccadic shifts in receptive field location and perisaccadic shifts of attentional focus, review and synthesize behavioral and neurophysiological studies of perisaccadic perception and perisaccadic attention, and identify open questions that remain to be experimentally addressed. PMID:26903820

  3. Serotonergic neurotransmission and lapses of attention in children and adolescents with attention deficit hyperactivity disorder: availability of tryptophan influences attentional performance.

    Science.gov (United States)

    Zepf, Florian D; Gaber, Tilman J; Baurmann, David; Bubenzer, Sarah; Konrad, Kerstin; Herpertz-Dahlmann, Beate; Stadler, Christina; Poustka, Fritz; Wöckel, Lars

    2010-08-01

    Deficiencies in serotonergic (5-HT) neurotransmission have frequently been linked to altered attention and memory processes. With attention deficit hyperactivity disorder (ADHD) being associated with impaired attention and working memory, this study investigated the effects of a diminished 5-HT turnover achieved by rapid tryptophan depletion (RTD) on attentional performance in children and adolescents with ADHD. Twenty-two male patients with ADHD (aged 9-15 yr) received the RTD procedure Moja-De and a tryptophan (Trp)-balanced placebo (Pla) in a randomized, double-blind, within-subject crossover design on two separate study days. Lapses of attention (LA) and phasic alertness (PA) were assessed within the test battery for attentional performance under depleted and sham-depleted conditions 120 (T1), 220 (T2) and 300 (T3) min after intake of RTD/Pla. At T1 there was a significant main effect for RTD, indicating more LA under intake of a Trp-balanced Pla compared to diminished 5-HT neurotransmission. For T2/T3 there were no such effects. PA was not affected by the factors RTD/Pla and time. Interactions of 5-HT with other neurotransmitters as possible underlying neurochemical processes could be subject to further investigations involving healthy controls as regards altered attentional performance in children and adolescents.

  4. Rapid Tooling via Stereolithography

    OpenAIRE

    Montgomery, Eva

    2006-01-01

    Approximately three years ago, composite stereolithography (SL) resins were introduced to the marketplace, offering performance features beyond what traditional SL resins could offer. In particular, the high heat deflection temperatures and high stiffness of these highly filled resins have opened the door to several new rapid prototyping (RP) applications, including wind tunnel test modelling and, more recently, rapid tooling.

  5. Shifting from manual to automatic gear when growing old : Good advice? Results from a driving simulator study

    NARCIS (Netherlands)

    Piersma, Dafne; de Waard, Dick; de Waard, D; Brookhuis, K; Wiczorek, R; di Nocera, F; Brouwer, R; Barham, P; Weikert, C; Kluge, A; Gerbino, W; Toffetti, A

    2014-01-01

    Older people may be advised to switch from manual to automatic gear shifting, because they may have difficulties with dividing their attention between gear shifting and other driving tasks such as perceiving other traffic participants. The question is whether older drivers show a better driving

  6. Eye and head movements shape gaze shifts in Indian peafowl.

    Science.gov (United States)

    Yorzinski, Jessica L; Patricelli, Gail L; Platt, Michael L; Land, Michael F

    2015-12-01

    Animals selectively direct their visual attention toward relevant aspects of their environments. They can shift their attention using a combination of eye, head and body movements. While we have a growing understanding of eye and head movements in mammals, we know little about these processes in birds. We therefore measured the eye and head movements of freely behaving Indian peafowl (Pavo cristatus) using a telemetric eye-tracker. Both eye and head movements contributed to gaze changes in peafowl. When gaze shifts were smaller, eye movements played a larger role than when gaze shifts were larger. The duration and velocity of eye and head movements were positively related to the size of the eye and head movements, respectively. In addition, the coordination of eye and head movements in peafowl differed from that in mammals; peafowl exhibited a near-absence of the vestibulo-ocular reflex, which may partly result from the peafowl's ability to move their heads as quickly as their eyes. © 2015. Published by The Company of Biologists Ltd.

  7. Rapid improvement teams.

    Science.gov (United States)

    Alemi, F; Moore, S; Headrick, L; Neuhauser, D; Hekelman, F; Kizys, N

    1998-03-01

    Suggestions, most of which are supported by empirical studies, are provided on how total quality management (TQM) teams can be used to bring about faster organizationwide improvements. Ideas are offered on how to identify the right problem, have rapid meetings, plan rapidly, collect data rapidly, and make rapid whole-system changes. Suggestions for identifying the right problem include (1) postpone benchmarking when problems are obvious, (2) define the problem in terms of customer experience so as not to blame employees nor embed a solution in the problem statement, (3) communicate with the rest of the organization from the start, (4) state the problem from different perspectives, and (5) break large problems into smaller units. Suggestions for having rapid meetings include (1) choose a nonparticipating facilitator to expedite meetings, (2) meet with each team member before the team meeting, (3) postpone evaluation of ideas, and (4) rethink conclusions of a meeting before acting on them. Suggestions for rapid planning include reducing time spent on flowcharting by focusing on the future, not the present. Suggestions for rapid data collection include (1) sample patients for surveys, (2) rely on numerical estimates by process owners, and (3) plan for rapid data collection. Suggestions for rapid organizationwide implementation include (1) change membership on cross-functional teams, (2) get outside perspectives, (3) use unfolding storyboards, and (4) go beyond self-interest to motivate lasting change in the organization. Additional empirical investigations of time saved as a consequence of the strategies provided are needed. If organizations solve their problems rapidly, fewer unresolved problems may remain.

  8. Temporal attention for visual food stimuli in restrained eaters.

    Science.gov (United States)

    Neimeijer, Renate A M; de Jong, Peter J; Roefs, Anne

    2013-05-01

    Although restrained eaters try to limit their food intake, they often fail and indulge in exactly those foods that they want to avoid. A possible explanation is a temporal attentional bias for food cues. It could be that for these people food stimuli are processed relatively efficiently and require less attentional resources to enter awareness. Once a food stimulus has captured attention, it may be preferentially processed and granted prioritized access to limited cognitive resources. This might help explain why restrained eaters often fail in their attempts to restrict their food intake. A Rapid Serial Visual Presentation task consisting of dual and single target trials with food and neutral pictures as targets and/or distractors was administered to restrained (n=40) and unrestrained (n=40) eaters to study temporal attentional bias. Results indicated that (1) food cues did not diminish the attentional blink in restrained eaters when presented as second target; (2) specifically restrained eaters showed an interference effect of identifying food targets on the identification of preceding neutral targets; (3) for both restrained and unrestrained eaters, food cues enhanced the attentional blink; (4) specifically in restrained eaters, food distractors elicited an attention blink in the single target trials. In restrained eaters, food cues get prioritized access to limited cognitive resources, even if this processing priority interferes with their current goals. This temporal attentional bias for food stimuli might help explain why restrained eaters typically have difficulties maintaining their diet rules. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Losing the left side of the world: rightward shift in human spatial attention with sleep onset.

    Science.gov (United States)

    Bareham, Corinne A; Manly, Tom; Pustovaya, Olga V; Scott, Sophie K; Bekinschtein, Tristan A

    2014-05-28

    Unilateral brain damage can lead to a striking deficit in awareness of stimuli on one side of space called Spatial Neglect. Patient studies show that neglect of the left is markedly more persistent than of the right and that its severity increases under states of low alertness. There have been suggestions that this alertness-spatial awareness link may be detectable in the general population. Here, healthy human volunteers performed an auditory spatial localisation task whilst transitioning in and out of sleep. We show, using independent electroencephalographic measures, that normal drowsiness is linked with a remarkable unidirectional tendency to mislocate left-sided stimuli to the right. The effect may form a useful healthy model of neglect and help in understanding why leftward inattention is disproportionately persistent after brain injury. The results also cast light on marked changes in conscious experience before full sleep onset.

  10. Shifting Attention Back to Students within the Sheltered Instruction Observation Protocol

    Science.gov (United States)

    Daniel, Shannon M.; Conlin, Luke

    2015-01-01

    The Sheltered Instruction Observation Protocol (SIOP) is increasingly used as an instructional framework to help elementary and secondary teachers support English language learners (ELLs). This useful tool has helped teachers gain the knowledge, skills, and dispositions they need to support ELLs learn subject-area content and skills while learning…

  11. Covert Shifts of Attention Function as an Implicit Aid to Insight

    Science.gov (United States)

    Thomas, Laura E.; Lleras, Alejandro

    2009-01-01

    Previous research shows that directed actions can unconsciously influence higher-order cognitive processing, helping learners to retain knowledge and guiding problem solvers to useful insights (e.g. Cook, S. W., Mitchell, Z., & Goldin-Meadow, S. (2008). Gesturing makes learning last. "Cognition," 106, 1047-1058; Thomas, L. E., & Lleras, A. (2007).…

  12. Functional_Category Shift, with particular attention to Classifying, Qualifying and Localizing Modifiers in the NP

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    of relational adjectives (with the possible exception of e.g. ethnic adjectives), which provides support for the idea that the different modifier functions of a relational adjective are not due to a gradual, diachronic change (Heynderickx 2001). Selected references    Croft, W. 1990. A conceptual framework...

  13. Rightward shift in temporal order judgements in the wake of the attentional blink

    Directory of Open Access Journals (Sweden)

    Mitchell Valdés-Sosa

    2008-01-01

    Full Text Available Cambio hacia la derecha en los juicios de orden temporal durante el parpadeo atencional. El orden temporal de dos eventos, cada uno de ellos presentado en un hemicampo visual diferente, puede ser juzgado correctamente por observadores típicos inclusive cuando la diferencia de tiempo entre las presentaciones sea muy pequeña. El presente trabajo analiza la influencia de un proceso endógeno sobre el juicio de orden temporal (JOT y nos muestra que la percepción del orden temporal está también afectada cuando los recursos atencionales disponibles son reducidos mediante un paradigma de parpadeo atencional (PA. A los participantes se les presentaron los siguientes estímulos: un primer estímulo visual (T1 en el centro de fijación y luego de un intervalo de tiempo variable (280 ó 1030 ms, un par de estímulos lateralizados (T2. Para la tarea dual con el intervalo de tiempo de 280 ms entre T1 y T2, la precisión en el JOT se deterioró, evidenciando un PA. Sin embargo, durante el PA en lugar de la asimetría favorable al lado izquierdo, aparece un significativo sesgo en contra de ese lado.

  14. Roles of Attention Shifting and Inhibitory Control in Fourth-Grade Reading Comprehension

    Science.gov (United States)

    Kieffer, Michael J.; Vukovic, Rose K.; Berry, Daniel

    2013-01-01

    Executive functioning (EF) refers to a set of higher order, core cognitive processes that facilitate planning, problem solving, and the initiation and maintenance of goal-directed behavior. Although recent research has established the importance of EF for word reading development in early childhood, few studies have investigated the role of EF in…

  15. A shift in perspective: Decentering through mindful attention to imagined stressful events

    NARCIS (Netherlands)

    Lebois, Lauren A M; Papies, Esther K; Gopinath, Kaundinya; Cabanban, Romeo; Quigley, Karen S; Krishnamurthy, Venkatagiri; Barrett, Lisa Feldman; Barsalou, Lawrence W

    Ruminative thoughts about a stressful event can seem subjectively real, as if the imagined event were happening in the moment. One possibility is that this subjective realism results from simulating the self as engaged in the stressful event (immersion). If so, then the process of

  16. Recurrent competition explains temporal effects of attention in MSTd

    Science.gov (United States)

    Layton, Oliver W.; Browning, N. Andrew

    2012-01-01

    Navigation in a static environment along straight paths without eye movements produces radial optic flow fields. A singularity called the focus of expansion (FoE) specifies the direction of travel (heading) of the observer. Cells in primate dorsal medial superior temporal area (MSTd) respond to radial fields and are therefore thought to be heading-sensitive. Humans frequently shift their focus of attention while navigating, for example, depending on the favorable or threatening context of approaching independently moving objects. Recent neurophysiological studies show that the spatial tuning curves of primate MSTd neurons change based on the difference in visual angle between an attentional prime and the FoE. Moreover, the peak mean population activity in MSTd retreats linearly in time as the distance between the attentional prime and FoE increases. We present a dynamical neural circuit model that demonstrates the same linear temporal peak shift observed electrophysiologically. The model qualitatively matches the neuron tuning curves and population activation profiles. After model MT dynamically pools short-range motion, model MSTd incorporates recurrent competition between units tuned to different radial optic flow templates, and integrates attentional signals from model area frontal eye fields (FEF). In the model, population activity peaks occur when the recurrent competition is most active and uncertainty is greatest about the relative position of the FoE. The nature of attention, multiplicative or non-multiplicative, is largely irrelevant, so long as attention has a Gaussian-like profile. Using an appropriately tuned sigmoidal signal function to modulate recurrent feedback affords qualitative fits of deflections in the population activity that otherwise appear to be low-frequency noise. We predict that these deflections mark changes in the balance of attention between the priming and FoE locations. PMID:23060788

  17. Orienting attention modulates pain perception: an ERP study.

    Directory of Open Access Journals (Sweden)

    Sam C C Chan

    Full Text Available INTRODUCTION: Research has shown that people with chronic pain have difficulty directing their attention away from pain. A mental strategy that incorporates focused attention and distraction has been found to modulate the perception of pain intensity. That strategy involves placing attention on the nociceptive stimulus felt and shifting attention to a self-generated sub-nociceptive image and rehearsing it. Event-related potential was used to study the possible processes associated with the focus-then-orient strategy. METHODS: Eighteen pain-free participants received different levels of 50-ms nociceptive stimulations elicited by electric shocks at the right lateral malleolus (ankle. In perception trials, participants maintained the perceived nociceptive stimulus in working memory for 3,000 ms. In imagery trials, participants mentally generated and maintained the corresponding sub-nociceptive image they had learned previously. After both types of trials, participants evaluated the pain intensity of the incoming stimulus by recalling the feeling of the nociceptive stimulation at the beginning of the trial. RESULTS: Shifting attention from the incoming nociceptive to a self-generated sub-nociceptive image elicited central P2 and centro-parietal P3 waves, which were found to correlate with proportional scores on the Stroop Test. They were followed by a frontal N400 and a parietal P600, denoting generation of sub-nociceptive images in working memory. The voltages elicited in these potentials correlated moderately with attenuation of the pain ratings of the recalled nociceptive stimulations. CONCLUSIONS: Focus-and-orient attention across nociceptive and sub-nociceptive images appears to be related to response inhibition. Mental rehearsal of the sub-nociceptive images was found to modulate the perception of the nociceptive sensation felt prior to the imagery. Such modulation seems to be mediated by generating and maintaining sub-nociceptive images in

  18. Orienting Attention Modulates Pain Perception: An ERP Study

    Science.gov (United States)

    Chan, Sam C. C.; Chan, Chetwyn C. H.; Kwan, Anne S. K.; Ting, Kin-hung; Chui, Tak-yi

    2012-01-01

    Introduction Research has shown that people with chronic pain have difficulty directing their attention away from pain. A mental strategy that incorporates focused attention and distraction has been found to modulate the perception of pain intensity. That strategy involves placing attention on the nociceptive stimulus felt and shifting attention to a self-generated sub-nociceptive image and rehearsing it. Event-related potential was used to study the possible processes associated with the focus-then-orient strategy. Methods Eighteen pain-free participants received different levels of 50-ms nociceptive stimulations elicited by electric shocks at the right lateral malleolus (ankle). In perception trials, participants maintained the perceived nociceptive stimulus in working memory for 3,000 ms. In imagery trials, participants mentally generated and maintained the corresponding sub-nociceptive image they had learned previously. After both types of trials, participants evaluated the pain intensity of the incoming stimulus by recalling the feeling of the nociceptive stimulation at the beginning of the trial. Results Shifting attention from the incoming nociceptive to a self-generated sub-nociceptive image elicited central P2 and centro-parietal P3 waves, which were found to correlate with proportional scores on the Stroop Test. They were followed by a frontal N400 and a parietal P600, denoting generation of sub-nociceptive images in working memory. The voltages elicited in these potentials correlated moderately with attenuation of the pain ratings of the recalled nociceptive stimulations. Conclusions Focus-and-orient attention across nociceptive and sub-nociceptive images appears to be related to response inhibition. Mental rehearsal of the sub-nociceptive images was found to modulate the perception of the nociceptive sensation felt prior to the imagery. Such modulation seems to be mediated by generating and maintaining sub-nociceptive images in working memory. Future

  19. Paying More Attention to Attention: Improving the Performance of Convolutional Neural Networks via Attention Transfer

    OpenAIRE

    Zagoruyko, Sergey; Komodakis, Nikos

    2016-01-01

    Attention plays a critical role in human visual experience. Furthermore, it has recently been demonstrated that attention can also play an important role in the context of applying artificial neural networks to a variety of tasks from fields such as computer vision and NLP. In this work we show that, by properly defining attention for convolutional neural networks, we can actually use this type of information in order to significantly improve the performance of a student CNN network by forcin...

  20. Attentional Performance in Children and Adolescents with Tic Disorder and Co-Occurring Attention-Deficit/Hyperactivity Disorder: New Insights from a 2 × 2 Factorial Design Study

    OpenAIRE

    Greimel, Ellen; Wanderer, Sina; Rothenberger, Aribert; Herpertz-Dahlmann, Beate; Konrad, Kerstin; Roessner, Veit

    2011-01-01

    The aim of the present study was to investigate the effect of both tic disorder (TD) and attention-deficit/hyperactivity disorder (ADHD) on attentional functions. N = 96 children and adolescents participated in the study, including n = 21 subjects with TD, n = 23 subjects with ADHD, n = 25 subjects with TD+ADHD, and n = 27 controls. Attentional performance was tested based on four computerized attention tasks (sustained attention, divided attention, go/nogo and set shifting). The effect of TD...

  1. Analysis on shift and rotation of intraocular lens after phakic collamer lens implantation

    Directory of Open Access Journals (Sweden)

    Yuan-Yuan Lu

    2016-05-01

    Full Text Available Recently, the incidence of myopia increases year by year. The effectiveness of refractive surgery for the correction of ametropia is widely recognized with rapid development of ophthalmic microsurgery. The laser in situ keratomileusis(LASIKhas been accepted as a regular refractive surgery technique to correct mild and moderate myopia. However, it shows inadequacy in ability to correct high refractive errors, and in patients with thin cornea and keratoconus. In 1993, Staar Surgical(A.G. Nidauintroduced a modified intraocular collamer lens(ICLfor the correction of high myopia, which emerged as a safe and effective operation for moderate or high myopia gradually. Although it has already been proved that ICL has safety and efficacy for the correction of high myopia, several studies reported dislocation and rotation of ICL after implantation, which led decreased vision and poor satisfaction. In severe cases, secondary glaucoma, anterior subcapsular cataract happened consequentially. These potential complications have drawn more and more attention by the majority of physicians and scholars. This paper aims to discuss the potential cause of shift and rotation of ICLs after implantation.

  2. Caffeine Modulates Attention Network Function

    Science.gov (United States)

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

    2010-01-01

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

  3. Concrete Operations and Attentional Capacity.

    Science.gov (United States)

    Chapman, Michael; Lindenberger, Ulman

    1989-01-01

    To test predictions regarding the attentional capacity requirements of Piaget's stage of concrete operations, a battery of concrete operational tasks and two measures of attentional capacity were administered to 120 first-, second-, and third-graders. Findings concern class inclusion, transitivity of length and weight, and multiplication of…

  4. Rapid response systems.

    Science.gov (United States)

    Lyons, Patrick G; Edelson, Dana P; Churpek, Matthew M

    2018-07-01

    Rapid response systems are commonly employed by hospitals to identify and respond to deteriorating patients outside of the intensive care unit. Controversy exists about the benefits of rapid response systems. We aimed to review the current state of the rapid response literature, including evolving aspects of afferent (risk detection) and efferent (intervention) arms, outcome measurement, process improvement, and implementation. Articles written in English and published in PubMed. Rapid response systems are heterogeneous, with important differences among afferent and efferent arms. Clinically meaningful outcomes may include unexpected mortality, in-hospital cardiac arrest, length of stay, cost, and processes of care at end of life. Both positive and negative interventional studies have been published, although the two largest randomized trials involving rapid response systems - the Medical Early Response and Intervention Trial (MERIT) and the Effect of a Pediatric Early Warning System on All-Cause Mortality in Hospitalized Pediatric Patients (EPOCH) trial - did not find a mortality benefit with these systems, albeit with important limitations. Advances in monitoring technologies, risk assessment strategies, and behavioral ergonomics may offer opportunities for improvement. Rapid responses may improve some meaningful outcomes, although these findings remain controversial. These systems may also improve care for patients at the end of life. Rapid response systems are expected to continue evolving with novel developments in monitoring technologies, risk prediction informatics, and work in human factors. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Practicing the Attentional Dwell Away?

    DEFF Research Database (Denmark)

    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus

    2007-01-01

    Studies of the time course of visual attention have identified a temporary functional blindness to the second of two spatially separated targets: attending to one visual stimulus may lead to impairments in identifying a second stimulus presented about 200-500 ms later than the first. The phenomenon...... is known as the attentional dwell time (e.g. Duncan, Ward, Shapiro, 1994). Previous studies of attentional dwell time have all used naive subjects running few (.... The results suggest that the majority of subjects may learn to optimize their performance reducing the attentional dwell time effect substantially. Further, the reduction in the attentional dwell time effect seems to be closely linked to the ability of the subject to inhibit eye movements while performing...

  6. What Attracts Decision Makers' Attention?

    DEFF Research Database (Denmark)

    Bentzen, Eric; Christiansen, John K.; Varnes, Claus J.

    2011-01-01

    portfolio meetings. The study seeks to investigate how managers allocate their attention and the role of different factors for their attention. Observations also make it possible to compare prior research and expectations with the actual observed behavior of decision makers. Design....../methodology/approach – The present analysis draws on insights from previous research into decision making in product and portfolio management and studies on organizational decision making. The authors frame why the attention of decision makers is so critical in complex situations. Data for this study were collected through direct......Purpose – Managers' attention is a scarce resource in complex innovation settings. Prior research on the factors to which managers pay attention is mostly based on surveys. The present study aims to address the need for knowledge about the behavior of decision makers based on observations from...

  7. Social reward shapes attentional biases.

    Science.gov (United States)

    Anderson, Brian A

    2016-01-01

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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Rebeca eMarfil

    2014-08-01

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

  10. Functional Connectivity of the Dorsal Attention Network Predicts Selective Attention in 4-7 year-old Girls.

    Science.gov (United States)

    Rohr, Christiane S; Vinette, Sarah A; Parsons, Kari A L; Cho, Ivy Y K; Dimond, Dennis; Benischek, Alina; Lebel, Catherine; Dewey, Deborah; Bray, Signe

    2017-09-01

    Early childhood is a period of profound neural development and remodeling during which attention skills undergo rapid maturation. Attention networks have been extensively studied in the adult brain, yet relatively little is known about changes in early childhood, and their relation to cognitive development. We investigated the association between age and functional connectivity (FC) within the dorsal attention network (DAN) and the association between FC and attention skills in early childhood. Functional magnetic resonance imaging data was collected during passive viewing in 44 typically developing female children between 4 and 7 years whose sustained, selective, and executive attention skills were assessed. FC of the intraparietal sulcus (IPS) and the frontal eye fields (FEF) was computed across the entire brain and regressed against age. Age was positively associated with FC between core nodes of the DAN, the IPS and the FEF, and negatively associated with FC between the DAN and regions of the default-mode network. Further, controlling for age, FC between the IPS and FEF was significantly associated with selective attention. These findings add to our understanding of early childhood development of attention networks and suggest that greater FC within the DAN is associated with better selective attention skills. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. Functional brain asymmetry, attentional modulation, and interhemispheric transfer in boys with Tourette syndrome

    DEFF Research Database (Denmark)

    Plessen, Kerstin J; Lundervold, Arvid; Grüner, Renate

    2007-01-01

    on the right ear stimulus in the dichotic listening situation is thought to involve the same prefrontal attentional and executive functions that are involved in the suppression of tics, whereas, performance when focusing attention on the left ear stimulus additionally involves a callosal transfer...... to shift attention normally when instructed to focus on the right ear stimulus. When instructed to focus attention on the left ear stimulus, however, performance deteriorated in the TS group. Correlations with CC area further supported the hypothesized presence of deviant callosal functioning in the TS...... of information. In light of presumed disturbances in transfer of information across the corpus callosum, we hypothesized that children with TS would, however, have difficulty modulating the functional lateralization that ensues through a shift of attention to the left side. This hypothesis was tested...

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

    Science.gov (United States)

    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.

  13. The Attentional Blink is Modulated by First Target Contrast: Implications of an Attention Capture Hypothesis

    DEFF Research Database (Denmark)

    Nielsen, Simon; Andersen, Tobias

    2011-01-01

    When two targets (T1 & T2) are presented in rapid succession, observers often fail to report T2 if they attend to T1. The bottleneck theory proposes that this attentional blink (AB) is due to T1 occupying a slow processing stage when T2 is presented. Accordingly, if increasing T1 difficulty...... increases T1 processing time, this should cause a greater AB. The attention capture hypothesis suggests that T1 captures attention, which cannot be reallocated to T2 in time. Accordingly, if increasing T1 difficulty decreases T1 saliency, this should cause a smaller AB. In two experiments we find support...... for an attention capture hypothesis. In Experiment 1 we find that AB magnitude increases with T1 contrast – but only when T1 is unmasked. In Experiment 2 we add Gaussian noise to targets and vary T1 contrast but keep T1 ‘s SNR constant. Again we find that AB magnitude increases with T1 contrast....

  14. The attentional blink is modulated by first target contrast: Implications of an attention capture hypothesis

    DEFF Research Database (Denmark)

    Nielsen, Simon; Andersen, Tobias S

    2011-01-01

    When two targets (T1 & T2) are presented in rapid succession, observers often fail to report T2 if they attend to T1. The bottleneck theory proposes that this attentional blink (AB) is due to T1 occupying a slow processing stage when T2 is presented. Accordingly, if increasing T1 difficulty...... increases T1 processing time, this should cause a greater AB. The attention capture hypothesis suggests that T1 captures attention, which cannot be reallocated to T2 in time. Accordingly, if increasing T1 difficulty decreases T1 saliency, this should cause a smaller AB. In two experiments we find support...... for an attention capture hypothesis. In Experiment 1 we find that AB magnitude increases with T1 contrast – but only when T1 is unmasked. In Experiment 2 we add Gaussian noise to targets and vary T1 contrast but keep T1 ‘s SNR constant. Again we find that AB magnitude increases with T1 contrast....

  15. Ocularity Feature Contrast Attracts Attention Exogenously

    Directory of Open Access Journals (Sweden)

    Li Zhaoping

    2018-02-01

    Full Text Available An eye-of-origin singleton, e.g., a bar shown to the left eye among many other bars shown to the right eye, can capture attention and gaze exogenously or reflexively, even when it appears identical to other visual input items in the scene and when the eye-of-origin feature is irrelevant to the observer’s task. Defining saliency as the strength of exogenous attraction to attention, we say that this eye-of-origin singleton, or its visual location, is salient. Defining the ocularity of a visual input item as the relative difference between its left-eye input and its right-eye input, this paper shows the general case that an ocularity singleton is also salient. For example, a binocular input item among monocular input items is salient, so is a left-eye-dominant input item (e.g., a bar with a higher input contrast to the left eye than to the right eye among right-eye-dominant items. Saliency by unique input ocularity is analogous to saliency by unique input colour (e.g., a red item among green ones, as colour is determined by the relative difference(s between visual inputs to different photoreceptor cones. Just as a smaller colour difference between a colour singleton and background items makes this singleton less salient, so does a smaller ocularity difference between an ocularity singleton and background items. While a salient colour difference is highly visible, a salient ocularity difference is often perceptually invisible in some cases and discouraging gaze shifts towards it in other cases, making its behavioural manifestation not as apparent. Saliency by ocularity contrast provides another support to the idea that the primary visual cortex creates a bottom-up saliency map to guide attention exogenously.

  16. Gaze-independent BCI-spelling using rapid serial visual presentation (RSVP).

    Science.gov (United States)

    Acqualagna, Laura; Blankertz, Benjamin

    2013-05-01

    A Brain Computer Interface (BCI) speller is a communication device, which can be used by patients suffering from neurodegenerative diseases to select symbols in a computer application. For patients unable to overtly fixate the target symbol, it is crucial to develop a speller independent of gaze shifts. In the present online study, we investigated rapid serial visual presentation (RSVP) as a paradigm for mental typewriting. We investigated the RSVP speller in three conditions, regarding the Stimulus Onset Asynchrony (SOA) and the use of color features. A vocabulary of 30 symbols was presented one-by-one in a pseudo random sequence at the same location of display. All twelve participants were able to successfully operate the RSVP speller. The results show a mean online spelling rate of 1.43 symb/min and a mean symbol selection accuracy of 94.8% in the best condition. We conclude that the RSVP is a promising paradigm for BCI spelling and its performance is competitive with the fastest gaze-independent spellers in literature. The RSVP speller does not require gaze shifts towards different target locations and can be operated by non-spatial visual attention, therefore it can be considered as a valid paradigm in applications with patients for impaired oculo-motor control. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  17. Training and transfer of training in rapid visual search for camouflaged targets.

    Directory of Open Access Journals (Sweden)

    Mark B Neider

    Full Text Available Previous examinations of search under camouflage conditions have reported that performance improves with training and that training can engender near perfect transfer to similar, but novel camouflage-type displays [1]. What remains unclear, however, are the cognitive mechanisms underlying these training improvements and transfer benefits. On the one hand, improvements and transfer benefits might be associated with higher-level overt strategy shifts, such as through the restriction of eye movements to target-likely (background display regions. On the other hand, improvements and benefits might be related to the tuning of lower-level perceptual processes, such as figure-ground segregation. To decouple these competing possibilities we had one group of participants train on camouflage search displays and a control group train on non-camouflage displays. Critically, search displays were rapidly presented, precluding eye movements. Before and following training, all participants completed transfer sessions in which they searched novel displays. We found that search performance on camouflage displays improved with training. Furthermore, participants who trained on camouflage displays suffered no performance costs when searching novel displays following training. Our findings suggest that training to break camouflage is related to the tuning of perceptual mechanisms and not strategic shifts in overt attention.

  18. George Kubler Shifting South: Architecture History Following Geopolitics

    Directory of Open Access Journals (Sweden)

    Sousa Santos, Eliana

    2016-07-01

    Full Text Available This essay aims to present the shifting relations between North America and the South - South America and the South of Europe - through the work of the historian George Kubler. At the beginning of his career as a scholar, Kubler was invited by the Department of State to participate in a conference on inter-American relations. Later, with the positioning of the United States in World War II, the transatlantic relationship between the US and Europe became more prominent. Kubler’s research interests followed this change: His research shift from South America to peripheral Southern Europe reflects an availability of funding given his country's geopolitical interests. So far, artists and other scholars have praised Kubler’s vast work regarding the art and architecture of different 'Souths' mainly as a sign of 'nonalignment' and of his attention to the condition of peripheral countries.

  19. Divided attention deficits in patients with chronic fatigue syndrome.

    Science.gov (United States)

    Ross, S; Fantie, B; Straus, S F; Grafman, J

    2001-01-01

    Chronic fatigue syndrome (CFS) patients and controls were compared on a variety of mood state, personality, and neuropsychological measures, including memory, word finding, and attentional tasks that required participants to focus, sustain, or divide their attention, or to perform a combination of these functions. CFS patients demonstrated a selective deficit on 3 measures of divided attention. Their performance on the other neuropsychological tests of intelligence, fluency, and memory was no different than that of normal controls despite their reports of generally diminished cognitive capacity. There was an inverse relation between CFS patient fatigue severity and performance on 1 of the divided attention measures. Given these findings, it is probable that CFS patients will report more cognitive difficulties in real-life situations that cause them to divide their effort or rapidly reallocate cognitive resources between 2 response channels (vision and audition).

  20. Improved control of exogenous attention in action video game players

    Directory of Open Access Journals (Sweden)

    Matthew S Cain

    2014-02-01

    Full Text Available Action video game players have demonstrated a number of attentional advantages over non-players. Here, we propose that many of those benefits might be underpinned by improved control over exogenous (i.e., stimulus-driven attention. To test this we used an anti-cuing task, in which a sudden-onset cue indicated that the target would likely appear in a separate location on the opposite side of the fixation point. When the time between the cue onset and the target onset was short (40 ms, non-players (nVGPs showed a typical exogenous attention effect. Their response times were faster to targets presented at the cued (but less probable location compared with the opposite (more probable location. Video game players (VGPs, however, were less likely to have their attention drawn to the location of the cue. When the onset asynchrony was long (600 ms, VGPs and nVGPs were equally able to endogenously shift their attention to the likely (opposite target location. In order to rule out processing-speed differences as an explanation for this result, we also tested VGPs and nVGPs on an attentional blink task. In a version of the attentional blink task that minimized demands on task switching and iconic memory, VGPs and nVGPs did not differ in second target identification performance (i.e., VGPs had the same magnitude of attentional blink as nVGPs, suggesting that the anti-cuing results were due to flexible control over exogenous attention rather than to more general speed-of-processing differences.

  1. Cortisol shifts financial risk preferences.

    Science.gov (United States)

    Kandasamy, Narayanan; Hardy, Ben; Page, Lionel; Schaffner, Markus; Graggaber, Johann; Powlson, Andrew S; Fletcher, Paul C; Gurnell, Mark; Coates, John

    2014-03-04

    Risk taking is central to human activity. Consequently, it lies at the focal point of behavioral sciences such as neuroscience, economics, and finance. Many influential models from these sciences assume that financial risk preferences form a stable trait. Is this assumption justified and, if not, what causes the appetite for risk to fluctuate? We have previously found that traders experience a sustained increase in the stress hormone cortisol when the amount of uncertainty, in the form of market volatility, increases. Here we ask whether these elevated cortisol levels shift risk preferences. Using a double-blind, placebo-controlled, cross-over protocol we raised cortisol levels in volunteers over 8 d to the same extent previously observed in traders. We then tested for the utility and probability weighting functions underlying their risk taking and found that participants became more risk-averse. We also observed that the weighting of probabilities became more distorted among men relative to women. These results suggest that risk preferences are highly dynamic. Specifically, the stress response calibrates risk taking to our circumstances, reducing it in times of prolonged uncertainty, such as a financial crisis. Physiology-induced shifts in risk preferences may thus be an underappreciated cause of market instability.

  2. Cortisol shifts financial risk preferences

    Science.gov (United States)

    Kandasamy, Narayanan; Hardy, Ben; Page, Lionel; Schaffner, Markus; Graggaber, Johann; Powlson, Andrew S.; Fletcher, Paul C.; Gurnell, Mark; Coates, John

    2014-01-01

    Risk taking is central to human activity. Consequently, it lies at the focal point of behavioral sciences such as neuroscience, economics, and finance. Many influential models from these sciences assume that financial risk preferences form a stable trait. Is this assumption justified and, if not, what causes the appetite for risk to fluctuate? We have previously found that traders experience a sustained increase in the stress hormone cortisol when the amount of uncertainty, in the form of market volatility, increases. Here we ask whether these elevated cortisol levels shift risk preferences. Using a double-blind, placebo-controlled, cross-over protocol we raised cortisol levels in volunteers over 8 d to the same extent previously observed in traders. We then tested for the utility and probability weighting functions underlying their risk taking and found that participants became more risk-averse. We also observed that the weighting of probabilities became more distorted among men relative to women. These results suggest that risk preferences are highly dynamic. Specifically, the stress response calibrates risk taking to our circumstances, reducing it in times of prolonged uncertainty, such as a financial crisis. Physiology-induced shifts in risk preferences may thus be an underappreciated cause of market instability. PMID:24550472

  3. Split-shift work in relation to stress, health and psychosocial work factors among bus drivers.

    Science.gov (United States)

    Ihlström, Jonas; Kecklund, Göran; Anund, Anna

    2017-01-01

    Shift work has been associated with poor health, sleep and fatigue problems and low satisfaction with working hours. However, one type of shift working, namely split shifts, have received little attention. This study examined stress, health and psychosocial aspects of split-shift schedules among bus drivers in urban transport. A questionnaire was distributed to drivers working more than 70% of full time which 235 drivers in total answered. In general, drivers working split-shift schedules (n = 146) did not differ from drivers not working such shifts (n = 83) as regards any of the outcome variables that were studied. However, when individual perceptions towards split-shift schedules were taken into account, a different picture appeared. Bus drivers who reported problems working split shifts (36%) reported poorer health, higher perceived stress, working hours interfering with social life, lower sleep quality, more persistent fatigue and lower general work satisfaction than those who did not view split shifts as a problem. Moreover, drivers who reported problems with split shifts also perceived lower possibilities to influence working hours, indicating lower work time control. This study indicates that split shifts were not associated with increased stress, poorer health and adverse psychosocial work factors for the entire study sample. However, the results showed that individual differences were important and approximately one third of the drivers reported problems with split shifts, which in turn was associated with stress, poor health and negative psychosocial work conditions. More research is needed to understand the individual and organizational determinants of tolerance to split shifts.

  4. Brain Connectivity and Visual Attention

    Science.gov (United States)

    Parks, Emily L.

    2013-01-01

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

  5. Selective attention without a neocortex.

    Science.gov (United States)

    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.

  6. Extended attention span training system

    Science.gov (United States)

    Pope, Alan T.; Bogart, Edward H.

    1991-01-01

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

  7. Attentional modulation of reflex cough.

    Science.gov (United States)

    Janssens, Thomas; Silva, Mitchell; Davenport, Paul W; Van Diest, Ilse; Dupont, Lieven J; Van den Bergh, Omer

    2014-07-01

    Reflex cough is a defensive response generated in the brainstem in response to chemical and mechanical stimulation of the airways. However, converging evidence shows that reflex cough is also influenced by central neural control processes. In this study, we investigate whether reflex cough can be modulated by attentional focus on either external stimuli or internal cough-related stimuli. Healthy volunteers (N = 24; seven men; age range, 18-25 years) completed four blocks of citric acid-induced cough challenges while, simultaneously, auditory stimuli were presented. Within each block, four concentrations were administered (30, 100, 300 and 1,000 mM, randomized). During two subsequent blocks, participants focused their attention externally (counting tones). During the other two blocks, participants focused their attention internally (counting coughs). The order of attentional focus was counterbalanced across participants. Ratings of the urge to cough were collected after each challenge. Cough frequency was determined by audio recording. Cough frequency was higher when participants focused their attention internally vs externally (P Reflex cough can be modulated by attentional focus. Internally focused attention may be a mechanism involved in excessive (idiopathic) cough, while an external focus may be introduced as part of treatments targeting excessive cough.

  8. Attention modulates visual size adaptation.

    Science.gov (United States)

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

    2015-01-01

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

  9. Fluorescence spectral shift of QD films with electron injection: Dependence on counterion proximity

    Science.gov (United States)

    Lu, Meilin; Li, Bo; Zhang, Yaxin; Liu, Weilong; Yang, Yanqiang; Wang, Yuxiao; Yang, Qingxin

    2017-05-01

    Due to the promising application of quantum dot (QD) films in solar cells, LEDs and environmental detectors, the fluorescence of charged QD films has achieved much attention during recent years. In this work, we observe the spectral shift of photoluminescence (PL) in charged CdSe/ZnS QD films controlled by electrochemical potential. The spectral center under negative bias changes from red-shift to blue-shift while introducing smaller inorganic counterions (potassium ions) into the electrolyte. This repeatable effect is attributed to the enhanced electron injection with smaller cations and the electronic perturbations of QD luminescence by these excess charges.

  10. Irrelevant stimulus processing in ADHD: catecholamine dynamics and attentional networks

    Directory of Open Access Journals (Sweden)

    Francisco eAboitiz

    2014-03-01

    Full Text Available A cardinal symptom of Attenion Deficit and Hyperactivity Disorder (ADHD is a general distractibility where children and adults shift their attentional focus to stimuli that are irrelevant to the ongoing behavior. This has been attributed to a deficit in dopaminergic signaling in cortico-striatal networks that regulate goal-directed behavior. Furthermore, recent imaging evidence points to an impairment of large scale, antagonistic brain networks that normally contribute to attentional engagement and disengagement, such as the task-positive networks and the Default Mode Network (DMN. Related networks are the ventral attentional network (VAN involved in attentional shifting, and the salience network (SN related to task expectancy. Here we discuss the tonic-phasic dynamics of catecholaminergic signaling in the brain, and attempt to provide a link between this and the activities of the large-scale cortical networks that regulate behavior. More specifically, we propose that a disbalance of tonic catecholamine levels during task performance produce an emphasis of phasic signaling and increased excitability of the VAN, yielding distractibility symptoms. Likewise, immaturity of the SN may relate to abnormal tonic signaling and an incapacity to build up a proper executive system during task performance. We discuss different lines of evidence including pharmacology, brain imaging and electrophysiology, that are consistent with our proposal. Finally, restoring the pharmacodynamics of catecholaminergic signaling seems crucial to alleviate ADHD symptoms; however, the possibility is open to explore cognitive rehabilitation strategies to top-down modulate network dynamics compensating the pharmacological deficits.

  11. Transformational Change and Regime Shifts in the Circumpolar Arctic

    Directory of Open Access Journals (Sweden)

    Annika E. Nilsson

    2016-11-01

    Full Text Available The Arctic is changing rapidly, and there are many indications that the region is in the midst of transformational change. While some of the focus relates to impacts of climate change, rapid economic development and the potential for shifts in political and social structures in the region have also been in the limelight. This article looks at the circumpolar Arctic as a potential case of a regime shift in a large-scale social–ecological system that includes reinforcing feedbacks. A special focus is placed on governance structures, as these play an important role in social negotiations on the relationship between societies and the environment. While climate change is often portrayed as a driver of social change in the Arctic, it does not appear that the ongoing changes in the biophysical features of the Arctic region have rocked current circumpolar governance structures out of kilter. On the contrary, the ongoing climate-related changes, in particular sea ice decline, appear to have reinforced political commitment to existing legal structures. Major past social regime shifts have mainly been related to access to resources and national identity ideology, with political dynamics reinforced at times by military security considerations.

  12. Continuous blood densitometry - Fluid shifts after graded hemorrhage in animals

    Science.gov (United States)

    Hinghofer-Szalkay, H.

    1986-01-01

    Rapid fluid shifts in four pigs and two dogs subjected to graded hemorrhage are investigated. Arterial blood density (BD), mean arterial pressure (MAP), central venous pressure (CVP), arterial plasma density (PD), hematocrit (Hct) and erythrocyte density were measured. The apparatus and mechancial oscillator technique for measuring density are described. Fluid shifts between red blood cells and blood plasma and alterations in the whole-body-to-large vessel Hct, F(cell) are studied using two models. The bases of the model calculations are discussed. A decrease in MAP, CVP, and BP is detected at the beginning of hemorrhaging; continued bleeding results in further BD decrease correlating with volume displacement. The data reveal that at 15 ml/kg blood loss the mean PD and BD dropped by 0.99 + or - 0.15 and 2.42 + or 0.26 g/liter, respectively, and the Hct dropped by 2.40 + or 0.47 units. The data reveal that inward-shifted fluid has a higher density than normal ultrafiltrate and/or there is a rise in the F(cell) ratio. It is noted that rapid fluid replacement ranged from 5.8 + or - 0.8 to 10.6 + or - 2.0 percent of the initial plasma volume.

  13. External noise distinguishes attention mechanisms.

    Science.gov (United States)

    Lu, Z L; Dosher, B A

    1998-05-01

    We developed and tested a powerful method for identifying and characterizing the effect of attention on performance in visual tasks as due to signal enhancement, distractor exclusion, or internal noise suppression. Based on a noisy Perceptual Template Model (PTM) of a human observer, the method adds increasing amounts of external noise (white gaussian random noise) to the visual stimulus and observes the effect on performance of a perceptual task for attended and unattended stimuli. The three mechanisms of attention yield three "signature" patterns of performance. The general framework for characterizing the mechanisms of attention is used here to investigate the attentional mechanisms in a concurrent location-cued orientation discrimination task. Test stimuli--Gabor patches tilted slightly to the right or left--always appeared on both the left and the right of fixation, and varied independently. Observers were cued on each trial to attend to the left, the right, or evenly to both stimuli, and decide the direction of tilt of both test stimuli. For eight levels of added external noise and three attention conditions (attended, unattended, and equal), subjects' contrast threshold levels were determined. At low levels of external noise, attention affected threshold contrast: threshold contrasts for non-attended stimuli were systematically higher than for equal attention stimuli, which were, in turn, higher than for attended stimuli. Specifically, when the rms contrast of the external noise is below 10%, there is a consistent 17% elevation of contrast threshold from attended to unattended condition across all three subjects. For higher levels of external noise, attention conditions did not affect threshold contrast values at all. These strong results are characteristic of a signal enhancement, or equivalently, an internal additive noise reduction mechanism of attention.

  14. Cold-Blooded Attention: Finger Temperature Predicts Attentional Performance.

    Science.gov (United States)

    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.

  15. Cold-Blooded Attention: Finger Temperature Predicts Attentional Performance

    Directory of Open Access Journals (Sweden)

    Rodrigo C. Vergara

    2017-09-01

    Full Text Available 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.

  16. Assessing attentional systems in children with Attention Deficit Hyperactivity Disorder.

    Science.gov (United States)

    Casagrande, Maria; Martella, Diana; Ruggiero, Maria Cleonice; Maccari, Lisa; Paloscia, Claudio; Rosa, Caterina; Pasini, Augusto

    2012-01-01

    The aim of this study was to evaluate the efficiency and interactions of attentional systems in children with Attention Deficit Hyperactivity Disorder (ADHD) by considering the effects of reinforcement and auditory warning on each component of attention. Thirty-six drug-naïve children (18 children with ADHD/18 typically developing children) performed two revised versions of the Attentional Network Test, which assess the efficiency of alerting, orienting, and executive systems. In feedback trials, children received feedback about their accuracy, whereas in the no-feedback trials, feedback was not given. In both conditions, children with ADHD performed more slowly than did typically developing children. They also showed impairments in the ability to disengage attention and in executive functioning, which improved when alertness was increased by administering the auditory warning. The performance of the attentional networks appeared to be modulated by the absence or the presence of reinforcement. We suggest that the observed executive system deficit in children with ADHD could depend on their low level of arousal rather than being an independent disorder. © The Author 2011. Published by Oxford University Press. All rights reserved.

  17. What You Smell Affects Different Components of Your Visual Attention

    Directory of Open Access Journals (Sweden)

    Chen-An Li

    2011-10-01

    Full Text Available It is commonly held that different essential oils produce different effects, as reflected in various commercial advertisements. Yet, little is known about whether smelling essential oils would affect our attention and whether smelling different essential oils affects attentional components differently, due to the lack of empirical data. Here we provide such data. Participants conducted the Attention Network Test (ANT while smelling the essential oil of Chamaecyparis formosensis (Experiment 1, the wood usually used in shrine or furniture or Eucalyptus globules (Experiment 2, smelling like camphor or mint, compared with the control condition of smelling water. The order of the essential oil condition and the water condition was counterbalanced between participants. Three attention systems were measured: alertness, orienting and executive control. Results showed that Chamaecyparis formosens reduced the effect of orienting, implying that smelling this odor would prevent involuntary attentional shift by an exogenous cue. On the other hand, Eucalyptus globules produced a larger interference effect in the executive control system, suggesting a larger span of spatial attention that is associated with a positive emotion(Rowe, Hirsh, & Anderson, 2007.

  18. Detection is unaffected by the deployment of focal attention

    Directory of Open Access Journals (Sweden)

    Jeff eMoher

    2013-05-01

    Full Text Available There has been much debate regarding how much information humans can extract from their environment without the use of limited attentional resources. In a recent study, Theeuwes, Van der Burg, and Belopolsky (2008 argued that even detection of simple feature targets is not possible without selection by focal attention. Supporting this claim, they found response time benefits in a simple feature (color detection task when a target letter’s identity was repeated on consecutive trials, suggesting that the letter was selected by focal attention and identified prior to detection. This intertrial repetition benefit remained even when observers were required to simultaneously identify a central digit. However, we found that intertrial repetition benefits disappeared when a simple color target was presented among a heterogeneously (rather than homogeneously colored set of distractors, thus reducing its bottom-up salience. Still, detection performance remained high. Thus, detection performance was unaffected by whether a letter was focally attended and identified prior to detection or not. Intertrial identity repetition benefits also disappeared when observers were required to perform a simultaneous, attention-demanding central task (Experiment 2, or when unfamiliar Chinese characters were used (Experiment 3. Together, these results suggest that while shifts of focal attention can be affected by target salience, by the availability of excess cognitive resources, and by target familiarity, detection performance itself is unaffected by these manipulations and is thus unaffected by the deployment of focal attention.

  19. Object width modulates object-based attentional selection.

    Science.gov (United States)

    Nah, Joseph C; Neppi-Modona, Marco; Strother, Lars; Behrmann, Marlene; Shomstein, Sarah

    2018-04-24

    Visual input typically includes a myriad of objects, some of which are selected for further processing. While these objects vary in shape and size, most evidence supporting object-based guidance of attention is drawn from paradigms employing two identical objects. Importantly, object size is a readily perceived stimulus dimension, and whether it modulates the distribution of attention remains an open question. Across four experiments, the size of the objects in the display was manipulated in a modified version of the two-rectangle paradigm. In Experiment 1, two identical parallel rectangles of two sizes (thin or thick) were presented. Experiments 2-4 employed identical trapezoids (each having a thin and thick end), inverted in orientation. In the experiments, one end of an object was cued and participants performed either a T/L discrimination or a simple target-detection task. Combined results show that, in addition to the standard object-based attentional advantage, there was a further attentional benefit for processing information contained in the thick versus thin end of objects. Additionally, eye-tracking measures demonstrated increased saccade precision towards thick object ends, suggesting that Fitts's Law may play a role in object-based attentional shifts. Taken together, these results suggest that object-based attentional selection is modulated by object width.

  20. Measuring and monitoring collective attention during shocking events

    Directory of Open Access Journals (Sweden)

    Xingsheng He

    2017-11-01

    Full Text Available Abstract There has been growing interest in leveraging Web-based social and communication technologies for better crisis response. How might the Web platforms be used as an observatory to systematically understand the dynamics of the public’s attention during disaster events? And how could we monitor such attention in a cost-effective way? In this work, we propose an ‘attention shift network’ framework to systematically observe, measure, and analyze the dynamics of collective attention in response to real-world exogenous shocks such as disasters. Through tracing hashtags that appeared in Twitter users’ complete timeline around several violent terrorist attacks, we study the properties of network structures and reveal the temporal dynamics of the collective attention across multiple disasters. Further, to enable an efficient monitoring of the collective attention dynamics, we propose an effective stochastic sampling approach that accounts for the users’ hashtag adoption frequency, connectedness and diversity, as well as data variability. We conduct extensive experiments to show that the proposed sampling approach significantly outperforms several alternative methods in both retaining the network structures and preserving the information with a small set of sampling targets, suggesting the utility of the proposed method in various realistic settings.