WorldWideScience

Sample records for rapidly shifting attention

  1. 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.

  2. 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…

  3. The mental wormhole: internal attention shifts without regard for distance.

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    Tanoue, Ryan T; Berryhill, Marian E

    2012-08-01

    Attention operates perceptually on items in the environment, and internally on objects in visuospatial working memory. In the present study, we investigated whether spatial and temporal constraints affecting endogenous perceptual attention extend to internal attention. A retro-cue paradigm in which a cue is presented beyond the range of iconic memory and after stimulus encoding was used to manipulate shifts of internal attention. Participants' memories were tested for colored circles (Experiments 1, 2, 3a, 4) or for novel shapes (Experiment 3b) and their locations within an array. In these experiments, the time to shift internal attention (Experiments 1 and 3) and the eccentricity of encoded objects (Experiments 2-4) were manipulated. Our data showed that, unlike endogenous perceptual attention, internal shifts of attention are not modulated by stimulus eccentricity. Across several timing parameters and stimuli, we found that shifts of internal attention require a minimum quantal amount of time regardless of the object eccentricity at encoding. Our findings are consistent with the view that internal attention operates on objects whose spatial information is represented in relative terms. Although endogenous perceptual attention abides by the laws of space and time, internal attention can shift across spatial representations without regard for physical distance.

  4. Decoding covert shifts of attention induced by ambiguous visuospatial cues

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    Romain eTrachel

    2015-06-01

    Full Text Available Simple and unambiguous visual cues (e.g. an arrow can be used to trigger covert shifts of visual attention away from the center of gaze. The processing of visual stimuli is enhanced at the attended location. Covert shifts of attention modulate the power of cerebral oscillations in the alpha band over parietal and occipital regions. These modulations are sufficiently robust to be decoded on a single trial basis from electro-encephalography (EEG signals. It is often assumed that covert attention shifts are under voluntary control, and also occur in more natural and complex environments, but there is no direct evidence to support this assumption. We address this important issue by using random-dot stimuli to cue one of two opposite locations, where a visual target is presented. We contrast two conditions in which the random-dot motion is either predictive of the target location or contains ambiguous information. Behavioral results show attention shifts in anticipation of the visual target, in both conditions. In addition, these attention shifts involve similar neural sources, and the EEG can be decoded on a single trial basis. These results shed a new light on the behavioral and neural correlates of visuospatial attention, with implications for Brain-Computer Interfaces (BCI based on covert attention shifts.

  5. The neurodynamics underlying attentional control in set shifting tasks.

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    Stemme, Anja; Deco, Gustavo; Busch, Astrid

    2007-09-01

    In this work we address key phenomena observed with classical set shifting tasks as the "Wisconsin Card Sorting Test" or the "Stroop" task: Different types of errors and increased response times reflecting decreased attention. A component of major importance in these tasks is referred to as the "attentional control" thought to be implemented by the prefrontal cortex which acts primarily by an amplification of task relevant information. This mode of operation is illustrated by a neurodynamical model developed for a new kind of set shifting experiment: The Wisconsin-Delayed-Match-to-Sample task combines uninstructed shifts as investigated in Wisconsin-like tasks with a Delayed-Match-to-Sample paradigm. These newly developed WDMS experiments in conjunction with the neurodynamical simulations are able to explain the reason for decreased attention in set shifting experiments as well the different consequences of decreased attention in tasks requiring bivalent yes/no responses compared to tasks requiring multivalent responses.

  6. 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

    . Target position was cued after stimulus offset, requiring subjects to perform target detection from iconic visual memory. We found positionally specific responses at multiple thalamic sites, with individual voxels activating at more than one direction of attentional shift. Voxel clusters at anatomically...... the thalamic territory of cortical "eye-field" areas, thus supporting theories which propose the visuomotor origins of covert attentional selection....

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

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    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.

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

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    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.

  9. Distinct representations of attentional control during voluntary and stimulus-driven shifts across objects and locations.

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    Stoppel, Christian Michael; Boehler, Carsten Nicolas; Strumpf, Hendrik; Krebs, Ruth Marie; Heinze, Hans-Jochen; Hopf, Jens-Max; Schoenfeld, Mircea Ariel

    2013-06-01

    Efficient interaction with the sensory environment requires the rapid reallocation of attentional resources between spatial locations, perceptual features, and objects. It is still a matter of debate whether one single domain-general network or multiple independent domain-specific networks mediate control during shifts of attention across features, locations, and objects. Here, we employed functional magnetic resonance imaging to directly compare the neural mechanisms controlling attention during voluntary and stimulus-driven shifts across objects and locations. Subjects either maintained or switched voluntarily and involuntarily their attention to objects located at the same or at a different visual location. Our data demonstrate shift-related activity in multiple frontoparietal, extrastriate visual, and default-mode network regions, several of which were commonly recruited by voluntary and stimulus-driven shifts between objects and locations. However, our results also revealed object- and location-selective activations, which, moreover, differed substantially between voluntary and stimulus-driven attention. These results suggest that voluntary and stimulus-driven shifts between objects and locations recruit partially overlapping, but also separable, cortical regions, implicating the parallel existence of domain-independent and domain-specific reconfiguration signals that initiate attention shifts in dependence of particular demands.

  10. Shifting Attention within Memory Representations Involves Early Visual Areas

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    Munneke, Jaap; Belopolsky, Artem V.; Theeuwes, Jan

    2012-01-01

    Prior studies have shown that spatial attention modulates early visual cortex retinotopically, resulting in enhanced processing of external perceptual representations. However, it is not clear whether the same visual areas are modulated when attention is focused on, and shifted within a working memory representation. In the current fMRI study participants were asked to memorize an array containing four stimuli. After a delay, participants were presented with a verbal cue instructing them to actively maintain the location of one of the stimuli in working memory. Additionally, on a number of trials a second verbal cue instructed participants to switch attention to the location of another stimulus within the memorized representation. Results of the study showed that changes in the BOLD pattern closely followed the locus of attention within the working memory representation. A decrease in BOLD-activity (V1–V3) was observed at ROIs coding a memory location when participants switched away from this location, whereas an increase was observed when participants switched towards this location. Continuous increased activity was obtained at the memorized location when participants did not switch. This study shows that shifting attention within memory representations activates the earliest parts of visual cortex (including V1) in a retinotopic fashion. We conclude that even in the absence of visual stimulation, early visual areas support shifting of attention within memorized representations, similar to when attention is shifted in the outside world. The relationship between visual working memory and visual mental imagery is discussed in light of the current findings. PMID:22558165

  11. Night shifts, sleep deprivation, and attention performance in medical students.

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    Pérez-Olmos, Isabel; Ibáñez-Pinilla, Milcíades

    2014-03-29

    To determine attention performance of medical students after sleep deprivation due to night shift work. Prospective cohort design. All seventh, eighth and ninth semester students were invited to participate (n= 209). The effectiveness and concentration indices (d2 Test for attention, dependent variable) from 180 students at 3 evaluations during the semester were compared. Eighth and ninth semester students underwent their second evaluation after a night shift. The independent variables were nocturnal sleep measurements. No differences in nocturnal sleep hours during the previous week (p=0.966), sleep deprivation (p=0.703) or effectiveness in the d2 Test (p=0.428) were found between the groups at the beginning of the semester. At the beginning and the end of the semester, the d2 Test results were not different between groups (p=0.410, p=0.394) respectively. The second evaluation showed greater sleep deprivation in students with night shift work (p=0.001). The sleep deprived students had lower concentration indices (p=0.001).The differences were associated with the magnitude of sleep deprivation (p=0.008). Multivariate regression analysis showed that attention performance was explained by sleep deprivation due to night shift work, adjusting for age and gender. Students with sleep deprivation had worse concentration than those without. Sleep deprivation due to night shift work in medical students had a negative impact on their attention performance. Medical educators should address these potential negative learning and patient care consequences of sleep deprivation in medical students due to night shifts.

  12. Eye gaze triggers reflexive attention shifts: evidence from lateralised ERPs.

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    Feng, Qing; Zhang, Xuemin

    2014-11-17

    Social cues, such as another individual׳s eye gaze, provide valuable information regarding the actions and intentions of others. Previous studies have suggested that seeing another׳s gaze automatically orients one׳s attention in the gaze direction. In this event-related potential (ERP) study, a spatial cuing paradigm was combined with a visual search task in which targets were defined by feature conjunctions in order to eliminate effects of target/distractor salience. Participants viewed centrally presented faces with neutral expressions in which eyes looked to the left or right. The participants׳ task was to identify a target object (with or without gap) defined by a combination of shape and orientation, which appeared in either the same (cued) or the opposite (uncued) location as the direction of the eye gaze. There was behavioural evidence of a gaze congruency effect, as reaction times (RTs) were faster when the eyes looked towards the target rather than away from the location of the target. The ERP data indicated the presence of significant gaze-congruent early directing attention negativity (EDAN) and anterior directing attention negativity (ADAN), reflecting attention shifts to the cued location in advance of the target presentation. ERP data did not show evidence of later orienting of attention triggered by gaze cues in the late attention-directing attention positivity (LDAP) at posterior sites. The results disclosed the neural response during reflexive attention shifting triggered by gazes and ascertained the relationship among EDAN, ADAN, LDAP and gaze-elicited attention shifts. After the presentation of the target array without salient stimuli, the presence of the N2-posterior-contralateral (N2pc) in the cued trials and the absence in the uncued trials further supported that attention had been directed to the possible target location prior to the target onset. The ERPs in response to the target array also extend our understanding of the neural

  13. Individual differences in multiple types of shifting attention.

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    Wager, Tor D; Jonides, John; Smith, Edward E

    2006-12-01

    Many researchers consider costs in shifting attention and mental set to reflect a basic ability to use top-down goal information to guide action. Although switch costs have been used as measures of individuals' executive function, whether common abilities underlie task set switching across different types of shifting tasks has not been well studied. In 249 participants, we studied whether switch costs in a novel two-choice reaction time task were correlated across variations in two variables: thelocus of representation (stimuli were either perceptually available or stored in working memory [WM]) and which of two judgment tasks was performed. Switch costs were asymmetrical, in that it was easier to switch to the easier judgment, and were related to overall and relative processing speed: Switch costs were higher when the task was more difficult. These factors should be accounted for when one is measuring individual differences in switch costs. After controlling for these effects, we found evidence for a common ability underlying switch costs that involved both task set preparation and response selection; however, residual shift costs, which involve only response selection, were uncorrelated across tasks. Correlations among switch costs were substantially higher within task type (e.g., correlations of WM shifting tasks with other WM shifting tasks and of perceptual tasks with perceptual ones), suggesting that there are also processes unique to switching within WM and switching among visible stimuli.

  14. Attention shifts the language network reflecting paradigm presentation.

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    Kollndorfer, Kathrin; Furtner, Julia; Krajnik, Jacqueline; Prayer, Daniela; Schöpf, Veronika

    2013-01-01

    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. 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. 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. 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.

  15. 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.

  16. Effects of trait anxiety and situational stress on attentional shifting are buffered by working memory capacity.

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    Edwards, Mark S; Moore, Philippa; Champion, James C; Edwards, Elizabeth J

    2015-01-01

    Attentional Control Theory (ACT) predicts that trait anxiety and situation stress combine to reduce performance efficiency on tasks requiring rapid shifts in attention. Recent evidence has also suggested that working memory capacity (WMC) might moderate this relationship. We controlled for methodological difficulties in the existing literature to investigate the relationships between trait anxiety, situational stress, and WMC on attentional shifting. Seventy undergraduate students participated in the study. Trait anxiety was operationalized using questionnaire scores, situational stress was manipulated through a pressured counting task, and WMC was based on performance on the Automated Operation Span Task (AOSPAN). The shifting task involved a modified version of the Sternberg paradigm as the primary task and an oddball tone-discrimination task as the secondary task. Dependent variables were performance effectiveness (accuracy) and processing efficiency (accuracy divided by response time) on the secondary task. There was no effect of anxiety, stress, or WMC in predicting performance effectiveness; however, a significant three-way interaction on processing efficiency was observed. At higher WMC, anxiety and situational stress were not associated with processing efficiency. Conversely, at lower WMC, higher trait anxiety was associated with poorer efficiency but only for those who reported higher situational stress; for those who reported lower situational stress higher trait anxiety predicted facilitated efficiency. Results are interpreted with respect to ACT and directions for future research are discussed.

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

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

    2017-12-01

    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 structure) and to significantly outperform other shift-based or threading-based structure determination methods (in terms of top template model accuracy)-with an average TM-score performance of 0.68 (vs. 0.50-0.62 for other methods). Coupled with recent developments in 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 .

  18. 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.

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

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    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.

  20. The role of intrinsic motivations in attention allocation and shifting

    OpenAIRE

    Dario edi Nocera; Alberto eFinzi; Silvia eRossi; Mariacarla eStaffa

    2014-01-01

    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 Learni...

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

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    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,…

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

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    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…

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

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    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…

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

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    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.

  5. Attention control and ability level in a complex cognitive skill: attention shifting and second-language proficiency.

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    Segalowitz, Norman; Frenkiel-Fishman, Sarah

    2005-06-01

    In this study, we investigated the relationship between attention control and proficiency in a complex cognitive skill. The participants were English-French bilinguals with varying degrees of second-language (French) proficiency. Proficiency was operationalized as efficiency of lexical access in an animacy judgment task, as reflected in the coefficient of variability of response time adjusted for first-language performance on the same task. Attention control was operationalized as the shift cost obtained in a linguistic version of the alternating runs task-switching paradigm. Hierarchical regression revealed that, overall, attention control accounted for 59% of the variance of proficiency and that second-language attention control alone accounted for 32% of the unique variance of proficiency, indicating a high degree of skill domain (second language) specificity in the relationship between attention control and proficiency. The results speak to issues regarding the development of expertise, second-language acquisition, and a cognitive linguistic approach to language and attention.

  6. Attention shifting in Parkinson's disease: an analysis of behavioral and cortical responses.

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    Rustamov, Nabi; Rodriguez-Raecke, Rea; Timm, Lydia; Agrawal, Deepashri; Dressler, Dirk; Schrader, Christoph; Tacik, Pawel; Wegner, Florian; Dengler, Reinhard; Wittfoth, Matthias; Kopp, Bruno

    2014-11-01

    The study was designed to examine persistent (input selection) versus transient (input shifting) mechanisms of attention control in Parkinson's disease (PD). The study identifies behavioral and neural markers of selective control and shifting control using a novel combination of a flanker task with an attentional set-shifting task, and it compares patients with PD with matched controls. Event-related brain potentials (ERPs) were recorded, and analyses focused on frontally distributed N2 waves, parietally distributed P3 waves, and error-related negativities (Ne/ERN). Controls showed robust shifting costs (prolonged response times), but patients with PD did not show evidence for comparable shifting costs. Patients with PD made more errors than controls when required to shift between attentional sets, but also when they had to initially maintain an attentional set. At the neural level it was found that contrary to controls, patients with PD did not display any N2 and P3 augmentations on shift trials. Patients with PD further did not display any error-related activity or posterror N2 augmentation. Our results reveal that intact selective control and disrupted shifting control are dissociable in patients with PD, but additional work is required to dissect the proportionate effects of disease and treatment on shifting control in PD. Our ERP-based approach opens a new window onto an understanding of motor and cognitive flexibility that seems to be associated with the dopaminergic innervation of cortico-striatal loops. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  7. The Attentional Blink Reveals Sluggish Attentional Shifting in Adolescents with Specific Language Impairment

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    Lum, Jarrad A. G.; Conti-Ramsden, Gina; Lindell, Annukka K.

    2007-01-01

    Rapid processing deficits have been the subject of much debate in the literature on specific language impairment (SLI). Hari and Renvall (2001) [Hari, R. & Renvall, H. (2001). Impaired processing of rapid stimulus sequences in dyslexia. "Trends in cognitive sciences", 5, 525-532.] proposed that the source of this deficit can be attributed to…

  8. Eye Direction, Not Movement Direction, Predicts Attention Shifts in Those with Autism Spectrum Disorders

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    Rutherford, M. D.; Krysko, Kristen M.

    2008-01-01

    Experiments suggesting that a change in eye gaze creates a reflexive attention shift tend to confound motion direction and terminal eye direction. However, motion and the onset of motion are known to capture attention. Current thinking about social cognition in autism suggests that there might be a deficit in responding to social (eye gaze) cues…

  9. Video game players show higher performance but no difference in speed of attention shifts.

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    Mack, David J; Wiesmann, Helene; Ilg, Uwe J

    2016-09-01

    Video games have become both a widespread leisure activity and a substantial field of research. In a variety of tasks, video game players (VGPs) perform better than non-video game players (NVGPs). This difference is most likely explained by an alteration of the basic mechanisms underlying visuospatial attention. More specifically, the present study hypothesizes that VGPs are able to shift attention faster than NVGPs. Such alterations in attention cannot be disentangled from changes in stimulus-response mappings in reaction time based measurements. Therefore, we used a spatial cueing task with varying cue lead times (CLTs) to investigate the speed of covert attention shifts of 98 male participants divided into 36 NVGPs and 62 VGPs based on their weekly gaming time. VGPs exhibited higher peak and mean performance than NVGPs. However, we did not find any differences in the speed of covert attention shifts as measured by the CLT needed to achieve peak performance. Thus, our results clearly rule out faster stimulus-response mappings as an explanation for the higher performance of VGPs in line with previous studies. More importantly, our data do not support the notion of faster attention shifts in VGPs as another possible explanation. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Rapid Hydrogen Shift Reactions in Acyl Peroxy Radicals

    DEFF Research Database (Denmark)

    Knap, Hasse Christian; Jørgensen, Solvejg

    2017-01-01

    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...

  11. 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.

  12. Shifts of visuospatial attention do not cause the spatial distortions of the Roelofs effect.

    Science.gov (United States)

    Lester, Benjamin D; Dassonville, Paul

    2013-10-08

    When a visible frame is offset left or right of an observer's objective midline, subjective midline is pulled toward the frame's center, resulting in an illusion of perceived space known as the Roelofs effect. However, a large frame is not necessary to generate the effect-even a small peripheral stimulus is sufficient, raising the possibility that the effect would be brought about by any stimulus that draws attention away from the midline. To assess the relationship between attention and distortions of perceived space, we adopted a paradigm that included a spatial cue that attracted the participant's attention, and an occasional probe whose location was to be reported. If shifts of attention cause the Roelofs effect, the probe's perceived location should vary with the locus of attention. Exogenous attentional cues caused a Roelofs-like effect, but these cues created an asymmetry in the visual display that may have driven the effect directly. In contrast, there was no mislocation after endogenous cues that contained no asymmetry in the visual display. A final experiment used color-contingent attentional cues to eliminate the confound between cue location and asymmetry in the visual display, and provided a clear demonstration that the Roelofs effect is caused by an asymmetric visual display, independent of any shift of attention.

  13. 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...

  14. Impact of extended-duration shifts on medical errors, adverse events, and attentional failures.

    Directory of Open Access Journals (Sweden)

    Laura K Barger

    2006-12-01

    Full Text Available A recent randomized controlled trial in critical-care units revealed that the elimination of extended-duration work shifts (> or =24 h reduces the rates of significant medical errors and polysomnographically recorded attentional failures. This raised the concern that the extended-duration shifts commonly worked by interns may contribute to the risk of medical errors being made, and perhaps to the risk of adverse events more generally. Our current study assessed whether extended-duration shifts worked by interns are associated with significant medical errors, adverse events, and attentional failures in a diverse population of interns across the United States.We conducted a Web-based survey, across the United States, in which 2,737 residents in their first postgraduate year (interns completed 17,003 monthly reports. The association between the number of extended-duration shifts worked in the month and the reporting of significant medical errors, preventable adverse events, and attentional failures was assessed using a case-crossover analysis in which each intern acted as his/her own control. Compared to months in which no extended-duration shifts were worked, during months in which between one and four extended-duration shifts and five or more extended-duration shifts were worked, the odds ratios of reporting at least one fatigue-related significant medical error were 3.5 (95% confidence interval [CI], 3.3-3.7 and 7.5 (95% CI, 7.2-7.8, respectively. The respective odds ratios for fatigue-related preventable adverse events, 8.7 (95% CI, 3.4-22 and 7.0 (95% CI, 4.3-11, were also increased. Interns working five or more extended-duration shifts per month reported more attentional failures during lectures, rounds, and clinical activities, including surgery and reported 300% more fatigue-related preventable adverse events resulting in a fatality.In our survey, extended-duration work shifts were associated with an increased risk of significant medical

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

    National Research Council Canada - National Science Library

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

    2017-01-01

    .... 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...

  16. 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.

  17. 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.

  18. A shift in perspective: Decentering through mindful attention to imagined stressful events.

    Science.gov (United States)

    Lebois, Lauren A M; Papies, Esther K; Gopinath, Kaundinya; Cabanban, Romeo; Quigley, Karen S; Krishnamurthy, Venkatagiri; Barrett, Lisa Feldman; Barsalou, Lawrence W

    2015-08-01

    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 decentering--disengaging the self from the event--should reduce the subjective realism associated with immersion, and therefore perceived stressfulness. To assess this account of decentering, we taught non-meditators a strategy for disengaging from imagined events, simply viewing these events as transient mental states (mindful attention). In a subsequent neuroimaging session, participants imagined stressful and non-stressful events, while either immersing themselves or adopting mindful attention. In conjunction analyses, mindful attention down-regulated the processing of stressful events relative to baseline, whereas immersion up-regulated their processing. In direct contrasts between mindful attention and immersion, mindful attention showed greater activity in brain areas associated with perspective shifting and effortful attention, whereas immersion showed greater activity in areas associated with self-processing and visceral states. These results suggest that mindful attention produces decentering by disengaging embodied senses of self from imagined situations so that affect does not develop. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. 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 (rnoise) 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 rnoise 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 rnoise 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 (rnoise) in rhesus macaque A1 during task performance. Unlike previous studies showing that the effect of attention on rnoise depends on population tuning to the attended feature, we show that the effect of attention depends on the tuning to the

  20. Set-Shifting in a Rodent Model of Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Chess, Amy C.; Raymond, Brittany E.; Gardner-Morse, Ira G.; Stefani, Mark R.; Green, John T.

    2011-01-01

    Two experiments compared Spontaneously Hypertensive Rats (SHRs; a rodent model of attention-deficit/hyperactivity disorder) and Wistars (a normoactive control strain), on the acquisition of a set-shifting strategy. In Experiment 1, SHRs and Wistars were equivalent in trials to criterion to learn a brightness or a texture discrimination but SHRs were faster than Wistars in shifting to the opposite discrimination when there was one or two days between the initial discrimination and the shift. In Experiment 2, SHRs and Wistars were equivalent in shifting when the shift between discriminations occurred immediately after a criterion had been met in the first discrimination. The results are discussed in terms of a failure of SHRs to store or retrieve an initial discrimination and/or latent inhibition over a delay, leading to faster acquisition of a set-shift. This failure in storage or retrieval may be the result of a hypoactive dopamine system in the prefrontal cortex and nucleus accumbens shell as well as abnormalities in entorhinal cortex in SHRs. PMID:21500882

  1. Set shifting in a rodent model of attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Chess, Amy C; Raymond, Brittany E; Gardner-Morse, Ira G; Stefani, Mark R; Green, John T

    2011-06-01

    Two experiments compared spontaneously hypertensive rats (SHRs; a rodent model of attention-deficit/hyperactivity disorder) and Wistar rats (a normoactive control strain), on the acquisition of a set-shifting strategy. In Experiment 1, SHRs and Wistar rats were equivalent in trials to criterion to learn a brightness or a texture discrimination but SHRs were faster than Wistar rats in shifting to the opposite discrimination when there was 1 or 2 days between the initial discrimination and the shift. In Experiment 2, SHRs and Wistar rats were equivalent in shifting when the shift between discriminations occurred immediately after a criterion had been met in the first discrimination. The results are discussed in terms of a failure of SHRs to store or retrieve an initial discrimination and/or latent inhibition over a delay, leading to faster acquisition of a set-shift. This failure in storage or retrieval may be the result of a hypoactive dopamine system in the prefrontal cortex and nucleus accumbens shell as well as abnormalities in entorhinal cortex in SHRs.

  2. [Evaluation of the attention shift effect of a video-audio eyewear in pediatric dental treatment].

    Science.gov (United States)

    Jing, Quan; Wan, Kuo; Ma, Lin

    2010-06-01

    To evaluate the attention shift effect produced by a video-audio eyewear in pediatric dentistry. Totally 40 children aged 4-7 years were equally randomized into fissure sealant group(group S) and caries filling group(group F). A self-control comparison method was used in each group: each child took two visits to finish the whole study, they received the dental treatment either with normal method(SC, FC) or with attention shift by wearing the video-audio eyewear (SI, FI) for each visit. The degree of pain, accomplishment of treatment, and co-operation were analyzed and compared. All children were successfully managed in the whole course. The pain scores were not significantly different between SC group and SI group or between FC group and FI group (P0.05), while the Frankl scores were significantly different between SC group and SI group (P=0.04) and between FC group and FI group (P=0.03). Houpt scores were significantly different between SC group and SI group (P=0.04), but not between FC group and FI group (P=0.85). Most children (90% in group S) and (85% in group F) expressed the willingness to receive the video-audio eyewear if they were asked to do so again. The video-audio eyewear provides satisfactory attention shift for children during dental treatment and increases their cooperation. However, it has little effect on pain relieving.

  3. Cognitive trait anxiety, situational stress, and mental effort predict shifting efficiency: Implications for attentional control theory.

    Science.gov (United States)

    Edwards, Elizabeth J; Edwards, Mark S; Lyvers, Michael

    2015-06-01

    Attentional control theory (ACT) predicts that trait anxiety and situational stress interact to impair performance on tasks that involve attentional shifting. The theory suggests that anxious individuals recruit additional effort to prevent shortfalls in performance effectiveness (accuracy), with deficits becoming evident in processing efficiency (the relationship between accuracy and time taken to perform the task). These assumptions, however, have not been systematically tested. The relationship between cognitive trait anxiety, situational stress, and mental effort in a shifting task (Wisconsin Card Sorting Task) was investigated in 90 participants. Cognitive trait anxiety was operationalized using questionnaire scores, situational stress was manipulated through ego threat instructions, and mental effort was measured using a visual analogue scale. Dependent variables were performance effectiveness (an inverse proportion of perseverative errors) and processing efficiency (an inverse proportion of perseverative errors divided by response time on perseverative error trials). The predictors were not associated with performance effectiveness; however, we observed a significant 3-way interaction on processing efficiency. At higher mental effort (+1 SD), higher cognitive trait anxiety was associated with poorer efficiency independently of situational stress, whereas at lower effort (-1 SD), this relationship was highly significant and most pronounced for those in the high-stress condition. These results are important because they provide the first systematic test of the relationship between trait anxiety, situational stress, and mental effort on shifting performance. The data are also consistent with the notion that effort moderates the relationship between anxiety and shifting efficiency, but not effectiveness. (c) 2015 APA, all rights reserved).

  4. A binary phase-shift keying receiver for the detection of attention to human speech.

    Science.gov (United States)

    Lopez-Gordo, M A; Pelayo, F

    2013-08-01

    Synthetic sounds, tone-beeps, vowels or syllables are typically used in the assessment of attention to auditory stimuli because they evoke a set of well-known event-related potentials, whose characteristics can be statistically contrasted. Such approach rules out the use of stimuli with non-predictable response, such as human speech. In this study we present a procedure based on the robust binary phase-shift keying (BPSK) receiver that permits the real-time detection of selective attention to human speeches in dichotic listening tasks. The goal was achieved by tagging the speeches with two barely-audible tags whose joined EEG response constitutes a reliable BPSK constellation, which can be detected by means of a BPSK receiver. The results confirmed the expected generation of the BPSK constellation by the human auditory system. Also, the bit-error rate and the information transmission rate achieved in the detection of attention fairly followed the expected curves and equations of the standard BPSK receiver. Actually, it was possible to detect attention as well as the estimation a priori of its accuracy based on the signal-to-noise ratio of the BPSK signals. This procedure, which permits the detection of the attention to human speeches, can be of interest for new potential applications, such as brain-computer interfaces, clinical assessment of the attention in real time or for entertainment.

  5. Rapid Shifts in Soil Nutrients and Decomposition Enzyme Activity in Early Succession Following Forest Fire

    OpenAIRE

    Knelman, Joseph E.; Graham, Emily B; Scott Ferrenberg; Aurélien Lecoeuvre; Amanda Labrado; Darcy, John L.; Nemergut, Diana R; Schmidt, Steven K.

    2017-01-01

    While past research has studied forest succession on decadal timescales, ecosystem responses to rapid shifts in nutrient dynamics within the first months to years of succession after fire (e.g., carbon (C) burn-off, a pulse in inorganic nitrogen (N), accumulation of organic matter, etc.) have been less well documented. This work reveals how rapid shifts in nutrient availability associated with fire disturbance may drive changes in soil enzyme activity on short timescales in forest secondary s...

  6. Video-Based Eye Tracking to Detect the Attention Shift: A Computer Classroom Context-Aware System

    Science.gov (United States)

    Kuo, Yung-Lung; Lee, Jiann-Shu; Hsieh, Min-Chai

    2014-01-01

    Eye and head movements evoked in response to obvious visual attention shifts. However, there has been little progress on the causes of absent-mindedness so far. The paper proposes an attention awareness system that captures the conditions regarding the interaction of eye gaze and head pose under various attentional switching in computer classroom.…

  7. 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

  8. 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.

  9. Ocean warming, a rapid distributional shift, and the hybridization of a coastal fish species.

    Science.gov (United States)

    Potts, Warren M; Henriques, Romina; Santos, Carmen V; Munnik, Kate; Ansorge, Isabelle; Dufois, Francois; Booth, Anthony J; Kirchner, Carola; Sauer, Warwick H H; Shaw, Paul W

    2014-09-01

    Despite increasing awareness of large-scale climate-driven distribution shifts in the marine environment, no study has linked rapid ocean warming to a shift in distribution and consequent hybridization of a marine fish species. This study describes rapid warming (0.8 °C per decade) in the coastal waters of the Angola-Benguela Frontal Zone over the last three decades and a concomitant shift by a temperature sensitive coastal fish species (Argyrosomus coronus) southward from Angola into Namibia. In this context, rapid shifts in distribution across Economic Exclusive Zones will complicate the management of fishes, particularly when there is a lack of congruence in the fisheries policy between nations. Evidence for recent hybridization between A. coronus and a congener, A. inodorus, indicate that the rapid shift in distribution of A. coronus has placed adults of the two species in contact during their spawning events. Ocean warming may therefore revert established species isolation mechanisms and alter the evolutionary history of fishes. While the consequences of the hybridization on the production of the resource remain unclear, this will most likely introduce additional layers of complexity to their management. © 2014 John Wiley & Sons Ltd.

  10. More rapid shift to a benthic niche in larger Gadus morhua juveniles.

    Science.gov (United States)

    Ólafsdóttir, G Á; Gunnarsson, G S; Karlsson, H

    2015-08-01

    Trophic use by Atlantic cod Gadus morhua juveniles was examined early and late in the shift from pelagic to benthic habitats. Changes in the proportion of pelagic copepods, estimates of benthic prey indicated by isotope mixing models and stable-isotope values between sample periods suggested a gradual shift towards a benthic niche. Values of the trophic proxies, however, changed most markedly in the largest juvenile group, suggesting a more rapid trophic niche shift, and in turn competitive advantage, of larger juveniles. © 2015 The Fisheries Society of the British Isles.

  11. 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.

  12. 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.

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

    National Research Council Canada - National Science Library

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

    2016-01-01

    .... 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.

  14. Focusing and shifting attention in human children (Homo sapiens) and chimpanzees (Pan troglodytes).

    Science.gov (United States)

    Herrmann, Esther; Tomasello, Michael

    2015-08-01

    Humans often must coordinate co-occurring activities, and their flexible skills for doing so would seem to be uniquely powerful. In 2 studies, we compared 4- and 5-year-old children and one of humans' nearest relatives, chimpanzees, in their ability to focus and shift their attention when necessary. The results of Study 1 showed that 4-year-old children and chimpanzees were very similar in their ability to monitor two identical devices and to sequentially switch between the two to collect a reward, and that they were less successful at doing so than 5-year-old children. In Study 2, which required subjects to alternate between two different tasks, one of which had rewards continuously available whereas the other one only occasionally released rewards, no species differences were found. These results suggest that chimpanzees and human children share some fundamental attentional control skills, but that such abilities continue to develop during human ontogeny, resulting in the uniquely human capacity to succeed at complex multitasking. (c) 2015 APA, all rights reserved).

  15. Eye movements and attention: The role of pre-saccadic shifts of attention in perception, memory and the control of saccades

    Science.gov (United States)

    Gersch, Timothy M.; Schnitzer, Brian S.; Dosher, Barbara A.; Kowler, Eileen

    2012-01-01

    Saccadic eye movements and perceptual attention work in a coordinated fashion to allow selection of the objects, features or regions with the greatest momentary need for limited visual processing resources. This study investigates perceptual characteristics of pre-saccadic shifts of attention during a sequence of saccades using the visual manipulations employed to study mechanisms of attention during maintained fixation. The first part of this paper reviews studies of the connections between saccades and attention, and their significance for both saccadic control and perception. The second part presents three experiments that examine the effects of pre-saccadic shifts of attention on vision during sequences of saccades. Perceptual enhancements at the saccadic goal location relative to non-goal locations were found across a range of stimulus contrasts, with either perceptual discrimination or detection tasks, with either single or multiple perceptual targets, and regardless of the presence of external noise. The results show that the preparation of saccades can evoke a variety of attentional effects, including attentionally-mediated changes in the strength of perceptual representations, selection of targets for encoding in visual memory, exclusion of external noise, or changes in the levels of internal visual noise. The visual changes evoked by saccadic planning make it possible for the visual system to effectively use saccadic eye movements to explore the visual environment. PMID:22809798

  16. Eye movements and attention: the role of pre-saccadic shifts of attention in perception, memory and the control of saccades.

    Science.gov (United States)

    Zhao, Min; Gersch, Timothy M; Schnitzer, Brian S; Dosher, Barbara A; Kowler, Eileen

    2012-12-01

    Saccadic eye movements and perceptual attention work in a coordinated fashion to allow selection of the objects, features or regions with the greatest momentary need for limited visual processing resources. This study investigates perceptual characteristics of pre-saccadic shifts of attention during a sequence of saccades using the visual manipulations employed to study mechanisms of attention during maintained fixation. The first part of this paper reviews studies of the connections between saccades and attention, and their significance for both saccadic control and perception. The second part presents three experiments that examine the effects of pre-saccadic shifts of attention on vision during sequences of saccades. Perceptual enhancements at the saccadic goal location relative to non-goal locations were found across a range of stimulus contrasts, with either perceptual discrimination or detection tasks, with either single or multiple perceptual targets, and regardless of the presence of external noise. The results show that the preparation of saccades can evoke a variety of attentional effects, including attentionally-mediated changes in the strength of perceptual representations, selection of targets for encoding in visual memory, exclusion of external noise, or changes in the levels of internal visual noise. The visual changes evoked by saccadic planning make it possible for the visual system to effectively use saccadic eye movements to explore the visual environment. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. 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.

  18. Shifting of attentional set is inadequate in severe burnout: Evidence from an event-related potential study.

    Science.gov (United States)

    Sokka, Laura; Leinikka, Marianne; Korpela, Jussi; Henelius, Andreas; Lukander, Jani; Pakarinen, Satu; Alho, Kimmo; Huotilainen, Minna

    2017-02-01

    Individuals with prolonged occupational stress often report difficulties in concentration. Work tasks often require the ability to switch back and forth between different contexts. Here, we studied the association between job burnout and task switching by recording event-related potentials (ERPs) time-locked to stimulus onset during a task with simultaneous cue-target presentation and unpredictable switches in the task. Participants were currently working people with severe, mild, or no burnout symptoms. In all groups, task performance was substantially slower immediately after task switch than during task repetition. However, the error rates were higher in the severe burnout group than in the mild burnout and control groups. Electrophysiological data revealed an increased parietal P3 response for the switch trials relative to repetition trials. Notably, the response was smaller in amplitude in the severe burnout group than in the other groups. The results suggest that severe burnout is associated with inadequate processing when rapid shifting of attention between tasks is required resulting in less accurate performance. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Rapid Shifts in Soil Nutrients and Decomposition Enzyme Activity in Early Succession Following Forest Fire

    Directory of Open Access Journals (Sweden)

    Joseph E. Knelman

    2017-09-01

    Full Text Available While past research has studied forest succession on decadal timescales, ecosystem responses to rapid shifts in nutrient dynamics within the first months to years of succession after fire (e.g., carbon (C burn-off, a pulse in inorganic nitrogen (N, accumulation of organic matter, etc. have been less well documented. This work reveals how rapid shifts in nutrient availability associated with fire disturbance may drive changes in soil enzyme activity on short timescales in forest secondary succession. In this study, we evaluate soil chemistry and decomposition extracellular enzyme activity (EEA across time to determine whether rapid shifts in nutrient availability (1–29 months after fire might control microbial enzyme activity. We found that, with advancing succession, soil nutrients correlate with C-targeting β-1,4-glucosidase (BG EEA four months after the fire, and with N-targeting β-1,4-N-acetylglucosaminidase (NAG EEA at 29 months after the fire, indicating shifting nutrient limitation and decomposition dynamics. We also observed increases in BG:NAG ratios over 29 months in these recently burned soils, suggesting relative increases in microbial activity around C-cycling and C-acquisition. These successional dynamics were unique from seasonal changes we observed in unburned, forested reference soils. Our work demonstrates how EEA may shift even within the first months to years of ecosystem succession alongside common patterns of post-fire nutrient availability. Thus, this work emphasizes that nutrient dynamics in the earliest stages of forest secondary succession are important for understanding rates of C and N cycling and ecosystem development.

  20. Rapid chemical shift encoding with single-acquisition single-slab 3D GRASE.

    Science.gov (United States)

    Kim, Hahnsung; Kim, Dong-Hyun; Sohn, Chul-Ho; Park, Jaeseok

    2017-11-01

    To investigate the feasibility of chemical shift encoded, single-slab 3D GRASE for rapid fat-water separation within a single acquisition. The proposed method incorporates signal-to-noise-ratio-optimal chemical shift encoding into single-slab 3D GRASE with variable flip angles. Chemical shift induced phase information was encoded in succession to different positions in k-space by inserting phase encoding blips between adjacent lobes of the oscillating readout gradients. To enhance imaging efficiency, signal prescription-based variable flip angles were used in the long refocusing pulse train. After echo-independent phase correction, missing signals in k-echo space were interpolated using convolution kernels that span over all echoes. Fat-water separation in a single acquisition was performed using both multi-echo fast spin echo and GRASE as compared to conventional multiacquisition fast spin echo with echo shifts. The proposed single-slab 3D GRASE shows superior performance in accurately delineating cartilage structures compared to its counterpart, multi-echo 3D fast spin echo. Compared with multiacquisition fast spin echo with three echo shifts (63 min), the proposed method substantially speeds up imaging time (7 min), and achieves 0.6 mm isotropic resolution in knee imaging with reduced artifacts and noise. We successfully demonstrated the feasibility of rapid chemical shift encoding and separation using the proposed, single-acquisition single-slab 3D GRASE for high resolution isotropic imaging within clinically acceptable time. Magn Reson Med 78:1852-1861, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  1. 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.

  2. P3 latency shifts in the attentional blink: further evidence for second target processing postponement.

    Science.gov (United States)

    Sessa, P; Luria, R; Verleger, R; Dell'Acqua, R

    2007-03-16

    A rapid serial visual presentation technique was used to display sequentially two targets, T1 and T2, and monitor P3 amplitude and latency variations associated with the attentional blink (AB) effect. A red T1 digit was embedded on each trial in a sequence of black letters. T2 was either masked by a trailing stimulus or not masked. T1 had to be identified on a proportion of trials, or ignored in other trials. T2 was the black letter 'E' on 20% of the trials, or any other non-'E' black letter in the other 80% of the trials. A delayed 'E' detection task was required at the end of each trial. An AB was observed when T1 had to be reported and T2 was masked. The AB effect was associated with a sizable amplitude reduction of the P3 component time locked to T2 onset. When T2 was not masked, no AB or P3 amplitude variations were observed. When T1 had to be reported, a delayed P3 peak latency was observed at short compared to long T1-T2 intervals. No effect of T1-T2 interval was observed on the T2-locked P3 peak latency when T1 could be ignored. Taken together these findings provide converging evidence in support of temporal attention models bridging behavior and electrophysiology that postulate a direct link between the cause of the AB effect and the sources of both amplitude and latency variations in the T2-locked P3 component.

  3. 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.

  4. Using temporally aligned event-related potentials for the investigation of attention shifts prior to and during saccades.

    Science.gov (United States)

    Huber-Huber, Christoph; Ditye, Thomas; Marchante Fernández, María; Ansorge, Ulrich

    2016-11-01

    According to the pre-motor theory of attention, attention is shifted to a saccade's landing position before the saccade is executed. Such pre-saccadic attention shifts are usually studied in psychophysical dual-task conditions, with a target-discrimination task before saccade onset. Here, we present a novel approach to investigate pre-saccadic attention shifts with the help of event-related potentials (ERPs). Participants executed one or two saccades to color-defined targets while ERPs and eye-movements were recorded. In single-target blocks participants executed a single saccade. In two-targets blocks participants made either a single saccade to one of the targets, or two successive saccades to both targets. Importantly, in two-targets blocks, targets could appear on the same or on opposite sides of the vertical midline. This allowed us to study contra-to-ipsilateral ERP differences (such as the N2pc or PCN) that reflect attention shifts to the targets, prior to saccade onset and during saccades. If pre-saccadic attention shifts to saccade target locations are necessary for saccade execution and if searched-for saccade targets capture attention, there should be enhanced attentional competition (1) between two targets compared to single targets; (2) between two opposite-sides targets compared to two same-side targets; and (3) in two saccades rather than one saccade conditions: More attentional competition was expected to delay saccade latency and to weaken pre-saccadic laterality effects in ERPs. Hypotheses were tested by means of temporally aligned ERPs that were simultaneously time-locked to stimulus onsets, saccade onsets, and saccade offsets. Predictions (1) and (2) were partly and fully confirmed, respectively, but no evidence was found for (3). We explain the implications of our results for the role of attention during saccade preparation, and we point out how temporally aligned ERPs compare to ICA-based electroencephalogram (EEG) artifact correction

  5. 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...

  6. 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.

  7. Conflict inside and outside: Social comparisons and attention shifts in multidivisional firms

    NARCIS (Netherlands)

    Hu, S.; He, Zilin; Blettner, D.P.; Bettis, R.

    Behavioral Theory highlights the crucial role of social comparisons in attention allocation in adaptive aspirations. Yet, both the specification of social reference points and the dynamics of attention allocation have received little scholarly examination. We address performance feedback from two

  8. Stress-induced alterations in prefrontal cortical dendritic morphology predict selective impairments in perceptual attentional set-shifting.

    Science.gov (United States)

    Liston, Conor; Miller, Melinda M; Goldwater, Deena S; Radley, Jason J; Rocher, Anne B; Hof, Patrick R; Morrison, John H; McEwen, Bruce S

    2006-07-26

    Stressful life events have been implicated clinically in the pathogenesis of mental illness, but the neural substrates that may account for this observation remain poorly understood. Attentional impairments symptomatic of these psychiatric conditions are associated with structural and functional abnormalities in a network of prefrontal cortical structures. Here, we examine whether chronic stress-induced dendritic alterations in the medial prefrontal cortex (mPFC) and orbital frontal cortex (OFC) underlie impairments in the behaviors that they subserve. After 21 d of repeated restraint stress, rats were tested on a perceptual attentional set-shifting task, which yields dissociable measures of reversal learning and attentional set-shifting, functions that are mediated by the OFC and mPFC, respectively. Intracellular iontophoretic injections of Lucifer yellow were performed in a subset of these rats to examine dendritic morphology in layer II/III pyramidal cells of the mPFC and lateral OFC. Chronic stress induced a selective impairment in attentional set-shifting and a corresponding retraction (20%) of apical dendritic arbors in the mPFC. In stressed rats, but not in controls, decreased dendritic arborization in the mPFC predicted impaired attentional set-shifting performance. In contrast, stress was not found to adversely affect reversal learning or dendritic morphology in the lateral OFC. Instead, apical dendritic arborization in the OFC was increased by 43%. This study provides the first direct evidence that dendritic remodeling in the prefrontal cortex may underlie the functional deficits in attentional control that are symptomatic of stress-related mental illnesses.

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

    OpenAIRE

    Antje von Suchodoletz; Anika Fäsche; Skuballa, Irene T.

    2017-01-01

    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;...

  10. 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.

  11. Priming from distractors in rapid serial visual presentation is modulated by image properties and attention.

    Science.gov (United States)

    Harris, Irina M; Benito, Claire T; Dux, Paul E

    2010-12-01

    We investigated distractor processing in a dual-target rapid serial visual presentation (RSVP) task containing familiar objects, by measuring repetition priming from a priming distractor (PD) to Target 2 (T2). Priming from a visually identical PD was contrasted with priming from a PD in a different orientation from T2. We also tested the effect of attention on distractor processing, by placing the PD either within or outside the attentional blink (AB). PDs outside the AB induced positive priming when they were in a different orientation to T2 and no priming, or negative priming, when they were perceptually identical to T2. PDs within the AB induced positive priming regardless of orientation. These findings demonstrate (1) that distractors are processed at multiple levels of representation; (2) that the view-specific representations of distractors are actively suppressed during RSVP; and (3) that this suppression fails in the absence of attention.

  12. Dynamic habitat suitability modelling reveals rapid poleward distribution shift in a mobile apex predator.

    Science.gov (United States)

    Hill, Nicholas J; Tobin, Andrew J; Reside, April E; Pepperell, Julian G; Bridge, Tom C L

    2016-03-01

    Many taxa are undergoing distribution shifts in response to anthropogenic climate change. However, detecting a climate signal in mobile species is difficult due to their wide-ranging, patchy distributions, often driven by natural climate variability. For example, difficulties associated with assessing pelagic fish distributions have rendered fisheries management ill-equipped to adapt to the challenges posed by climate change, leaving pelagic species and ecosystems vulnerable. Here, we demonstrate the value of citizen science data for modelling the dynamic habitat suitability of a mobile pelagic predator (black marlin, Istiompax indica) within the south-west Pacific Ocean. The extensive spatial and temporal coverage of our occurrence data set (n = 18 717), collected at high resolution (~1.85 km(2) ), enabled identification of suitable habitat at monthly time steps over a 16-year period (1998-2013). We identified considerable monthly, seasonal and interannual variability in the extent and distribution of suitable habitat, predominately driven by chlorophyll a and sea surface height. Interannual variability correlated with El Nino Southern Oscillation (ENSO) events, with suitable habitat extending up to ~300 km further south during La Nina events. Despite the strong influence of ENSO, our model revealed a rapid poleward shift in the geometric mean of black marlin habitat, occurring at 88.2 km decade(-1) . By incorporating multiple environmental factors at monthly time steps, we were able to demonstrate a rapid distribution shift in a mobile pelagic species. Our findings suggest that the rapid velocity of climate change in the south-west Pacific Ocean is likely affecting mobile pelagic species, indicating that they may be more vulnerable to climate change than previously thought. © 2015 John Wiley & Sons Ltd.

  13. Effects of shifts in the rate of repetitive stimulation on sustained attention

    Science.gov (United States)

    Krulewitz, J. E.; Warm, J. S.; Wohl, T. H.

    1975-01-01

    The effects of shifts in the rate of presentation of repetitive neutral events (background event rate) were studied in a visual vigilance task. Four groups of subjects experienced either a high (21 events/min) or a low (6 events/min) event rate for 20 min and then experienced either the same or the alternate event rate for an additional 40 min. The temporal occurrence of critical target signals was identical for all groups, irrespective of event rate. The density of critical signals was 12 signals/20 min. By the end of the session, shifts in event rate were associated with changes in performance which resembled contrast effects found in other experimental situations in which shift paradigms were used. Relative to constant event rate control conditions, a shift from a low to a high event rate depressed the probability of signal detections, while a shift in the opposite direction enhanced the probability of signal detections.

  14. 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

    2016-04-16

    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.

  15. 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.

  16. 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

  17. A collection of pseudo-words to study multi-talker speech intelligibility without shifts of spatial attention

    Directory of Open Access Journals (Sweden)

    Kachina eAllen

    2012-03-01

    Full Text Available A new collection of pseudo-words was recorded from a single female speaker of American English for use in multi-talker speech intelligibility research. The pseudo-words (known as the PARG collection consist of three groups of single syllable pseudo-words varying only by the initial phoneme. The PARG method allows speech intelligibility to be studied free of the influence of shifts of spatial attention from one loudspeaker location to another in multi-talker contexts. To achieve this, all PARG pseudo-words share the same concluding rimes, with only the first phoneme serving as a distinguishing identifier. This ensures that listeners are unable to correctly identify the target pseudo-word without hearing the initial phoneme. As the duration of all the initial phonemes are brief, much shorter than the time required to spatially shift attention, the PARG method assesses speech intelligibility without the confound of shifting spatial attention. The PARG collection is available free for research purposes.

  18. Electrocorticography of Spatial Shifting and Attentional Selection in Human Superior Parietal Cortex

    Directory of Open Access Journals (Sweden)

    Maarten Schrooten

    2017-05-01

    Full Text Available Spatial-attentional reorienting and selection between competing stimuli are two distinct attentional processes of clinical and fundamental relevance. In the past, reorienting has been mainly associated with inferior parietal cortex. In a patient with a subdural grid covering the upper and lower bank of the left anterior and middle intraparietal sulcus (IPS and the superior parietal lobule (SPL, we examined the involvement of superior parietal cortex using a hybrid spatial cueing paradigm identical to that previously applied in stroke and in healthy controls. In SPL, as early as 164 ms following target onset, an invalidly compared to a validly cued target elicited a positive event-related potential (ERP and an increase in intertrial coherence (ITC in the theta band, regardless of the direction of attention. From around 400–650 ms, functional connectivity [weighted phase lag index (wPLI analysis] between SPL and IPS briefly inverted such that SPL activity was driving IPS activity. In contrast, the presence of a competing distracter elicited a robust change mainly in IPS from 300 to 600 ms. Within superior parietal cortex reorienting of attention is associated with a distinct and early electrophysiological response in SPL while attentional selection is indexed by a relatively late electrophysiological response in the IPS. The long latency suggests a role of IPS in working memory or cognitive control rather than early selection.

  19. 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

  20. 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…

  1. On the stochastic nature of the rapid climate shifts during the last ice age

    DEFF Research Database (Denmark)

    Ditlevsen, Peter Dalager; Ditlevsen, Ove Dalager

    2009-01-01

    The rapid climate shifts observed in the glacial climate are analysed. The transitions into the warm interstadial states, the onsets, are easy identifiable in the record. The distribution of waiting times between consecutive onsets is well fitted assuming the remaining residence time in each state...... to exponential distributions with mean waiting times of around 800 y in the warm state and around 1600 y in the cold state. This observation is an important piece in the climate puzzle, since the fact that the climate is a no memory process indicates that the transitions are noise induced and the mean residence...... to be independent on the past. That implies that it has a simple no memory exponential waiting time distribution, but with mean waiting time depending on the climate state. The mean waiting time from one onset to the next is around 2400 y. The most likely (maximum likelihood) distribution derived solely from...

  2. Selecting One Among the Many: A Simple Network Implementing Shifts in Selective Visual Attention.

    Science.gov (United States)

    1984-01-01

    Acknowledgments: We would like to thank Francis Crick , Ellen Hildreth, James Mahoney and Tomaso Poggio for their enlightening comments. Gady Geiger pointed out...the visual field -- (Atkinson, Campbell & Francis 1976). Consider next the problem of performing a conjunctive search task (Treisman & Gelade, 1080...central representation. Interestingly, Crick proposed recently (1984; see also Yingling & Skinner, 1977) - - that the attentional searchlight is controlled

  3. Rightward Shift in Temporal Order Judgements in the Wake of the Attentional Blink

    Science.gov (United States)

    Perez, Alejandro; Penton, Lorna Garcia; Valdes-Sosa, Mitchell

    2008-01-01

    The temporal order of two events, each presented in a different visual hemifield, is judged correctly by typical observers even when their onsets differ only slightly. The present study examined the influence of an endogenous process on TOJ, and shows that the perception of temporal order is also affected when available attentional resources are…

  4. 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

  5. Rapid serial processing of natural scenes: color modulates detection but neither recognition nor the attentional blink.

    Science.gov (United States)

    Marx, Svenja; Hansen-Goos, Onno; Thrun, Michael; Einhäuser, Wolfgang

    2014-12-16

    The exact function of color vision for natural-scene perception has remained puzzling. In rapid serial visual presentation (RSVP) tasks, categorically defined targets (e.g., animals) are detected typically slightly better for color than for grayscale stimuli. Here we test the effect of color on animal detection, recognition, and the attentional blink. We present color and grayscale RSVP sequences with up to two target images (animals) embedded. In some conditions, we modify either the hue or the intensity of each pixel. We confirm a benefit of color over grayscale images for animal detection over a range of stimulus onset asynchronies (SOAs), with improved hit rates from 50 to 120 ms and overall improved performance from 90 to 120 ms. For stimuli in which the hue is inverted, performance is similar to grayscale for small SOAs and indistinguishable from original color only for large SOAs. For subordinate category discrimination, color provides no additional benefit. Color and grayscale sequences show an attentional blink, but differences between color and grayscale are fully explained by single-target differences, ruling out the possibility that the color benefit is purely attentional. © 2014 ARVO.

  6. Mycobacteria mobility shift assay: a method for the rapid identification of Mycobacterium tuberculosis and nontuberculous mycobacteria

    Directory of Open Access Journals (Sweden)

    Letícia Muraro Wildner

    2014-06-01

    Full Text Available The identification of mycobacteria is essential because tuberculosis (TB and mycobacteriosis are clinically indistinguishable and require different therapeutic regimens. The traditional phenotypic method is time consuming and may last up to 60 days. Indeed, rapid, affordable, specific and easy-to-perform identification methods are needed. We have previously described a polymerase chain reaction-based method called a mycobacteria mobility shift assay (MMSA that was designed for Mycobacterium tuberculosis complex (MTC and nontuberculous mycobacteria (NTM species identification. The aim of this study was to assess the MMSA for the identification of MTC and NTM clinical isolates and to compare its performance with that of the PRA-hsp65 method. A total of 204 clinical isolates (102 NTM and 102 MTC were identified by the MMSA and PRA-hsp65. For isolates for which these methods gave discordant results, definitive species identification was obtained by sequencing fragments of the 16S rRNA and hsp65 genes. Both methods correctly identified all MTC isolates. Among the NTM isolates, the MMSA alone assigned 94 (92.2% to a complex or species, whereas the PRA-hsp65 method assigned 100% to a species. A 91.5% agreement was observed for the 94 NTM isolates identified by both methods. The MMSA provided correct identification for 96.8% of the NTM isolates compared with 94.7% for PRA-hsp65. The MMSA is a suitable auxiliary method for routine use for the rapid identification of mycobacteria.

  7. Rapid and Profound Shifts in the Vaginal Microbiota Following Antibiotic Treatment for Bacterial Vaginosis.

    Science.gov (United States)

    Mayer, Bryan T; Srinivasan, Sujatha; Fiedler, Tina L; Marrazzo, Jeanne M; Fredricks, David N; Schiffer, Joshua T

    2015-09-01

    Bacterial vaginosis (BV) is a common polymicrobial disease associated with numerous negative reproductive health outcomes, including an increased risk of human immunodeficiency virus acquisition. BV is treatable with antibiotics, but relapse is common. A more detailed understanding of bacterial dynamics during antibiotic therapy for BV could identify conditions that favor establishment, maintenance, and eradication of BV-associated bacterial species, thereby improving treatment outcomes. We used mathematical models to analyze daily quantitative measurements of 11 key bacterial species during metronidazole treatment for 15 cases of BV. We identified complete reorganization of vaginal bacterial composition within a day of initiating therapy. Although baseline bacterial levels predicted a longer time to clearance, all anaerobic species were eliminated rapidly within a median of 3 days. However, reemergence of BV-associated species was common following treatment cessation. Gardnerella vaginalis, a facultative anaerobe, was cleared more slowly than anaerobic BV-associated species, and levels of G. vaginalis often rebounded during treatment. We observed gradual Lactobacillus species growth, indicating that untargeted microbes fill the transient vacuum formed during treatment. Under antibiotic pressure, the human microbiome can undergo rapid shifts on a scale of hours. When treatment is stopped, BV-associated bacteria quickly reemerge, suggesting a possible role for intermittent prophylactic treatment. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. Mycobacteria mobility shift assay: a method for the rapid identification of Mycobacterium tuberculosis and nontuberculous mycobacteria.

    Science.gov (United States)

    Wildner, Letícia Muraro; Bazzo, Maria Luiza; Liedke, Susie Coutinho; Nogueira, Christiane Lourenço; Segat, Gabriela; Senna, Simone Gonçalves; Schlindwein, Aline Daiane; Oliveira, Jaquelline Germano de; Rovaris, Darcita B; Bonjardim, Claudio A; Kroon, Erna G; Ferreira, Paulo C P

    2014-06-01

    The identification of mycobacteria is essential because tuberculosis (TB) and mycobacteriosis are clinically indistinguishable and require different therapeutic regimens. The traditional phenotypic method is time consuming and may last up to 60 days. Indeed, rapid, affordable, specific and easy-to-perform identification methods are needed. We have previously described a polymerase chain reaction-based method called a mycobacteria mobility shift assay (MMSA) that was designed for Mycobacterium tuberculosis complex (MTC) and nontuberculous mycobacteria (NTM) species identification. The aim of this study was to assess the MMSA for the identification of MTC and NTM clinical isolates and to compare its performance with that of the PRA-hsp65 method. A total of 204 clinical isolates (102 NTM and 102 MTC) were identified by the MMSA and PRA-hsp65. For isolates for which these methods gave discordant results, definitive species identification was obtained by sequencing fragments of the 16S rRNA and hsp65 genes. Both methods correctly identified all MTC isolates. Among the NTM isolates, the MMSA alone assigned 94 (92.2%) to a complex or species, whereas the PRA-hsp65 method assigned 100% to a species. A 91.5% agreement was observed for the 94 NTM isolates identified by both methods. The MMSA provided correct identification for 96.8% of the NTM isolates compared with 94.7% for PRA-hsp65. The MMSA is a suitable auxiliary method for routine use for the rapid identification of mycobacteria.

  9. 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.

  10. 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.

  11. Sleep loss, circadian mismatch, and abnormalities in reorienting of attention in night workers with shift work disorder.

    Science.gov (United States)

    Gumenyuk, Valentina; Howard, Ryan; Roth, Thomas; Korzyukov, Oleg; Drake, Christopher L

    2014-03-01

    Permanent night-shift workers may develop shift-work disorder (SWD). In the current study, we evaluated neurophysiological and behavioral indices of distractibility across times prior to the night shift (T1), during night hours (T2), and after acute sleep deprivation (T3) in permanent hospital night workers with and without SWD. Ten asymptomatic night workers (NW) and 18 NW with SWD participated in a 25-h sleep deprivation study. Circadian phase was evaluated by dim-light salivary melatonin onset (DLMO). Objective sleepiness was evaluated using the Multiple Sleep Latency Test (MSLT). Electrophysiological distractibility was evaluated by brain event-related potentials (ERP), whereas behavioral distractibility was evaluated by performance on a visual task in an auditory-visual distraction paradigm. Comparisons of ERP results were performed by repeated-measures analysis of variance, and t-tests were used where appropriate. A Mann-Whitney U test was used for comparison of variables (MLST, Stanford Sleepiness Scale, and DLMO) that deviated from normal. First, in the SWD group, the reorienting negativity ERP amplitude was significantly attenuated compared to that in the NW group. Second, the SWD group had shorter MSLT during night shift hours (4.8 ± 4.9 min) compared to that in NW (7.8 ± 3.7 min; U = 47; z = -2.1; P sleep deprivation impaired behavioral performance and the P3a ERP in both groups. Our results demonstrate specific deficits in neurophysiological activity in the attentional domain among the shift-work disorder group relative to night workers.

  12. Visual attention distracter insertion for improved EEG rapid serial visual presentation (RSVP) target stimuli detection

    Science.gov (United States)

    Khosla, Deepak; Huber, David J.; Martin, Kevin

    2017-05-01

    This paper† describes a technique in which we improve upon the prior performance of the Rapid Serial Visual Presentation (RSVP) EEG paradigm for image classification though the insertion of visual attention distracters and overall sequence reordering based upon the expected ratio of rare to common "events" in the environment and operational context. Inserting distracter images maintains the ratio of common events to rare events at an ideal level, maximizing the rare event detection via P300 EEG response to the RSVP stimuli. The method has two steps: first, we compute the optimal number of distracters needed for an RSVP stimuli based on the desired sequence length and expected number of targets and insert the distracters into the RSVP sequence, and then we reorder the RSVP sequence to maximize P300 detection. We show that by reducing the ratio of target events to nontarget events using this method, we can allow RSVP sequences with more targets without sacrificing area under the ROC curve (azimuth).

  13. Winter storms drive rapid phenotypic, regulatory, and genomic shifts in the green anole lizard.

    Science.gov (United States)

    Campbell-Staton, Shane C; Cheviron, Zachary A; Rochette, Nicholas; Catchen, Julian; Losos, Jonathan B; Edwards, Scott V

    2017-08-04

    Extreme environmental perturbations offer opportunities to observe the effects of natural selection in wild populations. During the winter of 2013-2014, the southeastern United States endured an extreme cold event. We used thermal performance, transcriptomics, and genome scans to measure responses of lizard populations to storm-induced selection. We found significant increases in cold tolerance at the species' southern limit. Gene expression in southern survivors shifted toward patterns characteristic of northern populations. Comparing samples before and after the extreme winter, 14 genomic regions were differentiated in the surviving southern population; four also exhibited signatures of local adaptation across the latitudinal gradient and implicate genes involved in nervous system function. Together, our results suggest that extreme winter events can rapidly produce strong selection on natural populations at multiple biological levels that recapitulate geographic patterns of local adaptation. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  14. Gaze position reveals impaired attentional shift during visual word recognition in dysfluent readers.

    Directory of Open Access Journals (Sweden)

    Jarkko Hautala

    Full Text Available Effects reflecting serial within-word processing are frequently found in pseudo- and non-word recognition tasks not only among fluent, but especially among dyslexic readers. However, the time course and locus of these serial within-word processing effects in the cognitive hierarchy (i.e., orthographic, phonological, lexical have remained elusive. We studied whether a subject's eye movements during a lexical decision task would provide information about the temporal dynamics of serial within-word processing. We assumed that if there is serial within-word processing proceeding from left to right, items with informative beginnings would attract the gaze position and (micro-saccadic eye movements earlier in time relative to those with informative endings. In addition, we compared responses to word, non-word, and pseudo-word items to study whether serial within-word processing stems mainly from a lexical, orthographic, or phonological processing level, respectively. Gaze positions showed earlier responses to anomalies located at pseudo- and non-word beginnings rather than endings, whereas informative word beginnings or endings did not affect gaze positions. The overall pattern of results suggests parallel letter processing of real words and rapid serial within-word processing when reading novel words. Dysfluent readers' gaze position responses toward anomalies located at pseudo- and non-word endings were delayed substantially, suggesting impairment in serial processing at an orthographic processing level.

  15. 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

  16. Attention-shift vs. response-priming explanations for the spatial cueing effect in cross-modal tasks.

    Science.gov (United States)

    Paavilainen, Petri; Illi, Janne; Moisseinen, Nella; Niinisalo, Maija; Ojala, Karita; Reinikainen, Johanna; Vainio, Lari

    2016-06-01

    The task-irrelevant spatial location of a cue stimulus affects the processing of a subsequent target. This "Posner effect" has been explained by an exogenous attention shift to the spatial location of the cue, improving perceptual processing of the target. We studied whether the left/right location of task-irrelevant and uninformative tones produces cueing effects on the processing of visual targets. Tones were presented randomly from left or right. In the first condition, the subsequent visual target, requiring response either with the left or right hand, was presented peripherally to left or right. In the second condition, the target was a centrally presented left/right-pointing arrow, indicating the response hand. In the third condition, the tone and the central arrow were presented simultaneously. Data were recorded on compatible (the tone location and the response hand were the same) and incompatible trials. Reaction times were longer on incompatible than on compatible trials. The results of the second and third conditions are difficult to explain with the attention-shift model emphasizing improved perceptual processing in the cued location, as the central target did not require any location-based processing. Consequently, as an alternative explanation they suggest response priming in the hand corresponding to the spatial location of the tone. Simultaneous lateralized readiness potential (LRP) recordings were consistent with the behavioral data, the tone cues eliciting on incompatible trials a fast preparation for the incorrect response and on compatible trials preparation for the correct response. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  17. 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).…

  18. 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. ...

  19. Rapid naming in Brazilian students with dyslexia and Attention Deficit Hyperactivity Disorder

    Directory of Open Access Journals (Sweden)

    Luciana eMendonça Alves

    2016-01-01

    Full Text Available Introduction: The effective development of reading and writing skills requires the concerted action of several abilities, one of which is phonological processing. One of the foremost components of phonological processing is rapid automatized naming (RAN- the ability to identify and recognize a given item by the activation and concomitant articulation of its name. Objective: To assess the RAN performance of schoolchildren with dyslexia and attention-deficit/hyperactivity disorder (ADHD compared with their peers. Methods: In total, 70 schoolchildren aged between 8‒11 years participated in the study. Of these, 16 children had a multiprofessional diagnosis of ADHD while 14 had been diagnosed with dyslexia. Matched with these groups, 40 schoolchildren with no history of developmental impairments were also evaluated. The RAN test was administered to assess the length of time required to name a series of familiar visual stimuli. The statistical analysis was conducted using measures of descriptive statistics and the 2-sample t-test at the 5% significance level. Results: The performance of the group with dyslexia was inferior to that of the control group, in all tasks and the ADHD group had inferior performance for color and letters-naming tasks. The schoolchildren with dyslexia and those with ADHD showed very similar response times. Age has shown to be an important variable to be analyzed separately. Children with typical language development have faster answers as they aged on colors and digits tasks while children with dyslexia or ADHD do not show improvement with age. Conclusions: The schoolchildren with dyslexia took longer to complete all tasks and ADHD took longer to complete digits and objects tasks in comparison to their peers with typical development. This ability tends to improve with age, which is not the case, however, with schoolchildren who have ADHD or dyslexia.

  20. 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…

  1. 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.

  2. 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

  3. 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

  4. The effect of valence on young and older adults' attention in a rapid serial visual presentation task.

    Science.gov (United States)

    Steinmetz, Katherine R Mickley; Muscatell, Keely A; Kensinger, Elizabeth A

    2010-03-01

    Using a rapid serial visual presentation task, the authors examined how the emotional valence of a word affected young and older adults' abilities to detect another word that closely followed it in temporal proximity. Both age groups detected neutral words better when such words followed a positive or negative arousing word rather than a neutral arousing word. These results suggest that emotion influences attention in a similar fashion for young and older adults. Despite evidence that older adults can sometimes show a "positivity effect" in memory, we found no evidence of increased attention toward positive words for older adults.

  5. 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. ...... species assemblage in responses to recent climate change. Even among the most mobile species and without anthropogenic barriers to dispersal, these pollinators have been unable to extend their ranges as fast as required to keep pace with climate change....

  6. rTMS-induced virtual lesion of the posterior parietal cortex (PPC) alters the control of reflexive shifts of social attention triggered by pointing hands.

    Science.gov (United States)

    Porciello, Giuseppina; Crostella, Filippo; Liuzza, Marco Tullio; Valentini, Elia; Aglioti, Salvatore Maria

    2014-07-01

    In highly social groups like human and non-human primates, gaze and pointing cues are fundamentally important for directing the attention of conspecifics. Although neuroimaging studies indicate that shifts of attention triggered by observation of social cues activate the onlookers׳ fronto-parietal cortices, information on whether these regions play a causative role in orienting and re-orienting of social attention is lacking. To advance our understanding of this, we used event-related repetitive dual pulse transcranial magnetic stimulation to interfere with neural activity in the right frontal eye field (rFEF) and posterior parietal cortex (rPPC). This procedure allowed us to explore how inhibiting rFEF and rPPC influences shifts of attention triggered by the observation of body-related (gaze and hand) and non body-related (arrow) directional distractors. Participants were asked to perform a leftward or rightward pointing movement according to the color change of a central imperative signal while ignoring a distractor, which was either a gaze, a pointing hand or an arrow. Stimulation of rPPC in a region supposedly linked to attentional re-orienting and to planning and execution of upper limb movements increased the reflexive tendency to follow distracting pointing hands but not oriented gaze or arrows. These findings suggest that inhibition of cortical structures that control attentional shifts triggered by social stimuli brings forth an increase of the cost of attentional re-orienting. Moreover, our results provide the first causative evidence that reflexive social attention in humans may be coded according to body-part-centered frames of reference. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. FMRP regulates an ethanol-dependent shift in GABABR function and expression with rapid antidepressant properties.

    Science.gov (United States)

    Wolfe, Sarah A; Workman, Emily R; Heaney, Chelcie F; Niere, Farr; Namjoshi, Sanjeev; Cacheaux, Luisa P; Farris, Sean P; Drew, Michael R; Zemelman, Boris V; Harris, R Adron; Raab-Graham, Kimberly F

    2016-09-26

    Alcohol promotes lasting neuroadaptive changes that may provide relief from depressive symptoms, often referred to as the self-medication hypothesis. However, the molecular/synaptic pathways that are shared by alcohol and antidepressants are unknown. In the current study, acute exposure to ethanol produced lasting antidepressant and anxiolytic behaviours. To understand the functional basis of these behaviours, we examined a molecular pathway that is activated by rapid antidepressants. Ethanol, like rapid antidepressants, alters γ-aminobutyric acid type B receptor (GABABR) expression and signalling, to increase dendritic calcium. Furthermore, new GABABRs are synthesized in response to ethanol treatment, requiring fragile-X mental retardation protein (FMRP). Ethanol-dependent changes in GABABR expression, dendritic signalling, and antidepressant efficacy are absent in Fmr1-knockout (KO) mice. These findings indicate that FMRP is an important regulator of protein synthesis following alcohol exposure, providing a molecular basis for the antidepressant efficacy of acute ethanol exposure.

  8. 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.

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

    OpenAIRE

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

    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) p...

  10. 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)

  11. No correlation, no evidence for attention shift in category learning: different mechanisms behind illusory correlations and the inverse base-rate effect.

    Science.gov (United States)

    Kutzner, Florian L; Fiedler, Klaus

    2015-02-01

    When common and rare attributes are equally prevalent for frequent and infrequent categories, the frequent categories (e.g., majority groups) are associated more strongly with the common attributes (e.g., positive valence) than infrequent categories (e.g., minority groups). Such a frequency-based illusory correlation (IC) effect has been shown to arise through unbiased learning, which is less complete for infrequent than for frequent categories. On the other hand, when frequent categories are always paired with corresponding common attributes and infrequent categories with corresponding rare attributes, an inverse base-rate effect (IBRE) arises. The association of the infrequent categories with the rare attributes is stronger than the association of the frequent categories with the common attributes. Recently, it has been proposed that the attention shift mechanism that produces the IBRE is also essential to explaining IC effects (Sherman, Kruschke, Sherman, Percy, Petrocelli, & Conrey, 2009). No evidence was found for this explanation of standard IC effects across 4 experiments and related computational modeling of attention shift (using a model called EXIT, derived from "extended ADIT" model, where the name ADIT is an acronym for "attention to distinctive input"). In a fifth experiment, evidence for attention shift was found for perfect category-attribute correlations. In sum, incomplete learning continues to offer a sufficient and parsimonious account of IC effects.

  12. Rapid northward shift of the Indian Monsoon on the Tibetan Plateau at the end of the Little Ice Age

    Science.gov (United States)

    Zhang, Xiaolong; Xu, Baiqing; Günther, Franziska; Witt, Roman; Wang, Mo; Xie, Ying; Zhao, Huabiao; Li, Jiule; Gleixner, Gerd

    2017-09-01

    Variations in the Indian Monsoon (IM) and Westerlies (WS) significantly affect the climate on the Tibetan Plateau (TP) and have widespread ecological and socioeconomic impacts on the whole of Asian society. So far, however, the rate and magnitude of changes in the IM have still remained unclear. Here we report for the first time that the IM rapidly shifted northward at the end of the Little Ice Age (LIA). We used sediment proxies for humidity and moisture sources from the Taro Co Lake, which is located in the transition zone between the WS and IM. Our comprehensive survey of climate records for the TP and its peripheral mountain ranges revealed that the northern boundary of the IM (i.e., the southern boundary of the WS) lay along the southern slope of the Gandise Range ( 29.5°N) in the late LIA. In contrast, it passed quickly over the Gandise Range by at least 1.5° in latitude at the end of the LIA. Our results suggest that this rapid climatic shift was potentially triggered by the counteracting effects of blocking by the TP and its marginal orography, which hindered the northward movement of the IM, and the pulling thermal gradient of the TP.

  13. Wavelength shifting of intra-cavity photons: Adiabatic wavelength tuning in rapidly wavelength-swept lasers.

    Science.gov (United States)

    Jirauschek, Christian; Huber, Robert

    2015-07-01

    We analyze the physics behind the newest generation of rapidly wavelength tunable sources for optical coherence tomography (OCT), retaining a single longitudinal cavity mode during operation without repeated build up of lasing. In this context, we theoretically investigate the currently existing concepts of rapidly wavelength-swept lasers based on tuning of the cavity length or refractive index, leading to an altered optical path length inside the resonator. Specifically, we consider vertical-cavity surface-emitting lasers (VCSELs) with microelectromechanical system (MEMS) mirrors as well as Fourier domain mode-locked (FDML) and Vernier-tuned distributed Bragg reflector (VT-DBR) lasers. Based on heuristic arguments and exact analytical solutions of Maxwell's equations for a fundamental laser resonator model, we show that adiabatic wavelength tuning is achieved, i.e., hopping between cavity modes associated with a repeated build up of lasing is avoided, and the photon number is conserved. As a consequence, no fundamental limit exists for the wavelength tuning speed, in principle enabling wide-range wavelength sweeps at arbitrary tuning speeds with narrow instantaneous linewidth.

  14. Shifting Thresholds: Rapid Evolution of Migratory Life Histories in Steelhead/Rainbow Trout, Oncorhynchus mykiss.

    Science.gov (United States)

    Phillis, Corey C; Moore, Jonathan W; Buoro, Mathieu; Hayes, Sean A; Garza, John Carlos; Pearse, Devon E

    2016-01-01

    Expression of phenotypic plasticity depends on reaction norms adapted to historic selective regimes; anthropogenic changes in these selection regimes necessitate contemporary evolution or declines in productivity and possibly extinction. Adaptation of conditional strategies following a change in the selection regime requires evolution of either the environmentally influenced cue (e.g., size-at-age) or the state (e.g., size threshold) at which an individual switches between alternative tactics. Using a population of steelhead (Oncorhynchus mykiss) introduced above a barrier waterfall in 1910, we evaluate how the conditional strategy to migrate evolves in response to selection against migration. We created 9 families and 917 offspring from 14 parents collected from the above- and below-barrier populations. After 1 year of common garden-rearing above-barrier offspring were 11% smaller and 32% lighter than below-barrier offspring. Using a novel analytical approach, we estimate that the mean size at which above-barrier fish switch between the resident and migrant tactic is 43% larger than below-barrier fish. As a result, above-barrier fish were 26% less likely to express the migratory tactic. Our results demonstrate how rapid and opposing changes in size-at-age and threshold size contribute to the contemporary evolution of a conditional strategy and indicate that migratory barriers may elicit rapid evolution toward the resident life history on timescales relevant for conservation and management of conditionally migratory species. © The American Genetic Association. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Sleep-Wake Cycle, Daytime Sleepiness, and Attention Components in Children Attending Preschool in the Morning and Afternoon Shifts

    Science.gov (United States)

    Belísio, Aline S.; Kolodiuk, Fernanda F.; Louzada, Fernando M.; Valdez, Pablo; Azevedo, Carolina V. M.

    2017-01-01

    Children tend to sleep and wake up early and to exhibit daytime sleep episodes. To evaluate the impact of school start times on sleepiness and attention in preschool children, this study compared the temporal patterns of sleep, daytime sleepiness, and the components of attention between children aged 4-6 years that study in the morning (n = 66)…

  16. 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.

  17. 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.

  18. Attentional biases using the body in the crowd task: are angry body postures detected more rapidly?

    Science.gov (United States)

    Gilbert, Tracy; Martin, Rachael; Coulson, Mark

    2011-06-01

    Research using schematic faces has consistently demonstrated attentional biases towards threatening information (angry faces), which are accentuated for individuals with higher levels of anxiety. However, research has yet to reveal whether this is the case for other nonverbal channels of communication. In the research reported here, ninety-five undergraduates completed a body in the crowd task analogous to the face in the crowd task, to examine whether attentional biases for threat existed for schematic body postures. Participants demonstrated faster detection of threat. A discrepant angry posture in a neutral crowd was identified quicker than a discrepant happy posture in a neutral crowd. This effect was pronounced for individuals with higher self-reported levels of trait anxiety. Results also demonstrated evidence of delayed disengagement from threat. Individuals were slower (i.e., more distracted) by identical crowds of angry postures rather than happy or neutral crowds and were slower to detect a discrepant neutral posture among an angry crowd than neutral among a happy crowd. These findings are the first to establish threat biases using body postures in a visual search paradigm. The results are in accordance with previous research using schematic face stimuli. Theoretical and practical implications are discussed.

  19. Drought drives rapid shifts in soil biogeochemistry and greenhouse gas emissions in a wet tropical forest

    Science.gov (United States)

    O'Connell, C.; Silver, W. L.; Ruan, L.

    2016-12-01

    Global circulation models suggest that climate change will increase the frequency and severity of drought in the humid tropics (Neelin et al., 2006). There is considerable uncertainty about the effects of drought on biogeochemical cycling in these ecosystems (Chambers et al., 2012), which play a key role in global carbon (C) and nitrogen (N) budgets (Vitousek & Sanford, 1986; Wright, 2005; Le Quéré et al., 2009). We used an automated sensor array to determine the effects of a recent severe drought on soil moisture, oxygen (O2), greenhouse gas emissions, and key nutrients across a wet tropical forest landscape. The onset of drought led to a rapid decline in soil moisture (46% drop in 21 days) and an associated rise in soil aeration. Drying also led to significant declines in inorganic P concentrations, an element commonly limiting to net primary productivity (NPP) in humid tropical forests (Cleveland et al. 2011). Drought increased soil carbon dioxide (CO2) emissions from slopes by 60% (from 3.79 ± 2.92 to 6.06 ± 4.26 µmol m-2 s-1) and valleys by 163% (from 0.57 ± 0.17 to 1.51 ± 0.75 µmol m-2 s-1). Methane (CH4) fluxes declined by 90% in valleys after the drought (from 17.43 ± 29.60 to 1.67 ± 4.09 nmol m-2 s-1) but increased above pre-drought baseline by tenfold and hundredfold in ridges and slopes, respectively, post-drought, offsetting the initial decline in soil CH4 emissions. Soil moisture and soil O2 concentrations were slow to recover after the onset of rains, effectively increasing the length of the drought effect by up to 65%. Results indicate that drought is likely to result in soil C losses and increased soil P limitation, potentially decreasing tropical forest C uptake and storage in the future.

  20. The role of temporal predictability in the anticipatory biasing of sensory cortex during visuospatial shifts of attention.

    Science.gov (United States)

    Green, Jessica J; McDonald, John J

    2010-11-01

    The presentation of an attention-directing cue elicits a lateralized ERP deflection called the late directing attention positivity (LDAP) and lateralized changes in alpha-band elelctroencephalogram oscillations. Both of these electrophysiological responses have been independently linked to biasing of visual cortex in anticipation of an impending target. However, the LDAP is not always observed, and the link between the ERP and alpha-band modulations remains unclear. Here, we examined the effect of advance knowledge of the time of target onset on the ERP and alpha-band responses to cues. The LDAP was present only when the attention-directing cues accurately indicated the time of target appearance, whereas two sequential attention-related alpha-band modulations were observed regardless of the temporal information provided by the cues. Thus, alpha-band activity may be a more reliable index of pretarget biasing of visual cortical activity than lateralized ERP effects. Copyright © 2010 Society for Psychophysiological Research.

  1. 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...... associated with cell walls, rather than toward structural cell wall components such as cellulose and hemicelluloses. Substrate constituents are also known to be sequentially degraded in different sections of the fungus garden. To test the plasticity in the extracellular expression of fungus-garden enzymes......, 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...

  2. Neuronal substrates participating in attentional set-shifting of rules for visually guided motor selection: a functional magnetic resonance imaging investigation.

    Science.gov (United States)

    Omori, M; Yamada, H; Murata, T; Sadato, N; Tanaka, M; Ishii, Y; Isaki, K; Yonekura, Y

    1999-04-01

    To investigate the neuronal substrates participating in attentional set-shifting for motor selection rules, a functional magnetic resonance imaging study was performed during hand-shape selection tasks. During the session, six right-handed subjects were required to make one of three hand-shapes using their right hands, in response to the hand-shape images on a video screen, following one of the three predefined rules of win, lose, and tie. The selection rules were consistently applied in three conditions (win, tie, and lose), and changed alternately in one condition (alternate win-lose). Thus the alternate win-lose condition requires the shift of rules for motor selection. This alternate condition compared with the win, tie, and lose conditions showed activation in the left middle frontal gyrus, the bilateral inferior frontal gyri, and the left posterior fusiform and lingual gyri. These activation patterns in the prefrontal cortex were similar to those observed during the performance of the Wisconsin Card Sorting Test (WCST), which requires a typical set-shifting ability from one perceptual dimension to another (Berman et al., 1995. Neuropsychologia 33, 1027-1046; Nagahama et al., 1996. Brain 119, 1667-1675; Konishi et al., 1998. Nature Neuroscience 1, 80-84.). Our data may indicate that the dorsolateral prefrontal cortex including the middle and inferior frontal gyri are important in attentional set-shifting of both perceptual and non-perceptual characteristics. Another activation in the fusiform and lingual gyri may have reflected the increased attentional demand for visual processing in the light of a current rule for motor selection.

  3. 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

  4. 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

  5. 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.

  6. Lateralized frontal eye field activity precedes occipital activity shortly before saccades: evidence for cortico-cortical feedback as a mechanism underlying covert attention shifts.

    Science.gov (United States)

    Gutteling, Tjerk P; van Ettinger-Veenstra, Helene M; Kenemans, J Leon; Neggers, Sebastiaan F W

    2010-09-01

    When an eye movement is prepared, attention is shifted toward the saccade end-goal. This coupling of eye movements and spatial attention is thought to be mediated by cortical connections between the FEFs and the visual cortex. Here, we present evidence for the existence of these connections. A visual discrimination task was performed while recording the EEG. Discrimination performance was significantly improved when the discrimination target and the saccade target matched. EEG results show that frontal activity precedes occipital activity contralateral to saccade direction when the saccade is prepared but not yet executed; these effects were absent in fixation conditions. This is consistent with the idea that the FEF exerts a direct modulatory influence on the visual cortex and enhances perception at the saccade end-goal.

  7. Potential for modal shift by passenger car and motorcycle users towards Bus Rapid Transit (BRT in an Asian developing city

    Directory of Open Access Journals (Sweden)

    Thaned Satiennam

    2016-03-01

    Full Text Available Many developing Asian cities consider a Bus Rapid Transit (BRT system in their public transport planning because of its advantages, offering lower investment cost and flexible implementation over rail systems. The objective of this research is to assess the potential of BRT for attracting travelers from passenger cars and motorcycles. Three different BRT systems were designed for the main corridor passing through Khon Kaen City in Thailand. The study developed modal split models for predicting the choices of passenger car users and motorcycle users. The models were developed based on a Stated Preference (SP survey. It was found that BRT could attract significantly private vehicle users to change mode choice. The proportion of motorcycle users shifting is higher than passenger car users. However, the majority of private vehicle users still prefer their own private vehicles. Both travel time and travel cost affects the mode choice, in which travel time has a highly significant effect on passenger car users' choice of BRT, but travel cost has a highly significant effect on motorcyclists' choice. Some socio-economic factors, including gender, age, driving license holding and residence location also influence the choice of BRT.

  8. Heterochronic shifts in germband movements contribute to the rapid embryonic development of the coffin fly Megaselia scalaris.

    Science.gov (United States)

    Wotton, Karl R

    2014-11-01

    The coffin fly, Megaselia scalaris, is a species of medical and forensic importance and is increasingly being used for the study of genetics. Postmortem interval can be estimated based on the life stage of M. scalaris recovered from corpses, therefore many studies have addressed the duration of each life stage. These studies demonstrate that embryogenesis completes significantly faster in M. scalaris than in the congener Megaselia abdita and faster even than the 24 h needed for Drosophila melanogaster embryogenesis. However, until now it has been unclear if this increased speed is achieved by reducing developmental time across all embryonic stages or by the acceleration of individual stages and processes. Here I use time-lapse imaging to create a staging scheme for M. scalaris embryogenesis. Comparison of stages between D. melanogaster and both Megaselia species reveals that heterochronic shifts, simultaneous morphogenetic movements and compression of individual stages all contribute to the rapid development of M. scalaris. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Cariprazine, a dopamine D(3)-receptor-preferring partial agonist, blocks phencyclidine-induced impairments of working memory, attention set-shifting, and recognition memory in the mouse.

    Science.gov (United States)

    Zimnisky, Ross; Chang, Gloria; Gyertyán, István; Kiss, Béla; Adham, Nika; Schmauss, Claudia

    2013-03-01

    A major challenge in the pharmacological treatment of psychotic disorders is the effective management of the associated cognitive dysfunctions. Novel concepts emphasize a potential benefit of partial agonists acting upon dopamine D(2)-like receptors in ameliorating these cognitive deficits, and pre-clinical studies suggest that D(3)-receptor-preferring compounds can exert pro-cognitive effects. The objective of the study was to use acute phencyclidine (PCP) treatment to model the cognitive deficits of schizophrenia in mice, and to test the efficacy of the novel, dopamine D(3)-receptor-preferring drug cariprazine in ameliorating the severity of PCP-triggered cognitive deficits. One group of wild-type or D(3)-receptor knockout mice was acutely treated with either saline or phencyclidine (PCP, 1 mg/kg). A separate group of mice was treated with cariprazine prior to PCP administration. Both groups were then tested in three cognitive tasks: social interaction/recognition and recognition memory, spatial working memory, and attention-set-shifting. PCP effectively disrupted social recognition and social recognition memory, spatial working memory, and extradimensional attention set-shifting. Cariprazine pretreatment significantly attenuated the emergence of these cognitive deficits in PCP-treated wild-type mice, but not in PCP-treated D(3)-receptor knockout mice. In an animal model of PCP-induced cognitive impairment, cariprazine pretreatment significantly diminished PCP-triggered cognitive deficits, and studies on knockout mice show that dopamine D(3) receptors contribute to this effect.

  10. Increased cortical neuronal responses to NMDA and improved attentional set-shifting performance in rats following prebiotic (B-GOS®) ingestion.

    Science.gov (United States)

    Gronier, Benjamin; Savignac, Helene M; Di Miceli, Mathieu; Idriss, Sherif M; Tzortzis, George; Anthony, Daniel; Burnet, Philip W J

    2018-01-01

    We have previously shown that prebiotics (dietary fibres that augment the growth of indigenous beneficial gut bacteria) such as Bimuno™ galacto-oligosaccharides (B-GOS®), increased N-methyl-D-aspartate (NMDA) receptor levels in the rat brain. The current investigation examined the functional correlates of these changes in B-GOS®-fed rats by measuring cortical neuronal responses to NMDA using in vivo NMDA micro-iontophoresis electrophysiology, and performance in the attentional set-shifting task. Adult male rats were supplemented with B-GOS® in the drinking water 3 weeks prior to in vivo iontophoresis or behavioural testing. Cortical neuronal responses to NMDA iontophoresis, were greater (+30%) in B-GOS® administered rats compared to non-supplemented controls. The intake of B-GOS® also partially hindered the reduction of NMDA responses by the glycine site antagonist, HA-966. In the attentional set-shifting task, B-GOS® -fed rats shifted from an intra-dimensional to an extra-dimensional set in fewer trials than controls, thereby indicating greater cognitive flexibility. An initial exploration into the mechanisms revealed that rats ingesting B-GOS® had increased levels of plasma acetate, and cortical GluN2B subunits and Acetyl Co-A Carboxylase mRNA. These changes were also observed in rats fed daily for 3 weeks with glyceryl triacetate, though unlike B-GOS®, cortical histone deacetylase (HDAC1, HDAC2) mRNAs were also increased which suggested an additional epigenetic action of direct acetate supplementation. Our data demonstrate that a pro-cognitive effect of B-GOS® intake in rats is associated with an increase in cortical NMDA receptor function, but the role of circulating acetate derived from gut bacterial fermentation of this prebiotic requires further investigation. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.

  11. Electrophysiological recordings in humans reveal reduced location-specific attentional-shift activity prior to recentering saccades.

    Science.gov (United States)

    Krebs, Ruth M; Boehler, C Nicolas; Zhang, Helen H; Schoenfeld, Mircea A; Woldorff, Marty G

    2012-03-01

    Being able to effectively explore the visual world is of fundamental importance, and it has been suggested that the straight-ahead gaze position within the egocentric reference frame ("primary position") might play a special role in this context. In the present study we employed human electroencephalography (EEG) to examine neural activity related to the spatial guidance of saccadic eye movements. Moreover, we sought to investigate whether such activity would be modulated by the spatial relation of saccade direction to the primary gaze position (recentering saccades). Participants executed endogenously cued saccades between five equidistant locations along the horizontal meridian. This design allowed for the comparison of isoamplitude saccades from the same starting position that were oriented either toward the primary position (centripetal) or further away from it (centrifugal). By back-averaging time-locked to the saccade onset on each trial, we identified a parietally distributed, negative-polarity EEG deflection contralateral to the direction of the upcoming saccade. Importantly, this contralateral presaccadic negativity, which appeared to reflect the location-specific attentional guidance of the eye movement, was attenuated for recentering saccades relative to isoamplitude centrifugal saccades. This differential electrophysiological signature was paralleled by faster saccadic reaction times and was substantially more apparent when time-locking the data to the onset of the saccade rather than to the onset of the cue, suggesting a tight temporal association with saccade initiation. The diminished level of this presaccadic component for recentering saccades may reflect the preferential coding of the straight-ahead gaze position, in which both the eye-centered and head-centered reference frames are perfectly aligned and from which the visual world can be effectively explored.

  12. Rapid calculation of protein chemical shifts using bond polarization theory and its application to protein structure refinement.

    Science.gov (United States)

    Jakovkin, Igor; Klipfel, Marco; Muhle-Goll, Claudia; Ulrich, Anne S; Luy, Burkhard; Sternberg, Ulrich

    2012-09-21

    Although difficult to analyze, NMR chemical shifts provide detailed information on protein structure. We have adapted the semi-empirical bond polarization theory (BPT) to protein chemical shift calculation and chemical shift driven protein structure refinement. A new parameterization for BPT amide nitrogen chemical shift calculation has been derived from MP2 ab initio calculations and successfully evaluated using crystalline tripeptides. We computed the chemical shifts of the small globular protein ubiquitin, demonstrating that BPT calculations can match the results obtained at the DFT level of theory at very low computational cost. In addition to the calculation of chemical shift tensors, BPT allows the calculation of chemical shift gradients and consequently chemical shift driven geometry optimizations. We applied chemical shift driven protein structure refinement to the conformational analysis of a set of Trypanosoma brucei (the causative agent of African sleeping sickness) tryparedoxin peroxidase Px III structures. We found that the interaction of Px III with its reaction partner Tpx seems to be governed by conformational selection rather than by induced fit.

  13. Rapid Shifts in Soil and Forest Floor Microbial Communities with Changes in Vegetation during Secondary Tropical Forest Succession

    Science.gov (United States)

    Smith, A.; Marin-Spiotta, E.; Balser, T. C.

    2012-12-01

    anaerobic gram-negative bacteria (c19:0) in the wet season, which suggests the presence of anaerobic microsites in these very clayey Oxisols. Enzymatic activity did not differ with succession but was highest in the dry season. We expect this may be due to decreased turnover of enzymes with low soil moisture. Interannual sampling has revealed a very rapid microbial response to changes in aboveground cover. Within a year following woody biomass encroachment, we detected a shift in the soil microbial community from a pasture-associated community to an early secondary forest community in one of our replicate pasture sites. This very rapid response in the belowground microbial community structure to changes in vegetation has not been strongly documented in the literature. This data supports a direct link between aboveground and belowground biotic community structures and highlights the importance of long-term repeated sampling of microbial communities in dynamic ecosystems. Our findings have implications for predicting rapid ecological responses to land-cover change.

  14. Rapid Cerebral Hemodynamic Modulation during Set Shifting: Evidence of Time-Locked Associations with Cognitive Control in Females

    Science.gov (United States)

    Schuepbach, Daniel; Huizinga, Mariette; Duschek, Stefan; Grimm, Simone; Boeker, Heinz; Hell, Daniel

    2009-01-01

    Set shifting provokes specific alterations of cerebral hemodynamics in basal cerebral arteries. However, no gender differences have been reported. In the following functional transcranial Doppler study, we introduced cerebral hemodynamic modulation to the aspects of set shifting during Wisconsin Card Sorting Test (WCST). Twenty-one subjects…

  15. Phase resetting of the mammalian circadian clock relies on a rapid shift of a small population of pacemaker neurons.

    Directory of Open Access Journals (Sweden)

    Jos H T Rohling

    Full Text Available The circadian pacemaker of the suprachiasmatic nuclei (SCN contains a major pacemaker for 24 h rhythms that is synchronized to the external light-dark cycle. In response to a shift in the external cycle, neurons of the SCN resynchronize with different pace. We performed electrical activity recordings of the SCN of rats in vitro following a 6 hour delay of the light-dark cycle and observed a bimodal electrical activity pattern with a shifted and an unshifted component. The shifted component was relatively narrow as compared to the unshifted component (2.2 h and 5.7 h, respectively. Curve fitting and simulations predicted that less than 30% of the neurons contribute to the shifted component and that their phase distribution is small. This prediction was confirmed by electrophysiological recordings of neuronal subpopulations. Only 25% of the neurons exhibited an immediate shift in the phase of the electrical activity rhythms, and the phases of the shifted subpopulations appeared significantly more synchronized as compared to the phases of the unshifted subpopulations (p<0.05. We also performed electrical activity recordings of the SCN following a 9 hour advance of the light-dark cycle. The phase advances induced a large desynchrony among the neurons, but consistent with the delays, only 19% of the neurons peaked at the mid of the new light phase. The data suggest that resetting of the central circadian pacemaker to both delays and advances is brought about by an initial shift of a relatively small group of neurons that becomes highly synchronized following a shift in the external cycle. The high degree of synchronization of the shifted neurons may add to the ability of this group to reset the pacemaker. The large desynchronization observed following advances may contribute to the relative difficulty of the circadian system to respond to advanced light cycles.

  16. Visual attention during spatial language comprehension.

    Directory of Open Access Journals (Sweden)

    Michele Burigo

    Full Text Available Spatial terms such as "above", "in front of", and "on the left of" are all essential for describing the location of one object relative to another object in everyday communication. Apprehending such spatial relations involves relating linguistic to object representations by means of attention. This requires at least one attentional shift, and models such as the Attentional Vector Sum (AVS predict the direction of that attention shift, from the sausage to the box for spatial utterances such as "The box is above the sausage". To the extent that this prediction generalizes to overt gaze shifts, a listener's visual attention should shift from the sausage to the box. However, listeners tend to rapidly look at referents in their order of mention and even anticipate them based on linguistic cues, a behavior that predicts a converse attentional shift from the box to the sausage. Four eye-tracking experiments assessed the role of overt attention in spatial language comprehension by examining to which extent visual attention is guided by words in the utterance and to which extent it also shifts "against the grain" of the unfolding sentence. The outcome suggests that comprehenders' visual attention is predominantly guided by their interpretation of the spatial description. Visual shifts against the grain occurred only when comprehenders had some extra time, and their absence did not affect comprehension accuracy. However, the timing of this reverse gaze shift on a trial correlated with that trial's verification time. Thus, while the timing of these gaze shifts is subtly related to the verification time, their presence is not necessary for successful verification of spatial relations.

  17. 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.

  18. 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

  19. Lower-Income Countries That Face The Most Rapid Shift In Noncommunicable Disease Burden Are Also The Least Prepared.

    Science.gov (United States)

    Bollyky, Thomas J; Templin, Tara; Cohen, Matthew; Dieleman, Joseph L

    2017-11-01

    Demographic and epidemiological changes are shifting the disease burden from communicable to noncommunicable diseases in lower-income countries. Within a generation, the share of disease burden attributed to noncommunicable diseases in some poor countries will exceed 80 percent, rivaling that of rich countries, but this burden is likely to affect much younger people in poorer countries. The health systems of lower-income countries are unprepared for this change. We examined the shift to noncommunicable diseases and estimated preparedness for the shift by ranking 172 nations using a health system capacity index for noncommunicable disease. We project that the countries with the greatest increases in the share of disease burden attributable to noncommunicable disease over the next twenty-five years will also be the least prepared for the change, as they ranked low on our capacity index and are expected to have the smallest increases in national health spending. National governments and donors must invest more in preparing the health systems of lower-income countries for the dramatic shift to noncommunicable diseases and in reducing modifiable noncommunicable disease risks.

  20. Drug treatment and familiar music aids an attention shift from vision to somatosensation in Parkinson's disease on the reach-to-eat task.

    Science.gov (United States)

    Sacrey, Lori-Ann R; Travis, Scott G; Whishaw, Ian Q

    2011-03-01

    Sensory control of the natural skilled movement of reaching for a food target to eat (reach-to-eat) is closely coupled to the successive phases of the movement. Control subjects visually fixate the target from hand movement onset to the point that the digits contact the food, at which point they look away. This relationship between sensory attention and limb movement suggests that whereas limb advance is under visual control, grasping, limb withdrawal, and releasing the food to the mouth is guided by somatosensation. The pattern of sensory control is altered in Parkinson's disease (PD). PD subjects may visually fixate the target for longer durations prior to movement initiation, during the grasp, and during the initial portion of hand withdrawal suggesting that vision compensates for a somatosensory impairment. Because both medication and listening to favorite musical pieces have been reported to normalize some movements in subjects with PD, the present study compared the effect of medication and listening to preferred musical pieces on sensory attention shifts from vision to somatosensation during the reach-to-eat movement. Biometric measures of eye movement and the movement of the reaching limb were collected from PD subjects and aged-matched control subjects in four conditions in their own homes: off medication, off medication with music, on medication, and on medication with music. Unmedicated PD subjects were slower to visually disengage the target after grasping it. Their disengage latency was shortened by both music and medication. Medication and music did not improve other aspects of reaching, including reaching duration and the ratings of the movement elements of limb advance, grasping, and limb withdrawal. The results are discussed in relation to the idea that one way in which medication and music may aid movement in PD by normalizing somatosensory control of forelimb movement thus reducing compensatory visual monitoring. Copyright © 2010 Elsevier B

  1. 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.

  2. A role for prostaglandins in rapid cycling suggested by episode-specific gene expression shifts in peripheral blood mononuclear cells

    DEFF Research Database (Denmark)

    Gurvich, Artem; Begemann, Martin; Dahm, Liane

    2014-01-01

    OBJECTIVES: Over 12% of patients with bipolar disorder exhibit rapid cycling. The underlying biological mechanisms of this extreme form of bipolar disease are still unknown. This study aimed at replicating and extending findings of our previously published case report, where an involvement of pro...

  3. Shifts in Mortality During a Hot Weather Event in Vancouver, British Columbia: Rapid Assessment With Case-Only Analysis

    Science.gov (United States)

    Henderson, Sarah B.; Pollock, Sue L.

    2012-01-01

    Objectives. We assessed shifts in patterns of mortality during a hot weather event in greater Vancouver, British Columbia. Methods. We used a case-only analysis to compare characteristics of individuals who died during the hottest week of 2009 with those who died (1) during earlier summer weeks in 2009 and (2) during the same calendar weeks in the summers of 2001 through 2008. Results. Compared with the 8 previous weeks of 2009, odds of mortality during the summer’s hottest week were highest in the 65 to 74 years age category, compared with the 85 years and older category (odds ratio [OR] = 1.47; 95% confidence interval [CI] = 1.06, 2.03). The number of deaths at home increased over deaths in hospitals or institutions (OR = 1.43; 95% CI = 1.10, 1.86). Densely populated administrative health areas were more affected. Conclusions. A shift toward deaths at home suggests that in-home–based protective measures should be part of planning for hot weather events in greater Vancouver. Targeting should be considered for those aged 65 to 74 years. The case-only approach is quick and easy to apply and can provide useful information about localized, time-limited events. PMID:23078510

  4. Anxiety is associated with freezing of gait and attentional set-shifting in Parkinson's disease: A new perspective for early intervention.

    Science.gov (United States)

    Martens, K A Ehgoetz; Hall, J M; Gilat, M; Georgiades, M J; Walton, C C; Lewis, S J G

    2016-09-01

    Previous research has shown that anxiety in Parkinson's disease (PD) is associated with freezing of gait (FOG), and may even contribute to the underlying mechanism. However, limited research has investigated whether PD patients with FOG (PD+FOG) have higher anxiety levels when compared directly to non-freezing PD patients (PD-NF) and moreover, how anxiety might contribute to FOG. The current study evaluated whether: (i) PD+FOG have greater anxiety compared to PD-NF, and (ii) anxiety in PD is related to attentional set-shifting, in order to better understand how anxiety might be contributing to FOG. In addition, we explored whether anxiety levels differed between those PD patients with mild FOG (PD+MildFOG) compared to PD-NF. Four hundred and sixty-one patients with PD (231 PD-NF, 180 PD+FOG, 50 PD+MildFOG) were assessed using the Freezing of Gait Questionnaire item 3 (FOG-Q3), Hospital Anxiety and Depression Scale (HADS), Digit Span Test, Logical Memory Retention Test and Trail Making Tests. Compared to PD-NF, PD+FOG had significantly greater anxiety (panxiety as the PD+FOG. In all patients, the severity of anxiety symptoms was significantly correlated to their degree of self-reported FOG on FOG-Q3 (panxiety in FOG and also suggest that anxiety might be a promising biomarker for FOG. Future research should consider whether treating anxiety with pharmacological and/or cognitive behavioural therapies at early stages of gait impairment in PD may alleviate troublesome FOG. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. PNU-120596, a positive allosteric modulator of α7 nicotinic acetylcholine receptors, reverses a sub-chronic phencyclidine-induced cognitive deficit in the attentional set-shifting task in female rats.

    Science.gov (United States)

    McLean, Samantha L; Idris, Nagi F; Grayson, Ben; Gendle, David F; Mackie, Claire; Lesage, Anne S; Pemberton, Darrel J; Neill, Jo C

    2012-09-01

    The α7 nicotinic acetylcholine receptors (nAChRs) have been highlighted as a target for cognitive enhancement in schizophrenia. Adult female hooded Lister rats received sub-chronic phencyclidine (PCP) (2 mg/kg) or vehicle i.p. twice daily for 7 days, followed by 7 days' washout. PCP-treated rats then received PNU-120596 (10 mg/kg; s.c.) or saline and were tested in the attentional set-shifting task. Sub-chronic PCP produced a significant cognitive deficit in the extra-dimensional shift (EDS) phase of the task (p < 0.001, compared with vehicle). PNU-120596 significantly improved performance of PCP-treated rats in the EDS phase of the attentional set-shifting task (p < 0.001). In conclusion, these data demonstrate that PNU-120596 improves cognitive dysfunction in our animal model of cognitive dysfunction in schizophrenia, most likely via modulation of α7 nACh receptors.

  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. Characterization of a rapid climate shift at the MIS 8/7 transition in central Spain (Valdocarros II, Autonomous Region of Madrid) by means of the herpetological assemblages

    Science.gov (United States)

    Blain, Hugues-Alexandre; Panera, Joaquin; Uribelarrea, David; Rubio-Jara, Susana; Pérez-González, Alfredo

    2012-07-01

    Climate instability with high-amplitude and rapid shifts during the Middle Pleistocene is well known from pollen records and deep-ocean sediment cores. Although poorly correlatable with such long climate/environment records, the successive fossil amphibian and reptile assemblages from the Middle Pleistocene site of Valdocarros II (Autonomous Region of Madrid, central Spain) provide a unique opportunity to characterize the climatic and environmental features of such rapid (certainly less than 1000 years) shifts from cold to warm conditions in a terrestrial sequence. As the amphibians and reptiles do not differ at species level from the extant herpetofauna of the Iberian Peninsula, they can contribute to the reconstruction of the landscape and climate. In this paper, the mutual climatic range and habitat weighting methods are applied to the herpetofaunistic assemblages in order to estimate quantitative data. The difference in mean annual temperature between "cold" and "warm" periods is estimated at 3.2 °C, with a greater increase in temperature during winter (+3 °C) than during summer (+1 °C). During "cold" periods the climate was more Oceanic (although preserving some dryness during the summers), whereas during "warm" periods the climate became Mediterranean (with mild winters and a long period of dryness in the summer and early autumn). Though higher during cold periods, the continentality (or atmospheric temperature range) remained roughly similar, in accordance with the geographical location of the site in the centre of the Iberian Peninsula. A greater amount of open landscape occurred during "cold" periods, whereas during "warm" periods the wooded areas expanded from 20% to 40% of the landscape surface. Such climatic/environmental changes, together with the numeric datings of the site, suggest that this shift may correspond to the transition from MIS 8 to MIS 7, also called Termination III.

  8. 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,…

  9. Making our data impactful: Working with researchers to meet diverse data needs in a rapidly shifting technological world.

    Science.gov (United States)

    Laney, C. M.

    2016-12-01

    Making data easily accessible and actionable is critical in our drive to understand ecological drivers and responses in our rapidly changing world. The National Ecological Observatory Network (NEON), operated by Battelle and sponsored by the National Science Foundation, is a continental-scale, long-term observation facility built specifically to meet such needs. By the end of construction at the end of 2017, NEON will be generating and synthesizing data from in situ instruments, field sampling, and airborne platforms covering 81 field sites across the U.S. A challenge of such observatories is not only to generate, quality-control, and synthesize enormous and high-resolution datasets, but to provide it freely to researchers in formats that are easy to understand and integrate with other datasets. Here, we present how NEON is preparing publication-ready data for ready reuse by a broad range of practitioners through numerous mechanisms: 1) developing a robust and intuitive data portal and public API, 2) collaborating with numerous partners to support and enrich standards to assure interoperability and reproducibility, and 3) providing training materials covering the key concepts and tools researchers may need to fully leverage NEON data. In addition, we will solicit feedback on NEON's current, in-design, and proposed data services and portal features in order to best serve the diverse research interests of a AGU's scientific community.

  10. 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

  11. IMPACT OF SHIFT IN FOCUS OF ATTENTION ON LEARNING TABLE TENNIS BACKHAND WITH SELF-TALK IN HIGH SCHOOL FEMALES STUDENTS

    Directory of Open Access Journals (Sweden)

    Ghazal Mohamadi

    2014-11-01

    Full Text Available Aim: The purpose of the present study was to investigate the effect of variability of attentional focus distance by self-talk on the learning of table tennis backhand. Methods: Therefore, 80 high school girls by mean age 16(±0/62 yr. were randomly selected from sport school of Sanandaj and assigned to 5 groups. After pretest, the participants performed 180 forehand strokes during 6 sessions with repeating the words “slightly rotation” in the internal focus group “slightly open” in the near external focus group, “over the net” in the far external focus group, and each of the words “slightly rotation, slightly open, and over the net” respectively in each 2 sessions in the increasing distance of attentional focus group. Control group performed without self-talk during acquisition phase. Retention test was performed 48 hours after acquisition test in the same situation without self-talk, and after half an hour break, transfer test was done by changing the direction of target (parallel forehand without self-talk. The accuracy and the pattern of forehand strokes were measured by a 5 point-scale (Liao and Masters, 2001 and researcher-made scale, respectively. At the end of acquisition phase, participants filled out the frequency and self-talk beliefs questionnaire. Results: According to the results of 2-factor mixed ANOVA, acquisition, retention, and transfer of backhand accuracy in internal focus of attention group were significantly lower than other groups (p<0.05. Furthermore, the effect of increasing attentional focus distance on acquisition of backhand pattern was significant. The effect of near external attentional focus on retention of pattern was significant. But transfer of stroke pattern in control group was significantly more than far external focus group (p<0.05. Conclusions: Thus, it is recommended to use self-talk by increasing attentional focus and near external attentional focus and not to use internal focus of

  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. Attentional Blink Differences between Adolescent Dyslexic and Normal Readers

    Science.gov (United States)

    Lacroix, G.L.; Constantinescu, I.; Cousineau, D.; de Almeida, R.G.; Segalowitz, N.; Grunau, M.v.

    2005-01-01

    The goal of this study was to evaluate the possibility that dyslexic individuals require more working memory resources than normal readers to shift attention from stimulus to stimulus. To test this hypothesis, normal and dyslexic adolescents participated in a Rapid Serial Visual Presentation experiment (Raymond, Shapiro, & Arnell, 1992).…

  14. Measuring the emotion-specificity of rapid stimulus-driven attraction of attention to fearful faces: evidence from emotion categorization and a comparison with disgusted faces.

    Science.gov (United States)

    Khalid, Shah; Horstmann, Gernot; Ditye, Thomas; Ansorge, Ulrich

    2017-03-01

    In the current study, we tested whether a fear advantage-rapid attraction of attention to fearful faces that is more stimulus-driven than to neutral faces-is emotion specific. We used a cueing task with face cues preceding targets. Cues were non-predictive of the target locations. In two experiments, we found enhanced cueing of saccades towards the targets with fearful face cues than with neutral face cues: Saccades towards targets were more efficient with cues and targets at the same position (under valid conditions) than at opposite positions (under invalid conditions), and this cueing effect was stronger with fearful than with neutral face cues. In addition, this cueing effect difference between fearful and neutral faces was absent with inverted faces as cues, indicating that the fear advantage is face-specific. We also show that emotion categorization of the face cues mirrored these effects: Participants were better at categorizing face cues as fearful or neutral with upright than with inverted faces (Experiment 1). Finally, in alternative blocks including disgusted faces instead of fearful faces, we found more similar cueing effects with disgusted faces and neutral faces, and with upright and inverted faces (Experiment 2). Jointly, these results demonstrate that the fear advantage is emotion-specific. Results are discussed in light of evolutionary explanations of the fear advantage.

  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. 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...... this interpretation theoretically through systems theory and medium theory. Further we present initial results from the action research project Socio Media Education (SME) in which we work with how teachers and pupils can handle the new attention-demanding situation, so the new media do not mean spoiled teaching...

  17. 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 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...... postnatal phencyclidine (PCP) treatment regimes: (a) Administration of either saline or PCP (5 mg/kg, intraperitonally b.i.d. for 7 days) followed by a 7-day washout period and testing on day 8. (b) On postnatal days (PNDs) 7, 9, and 11, rats were subjected to administration of either saline or PCP (20 mg...

  18. Rare HIV-1 transmitted/founder lineages identified by deep viral sequencing contribute to rapid shifts in dominant quasispecies during acute and early infection

    Science.gov (United States)

    Sanders-Buell, Eric; Chenine, Agnes-Laurence; Goonetilleke, Nilu; Thomas, Rasmi; Harbolick, Elizabeth A.; Bose, Meera; Pham, Phuc; Oropeza, Celina; Poltavee, Kultida; O’Sullivan, Anne Marie; Costanzo, Margaret C.; Warren, Joanna A.; Slike, Bonnie; Li, Hui; Peachman, Kristina K.; Gao, Feng; Cicala, Claudia; Arthos, James; O’Connell, Robert J.; Sinei, Samuel; Maganga, Lucas; Rao, Mangala; Marovich, Mary A.; Krebs, Shelly J.; Rolland, Morgane; Shaw, George M.

    2017-01-01

    In order to inform the rational design of HIV-1 preventive and cure interventions it is critical to understand the events occurring during acute HIV-1 infection (AHI). Using viral deep sequencing on six participants from the early capture acute infection RV217 cohort, we have studied HIV-1 evolution in plasma collected twice weekly during the first weeks following the advent of viremia. The analysis of infections established by multiple transmitted/founder (T/F) viruses revealed novel viral profiles that included: a) the low-level persistence of minor T/F variants, b) the rapid replacement of the major T/F by a minor T/F, and c) an initial expansion of the minor T/F followed by a quick collapse of the same minor T/F to low frequency. In most participants, cytotoxic T-lymphocyte (CTL) escape was first detected at the end of peak viremia downslope, proceeded at higher rates than previously measured in HIV-1 infection, and usually occurred through the exploration of multiple mutational pathways within an epitope. The rapid emergence of CTL escape variants suggests a strong and early CTL response. Minor T/F viral strains can contribute to rapid and varied profiles of HIV-1 quasispecies evolution during AHI. Overall, our results demonstrate that early, deep, and frequent sampling is needed to investigate viral/host interaction during AHI, which could help identify prerequisites for prevention and cure of HIV-1 infection. PMID:28759651

  19. Rare HIV-1 transmitted/founder lineages identified by deep viral sequencing contribute to rapid shifts in dominant quasispecies during acute and early infection.

    Directory of Open Access Journals (Sweden)

    Gustavo H Kijak

    2017-07-01

    Full Text Available In order to inform the rational design of HIV-1 preventive and cure interventions it is critical to understand the events occurring during acute HIV-1 infection (AHI. Using viral deep sequencing on six participants from the early capture acute infection RV217 cohort, we have studied HIV-1 evolution in plasma collected twice weekly during the first weeks following the advent of viremia. The analysis of infections established by multiple transmitted/founder (T/F viruses revealed novel viral profiles that included: a the low-level persistence of minor T/F variants, b the rapid replacement of the major T/F by a minor T/F, and c an initial expansion of the minor T/F followed by a quick collapse of the same minor T/F to low frequency. In most participants, cytotoxic T-lymphocyte (CTL escape was first detected at the end of peak viremia downslope, proceeded at higher rates than previously measured in HIV-1 infection, and usually occurred through the exploration of multiple mutational pathways within an epitope. The rapid emergence of CTL escape variants suggests a strong and early CTL response. Minor T/F viral strains can contribute to rapid and varied profiles of HIV-1 quasispecies evolution during AHI. Overall, our results demonstrate that early, deep, and frequent sampling is needed to investigate viral/host interaction during AHI, which could help identify prerequisites for prevention and cure of HIV-1 infection.

  20. 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.

  1. Tough Shift

    DEFF Research Database (Denmark)

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

    2015-01-01

    in a student dormitory and found that players did not shift their electricity use, because they were unwilling to change their schedules and found it easier to focus on reducing electricity use. Based on our findings, we discuss the implications for encouraging shifting, and also the challenges of integrating......Modern electrical grids are increasingly reliant on generation from renewable sources that can vary from hour to hour. This variability has led to the desire to shift the times of the day when electricity is consumed to better match generation. One way to achieve these shifts is by encouraging...... 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...

  2. Towards a Unified Model of Vision and Attention: Effects of Visual Landmarks and Identity Cues on Covert and Overt Attention Movements.

    Science.gov (United States)

    Lambert, Anthony J; Wilkie, Jaimie; Greenwood, Andrea; Ryckman, Nathan; Sciberras-Lim, Evatte; Booker, Laura-Jane; Tahara-Eckl, Lenore

    2017-08-17

    To what extent are shifts of attention driven by encoding of visual-spatial landmarks, associated with useful locations, or by encoding of environmental cues that act as symbolic representations, providing information about where to look next? In Experiment 1 we found that when cues were presented with a long exposure time (300 ms) attention shifts were driven by the symbolic identity of cue stimuli, independently of their visual-spatial (landmark) features; but when cues were exposed very briefly, (66 ms), attention shifts were independent of symbolic information, and were driven instead by visual landmark features. This unexpected finding was interpreted in terms of the transient and sustained response characteristics of the M-cell and P-cell inputs to the dorsal and ventral visual streams, respectively, and informed our theoretical proposal that attentional effects elicited by visual-spatial landmarks may be driven by dorsal stream ("where pathway") encoding; while attentional effects driven by the symbolic identity of cues may be driven by ventral stream ("what pathway") encoding. Detailed predictions derived from this proposal, and based on distinct physiological properties of the 2 visual streams were tested and confirmed in Experiments 2-6. Our results suggest that a 2-process view of attention shifting can be integrated with dual-stream models of vision. According to this unified theory: (a) Landmarks associated with visually useful locations elicit rapid, nonconscious shifts of attention, via nonsemantic, dorsal visual stream encoding of their features and spatial relationships; (b) Slower, endogenous shifts of attention are elicited by ventral visual stream encoding of symbolic-semantic information. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  3. Shifting Boundaries

    DEFF Research Database (Denmark)

    Blaagaard, Bolette

    2013-01-01

    within journalistic practice of keeping up the idea as well as the practice of journalistic objectivity. Working on from Schudson (2003), Schudson and Anderson (2009) and Tumber and Prentoulis’ (2003) analyses of journalistic professionalism, the article develops the idea of journalistic objectivity...... further on the question of how the students address and react to this paradigmatic shift....

  4. 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

  5. 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

  6. Attention dysfunction subtypes of developmental dyslexia.

    Science.gov (United States)

    Lewandowska, Monika; Milner, Rafał; Ganc, Małgorzata; Włodarczyk, Elżbieta; Skarżyński, Henryk

    2014-11-12

    Previous studies indicate that many different aspects of attention are impaired in children diagnosed with developmental dyslexia (DD). The objective of the present study was to identify cognitive profiles of DD on the basis of attentional test performance. 78 children with DD (30 girls, 48 boys, mean age of 12 years ±8 months) and 32 age- and sex-matched non-dyslexic children (14 girls, 18 boys) were examined using a battery of standardized tests of reading, phonological and attentional processes (alertness, covert shift of attention, divided attention, inhibition, flexibility, vigilance, and visual search). Cluster analysis was used to identify subtypes of DD. Dyslexic children showed deficits in alertness, covert shift of attention, divided attention, flexibility, and visual search. Three different subtypes of DD were identified, each characterized by poorer performance on the reading, phonological awareness, and visual search tasks. Additionally, children in cluster no. 1 displayed deficits in flexibility and divided attention. In contrast to non-dyslexic children, cluster no. 2 performed poorer in tasks involving alertness, covert shift of attention, divided attention, and vigilance. Cluster no. 3 showed impaired covert shift of attention. These results indicate different patterns of attentional impairments in dyslexic children. Remediation programs should address the individual child's deficit profile.

  7. Attention visuelle

    OpenAIRE

    Rousserie, Marie

    2015-01-01

    William James, philosophe et psychologue américain, est le premier à parler de l’attention en 1890 dans son livre The Principles of Psychology : il dit que c’est un concept connu mais dont personne ne saurait en donner une définition précise. Il la définit alors ainsi : « L'attention est la prise de possession par l'esprit, sous une forme claire et vive, d'un objet ou d'une suite de pensées parmi plusieurs qui semblent possibles […] Elle implique le retrait de certains objets afin de traiter ...

  8. Effects of state anxiety on performance using a task-switching paradigm: An investigation of attentional control theory

    National Research Council Canada - National Science Library

    Derakshan, Nazanin; Smyth, Sinéad; Eysenck, Michael W

    2009-01-01

    .... According to attentional control theory (Eysenck, Derakshan, Santos, & Calvo, 2007), anxiety impairs attentional control processes required to shift attention optimally within and between tasks...

  9. Shifting Blame?

    DEFF Research Database (Denmark)

    Garofalo, Orsola; Rott, Christina

    2017-01-01

    by the spokesperson if there is room for shifting blame. The increased punishment results from the messenger’s style of delivery: spokespersons are more likely than decision makers to express emotional regret instead of rational need. Receivers seem to punish the former style of communication because they view......Decision makers frequently have a spokesperson communicate their decisions. In this paper, we address two questions. First, does it matter who communicates an unfair decision? Second, does it matter how the unfair decision is communicated? We conduct a modified dictator game experiment in which...... either the decision maker or a spokesperson communicates the decided allocation to recipients, who then determine whether to punish either of them. We find that receivers punish both the decision maker and the spokesperson more often, and more heavily, for unfair allocations communicated...

  10. 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

  11. 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.

  12. 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

  13. Task-Set Reconfiguration Suspends Perceptual Processing: Evidence from Semantic Priming during the Attentional Blink

    Science.gov (United States)

    Vachon, Francois; Tremblay, Sebastien; Jones, Dylan M.

    2007-01-01

    When two visual targets, Target 1 (T1) and Target 2 (T2), are presented among a rapid sequence of distractors, processing of T1 produces an attentional blink. Typically, processing of T2 is markedly impaired, except when T1 and T2 are adjacent (Lag 1 sparing). However, if a shift of task set--a change in task requirements from T1 to T2--occurs,…

  14. More attention must be paid: the neurobiology of attentional effort.

    Science.gov (United States)

    Sarter, Martin; Gehring, William J; Kozak, Rouba

    2006-08-01

    Increases in attentional effort are defined as the motivated activation of attentional systems in response to detrimental challenges on attentional performance, such as the presentation of distractors, prolonged time-on-task, changing target stimulus characteristics and stimulus presentation parameters, circadian phase shifts, stress or sickness. Increases in attentional effort are motivated by the expected performance outcome; in the absence of such motivation, attentional performance continues to decline or may cease altogether. The beneficial effects of increased attentional effort are due in part to the activation of top-down mechanisms that act to optimize input detection and processing, thereby stabilizing or recovering attentional performance in response to challenges. Following a description of the psychological construct "attentional effort", evidence is reviewed indicating that increases in the activity of cortical cholinergic inputs represent a major component of the neuronal circuitry mediating increases in attentional effort. A neuronal model describes how error detection and reward loss, indicating declining performance, are integrated with motivational mechanisms on the basis of neuronal circuits between prefrontal/anterior cingulate and mesolimbic regions. The cortical cholinergic input system is activated by projections of mesolimbic structures to the basal forebrain cholinergic system. In prefrontal regions, increases in cholinergic activity are hypothesized to contribute to the activation of the anterior attention system and associated executive functions, particularly the top-down optimization of input processing in sensory regions. Moreover, and influenced in part by prefrontal projections to the basal forebrain, increases in cholinergic activity in sensory and other posterior cortical regions contribute directly to the modification of receptive field properties or the suppression of contextual information and, therefore, to the mediation of

  15. 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…

  16. 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).

  17. Layer-dependent attentional processing by top-down signals in a visual cortical microcircuit model

    Directory of Open Access Journals (Sweden)

    Nobuhiko eWagatsuma

    2011-07-01

    Full Text Available A vast amount of information about the external world continuously flows into the brain, whereas its capacity to process such information is limited. Attention enables the brain to allocate its resources of information processing to selected sensory inputs for reducing its computational load, and effects of attention have been extensively studied in visual information processing. However, how the microcircuit of the visual cortex processes attentional information from higher areas remains largely unknown. Here, we explore the complex interactions between visual inputs and an attentional signal in a computational model of the visual cortical microcircuit. Our model not only successfully accounts for previous experimental observations of attentional effects on visual neuronal responses, but also predicts contrasting differences in the attentional effects of top-down signals between cortical layers: attention to a preferred stimulus of a column enhances neuronal responses of layers 2/3 and 5, the output stations of cortical microcircuits, whereas attention suppresses neuronal responses of layer 4, the input station of cortical microcircuits. We demonstrate that the specific modulation pattern of layer-4 activity, which emerges from inter-laminar synaptic connections, is crucial for a rapid shift of attention to a currently unattended stimulus. Our results suggest that top-down signals act differently on different layers of the cortical microcircuit.

  18. Irrelevant stimulus processing in ADHD: catecholamine dynamics and attentional networks

    National Research Council Canada - National Science Library

    Aboitiz, Francisco; Ossandón, Tomás; Zamorano, Francisco; Palma, Bárbara; Carrasco, Ximena

    2014-01-01

    A cardinal symptom of attention 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...

  19. [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.

  20. Large species shifts triggered by small forces

    NARCIS (Netherlands)

    Nes, van E.H.; Scheffer, M.

    2004-01-01

    Changes in species composition of communities seem to proceed gradually at first sight, but remarkably rapid shifts are known to occur. Although disrupting disturbances seem an obvious explanation for such shifts, evidence for large disturbances is not always apparent. Here we show that complex

  1. 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…

  2. Attention enhances apparent perceptual organization.

    Science.gov (United States)

    Barbot, Antoine; Liu, Sirui; Kimchi, Ruth; Carrasco, Marisa

    2017-08-28

    Perceptual organization and selective attention are two crucial processes that influence how we perceive visual information. The former structures complex visual inputs into coherent units, whereas the later selects relevant information. Attention and perceptual organization can modulate each other, affecting visual processing and performance in various tasks and conditions. Here, we tested whether attention can alter the way multiple elements appear to be perceptually organized. We manipulated covert spatial attention using a rapid serial visual presentation task, and measured perceptual organization of two multielements arrays organized by luminance similarity as rows or columns, at both the attended and unattended locations. We found that the apparent perceptual organization of the multielement arrays is intensified when attended and attenuated when unattended. We ruled out response bias as an alternative explanation. These findings reveal that attention enhances the appearance of perceptual organization, a midlevel vision process, altering the way we perceive our visual environment.

  3. 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...

  4. 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 increase...

  5. Attention decay in science

    CERN Document Server

    Parolo, Pietro Della Briotta; Ghosh, Rumi; Huberman, Bernardo A; Kaski, Kimmo; Fortunato, Santo

    2015-01-01

    The exponential growth in the number of scientific papers makes it increasingly difficult for researchers to keep track of all the publications relevant to their work. Consequently, the attention that can be devoted to individual papers, measured by their citation counts, is bound to decay rapidly. In this work we make a thorough study of the life-cycle of papers in different disciplines. Typically, the citation rate of a paper increases up to a few years after its publication, reaches a peak and then decreases rapidly. This decay can be described by an exponential or a power law behavior, as in ultradiffusive processes, with exponential fitting better than power law for the majority of cases. The decay is also becoming faster over the years, signaling that nowadays papers are forgotten more quickly. However, when time is counted in terms of the number of published papers, the rate of decay of citations is fairly independent of the period considered. This indicates that the attention of scholars depends on th...

  6. 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.

  7. 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.

  8. Habitual versus goal-driven attention.

    Science.gov (United States)

    Jiang, Yuhong V

    2017-07-04

    Recent research has expanded the list of factors that control spatial attention. Beside current goals and perceptual salience, statistical learning, reward, motivation and emotion also affect attention. But do these various factors influence spatial attention in the same manner, as suggested by the integrated framework of attention, or do they target different aspects of spatial attention? Here I present evidence that the control of attention may be implemented in two ways. Whereas current goals typically modulate where in space attention is prioritized, search habits affect how one moves attention in space. Using the location probability learning paradigm, I show that a search habit forms when people frequently find a visual search target in one region of space. Attentional cuing by probability learning differs from that by current goals. Probability cuing is implicit and persists long after the probability cue is no longer valid. Whereas explicit goal-driven attention codes space in an environment-centered reference frame, probability cuing is viewer-centered and is insensitive to secondary working memory load and aging. I propose a multi-level framework that separates the source of attentional control from its implementation. Similar to the integrated framework, the multi-level framework considers current goals, perceptual salience, and selection history as major sources of attentional control. However, these factors are implemented in two ways, controlling where spatial attention is allocated and how one shifts attention in space. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. 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.

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

    NARCIS (Netherlands)

    Roelofs, A.P.A.

    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

  11. [Selective visual attention and simultanagnosia].

    Science.gov (United States)

    Suzuki, K

    2001-12-01

    The parietal lobe is an important key station in the network for selective attention. We found that spontaneous shift of visual attention, depending on task requirement, was impaired by parietal lobe lesions and confirmed the relationship between parietal lobes and visual attention with cortical electric stimulation. Patient 1. A 52-year-old, right-handed carpenter with a diagnosis of 'visual form' of Alzheimer disease showed marked kanji (logogram) agraphia and constructional impairment. Cerebral atrophy and hypoperfusion were observed in bilateral parietal lobes. He showed preserved form and color perception and an ability to describe spatial relationship among several items. In contrast, he could not copy or match them. He seemed to look at only the site he was drawing. Patient 2. A 77-year-old man with cerebral infarction in bilateral parietal lobes and right frontotemporal areas, demonstrated simultanagnosia and visuomotor ataxia. He readily named an object but could not describe a scene. Furthermore he noticed a line between sentences when they were written in English, but could not notice a line when sentences were written in Japanese. Cortical electric mapping, in two patients with subdural electrodes on the left or right parietal lobe, revealed circumscribed regions related to global/local attention shift or line bisection tasks.

  12. 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.

  13. 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

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

    Science.gov (United States)

    Lin, Gaven; Carlile, Simon

    2015-01-01

    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-talker conversations.

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. Design principles for shift current photovoltaics.

    Science.gov (United States)

    Cook, Ashley M; M Fregoso, Benjamin; de Juan, Fernando; Coh, Sinisa; Moore, Joel E

    2017-01-25

    While the basic principles of conventional solar cells are well understood, little attention has gone towards maximizing the efficiency of photovoltaic devices based on shift currents. By analysing effective models, here we outline simple design principles for the optimization of shift currents for frequencies near the band gap. Our method allows us to express the band edge shift current in terms of a few model parameters and to show it depends explicitly on wavefunctions in addition to standard band structure. We use our approach to identify two classes of shift current photovoltaics, ferroelectric polymer films and single-layer orthorhombic monochalcogenides such as GeS, which display the largest band edge responsivities reported so far. Moreover, exploring the parameter space of the tight-binding models that describe them we find photoresponsivities that can exceed 100 mA W-1. Our results illustrate the great potential of shift current photovoltaics to compete with conventional solar cells.

  1. Design principles for shift current photovoltaics

    Science.gov (United States)

    Cook, Ashley M.; M. Fregoso, Benjamin; de Juan, Fernando; Coh, Sinisa; Moore, Joel E.

    2017-01-01

    While the basic principles of conventional solar cells are well understood, little attention has gone towards maximizing the efficiency of photovoltaic devices based on shift currents. By analysing effective models, here we outline simple design principles for the optimization of shift currents for frequencies near the band gap. Our method allows us to express the band edge shift current in terms of a few model parameters and to show it depends explicitly on wavefunctions in addition to standard band structure. We use our approach to identify two classes of shift current photovoltaics, ferroelectric polymer films and single-layer orthorhombic monochalcogenides such as GeS, which display the largest band edge responsivities reported so far. Moreover, exploring the parameter space of the tight-binding models that describe them we find photoresponsivities that can exceed 100 mA W-1. Our results illustrate the great potential of shift current photovoltaics to compete with conventional solar cells.

  2. Do ERP components triggered during attentional orienting represent supramodal attentional control?

    Science.gov (United States)

    Seiss, Ellen; Gherri, Elena; Eardley, Alison F; Eimer, Martin

    2007-11-01

    Lateralized ERP components triggered during cued shifts of spatial attention (anterior directing attention negativity [ADAN], late directing attention positivity [LDAP]) have been observed during visual, auditory, and tactile attention tasks, suggesting that these components reflect supramodal attentional control processes. This interpretation has recently been called into question by the finding that the ADAN is absent in response to auditory attention cues. Here we demonstrate that ADAN and LDAP components are reliably elicited in a purely unimodal auditory attention task where auditory cues are followed by auditory imperative stimuli. The fact that the ADAN is not restricted to task contexts where visual or tactile stimuli are relevant is consistent with the hypothesis that this component is linked to supramodal attentional control.

  3. Reservations About the Labovian Paradigm of Style Shifting and Its Extension to the Study of Interlanguage. Revised.

    Science.gov (United States)

    Beebe, Leslie M.

    An examination of the social psychological basis of style shifting suggests that, contrary to Labovian theory, many style shifts are not a function of shifts in attention to speech and that there are other more explanatory ways of analyzing style shifts. Some reasons for this view are: (1) attention to speech is sometimes negatively correlated…

  4. 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.

  5. Anxiety and cognitive performance: attentional control theory.

    Science.gov (United States)

    Eysenck, Michael W; Derakshan, Nazanin; Santos, Rita; Calvo, Manuel G

    2007-05-01

    Attentional control theory is an approach to anxiety and cognition representing a major development of Eysenck and Calvo's (1992) processing efficiency theory. It is assumed that anxiety impairs efficient functioning of the goal-directed attentional system and increases the extent to which processing is influenced by the stimulus-driven attentional system. In addition to decreasing attentional control, anxiety increases attention to threat-related stimuli. Adverse effects of anxiety on processing efficiency depend on two central executive functions involving attentional control: inhibition and shifting. However, anxiety may not impair performance effectiveness (quality of performance) when it leads to the use of compensatory strategies (e.g., enhanced effort; increased use of processing resources). Directions for future research are discussed.

  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 the present forced attention dichotic listening study, adults with moderate and severe dyslexia and nondisabled adults were tested on their ability to switch attention between ears for immediate recall. Blocks of pairs of consonant-vowel syllables were counterbalanced into left-ear first or right-ear first ordered conditions. Significant order effects showed that only those with severe dyslexia were poorer in switching attention to the left ear, whereas both groups with dyslexia were poorer switching attention to the right ear. Shifting left appears to be a normative function of reading level, whereas inferior ability to disengage attending to the left ear to report from the right ear qualifies as a dysfunctional facet of dyslexia with etiological significance. No support was found for the traditional proposition that dyslexia may be associated with atypical left hemisphere lateralization. Combining these results with previous dichotic and neuroimaging research implicates a dysfunctional frontostriatal cognitive control network in dyslexia. With due caution, the results suggest that a neurobiological feature of dyslexia may be a lack of control in downwardly modulating excessive left inferior frontal cortex activations. The results are consistent with impoverished connectedness between left anterior and posterior language areas and, pending future confirmation of these findings, suggest the need for a reconceptualization of remedial programming. © Hammill Institute on Disabilities 2014.

  7. Attention in Active Vision: A Perspective on Perceptual Continuity Across Saccades.

    Science.gov (United States)

    Rolfs, Martin

    2015-01-01

    Alfred L. Yarbus was among the first to demonstrate that eye movements actively serve our perceptual and cognitive goals, a crucial recognition that is at the heart of today's research on active vision. He realized that not the changes in fixation stick in memory but the changes in shifts of attention. Indeed, oculomotor control is tightly coupled to functions as fundamental as attention and memory. This tight relationship offers an intriguing perspective on transsaccadic perceptual continuity, which we experience despite the fact that saccades cause rapid shifts of the image across the retina. Here, I elaborate this perspective based on a series of psychophysical findings. First, saccade preparation shapes the visual system's priorities; it enhances visual performance and perceived stimulus intensity at the targets of the eye movement. Second, before saccades, the deployment of visual attention is updated, predictively facilitating perception at those retinal locations that will be relevant once the eyes land. Third, saccadic eye movements strongly affect the contents of visual memory, highlighting their crucial role for which parts of a scene we remember or forget. Together, these results provide insights on how attentional processes enable the visual system to cope with the retinal consequences of saccades. © The Author(s) 2015.

  8. Police officers attitude to different shift systems: association with age, present shift schedule, health and sleep/wake complaints.

    Science.gov (United States)

    Kecklund, Göran; Eriksen, Claire Anne; Akerstedt, Torbjörn

    2008-09-01

    It is often claimed that shift workers give priority to long series of days off and therefore prefer compressed work schedules at the expense of what is optimal for long-term health. The aim of the present study was to evaluate the attitude to six new shift systems among a randomly selected sample of police officers. The results showed that the most popular shift system was a rapidly, forward, rotating schedule with at least 16 h of rest between shifts, despite that it had fewer days off compared with some of the compressed shift systems. However, the individual differences were large and many individuals (32%) disliked the rapidly rotating shift system. Young age was associated with a positive attitude to the rapidly rotating shift system. The attitude to the shift system was also influenced by the present schedule, and shift systems that were similar to the present work hours received more positive evaluation. Sleep and health complaints showed no association with the attitude to the shift systems. In conclusion, the shift workers attitude to the new schedules was partly in agreement with the ergonomic recommendations of the design of three-shift systems that will facilitate sufficient sleep and minimize negative health consequences.

  9. Deployment of Attention on Handshakes.

    Science.gov (United States)

    Shen, Mowei; Yin, Jun; Ding, Xiaowei; Shui, Rende; Zhou, Jifan

    2016-01-01

    Understanding the social structures between objects, organizing, and selecting them accordingly, is fundamental to social cognition. We report an example that demonstrates the object association learned from social interactions could impact visual attention. Particularly, when two hands approach each other to perform a handshake, they tend to be attended to as a unit because of the cooperative relationship exhibited in the action: even a cue presented on a non-target hand may facilitate a response to the targets that appear on the non-cued hand (Experiment 1), indicating that attentional shift between two hands was facilitated; furthermore, the response to a target on one hand is significantly impaired by a distractor on the other hand (Experiment 2), implying that it is difficult to selectively confine attention to a single hand. These effects were dependent on the existence of the hands when cue and target appeared (Experiment 3); neither perceptual familiarity, or physical fit can explain all the attention effects (Experiment 4). These results have bearings on the perceptual root of social cognition.

  10. 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.

  11. 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.

  12. 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.

  13. Insights into the Control of Attentional Set in ADHD Using the Attentional Blink Paradigm

    Science.gov (United States)

    Mason, Deanna J.; Humphreys, Glyn W.; Kent, Lindsey

    2005-01-01

    Background: Previous work on visual selective attention in Attention Deficit Hyperactivity Disorder (ADHD) has utilised spatial search paradigms. This study compared ADHD to control children on a temporal search task using Rapid Serial Visual Presentation (RSVP). In addition, the effects of irrelevant singleton distractors on search performance…

  14. Regime shifts in the anthropocene: drivers, risks, and resilience.

    Science.gov (United States)

    Rocha, Juan Carlos; Peterson, Garry D; Biggs, Reinette

    2015-01-01

    Many ecosystems can experience regime shifts: surprising, large and persistent changes in the function and structure of ecosystems. Assessing whether continued global change will lead to further regime shifts, or has the potential to trigger cascading regime shifts has been a central question in global change policy. Addressing this issue has, however, been hampered by the focus of regime shift research on specific cases and types of regime shifts. To systematically assess the global risk of regime shifts we conducted a comparative analysis of 25 generic types of regime shifts across marine, terrestrial and polar systems; identifying their drivers, and impacts on ecosystem services. Our results show that the drivers of regime shifts are diverse and co-occur strongly, which suggests that continued global change can be expected to synchronously increase the risk of multiple regime shifts. Furthermore, many regime shift drivers are related to climate change and food production, whose links to the continued expansion of human activities makes them difficult to limit. Because many regime shifts can amplify the drivers of other regime shifts, continued global change can also be expected to increase the risk of cascading regime shifts. Nevertheless, the variety of scales at which regime shift drivers operate provides opportunities for reducing the risk of many types of regime shifts by addressing local or regional drivers, even in the absence of rapid reduction of global drivers.

  15. Shifting paradigms of nontuberculous mycobacteria in cystic fibrosis

    DEFF Research Database (Denmark)

    Qvist, Tavs; Pressler, Tania; Høiby, Niels

    2014-01-01

    Important paradigms of pulmonary disease with nontuberculous mycobacteria (NTM) are currently shifting based on an increasing attention within the field of cystic fibrosis (CF). These shifts are likely to benefit the management of all patients with pulmonary NTM, regardless of underlying pathology...

  16. Shifting employment revisited

    NARCIS (Netherlands)

    Cremers, Jan; Gramuglia, Alessia

    2014-01-01

    The CLR-network examined in 2006 the phenomenon of undeclared labour, with specific regard to the construction sector. The resulting study, Shifting Employment: undeclared labour in construction (Shifting-study hereafter), gave evidence that this is an area particularly affected by undeclared

  17. 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...

  18. 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.

  19. Attention Mosaics: Studies of Organizational Attention

    OpenAIRE

    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 limited cognitions of individuals and by the limited capability of organizations to distribute, coordinate and integrate those cognitions. The cross-level nature of organizational attention, its dua...

  20. 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...

  1. 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...

  2. Attention processes in autism

    National Research Council Canada - National Science Library

    Martos-Pérez, J

    2008-01-01

    ... findings that have been obtained so far are also reported. Some attentional processes, such as selective or sustained attention, are not altered in autism or not enough evidence has been found to support such a hypothesis...

  3. Attention Competition with Advertisement

    OpenAIRE

    Cetin, Uzay; Bingol, Haluk O.

    2012-01-01

    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 a...

  4. The time course of attention: It's better than we thought.

    NARCIS (Netherlands)

    Olivers, C.N.L.

    2007-01-01

    What is the time course of attention? Research using rapid-stimulus streams has suggested that it is rather slow: Attention takes half a second to recover from processing one thing before it can process the next. This period is referred to as the attentional blink, and it is thought to reflect a

  5. 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

  6. Instantaneous phase shifting deflectometry.

    Science.gov (United States)

    Trumper, Isaac; Choi, Heejoo; Kim, Dae Wook

    2016-11-28

    An instantaneous phase shifting deflectometry measurement method is presented and implemented by measuring a time varying deformable mirror with an iPhone ® 6. The instantaneous method is based on multiplexing phase shifted fringe patterns with color, and decomposing them in x and y using Fourier techniques. Along with experimental data showing the capabilities of the instantaneous deflectometry system, a quantitative comparison with the Fourier transform profilometry method, which is a distinct phase measuring method from the phase shifting approach, is presented. Sources of error, nonlinear color-multiplexing induced error correction, and hardware limitations are discussed.

  7. Attention as foraging for information and reward

    Directory of Open Access Journals (Sweden)

    Sanjay G Manohar

    2013-11-01

    Full Text Available What is the purpose of attention? One avenue of research has led to the proposal that attention might be crucial for gathering information about the environment, while other lines of study have demonstrated attention's role in guiding behavior to rewarded options. Many experiments to study attention require participants to make a decision based on information acquired discretely at one point in time. In real-world situations, however, we are usually not presented with information about which option to select in such a manner. Rather we must initially search for information, weighing up reward values of options before we commit to a decision.Here, we propose that attention plays a role in both foraging for information and foraging for value.When foraging for information, attention is guided towards the unknown. When foraging for reward, attention is guided towards high reward values, allowing decision-making to proceed by accept-or-reject decisions on the currently attended option. According to this account, attention can be regarded as a low-cost alternative to moving around and engaging with the environment—teleforaging—before a decision is made to interact physically with the world.To track the timecourse of attention, we asked participants to seek out and acquire information about two gambles by directing their gaze, before choosing one of them. Participants often made multiple refixations on items before making a decision. Their eye movements revealed that early in the trial, attention was guided towards information, i.e. towards locations that reduced uncertainty about value. In contrast, late in the trial, attention was guided by expected value of the options. At the end of the decision period, participants were generally attending to the item they eventually chose. We suggest that attentional foraging shifts from an uncertainty-driven to a reward-driven mode during the evolution of a decision, allowing choices to be made by an engage

  8. Attention as foraging for information and value.

    Science.gov (United States)

    Manohar, Sanjay G; Husain, Masud

    2013-01-01

    What is the purpose of attention? One avenue of research has led to the proposal that attention might be crucial for gathering information about the environment, while other lines of study have demonstrated how attention may play a role in guiding behavior to rewarded options. Many experiments that study attention require participants to make a decision based on information acquired discretely at one point in time. In real-world situations, however, we are usually not presented with information about which option to select in such a manner. Rather we must initially search for information, weighing up reward values of options before we commit to a decision. Here, we propose that attention plays a role in both foraging for information and foraging for value. When foraging for information, attention is guided toward the unknown. When foraging for reward, attention is guided toward high reward values, allowing decision-making to proceed by accept-or-reject decisions on the currently attended option. According to this account, attention can be regarded as a low-cost alternative to moving around and physically interacting with the environment-"teleforaging"-before a decision is made to interact physically with the world. To track the timecourse of attention, we asked participants to seek out and acquire information about two gambles by directing their gaze, before choosing one of them. Participants often made multiple refixations on items before making a decision. Their eye movements revealed that early in the trial, attention was guided toward information, i.e., toward locations that reduced uncertainty about value. In contrast, late in the trial, attention was guided by expected value of the options. At the end of the decision period, participants were generally attending to the item they eventually chose. We suggest that attentional foraging shifts from an uncertainty-driven to a reward-driven mode during the evolution of a decision, permitting decisions to be made by

  9. 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.

  10. 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.

  11. 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.

  12. Principles of visual attention

    DEFF Research Database (Denmark)

    Bundesen, Claus; Habekost, Thomas

    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...... 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....... 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...

  13. 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.

  14. Spatial attention systems in spatial neglect.

    Science.gov (United States)

    Karnath, Hans-Otto

    2015-08-01

    It has been established that processes relating to 'spatial attention' are implemented at cortical level by goal-directed (top-down) and stimulus-driven (bottom-up) networks. Spatial neglect in brain-damaged individuals has been interpreted as a distinguished exemplar for a disturbance of these processes. The present paper elaborates this assumption. Functioning of the two attentional networks seem to dissociate in spatial neglect; behavioral studies of patients' orienting and exploration behavior point to a disturbed stimulus-driven but preserved goal-directed attention system. When a target suddenly appears somewhere in space, neglect patients demonstrate disturbed detection and orienting if it is located in contralesional direction. In contrast, if neglect patients explore a scene with voluntarily, top-down controlled shifts of spatial attention, they perform movements that are oriented into all spatial directions without any direction-specific disturbances. The paper thus argues that not the top-down control of spatial attention itself, rather a body-related matrix on top of which this process is executed, seems affected. In that sense, the traditional role of spatial neglect as a stroke model for 'spatial attention' requires adjustment. Beyond its insights into the human stimulus-driven attentional system, the disorder most notably provides vistas in how our brain encodes topographical information and organizes spatially oriented action - including the top-down control of spatial attention - in relation to body position. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Saccadic adaptation alters the attentional field

    Directory of Open Access Journals (Sweden)

    Farahnaz Ahmed Wick

    2016-11-01

    Full Text Available It is currently unknown whether changes to the oculomotor system can induce changes to the distribution of spatial attention around a fixated target. Previous studies have used perceptual performance tasks to show that adaptation of saccadic eye movements affects dynamic properties of visual attention, in particular, attentional shifts to a cued location. In this study, we examined the effects of saccadic adaptation on the static distribution of visual attention around fixation (attentional field. We used the classic double step adaptation procedure and a flanker task to test for differences in the attentional field after forward and backward adaptation. RT measures revealed that the shape of the attentional field changed significantly after backward adaptation as shown through altered interference from distracters at different eccentricities but not after forward adaptation. This finding reveals that modification of saccadic amplitudes can affect metrics of not only dynamic properties of attention but also its static properties. A major implication is that the neural mechanisms underlying fundamental selection mechanisms and the oculomotor system can reweight each other.

  16. From distraction to mindfulness : Psychological and neural mechanisms of attention strategies in self-regulation

    NARCIS (Netherlands)

    Van Dillen, Lotte F.; Papies, Esther K.

    2015-01-01

    The current chapter examines attention strategies that may facilitate self-regulation. In particular, we focus on the attention strategies of distraction and mindfulness. By distraction, we mean shifting attention from the original object of attention onto a different focal object. Mindfulness, on

  17. 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,

  18. 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

  19. Attention to Advertising

    OpenAIRE

    Nilsson, Carl Patrik

    2006-01-01

    Attention to Advertising Carl Patrik Nilsson, Umeå School of Business, Umeå University SE-901 87 Umeå, Sweden Abstract In advertising, capturing consumers’ attention is imperative. Yet, how attention to advertising works in a World Wide Web context has not been researched extensively. This area is the main focus of this research. The World Wide Web is an interactive medium which has characteristics that deviate from traditional media channels. Considering the unique properties of the World Wi...

  20. Announcements to Attentive Agents

    DEFF Research Database (Denmark)

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

    2016-01-01

    In public announcement logic it is assumed that all agents pay attention to the announcement. Weaker observational conditions can be modelled in action model logic. In this work, we propose a version of public announcement logic wherein it is encoded in the states of the epistemic model which...... agents pay attention to the announcement. This logic is called attention-based announcement logic. We give an axiomatization of the logic and prove that complexity of satisfiability is the same as that of public announcement logic, and therefore lower than that of action model logic. An attention...

  1. Protein Chemical Shift Prediction

    CERN Document Server

    Larsen, Anders S

    2014-01-01

    The protein chemical shifts holds a large amount of information about the 3-dimensional structure of the protein. A number of chemical shift predictors based on the relationship between structures resolved with X-ray crystallography and the corresponding experimental chemical shifts have been developed. These empirical predictors are very accurate on X-ray structures but tends to be insensitive to small structural changes. To overcome this limitation it has been suggested to make chemical shift predictors based on quantum mechanical(QM) calculations. In this thesis the development of the QM derived chemical shift predictor Procs14 is presented. Procs14 is based on 2.35 million density functional theory(DFT) calculations on tripeptides and contains corrections for hydrogen bonding, ring current and the effect of the previous and following residue. Procs14 is capable at performing predictions for the 13CA, 13CB, 13CO, 15NH, 1HN and 1HA backbone atoms. In order to benchmark Procs14, a number of QM NMR calculatio...

  2. 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.

  3. 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.

  4. Fröhlich effect and delays of visual attention.

    Science.gov (United States)

    Adamian, Nika; Cavanagh, Patrick

    2017-01-01

    In the Fröhlich effect, the initial position of an object that suddenly appears in motion is perceived as being shifted in the direction of its motion. Here we establish that this shift is not an obligatory consequence of motion, but it is driven by focused attention. In Experiment 1 using different cueing conditions, we found that invalid cues produced larger perceptual shifts, although the Fröhlich effect was still present for valid and neutral cues. These results support Müsseler and Aschersleben's (1998) proposal that the Fröhlich effect is the result of the time it takes to shift focal attention to the moving stimulus. In Experiment 2 we found that the Fröhlich effect increased when the valid cue arrived more than 100 ms after the start of motion, suggesting again that a delay in attention's arrival shifted the location of the perceived motion onset. In Experiment 3 we compare the motion-induced shifts when the subjects attended to a set of moving stimuli as a group and when they attended to an orientation singleton. We showed that Fröhlich effect was only present when the target was individuated and disappeared when the stimulus was perceived globally. We conclude that the Fröhlich effect is a predictive spatial shift produced and modulated by focal attention.

  5. Nurses' shift reports

    DEFF Research Database (Denmark)

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

    2017-01-01

    practices were described as highly conventionalised and locally situated, but with occasional opportunities for improvisation and negotiation between nurses. Finally, shift reports were described as multifunctional meetings, with individual and social effects for nurses and teams. CONCLUSION: Innovations...... in between-shift communications can benefit from this analysis, by providing for the many functions of handovers that are revealed in field studies. RELEVANCE TO CLINICAL PRACTICE: Leaders and practising nurses may consider what are the best opportunities for nurses to work up clinical knowledge......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...

  6. 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.

  7. 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…

  8. Bioequivalence evaluation of epinephrine autoinjectors with attention to rapid delivery

    Directory of Open Access Journals (Sweden)

    Sclar DA

    2013-04-01

    Full Text Available David Alexander Sclar Department of Pharmacy Practice, College of Pharmacy, Midwestern University, Glendale, AZ, USA Abstract: Timely and proper injection of epinephrine is critical to prevent serious consequences relating to anaphylaxis. In a recent bioavailability study comparing epinephrine delivery from the Auvi-Q™ and EpiPen® epinephrine autoinjectors, the Auvi-Q failed to meet the bioequivalence threshold when using partial area under the curve (AUC analyses based on zero to Tmax recommended for highly variable drugs such as epinephrine. Peak plasma epinephrine concentrations for the EpiPen occurred 10 minutes (median Tmax after dosing, while peak concentrations for the Auvi-Q occurred 20 minutes after dosing. Though bioequivalence may be concluded for Cmax, AUCinf, and AUC0–t, for fast-acting therapeutics used to treat life-threatening conditions, such as epinephrine, additional pharmacokinetic parameters such as AUC zero to Tmax may be important to evaluate when assessing bioequivalence. Keywords: anaphylaxis, therapy, pharmacokinetics, bioavailability, EpiPen, Tmax

  9. Bioequivalence evaluation of epinephrine autoinjectors with attention to rapid delivery.

    Science.gov (United States)

    Sclar, David Alexander

    2013-01-01

    Timely and proper injection of epinephrine is critical to prevent serious consequences relating to anaphylaxis. In a recent bioavailability study comparing epinephrine delivery from the Auvi-Q™ and EpiPen(®) epinephrine autoinjectors, the Auvi-Q failed to meet the bioequivalence threshold when using partial area under the curve (AUC) analyses based on zero to Tmax recommended for highly variable drugs such as epinephrine. Peak plasma epinephrine concentrations for the EpiPen occurred 10 minutes (median Tmax) after dosing, while peak concentrations for the Auvi-Q occurred 20 minutes after dosing. Though bioequivalence may be concluded for Cmax, AUCinf, and AUC0-t, for fast-acting therapeutics used to treat life-threatening conditions, such as epinephrine, additional pharmacokinetic parameters such as AUC zero to Tmax may be important to evaluate when assessing bioequivalence.

  10. 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.

  11. Laughter catches attention!

    NARCIS (Netherlands)

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

    2017-01-01

    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.

  12. Unmasking the attentional blink

    NARCIS (Netherlands)

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

    2009-01-01

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

  13. Neural Mechanisms of Attention

    Science.gov (United States)

    1993-05-21

    attention deficit hyperactivity disorder ( ADHD ). These disorders may encompass a number of other cognitive deficits, but many theories focus on the...trial of methylphenidate in black adolescents. Attentional, behavioral, and physiological effects. CLINICAL.PEDIATRICS., 27,74-81. Bruto, V...Nakamura, K., Nishijo, H., & Fukuda, M. (1986). Hypothalamic neuron involvement in integration of reward , aversion, and cue signals. Journal of

  14. Dealing with a Paradigm Shift

    Science.gov (United States)

    Pack, Allan I.

    2015-01-01

    Recent changes in policies by insurance companies with respect to mandating home sleep apnea testing rather than in-laboratory studies have a large impact on the financial viability of clinical sleep centers. Coping with this disruptive change requires forward planning. First, it is important to be well positioned with respect to facilities so that these can be quickly downsized to control costs. There is also a need to develop, in advance, an accredited home sleep study program so that centers can respond to the rapidly changing environment. Following the change there is a need to control costs by rapidly downsizing the technology workforce. Technologists can be retrained for other essential roles. Centralizing the precertification process with knowledgeable, well-trained staff and a robust auditing process is an essential component. The approach taken at the University of Pennsylvania to this change is described as is how one can ensure continued financial viability of a comprehensive sleep center program in a major academic medical center. Citation: Pack AI. Dealing with a paradigm shift. J Clin Sleep Med 2015;11(8):925–929. PMID:26094918

  15. Attention and choice

    DEFF Research Database (Denmark)

    Orquin, Jacob Lund; Mueller Loose, Simone

    2013-01-01

    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...... 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...... 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...

  16. Attentional bias to affective faces and complex IAPS images in early visual cortex follows emotional cue extraction.

    Science.gov (United States)

    Bekhtereva, Valeria; Craddock, Matt; Müller, Matthias M

    2015-05-15

    Emotionally arousing stimuli are known to rapidly draw the brain's processing resources, even when they are task-irrelevant. The steady-state visual evoked potential (SSVEP) response, a neural response to a flickering stimulus which effectively allows measurement of the processing resources devoted to that stimulus, has been used to examine this process of attentional shifting. Previous studies have used a task in which participants detected periods of coherent motion in flickering random dot kinematograms (RDKs) which generate an SSVEP, and found that task-irrelevant emotional stimuli withdraw more attentional resources from the task-relevant RDKs than task-irrelevant neutral stimuli. However, it is not clear whether the emotion-related differences in the SSVEP response are conditional on higher-level extraction of emotional cues as indexed by well-known event-related potential (ERPs) components (N170, early posterior negativity, EPN), or if affective bias in competition for visual attention resources is a consequence of a time-invariant shifting process. In the present study, we used two different types of emotional distractors - IAPS pictures and facial expressions - for which emotional cue extraction occurs at different speeds, being typically earlier for faces (at ~170ms, as indexed by the N170) than for IAPS images (~220-280ms, EPN). We found that emotional modulation of attentional resources as measured by the SSVEP occurred earlier for faces (around 180ms) than for IAPS pictures (around 550ms), after the extraction of emotional cues as indexed by visual ERP components. This is consistent with emotion related re-allocation of attentional resources occurring after emotional cue extraction rather than being linked to a time-fixed shifting process. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Right-Rapid-Rough

    Science.gov (United States)

    Lawrence, Craig

    2003-01-01

    IDEO (pronounced 'eye-dee-oh') is an international design, engineering, and innovation firm that has developed thousands of products and services for clients across a wide range of industries. Its process and culture attracted the attention of academics, businesses, and journalists around the world, and are the subject of a bestselling book, The Art of Innovation by Tom Kelley. One of the keys to IDEO's success is its use of prototyping as a tool for rapid innovation. This story covers some of IDEO's projects, and gives reasons for why they were successful.

  18. Habitual attention in older and young adults.

    Science.gov (United States)

    Jiang, Yuhong V; Koutstaal, Wilma; Twedell, Emily L

    2016-12-01

    Age-related decline is pervasive in tasks that require explicit learning and memory, but such reduced function is not universally observed in tasks involving incidental learning. It is unknown if habitual attention, involving incidental probabilistic learning, is preserved in older adults. Previous research on habitual attention investigated contextual cuing in young and older adults, yet contextual cuing relies not only on spatial attention but also on context processing. Here we isolated habitual attention from context processing in young and older adults. Using a challenging visual search task in which the probability of finding targets was greater in 1 of 4 visual quadrants in all contexts, we examined the acquisition, persistence, and spatial-reference frame of habitual attention. Although older adults showed slower visual search times and steeper search slopes (more time per additional item in the search display), like young adults they rapidly acquired a strong, persistent search habit toward the high-probability quadrant. In addition, habitual attention was strongly viewer-centered in both young and older adults. The demonstration of preserved viewer-centered habitual attention in older adults suggests that it may be used to counter declines in controlled attention. This, in turn, suggests the importance, for older adults, of maintaining habit-related spatial arrangements. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  19. Illuminating geographical patterns in species' range shifts.

    Science.gov (United States)

    Grenouillet, Gaël; Comte, Lise

    2014-10-01

    Species' range shifts in response to ongoing climate change have been widely documented, but although complex spatial patterns in species' responses are expected to be common, comprehensive comparisons of species' ranges over time have undergone little investigation. Here, we outline a modeling framework based on historical and current species distribution records for disentangling different drivers (i.e. climatic vs. nonclimatic) and assessing distinct facets (i.e. colonization, extirpation, persistence, and lags) of species' range shifts. We used extensive monitoring data for stream fish assemblages throughout France to assess range shifts for 32 fish species between an initial period (1980-1992) and a contemporary one (2003-2009). Our results provide strong evidence that the responses of individual species varied considerably and exhibited complex mosaics of spatial rearrangements. By dissociating range shifts in climatically suitable and unsuitable habitats, we demonstrated that patterns in climate-driven colonization and extirpation were less marked than those attributed to nonclimatic drivers, although this situation could rapidly shift in the near future. We also found evidence that range shifts could be related to some species' traits and that the traits involved varied depending on the facet of range shift considered. The persistence of populations in climatically unsuitable areas was greater for short-lived species, whereas the extent of the lag behind climate change was greater for long-lived, restricted-range, and low-elevation species. We further demonstrated that nonclimatic extirpations were primarily related to the size of the species' range, whereas climate-driven extirpations were better explained by thermal tolerance. Thus, the proposed framework demonstrated its potential for markedly improving our understanding of the key processes involved in range shifting and also offers a template for informing management decisions. Conservation strategies

  20. Shifting employment revisited

    NARCIS (Netherlands)

    Cremers, J.; Gramuglia, A.

    2014-01-01

    The CLR-network examined in 2006 the phenomenon of undeclared labour, with specific regard to the construction sector. The resulting study, Shifting Employment: undeclared labour in construction, gave evidence that this is an area particularly affected by undeclared activities with one of the

  1. Shifting tasks in telecare

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2017-01-01

    with focus on shifting tasks was undertaken. Furthermore, the method of ‘Interview to double’ was used the analytical ambition being to explore the becoming of tasks and relations. Analytically the study draws predominantly on Stars notion of ‘infrastructure’. Infrastructure is seen as human and non...

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

    Science.gov (United States)

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

    2013-02-01

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

  3. [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.

  4. How automatic is manual gear shifting?

    Science.gov (United States)

    Shinar, D; Meir, M; Ben-Shoham, I

    1998-12-01

    Manual gear shifting is often used as an example of an automated (vs. controlled) process in driving. The present study provided an empirical evaluation of this assumption by evaluating sign detection and recall performance of novice and experienced drivers driving manual shift and automatic transmission cars in a downtown area requiring frequent gear shifting. The results showed that manual gear shifting significantly impaired sign detection performance of novice drivers using manual gears compared with novice drivers using an automatic transmission, whereas no such differences existed between the two transmission types for experienced drivers. The results clearly demonstrate that manual gear shifting is a complex psychomotor skill that is not easily (or quickly) automated and that until it becomes automated, it is an attention-demanding task that may impair other monitoring aspects of driving performance. Actual or potential applications of this research include a reevaluation of the learning process in driving and the need for phased instruction in driving from automatic gears to manual gears.

  5. 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 laparoscopic...... 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....

  6. Attentional capture by the onset and offset of motion signals outside the spatial focus of attention.

    Science.gov (United States)

    Kawahara, Jun; Yanase, Kaori; Kitazaki, Michiteru

    2012-11-16

    The present study examined whether participants were able to ignore a task-irrelevant commencement or cessation of optic flow while they were engaging in a letter-identification task, as claimed by adherents of the view that attentional set determines deployment of attention, or whether irrelevant events would capture attention regardless of observers' attentional set, as claimed by adherents of a broad range of views emphasizing the behavioral urgency of stimulus motion. Observers identified a green letter in a central rapid stream of heterogeneously colored nontargets. A completely task-irrelevant optic flow occurred in the periphery. If attentional deployment were governed by a top-down attentional set, the letter identification would be unaffected by the temporal change in the optic flow. The results reflected attentional capture by commencement or cessation of optic flow, which is inconsistent with the top-down view. When the peripheral dots expanded at various speeds before onset of the target, identification was impaired relative to when no motion occurred. Mere commencement or cessation of motion was sufficient to produce the capture effect. Qualitative (commencement or cessation) rather than quantitative changes (acceleration or deceleration) of the motion display were critical for the occurrence of attentional capture. We conclude that salient discontinuities in optic flow induce attentional capture when observers search for a feature in a different stimulus domain, an idea implying a unique role for of expanding global motion in the deployment of visual attention.

  7. Aspects of Attention in Rett Syndrome.

    Science.gov (United States)

    Rose, Susan A; Djukic, Aleksandra; Jankowski, Jeffery J; Feldman, Judith F; Rimler, Menachem

    2016-04-01

    We sought to examine fundamental aspects of attention in children with Rett syndrome, a severely disabling neurodevelopmental disorder caused by spontaneous mutations in the X-linked MECP2 gene. To gauge their attention, we used eye tracking, which bypasses the profound impairments in expressive language and hand use in Rett syndrome. We report two aspects of attention-shifting and sustaining-basic abilities known to drive cognitive growth. Two groups were compared: those with Rett syndrome (N = 20; 3-15 years) and a typically developing comparison group (N = 14; 3-16 years), using a task in which an attractive central stimulus was followed, after a short gap, by a dynamic target presented to one side. Time to shift to the target location (reactive and anticipatory saccades) and time fixating the target were assessed. Children with Rett syndrome were consistently slower to shift (largely because of fewer anticipations); their reactive saccades were also slower than those of typically developing children, but not significantly so. The Rett syndrome group spent considerable time looking at the target (over 75% of available time), although significantly less so than the typically developing group. These findings indicate that children with Rett syndrome could maintain attention on a stimulus and orient relatively quickly to the appearance of a target in the visual field. However, they had difficulty in anticipating predictable events, a difficulty in endogenous attention that is likely to have deleterious implications for executive functioning. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. 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.

  9. 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.

  10. Are You Paying Attention?

    DEFF Research Database (Denmark)

    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......A still understudied area in media research is how people pay attention to news in daily life. To do so, the chapter develops a theoretical framework grounded in news audience research and practice theory. This framework conceptualizes practices as different ways in which attention is directed....... In the concluding discussion, the chapter relates the findings to further perspectives on attention to news specifically and media content more generally. Accordingly, this chapter contributes to cross-media news research by analyzing ways in which people attend to news and how these ways of attending vary across...

  11. Attention as a Bayesian inference process

    Science.gov (United States)

    Chikkerur, Sharat; Serre, Thomas; Tan, Cheston; Poggio, Tomaso

    2011-03-01

    David Marr famously defined vision as "knowing what is where by seeing". In the framework described here, attention is the inference process that solves the visual recognition problem of what is where. The theory proposes a computational role for attention and leads to a model that performs well in recognition tasks and that predicts some of the main properties of attention at the level of psychophysics and physiology. We propose an algorithmic implementation a Bayesian network that can be mapped into the basic functional anatomy of attention involving the ventral stream and the dorsal stream. This description integrates bottom-up, feature-based as well as spatial (context based) attentional mechanisms. We show that the Bayesian model predicts well human eye fixations (considered as a proxy for shifts of attention) in natural scenes, and can improve accuracy in object recognition tasks involving cluttered real world images. In both cases, we found that the proposed model can predict human performance better than existing bottom-up and top-down computational models.

  12. The relationship between attention allocation and cheating.

    Science.gov (United States)

    Pittarello, Andrea; Motro, Daphna; Rubaltelli, Enrico; Pluchino, Patrik

    2016-04-01

    Little is known about the relationship between attention allocation and dishonesty. The goal of the present work was to address this issue using the eyetracking methodology. We developed a novel task in which participants could honestly report seeing a particular card and lose money, or they could falsely report not seeing the card and not lose money. When participants cheated, they allocated less attention (i.e., shorter fixation durations and fewer fixations) to the card than when they behaved honestly. Our results suggest that when dishonesty pays, shifting attention away from undesirable information can serve as a self-deception strategy that allows individuals to serve their self-interests while maintaining a positive self-concept.

  13. Unmasking the Attentional Blink

    Science.gov (United States)

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

    2009-01-01

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

  14. 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.

  15. 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.

  16. Spatial and temporal attention in developmental dyslexia

    Directory of Open Access Journals (Sweden)

    Milena eRuffino

    2014-05-01

    Full Text Available Although the dominant view posits that developmental dyslexia (DD arises from a deficit in phonological processing, emerging evidence suggest that DD could result from a more basic cross-modal letter-to-speech sound integration deficit. Letters have to be precisely selected from irrelevant and cluttering letters by rapid orienting of visual attention before the correct letter-to-speech sound integration applies. In the present study the time-course of spatial attention was investigated measuring target detection reaction times (RTs in a cuing paradigm, while temporal attention was investigated by assessing impaired identification of the first of two sequentially presented masked visual objects. Spatial and temporal attention were slower in dyslexic children with a deficit in pseudoword reading (N=14 compared to chronological age (N=43 and to dyslexics without a deficit in pseudoword reading (N=18, suggesting a direct link between visual attention efficiency and phonological decoding skills. Individual differences in these visual attention mechanisms were specifically related to pseudoword reading accuracy in dyslexics. The role of spatial and temporal attention in the graphemic parsing process might be related to a basic oscillatory temporal sampling dysfunction.

  17. Attentional and Contextual Priors in Sound Perception.

    Directory of Open Access Journals (Sweden)

    Michael Wolmetz

    Full Text Available 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.

  18. Rapid Prototyping

    Science.gov (United States)

    1999-01-01

    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  19. An Attention-Sensitive Memory Trace in Macaque MT Following Saccadic Eye Movements.

    Directory of Open Access Journals (Sweden)

    Tao Yao

    2016-02-01

    Full Text Available We experience a visually stable world despite frequent retinal image displacements induced by eye, head, and body movements. The neural mechanisms underlying this remain unclear. One mechanism that may contribute is transsaccadic remapping, in which the responses of some neurons in various attentional, oculomotor, and visual brain areas appear to anticipate the consequences of saccades. The functional role of transsaccadic remapping is actively debated, and many of its key properties remain unknown. Here, recording from two monkeys trained to make a saccade while directing attention to one of two spatial locations, we show that neurons in the middle temporal area (MT, a key locus in the motion-processing pathway of humans and macaques, show a form of transsaccadic remapping called a memory trace. The memory trace in MT neurons is enhanced by the allocation of top-down spatial attention. Our data provide the first demonstration, to our knowledge, of the influence of top-down attention on the memory trace anywhere in the brain. We find evidence only for a small and transient effect of motion direction on the memory trace (and in only one of two monkeys, arguing against a role for MT in the theoretically critical yet empirically contentious phenomenon of spatiotopic feature-comparison and adaptation transfer across saccades. Our data support the hypothesis that transsaccadic remapping represents the shift of attentional pointers in a retinotopic map, so that relevant locations can be tracked and rapidly processed across saccades. Our results resolve important issues concerning the perisaccadic representation of visual stimuli in the dorsal stream and demonstrate a significant role for top-down attention in modulating this representation.

  20. 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.

  1. Attention and reading skills.

    Science.gov (United States)

    Commodari, Elena; Guarnera, Maria

    2005-04-01

    Attention plays a critical role in information processing. Its adequate functioning is required for correct development of complex cognitive abilities and regular scholastic progress. Children with attention deficits often have difficulties in reading, writing, and arithmetic. The present study investigated interactions among reading skills, overall scholastic performance as rated by teachers, and components of attention: visual reaction time, simple immediate span of attention, and selectivity. The sample was 98 students in the first and second years of public junior high school (age range 11-14 years, M = 12.6, SD = 1.2), i.e., with expected already well-established reading. Reading was evaluated using Comprehension, Accuracy, and Speed tests. Overall scholastic performance was obtained by means of teachers' ratings. Simple Reaction Time, Digit Span, and Color-Word Interference, included in a multitask computerized test, assessed attention. Analysis confirmed the hypothesis that the reading skills are strongly predictive of the Scholastic Assessment rated by the teachers. High scholastic ratings were correlated with Reading Speed and Accuracy rather than Reading Comprehension. Poor readers showed worse performances on the Digit Span test which measures simple immediate span of attention. Good and poor readers obtained a similar score on the Color-Word Interference task. This observation seems to contrast with the more common interpretation of this effect, suggesting that reading is an automatic process and, therefore, the semantic dimension overcomes the controlled perceptual one. According to other studies, an alternative explanation is suggested. In conclusion, present results confirm the hypothesis of a strong link among reading speed and accuracy, scholastic assessment as rated by teachers, simple immediate span of attention, and visual reaction time.

  2. Effects of shift rotation and the flexibility of a shift system on daytime alertness and cardiovascular risk factors.

    Science.gov (United States)

    Viitasalo, Katriina; Kuosma, Eeva; Laitinen, Jaana; Härmä, Mikko

    2008-06-01

    A controlled intervention study was conducted to evaluate the effects of two changes in shift characteristics on alertness and cardiovascular risk factors: a change in shift rotation (direction and speed) and a change in the flexibility of the shift system. Altogether 84 male workers currently working in a backward-rotating shift system volunteered for the study. A total of 40 men changed to a rapidly forward-rotating shift system, 22 changed to a more flexible shift system, and 22 remained with the old shift system. Health effects were studied with the use of clinical measurements, blood tests, and questionnaires before and after the shift changes. Analyses of variance were used with repeated measures to study associations of cardiovascular risk factors and daytime sleepiness according to the change in shift systems. The mean number of days on which the workers reported sleepiness decreased in the group with the forward-rotating shift system when compared with that of the group on the old shift system (from 2.9 to 2.1 days/week, P=0.02). Systolic blood pressure decreased (from 142 to 136 mm Hg, P=0.049), and heart rate showed a declining trend (from 66 to 60 beats/minute, P=0.06) in the flexible shift system when the three groups were compared. The study indicates that a faster speed, together with a change to the forward direction, in shift rotation alleviates daytime sleepiness. Combining individual flexibility with company-based flexibility in a shift system may have favorable effects on shift workers' blood pressure.

  3. Effect of Attention Training on Attention Bias Variability and PTSD Symptoms: Randomized Controlled Trials in Israeli and U.S. Combat Veterans.

    Science.gov (United States)

    Badura-Brack, Amy S; Naim, Reut; Ryan, Tara J; Levy, Ofir; Abend, Rany; Khanna, Maya M; McDermott, Timothy J; Pine, Daniel S; Bar-Haim, Yair

    2015-12-01

    Attention allocation to threat is perturbed in patients with posttraumatic stress disorder (PTSD), with some studies indicating excess attention to threat and others indicating fluctuations between threat vigilance and threat avoidance. The authors tested the efficacy of two alternative computerized protocols, attention bias modification and attention control training, for rectifying threat attendance patterns and reducing PTSD symptoms. Two randomized controlled trials compared the efficacy of attention bias modification and attention control training for PTSD: one in Israel Defense Forces veterans and one in U.S. military veterans. Both utilized variants of the dot-probe task, with attention bias modification designed to shift attention away from threat and attention control training balancing attention allocation between threat and neutral stimuli. PTSD symptoms, attention bias, and attention bias variability were measured before and after treatment. Both studies indicated significant symptom improvement after treatment, favoring attention control training. Additionally, both studies found that attention control training, but not attention bias modification, significantly reduced attention bias variability. Finally, a combined analysis of the two samples suggested that reductions in attention bias variability partially mediated improvement in PTSD symptoms. Attention control training may address aberrant fluctuations in attention allocation in PTSD, thereby reducing PTSD symptoms. Further study of treatment efficacy and its underlying neurocognitive mechanisms is warranted.

  4. Modelling auditory attention.

    Science.gov (United States)

    Kaya, Emine Merve; Elhilali, Mounya

    2017-02-19

    Sounds in everyday life seldom appear in isolation. Both humans and machines are constantly flooded with a cacophony of sounds that need to be sorted through and scoured for relevant information-a phenomenon referred to as the 'cocktail party problem'. A key component in parsing acoustic scenes is the role of attention, which mediates perception and behaviour by focusing both sensory and cognitive resources on pertinent information in the stimulus space. The current article provides a review of modelling studies of auditory attention. The review highlights how the term attention refers to a multitude of behavioural and cognitive processes that can shape sensory processing. Attention can be modulated by 'bottom-up' sensory-driven factors, as well as 'top-down' task-specific goals, expectations and learned schemas. Essentially, it acts as a selection process or processes that focus both sensory and cognitive resources on the most relevant events in the soundscape; with relevance being dictated by the stimulus itself (e.g. a loud explosion) or by a task at hand (e.g. listen to announcements in a busy airport). Recent computational models of auditory attention provide key insights into its role in facilitating perception in cluttered auditory scenes.This article is part of the themed issue 'Auditory and visual scene analysis'. © 2017 The Authors.

  5. Spatial distribution of the attentional blink

    Directory of Open Access Journals (Sweden)

    FENG eDU

    2011-12-01

    Full Text Available In the present study subjects viewed streams of rapid serially presented characters and searched for a target digit. After presentation of the target digit, a second target consisting of an orientation singleton (Experiment 1 or a second digit (Experiment 2 was presented at one of several distances from the first target. The attentional blink impaired performance on the second target with the effect being strongest at distances somewhat removed from the first target location. These results are consistent with lateral inhibition theory and help to resolve some fundamental questions about the spatial distribution of the attentional blink.

  6. The shifting perspectives model of chronic illness.

    Science.gov (United States)

    Paterson, B L

    2001-01-01

    To present the Shifting Perspectives Model of Chronic Illness, which was derived from a metasynthesis of 292 qualitative research studies. The model was derived from a metasynthesis of qualitative research about the reported experiences of adults with a chronic illness. The 292 primary research studies included a variety of interpretive research methods and were conducted by researchers from numerous countries and disciplines. Metastudy, a metasynthesis method developed by the author in collaboration with six other researchers consisted of three analytic components (meta-data-analysis, metamethod, and metatheory), followed by a synthesis component in which new knowledge about the phenomenon was generated from the findings. Many of the assumptions that underlie previous models, such as a single, linear trajectory of living with a chronic disease, were challenged. The Shifting Perspectives Model indicated that living with chronic illness was an ongoing and continually shifting process in which an illness-in-the-foreground or wellness-in-the-foreground perspective has specific functions in the person's world. The Shifting Perspectives Model helps users provide an explanation of chronically ill persons' variations in their attention to symptoms over time, sometimes in ways that seem ill-advised or even harmful to their health. The model also indicates direction to health professionals about supporting people with chronic illness.

  7. 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.

  8. 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.

  9. Upward ant distribution shift corresponds with minimum, not maximum, temperature tolerance

    Science.gov (United States)

    Robert J. Warren; Lacy. Chick

    2013-01-01

    Rapid climate change may prompt species distribution shifts upward and poleward, but species movement in itself is not sufficient to establish climate causation. Other dynamics, such as disturbance history, may prompt species distribution shifts resembling those expected from rapid climate change. Links between species distributions, regional climate trends and...

  10. Catastrophic shifts in ecosystems

    Science.gov (United States)

    Scheffer, Marten; Carpenter, Steve; Foley, Jonathan A.; Folke, Carl; Walker, Brian

    2001-10-01

    All ecosystems are exposed to gradual changes in climate, nutrient loading, habitat fragmentation or biotic exploitation. Nature is usually assumed to respond to gradual change in a smooth way. However, studies on lakes, coral reefs, oceans, forests and arid lands have shown that smooth change can be interrupted by sudden drastic switches to a contrasting state. Although diverse events can trigger such shifts, recent studies show that a loss of resilience usually paves the way for a switch to an alternative state. This suggests that strategies for sustainable management of such ecosystems should focus on maintaining resilience.

  11. Backward Masked Snakes and Guns Modulate Spatial Attention

    OpenAIRE

    Joshua M. Carlson; Andrea L. Fee; Reinke, Karen S.

    2009-01-01

    Fearful faces are important social cues that alert others of potential threat. Even backward masked fearful faces facilitate spatial attention. However, visual stimuli other than fearful faces can signal potential threat. Indeed, unmasked snakes and spiders modulate spatial attention. Yet, it is unclear if the rapid threat-related facilitation of spatial attention to backward masked stimuli is elicited by non-face threat cues. Evolutionary theories claim that phylogenetic threats (i.e. snakes...

  12. Cognitive Penetration and Attention

    Science.gov (United States)

    Gross, Steven

    2017-01-01

    Zenon Pylyshyn argues that cognitively driven attentional effects do not amount to cognitive penetration of early vision because such effects occur either before or after early vision. Critics object that in fact such effects occur at all levels of perceptual processing. We argue that Pylyshyn’s claim is correct—but not for the reason he emphasizes. Even if his critics are correct that attentional effects are not external to early vision, these effects do not satisfy Pylyshyn’s requirements that the effects be direct and exhibit semantic coherence. In addition, we distinguish our defense from those found in recent work by Raftopoulos and by Firestone and Scholl, argue that attention should not be assimilated to expectation, and discuss alternative characterizations of cognitive penetrability, advocating a kind of pluralism. PMID:28275358

  13. Attention: an evolving construct.

    Science.gov (United States)

    Joyce, Arthur; Hrin, Skip

    2015-01-01

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

  14. Computational study of hydrogen shifts and ring-opening mechanisms in α-pinene ozonolysis products

    DEFF Research Database (Denmark)

    Kurtén, Theo; Rissanen, Matti P.; Mackeprang, Kasper

    2015-01-01

    Autoxidation by sequential peroxy radical hydrogen shifts (H-shifts) and O2 additions has recently emerged as a promising mechanism for the rapid formation of highly oxidized, low-volatility organic compounds in the atmosphere. A key prerequisite for autoxidation is that the H-shifts of the initial...

  15. Updating the Premotor Theory: The Allocation of Attention Is Not Always Accompanied by Saccade Preparation

    Science.gov (United States)

    Belopolsky, Artem V.; Theeuwes, Jan

    2012-01-01

    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…

  16. 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.

  17. 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...... 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...... networks that include several regions outside the visual system. The two visual capacity parameters are functionally separable, but seem to rely on largely overlapping brain areas....

  18. Saccadic and attentional abnormalities in patients with schizophrenia.

    Science.gov (United States)

    Maruff, P; Danckert, J; Pantelis, C; Currie, J

    1998-09-01

    Abnormal performance on the antisaccade task suggests that patients with schizophrenia have difficulty with the inhibition of reflexive attentional shifts. The aim of the study was to investigate whether deficits in the inhibition of reflexive attentional shifts were specific to the oculomotor modality or whether they could also occur when attentional shifts were made without eye movements (e.g. covert attentional shifts). Fifteen medicated patients with chronic schizophrenia and 15 matched controls performed the antisaccade task and the covert orientating task (COVAT) where the probability of targets appearing at the same location of a peripheral cue was varied so that voluntary and reflexive orientating systems had the same goal (80% probability of target and cued condition) or opposite goals (20% probability of target at cued location). A condition where only reflexive orientating was initiated was also included (50% probability of target at cued location). For each of these conditions the stimulus onset asynchrony (SOA) varied between 150 and 350 ms. Patients with schizophrenia showed normal latency and accuracy for visually guided saccades but increased error rates and latency on the antisaccade task. For the COVAT, patients with schizophrenia were unable to use voluntary orientating strategies to inhibit reflexive shifts of covert attention. On conditions where only reflexive orientating was required or when the goals of the reflexive and voluntary orientating systems were the same, patients with schizophrenia showed normal performance. These results suggest the reflexive orientating mode is normal in patients with chronic schizophrenia. However, these patients have a reduced ability to utilize the voluntary orientating mode to control or inhibit reflexive orientating. This impairment of voluntary control is evident for both overt and covert attentional shifts.

  19. 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.

  20. 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...

  1. 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...

  2. 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’

  3. Stable Core, Shifting Periphery?

    DEFF Research Database (Denmark)

    Gravier, Magali

    European empires of the past. The paper argues that colonial empires are just one type of empires and that another type should be given more scholarly attention. In order to account for the diversity of imperial patterns observed, the paper suggests using two concepts, inwards imperial governance...... and outwards imperial governance. Using these two concepts instead of one undifferentiated concept of empire makes it possible to shed a different light on the EU’s alleged empirehood and its evolution over time. It also offers an analytical tool that can account for differences between different empires...

  4. Phenomenology of Joint Attention

    African Journals Online (AJOL)

    denise

    of phenomenology by offering a phenomenology of joint attention. The first section reviews elementary. Husserlian phenomenology and introduces a system for symbolically representing the structure of intentional mental states. The second section summarizes Edith Stein's phenomenological description of empathy, the ...

  5. Attention, Predation, Counterintuition

    DEFF Research Database (Denmark)

    Clasen, Mathias

    2012-01-01

    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...

  6. The Attention Economy

    Directory of Open Access Journals (Sweden)

    Süreyya Çankırı

    2013-11-01

    Full Text Available Understanding the New Currency of Business (originally published by Harvard Business School Press stands out as a new and significant work. The book analyses the psychological dimensions of attention while presenting its key applications in advertising, e­commerce, information management and strategy.

  7. Electrophysiological attention effects in a virtual cocktail-party setting.

    Science.gov (United States)

    Münte, Thomas F; Spring, Dörte K; Szycik, Gregor R; Noesselt, Toemme

    2010-01-11

    The selection of one of two concurrent speech messages for comprehension was investigated in healthy young adults in two event-related potential experiments. The stories were presented from virtual locations located 30 degrees to the left and right azimuth by convolving the speech message by the appropriate head-related transfer function determined for each individual participant. In addition, task irrelevant probe stimuli were presented in rapid sequence from the same virtual locations. In experiment 1, phoneme probes (/da/ voiced by the same talkers as attended and unattended messages) and band-pass filtered noise probes were presented. Phoneme probes coinciding with the attended message gave rise to a fronto-central negativity similar to the Nd-attention effect relative to the phoneme probes coinciding with the unattended speech message, whereas noise probes from the attended message's location showed a more positive frontal ERP response compared to probes from the unattended location resembling the so-called rejection positivity. In experiment 2, phoneme probes (as in exp. 1) and frequency-shifted (+400 Hz) were compared. The latter were characterized by a succession of negative and positive components that were modulated by location. The results suggest that at least two different neural mechanisms contribute to stream segregation in a cocktail-party setting: enhanced neural processing of stimuli matching the attended message closely (indexed by the Nd-effect) and rejection of stimuli that do not match the attended message at the attended location only (indexed by the rejection positivity).

  8. Accurate phase-shift velocimetry in rock.

    Science.gov (United States)

    Shukla, Matsyendra Nath; Vallatos, Antoine; Phoenix, Vernon R; Holmes, William M

    2016-06-01

    Spatially resolved Pulsed Field Gradient (PFG) velocimetry techniques can provide precious information concerning flow through opaque systems, including rocks. This velocimetry data is used to enhance flow models in a wide range of systems, from oil behaviour in reservoir rocks to contaminant transport in aquifers. Phase-shift velocimetry is the fastest way to produce velocity maps but critical issues have been reported when studying flow through rocks and porous media, leading to inaccurate results. Combining PFG measurements for flow through Bentheimer sandstone with simulations, we demonstrate that asymmetries in the molecular displacement distributions within each voxel are the main source of phase-shift velocimetry errors. We show that when flow-related average molecular displacements are negligible compared to self-diffusion ones, symmetric displacement distributions can be obtained while phase measurement noise is minimised. We elaborate a complete method for the production of accurate phase-shift velocimetry maps in rocks and low porosity media and demonstrate its validity for a range of flow rates. This development of accurate phase-shift velocimetry now enables more rapid and accurate velocity analysis, potentially helping to inform both industrial applications and theoretical models. Copyright © 2016. Published by Elsevier Inc.

  9. ADAPTIVE NOISE CANCELLATION OF DOPPLER SHIFTED SIGNALS: A LINEAR FRAMEWORK

    OpenAIRE

    Stewart, R. W.; Weiss, S.

    1996-01-01

    In this paper we investigate the performance of single channel adaptive noise cancellation techniques for situations where the noise signal received by the two microphones cannot be related by a fixed weight canceller's (linear) digital filter due to Doppler shift on the two signals. A mathematical signal model is produced, which shows that the adaptive filter is in fact required to identify a time-varying system which incorporates Doppler shift, and potential rapid variations in signal power...

  10. Relations between emotion, memory, and attention: evidence from taboo stroop, lexical decision, and immediate memory tasks.

    Science.gov (United States)

    MacKay, Donald G; Shafto, Meredith; Taylor, Jennifer K; Marian, Diane E; Abrams, Lise; Dyer, Jennifer R

    2004-04-01

    This article reports five experiments demonstrating theoretically coherent effects of emotion on memory and attention. Experiments 1-3 demonstrated three taboo Stroop effects that occur when people name the color of taboo words. One effect is longer color-naming times for taboo than for neutral words, an effect that diminishes with word repetition. The second effect is superior recall of taboo words in surprise memory tests following color naming. The third effect is better recognition memory for colors consistently associated with taboo words rather than with neutral words. None of these effects was due to retrieval factors, attentional disengagement processes, response inhibition, or strategic attention shifts. Experiments 4 and 5 demonstrated that taboo words impair immediate recall of the preceding and succeeding words in rapidly presented lists but do not impair lexical decision times. We argue that taboo words trigger specific emotional reactions that facilitate the binding of taboo word meaning to salient contextual aspects, such as occurrence in a task and font color in taboo Stroop tasks.

  11. Shape-shifting colloids via stimulated dewetting

    Science.gov (United States)

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

    2016-07-01

    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.

  12. Shift in fire-ecosystems and weather changes

    Science.gov (United States)

    Bongani Finiza

    2013-01-01

    During recent decades too much focus fell on fire suppression and fire engineering methods. Little attention has been given to understanding the shift in the changing fire weather resulting from the global change in weather patterns. Weather change have gradually changed the way vegetation cover respond to fire occurrence and brought about changes in fire behavior and...

  13. INVESTOR ATTENTION AND SENTIMENT

    OpenAIRE

    Wang, Jessica Yichun

    2015-01-01

    Investor sentiment and attention are often linked to the same non-economic events making it difficult to understand why and how asset prices are affected. This thesis disentangles these two potential drivers of market behaviour by studying how investors react to sports outcomes, weather conditions and merger and acquisition announcements. Firstly, a new dataset of medals for major participating countries and sponsor firms over four Summer Olympic Games is analysed. Results show...

  14. Trends in shifting cultivation and the REDD mechanism

    DEFF Research Database (Denmark)

    Mertz, Ole

    2009-01-01

    In many parts of the forest-agriculture frontiers of the tropics, particularly in Southeast Asia, shifting cultivation is rapidly being transformed to other land uses. Yet, there is rather limited knowledge on the spatial and demographic extent of shifting cultivation and the consequences...... of the transitions taking place. The proposed mechanism for reduced greenhouse gas emissions from deforestation and degradation (REDD) can be both a challenge and opportunity for shifting cultivators. Very limited literature is available on this dilemma, but a few sources point to benefits from ‘compensated...

  15. Attention-Seeking Displays.

    Directory of Open Access Journals (Sweden)

    Szabolcs Számadó

    Full Text Available Animal communication abounds with extravagant displays. These signals are usually interpreted as costly signals of quality. However, there is another important function for these signals: to call the attention of the receiver to the signaller. While there is abundant empirical evidence to show the importance of this stage, it is not yet incorporated into standard signalling theory. Here I investigate a general model of signalling - based on a basic action-response game - that incorporates this searching stage. I show that giving attention-seeking displays and searching for them can be an ESS. This is a very general result and holds regardless whether only the high quality signallers or both high and low types give them. These signals need not be costly at the equilibrium and they need not be honest signals of any quality, as their function is not to signal quality but simply to call the attention of the potential receivers. These kind of displays are probably more common than their current weight in the literature would suggest.

  16. Shifting between mental sets: An individual differences approach to commonalities and differences of task switching components.

    Science.gov (United States)

    von Bastian, Claudia C; Druey, Michel D

    2017-09-01

    Switching between mental sets has been extensively investigated in both experimental and individual differences research using a wide range of task-switch paradigms. However, it is yet unclear whether these different tasks measure a unitary shifting ability or reflect different facets thereof. In this study, 20 task pairs were administered to 119 young adults to assess 5 proposed components of mental set shifting: switching between judgments, stimulus dimensions, stimulus-response mappings, response sets, and stimulus sets. Modeling latent factors for each of the components revealed that a model with 5 separate yet mostly correlated factors fit the data best. In this model, the components most strongly related to the other latent factors were stimulus-response mapping shifting and, to a lesser degree, response set shifting. In addition, both factors were statistically indistinguishable from a second-order general shifting factor. In contrast, shifting between judgments as well as stimulus dimensions consistently required separate factors and could, hence, not fully be accounted for by the general shifting factor. Finally, shifting between stimulus sets was unrelated to any other shifting component but mapping shifting. We conclude that tasks assessing shifting between mappings are most adequate to assess general shifting ability. In contrast, shifting between stimulus sets (e.g., as in the Trail Making Test) probably reflects shifts in visual attention rather than executive shifting ability. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. 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.

  18. Quantifying collective attention from tweet stream.

    Science.gov (United States)

    Sasahara, Kazutoshi; Hirata, Yoshito; Toyoda, Masashi; Kitsuregawa, Masaru; Aihara, Kazuyuki

    2013-01-01

    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.

  19. The impact of attentional training on the salivary cortisol and alpha amylase response to psychosocial stress: importance of attentional control.

    Science.gov (United States)

    Pilgrim, Kamala; Ellenbogen, Mark A; Paquin, Karine

    2014-06-01

    This study examined the effects of three consecutive days of attentional training on the salivary alpha amylase (sAA), cortisol, and mood response to the Trier Social Stress Test (TSST). The training was designed to elicit faster disengagement of attention away from threatening facial expressions and faster shifts of attention toward positive ones. Fifty-six healthy participants between the ages of 18 and 30 participated in a double-blind, within-subject experiment. Participants were randomly assigned to one of three attentional training conditions - supraliminal training: pictures shown with full conscious awareness, masked training: stimuli presented with limited conscious awareness, or control training: both supraliminal and masked pictures shown but no shifting of attention required. Following training, participants underwent the TSST. Self-reported mood and saliva samples were collected for the determination of emotional reactivity, cortisol, and sAA in response to stress post-training. Unexpectedly, participants in both attentional training groups exhibited a higher salivary cortisol response to the TSST relative to participants who underwent the control training, F (4, 86)=4.07, p=.005, ηp(2)=.16. Supraliminal training was also associated with enhanced sAA reactivity, F (2, 44)=13.90, p=.000, ηp(2)=.38, and a more hostile mood response (p=.021), to the TSST. Interestingly, the effect of attention training on the cortisol response to stress was more robust in those with high attentional control than those with low attentional control (β=-0.134; t=-2.24, p=.03). This is among the first experimental manipulations to demonstrate that attentional training can elicit a paradoxical increase in three different markers of stress reactivity. These findings suggest that attentional training, in certain individuals, can have iatrogenic effects. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. 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.

  1. Attracting attention. Posters.

    Science.gov (United States)

    1998-01-01

    Posters are useful in health education campaigns for announcing events, reinforcing messages communicated through other media, and providing a starting point for discussion. Posters should be clear enough to be understood on their own, sufficiently striking to attract attention, and displayed in places where they will be seen by the target population. The posters should be changed regularly or people will stop noticing them. All posters should be carefully planned and pretested with the intended target group. Use of color can help ensure that figures and symbols stand out from the background and lower case letters are easier to read than all capital letters. Finally, the lettering should be neat and even.

  2. 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.

  3. 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

    Directory of Open Access Journals (Sweden)

    Ferri P

    2016-09-01

    Full Text Available Paola Ferri,1 Matteo Guadi,1 Luigi Marcheselli,1 Sara Balduzzi,1 Daniela Magnani,1 Rosaria Di Lorenzo2 1Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, 2Department of Mental Health, AUSL di Modena, Service of Psychiatric Diagnosis and Treatment, Modena, Italy Background: 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.Objectives: 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.Methods: 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.Results: 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.Conclusion: 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. Keywords: shift work, night work

  4. Is shift work making your patient sick? Emerging theories and therapies for treating shift work disorder.

    Science.gov (United States)

    Rosenberg, Russell; Doghramji, Paul P

    2011-09-01

    "Shift work" is a term that applies to a wide array of nontraditional work schedules. Shift work disorder (SWD) is a circadian rhythm sleep disorder experienced by a subset of shift workers that is characterized by excessive sleepiness during work and/or insomnia during scheduled sleep times. It is estimated to affect up to 2 million Americans, and is associated with increased morbidity and mortality from metabolic risk factors, cardiovascular and gastrointestinal diseases, depression, accidents, and some kinds of cancers. Patient history is all that is needed to make a diagnosis with the International Classification of Sleep Disorders-Second Edition criteria as described herein. Circadian rhythm disorders, in which an underlying misalignment of circadian rhythm with the sleep-wake cycle occurs, may be treated by behavioral and pharmacologic approaches, including the use of hypnotics to improve the duration of sleep. However, evidence is limited with these approaches in patients diagnosed with SWD. Other treatment options may include pharmacologic interventions such as modafinil and armodafinil, which have shown efficacy in this population. Combined therapy can reduce insomnia and excessive sleepiness, and improve attention and alertness during work shifts and the subsequent commute home.

  5. Does attentional cueing affect dichotic listening performance in children?

    Science.gov (United States)

    Obrzut, John E; Boliek, Carol A; Asbjornsen, Arve

    2006-01-01

    This study addresses the effects of verbal versus nonverbal (tone) shifts of attention on dichotic listening (DL) performance with children. Theoretically, a tonal cue may be more effective in increasing attention than a verbal cue following instruction. The inconsistency of studies reporting substantial effects of attention on ear asymmetries in children with or without learning disabilities (LDs) may be due to a developmental difference in their ability to use verbal or tone cues to select stimuli for recall. Participants included 30 right-handed children (15 control, 15 with LDs) with a mean age of 10.8 years. Each participant received 60 trials of a monaural tone cue task, 60 trials of a binaural verbal cue task, and 60 trials of a monaural verbal cue task, to direct attention to either the left or right ear before the presentation of consonant-vowel syllable pairs in a DL task. A factorial design analysis of variance yielded a significant right-ear advantage for both groups. More important, the Group x Task interaction was found to be significant, indicating that group performance on ear scores was dependent on type of cueing condition. Whereas all 3 cue conditions were effective in orienting attention for control participants, larger shifts were apparent under both binaural and monaural verbal instructional cue conditions. In contrast, participants with LD showed larger shifts of attention under the tonal cue condition. These results show that control participants have greater ability to focus attention with the use of a verbal cue, whereas participants with LD show greater ability to orient attention with the use of a tone cue in reducing error rates in DL performance.

  6. Backward Masked Snakes and Guns Modulate Spatial Attention

    Directory of Open Access Journals (Sweden)

    Joshua M. Carlson

    2009-10-01

    Full Text Available Fearful faces are important social cues that alert others of potential threat. Even backward masked fearful faces facilitate spatial attention. However, visual stimuli other than fearful faces can signal potential threat. Indeed, unmasked snakes and spiders modulate spatial attention. Yet, it is unclear if the rapid threat-related facilitation of spatial attention to backward masked stimuli is elicited by non-face threat cues. Evolutionary theories claim that phylogenetic threats (i.e. snakes and spiders should preferentially elicit an automatic fear response, but it is untested as to whether this response extends to enhancements in spatial attention under restricted processing conditions. Thirty individuals completed a backward masking dot-probe task with both evolutionary relevant and irrelevant threat cues. The results suggest that backward masked visual fear stimuli modulate spatial attention. Both evolutionary relevant (snake and irrelevant (gun threat cues facilitated spatial attention.

  7. [Developmental effects of perinatal hypothyroidism on cognitive functions: focused on attention].

    Science.gov (United States)

    Wada, Hiromi; Seto, Yukina

    2012-01-01

    Thyroid hormones are essential for the development of brain. Perinatal hypothyroidism induced by environmental endocrine disrupters is reported to cause cognitive dysfunctions such as attention and memory deficits. The purpose of this study is whether perinatal hypothyroidism causes deficits of shift attention and divided attention in offspring using a target detection task. Pregnant rats were treated with the anti-thyroid drug methimazole [0.02% (w/v)] from gestational day 15 to postnatal day 21. The offspring received behavioral testing using shift attention and divided attention tasks. The testing of shift attention started with the presentation of one of two targets. A lever was inserted to the same side as the presented target (ipsilateral trial). However, a lever was inserted to the opposite side to the presented target with the probability of 20% (contralateral trial). Next, the testing of divided attention was introduced. The testing started with the presentation of one of the two targets (one-side trial). A lever was inserted to the same side as the presented target. However, both targets were presented (both-side trial) and one of the two levers was inserted with the probability of 20%. On the contralateral trials in the shift attention task, the untreated rats responded frequently with reaction times of 1.4-1.6 s, whereas the treated rats responded sporadically with a wide range of reaction times of 1.2-7.2 s. This indicates that the treated rats were not able to shift their attention quickly toward the opposite side. When the both-side targets were presented in the divided attention task, the untreated rats responded frequently with the reaction times of 0.6-0.8 s and 1.4-1.6 s. The treated rats responded frequently with reaction times of 0.8-1.0 s and 1.0-6.4 s. Both the untreated and treated rats did not divide their attention toward the both-side targets but probably paid attention to one of the two targets. They responded with the shorter reaction

  8. Are Gaze Shifts a Key to a Translator’s Text Segmentation?

    DEFF Research Database (Denmark)

    Lykke Jakobsen, Arnt

    2016-01-01

    blinks. However, in an experimental setup with tracking of a translator’s gaze movements across a screen showing the source text and (emerging) target text, gaze data show the translator’s shifts of visual attention between the two texts. Can such shifts be seen as an index of content processing units...

  9. New graduate nurses adaptation to shift work: can we help?

    Science.gov (United States)

    West, Sandra H; Ahern, Maureen; Byrnes, Margot; Kwanten, Lloyd

    2007-01-01

    Shift work's desynchronisation of physiologically determined circadian rhythms has a major effect on the psychobiology of every shift worker. It is also commonly perceived that the effects of shift work contribute to the current New Graduate Nurses (NGNs) attrition rate. NGNs must also adjust to work within the health care system as they adapt to shift work, but do the initial effects of shift work as experienced by NGNs get better with time? This study aimed to describe the adaptation of NGNs to shiftwork. Levels of general health, sleep, fatigue, circadian type, job satisfaction, levels of burnout and the coping processes of 150 final year undergraduate students were investigated in a questionnaire based longitudinal study conducted over their initial twelve months of clinical practice as NGNs. Correlational analysis indicates that whilst shift work initially seriously disturbs sleep and other variables associated with individual and situational differences some adaptation was evident by twelve months. Social dysfunction scores (GHQ28) remained significantly related with variables associated with burnout, job satisfaction, sleep disturbance and life disruption at the twelve month point. The presence of depression on pre-shift work scales was also significantly related to continuing experience of sleep disruption and increased levels of emotional exhaustion throughout the twelve month period. Further investigation is required to establish the effect of shiftwork on outcome measures such as levels of burnout and job satisfaction for NGNs. However, although it is possible that improved preparation for shift work may assist the adaptation of NGNs to shift work during their first year of practice it is clear that attention to the organisation of nursing shift work would also be timely.

  10. 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.

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

    Science.gov (United States)

    Miconi, Thomas; VanRullen, Rufin

    2016-02-01

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

  12. Attention and Distraction

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2010-01-01

    the fact that the behaviour of many visitors is characterised by a certain restlessness and distraction. The article suggests that, in contradistinction to traditional disciplines of art like painting and sculpture, video installations seem to stimulate a "reception in distraction" (Walter Benjamin......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......) that is at odds with the ideal of a reception in concentration that governs the institutions of fine art as well as aesthetic theory. It intends to demonstrate how the experience of video installation art can only be understood by recognising that the close connections between, on the one hand, video art and...

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

    OpenAIRE

    Dharmapala, Dhammika

    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. The role of set-shifting in auditory verbal hallucinations.

    Science.gov (United States)

    Siddi, Sara; Petretto, Donatella Rita; Burrai, Caterina; Scanu, Rosanna; Baita, Antonella; Trincas, Pierfranco; Trogu, Emanuela; Campus, Liliana; Contu, Augusto; Preti, Antonio

    2017-04-01

    Auditory verbal hallucinations (AVHs) are a cardinal characteristic of psychosis. Recent research on the neuropsychological mechanism of AVHs has focused on source monitoring failure, but a few studies have suggested the involvement of attention, working memory, processing speed, verbal learning, memory, and executive functions. In this study we examined the neuropsychological profile of patients with AVHs, assuming that the mechanism underlying this symptom could be a dysfunction of specific cognitive domains. A large neuropsychological battery including set-shifting, working memory, processing speed, attention, fluency, verbal learning and memory, and executive functions was administered to 90 patients with psychotic disorders and 44 healthy controls. The group of patients was divided into two groups: 46 patients with AVHs in the current episode and 44 who denied auditory hallucinations or other modalities in the current episode. AVHs were assessed with the Psychotic Symptom Rating Scales (PSYRATS); the Launay-Slade Hallucination Scale was used to measure long-term propensity to auditory verbal hallucination-like experiences (HLEs) in the sample. Patients showed poorer performances on all neuropsychological measures compared to the healthy controls' group. In the original dataset without missing data (n=58), patients with AVHs (n=29) presented poorer set shifting and verbal learning, higher levels of visual attention, and marginally significant poorer semantic fluency compared to patients without AVHs (n=29). In the logistic model on the multiple imputed dataset (n=90, 100 imputed datasets), lower capacity of set shifting and semantic fluency distinguished patients with AVHs from those without them. Patients experiencing persistent AVHs might fail to shift their attention away from the voices; poorer semantic fluency could be a secondary deficit of set-shifting failure. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Mechanisms of Choice Behavior Shift Using Cue-approach Training.

    Science.gov (United States)

    Bakkour, Akram; Leuker, Christina; Hover, Ashleigh M; Giles, Nathan; Poldrack, Russell A; Schonberg, Tom

    2016-01-01

    Cue-approach training has been shown to effectively shift choices for snack food items by associating a cued button-press motor response to particular food items. Furthermore, attention was biased toward previously cued items, even when the cued item is not chosen for real consumption during a choice phase. However, the exact mechanism by which preferences shift during cue-approach training is not entirely clear. In three experiments, we shed light on the possible underlying mechanisms at play during this novel paradigm: (1) Uncued, wholly predictable motor responses paired with particular food items were not sufficient to elicit a preference shift; (2) Cueing motor responses early - concurrently with food item onset - and thus eliminating the need for heightened top-down attention to the food stimulus in preparation for a motor response also eliminated the shift in food preferences. This finding reinforces our hypothesis that heightened attention at behaviorally relevant points in time is key to changing choice behavior in the cue-approach task; (3) Crucially, indicating choice using eye movements rather than manual button presses preserves the effect, thus demonstrating that the shift in preferences is not governed by a learned motor response but more likely via modulation of subjective value in higher associative regions, consistent with previous neuroimaging results. Cue-approach training drives attention at behaviorally relevant points in time to modulate the subjective value of individual items, providing a mechanism for behavior change that does not rely on external reinforcement and that holds great promise for developing real world behavioral interventions.

  16. Octave effect in auditory attention

    National Research Council Canada - National Science Library

    Tobias Borra; Huib Versnel; Chantal Kemner; A. John van Opstal; Raymond van Ee

    2013-01-01

    ... tones. Current auditory models explain this phenomenon by a simple bandpass attention filter. Here, we demonstrate that auditory attention involves multiple pass-bands around octave-related frequencies above and below the cued tone...

  17. 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 the presence ...

  18. 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.

  19. 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.

  20. Bottom-up gaze shifts and fixations learning by imitation.

    Science.gov (United States)

    Belardinelli, Anna; Pirri, Fiora; Carbone, Andrea

    2007-04-01

    The ability to follow the gaze of conspecifics is a critical component in the development of social behaviors, and many efforts have been directed to studying the earliest age at which it begins to develop in infants. Developmental and neurophysiological studies suggest that imitative learning takes place once gaze-following abilities are fully established and joint attention can support the shared behavior required by imitation. Accordingly, gaze-following acquisition should be precursory to most machine learning tasks, and imitation learning can be seen as the earliest modality for acquiring meaningful gaze shifts and for understanding the structural substrate of fixations. Indeed, if some early attentional process, based on a suitable combination of gaze shifts and fixations, could be learned by the robot, then several demonstration learning tasks would be dramatically simplified. In this paper, we describe a methodology for learning gaze shifts based on imitation of gaze following with a gaze machine, which we purposefully introduced to make the robot gaze imitation conspicuous. The machine allows the robot to share and imitate gaze shifts and fixations of a caregiver through a mutual vergence. This process is then suitably generalized by learning both the scene salient features toward which the gaze is directed and the way saccadic programming is attained. Salient features are modeled by a family of Gaussian mixtures. These together with learned transitions are generalized via hidden Markov models to account for humanlike gaze shifts allowing to discriminate salient locations.

  1. Learning-induced changes in attentional allocation during categorization: a sizable catalog of attention change as measured by eye movements.

    Directory of Open Access Journals (Sweden)

    Caitlyn M McColeman

    Full Text Available Learning how to allocate attention properly is essential for success at many categorization tasks. Advances in our understanding of learned attention are stymied by a chicken-and-egg problem: there are no theoretical accounts of learned attention that predict patterns of eye movements, making data collection difficult to justify, and there are not enough datasets to support the development of a rich theory of learned attention. The present work addresses this by reporting five measures relating to the overt allocation of attention across 10 category learning experiments: accuracy, probability of fixating irrelevant information, number of fixations to category features, the amount of change in the allocation of attention (using a new measure called Time Proportion Shift - TIPS, and a measure of the relationship between attention change and erroneous responses. Using these measures, the data suggest that eye-movements are not substantially connected to error in most cases and that aggregate trial-by-trial attention change is generally stable across a number of changing task variables. The data presented here provide a target for computational models that aim to account for changes in overt attentional behaviors across learning.

  2. 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.

  3. 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.

  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. 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.

  6. Neonatal Intensive-Care Unit Graduates Show Persistent Difficulties in an Intradimensional Shift Card Sort

    Science.gov (United States)

    Kittler, Phyllis M.; Brooks, Patricia J.; Rossi, Vanessa; Karmel, Bernard Z.; Gardner, Judith M.; Flory, Michael J.

    2013-01-01

    Neonatal intensive-care unit (NICU) graduates, a group at risk for attention problems and attention-deficit hyperactivity disorder, performed an intradimensional shift card sort at 34, 42, 51, and 60 months to assess executive function and to examine effects of individual risk factors. In the "silly" game, children sorted cards…

  7. 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.

  8. Stress shift in rhythmical speech

    Science.gov (United States)

    Quené, Hugo; Port, Robert

    2002-05-01

    In phrases like thirteen men, stress in thirteen is often shifted forward from its canonical final position. Presumably, the occurrence of this optional stress shift may be partly controlled by the rhythm of speech. Work on rhythmic speech production has demonstrated that given a repetition cycle, T, its harmonic fractions like T/2 attract stressed vowel onsets. Comparing phrases like ceMENT thirTEEN and GALaxy thirTEEN, differing in the number of weak syllables between strong ones, it was predicted that, during rhythmic production, the harmonic locations would attract shifted stress. Since shifting stress results in more even distribution of syllables through the cycle, we expected that faster repetition rates would also result in more stress shift. Dependent variables were the relative stress in the second word of each pair, and the location of onset of the nuclear vowel of the stressed syllable. Results confirmed the predictions, first, that with more intermediate unstressed syllables, stress was shifted forward more often (thereby locating the stressed vowel onset closer to T/2) and, second, that stress shifted forward more often at faster speaking rates. [Work supported by Fulbright Visiting Scholar program and by Utrecht University, The Netherlands.

  9. 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.

  10. Temporal dynamics underlying the modulation of social status on social attention.

    Directory of Open Access Journals (Sweden)

    Mario Dalmaso

    Full Text Available Fixating someone suddenly moving the eyes is known to trigger a corresponding shift of attention in the observer. This phenomenon, known as gaze-cueing effect, can be modulated as a function of the social status of the individual depicted in the cueing face. Here, in two experiments, we investigated the temporal dynamics underlying this modulation. To this end, a gaze-cueing paradigm was implemented in which centrally-placed faces depicting high- and low-status individuals suddenly shifted the eyes towards a location either spatially congruent or incongruent with that occupied by a subsequent target stimulus. Social status was manipulated by presenting fictive Curriculum Vitae before the experimental phase. In Experiment 1, in which two temporal intervals (50 ms vs. 900 ms occurred between the direct-gaze face and the averted-gaze face onsets, a stronger gaze-cueing effect in response to high-status faces than low-status faces was observed, irrespective of the time participants were allowed for extracting social information. In Experiment 2, in which two temporal intervals (200 ms vs. 1000 ms occurred between the averted-gaze face and target onset, a stronger gaze cueing for high-status faces was observed at the shorter interval only. Taken together, these results suggest that information regarding social status is extracted from faces rapidly (Experiment 1, and that the tendency to selectively attend to the locations gazed by high-status individuals may decay with time (Experiment 2.

  11. 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/.

  12. 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

  13. Attentional Selection Accompanied by Eye Vergence as Revealed by Event-Related Brain Potentials.

    Science.gov (United States)

    Sole Puig, Maria; Pallarés, Josep Marco; Perez Zapata, Laura; Puigcerver, Laura; Cañete, Josep; Supèr, Hans

    2016-01-01

    Neural mechanisms of attention allow selective sensory information processing. Top-down deployment of visual-spatial attention is conveyed by cortical feedback connections from frontal regions to lower sensory areas modulating late stimulus responses. A recent study reported the occurrence of small eye vergence during orienting top-down attention. Here we assessed a possible link between vergence and attention by comparing visual event related potentials (vERPs) to a cue stimulus that induced attention to shift towards the target location to the vERPs to a no-cue stimulus that did not trigger orienting attention. The results replicate the findings of eye vergence responses during orienting attention and show that the strength and time of eye vergence coincide with the onset and strength of the vERPs when subjects oriented attention. Our findings therefore support the idea that eye vergence relates to and possibly has a role in attentional selection.

  14. Attentional Selection Accompanied by Eye Vergence as Revealed by Event-Related Brain Potentials.

    Directory of Open Access Journals (Sweden)

    Maria Sole Puig

    Full Text Available Neural mechanisms of attention allow selective sensory information processing. Top-down deployment of visual-spatial attention is conveyed by cortical feedback connections from frontal regions to lower sensory areas modulating late stimulus responses. A recent study reported the occurrence of small eye vergence during orienting top-down attention. Here we assessed a possible link between vergence and attention by comparing visual event related potentials (vERPs to a cue stimulus that induced attention to shift towards the target location to the vERPs to a no-cue stimulus that did not trigger orienting attention. The results replicate the findings of eye vergence responses during orienting attention and show that the strength and time of eye vergence coincide with the onset and strength of the vERPs when subjects oriented attention. Our findings therefore support the idea that eye vergence relates to and possibly has a role in attentional selection.

  15. Attentional accounting: Voluntary spatial attention increases budget category prioritization.

    Science.gov (United States)

    Mrkva, Kellen; Van Boven, Leaf

    2017-09-01

    Too often, people fail to prioritize the most important activities, life domains, and budget categories. One reason for misplaced priorities, we argue, is that activities and categories people have frequently or recently attended to seem higher priority than other activities and categories. In Experiment 1, participants were cued to direct voluntary spatial attention toward 1 side of a screen while images depicting different budget categories were presented: 1 category on the cued side and 1 on the noncued side of the screen. Participants rated cued budget categories as higher priority than noncued budget categories. Cued attention also increased perceived distinctiveness, and a mediation model was consistent with the hypothesis that distinctiveness mediates the effect of cued attention on prioritization. Experiment 2 orthogonally manipulated 2 components of a spatial cuing manipulation-heightened visual attention and heightened mental attention-to examine how each influences prioritization. Visual attention and mental attention additively increased prioritization. In Experiment 3, attention increased prioritization even when prioritization decisions were incentivized, and even when heightened attention was isolated from primacy and recency. Across experiments, cued categories were prioritized more than noncued categories even though measures were taken to disguise the purpose of the experiments and manipulate attention incidentally (i.e., as a by-product of an unrelated task). (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Explaining (Missing) Regulator Paradigm Shifts

    DEFF Research Database (Denmark)

    Wigger, Angela; Buch-Hansen, Hubert

    2014-01-01

    of competition regulation is heaving into sight. It sets out to explain this from the vantage point of a critical political economy perspective, which identifies the circumstances under which a crisis can result in a regulatory paradigm shift. Contrasting the current situation with the shift in EC/EU competition...... capitalism; the social power configuration underpinning the neoliberal order remains unaltered; no clear counter-project has surfaced; the European Commission has been (and remains) in a position to oppose radical changes; and finally, there are no signs of a wider paradigm shift in the EU's regulatory...

  17. Controllable optical phase shift over one radian from a single isolated atom.

    Science.gov (United States)

    Jechow, A; Norton, B G; Händel, S; Blūms, V; Streed, E W; Kielpinski, D

    2013-03-15

    Fundamental optics such as lenses and prisms work by applying phase shifts of several radians to incoming light, and rapid control of such phase shifts is crucial to telecommunications. However, large, controllable optical phase shifts have remained elusive for isolated quantum systems. We have used a single trapped atomic ion to induce and measure a large optical phase shift of 1.3±0.1 radians in light scattered by the atom. Spatial interferometry between the scattered light and unscattered illumination light enables us to isolate the phase shift in the scattered component. The phase shift achieves the maximum value allowed by atomic theory over the accessible range of laser frequencies, pointing out new opportunities in microscopy and nanophotonics. Single-atom phase shifts of this magnitude open up new quantum information protocols, in particular long-range quantum phase-shift-keying cryptography.

  18. Mislocalization of visual stimuli: independent effects of static and dynamic attention.

    Science.gov (United States)

    Chien, Sung-en; Ono, Fuminori; Watanabe, Katsumi

    2011-01-01

    Shifts of visual attention cause systematic distortions of the perceived locations of visual objects around the focus of attention. In the attention repulsion effect, the perceived location of a visual target is shifted away from an attention-attracting cue when the cue is presented before the target. Recently it has been found that, if the visual cue is presented after the target, the perceived location of the target shifts toward the location of the following cue. One unanswered question is whether a single mechanism underlies both attentional repulsion and attraction effects. We presented participants with two disks at diagonal locations as visual cues and two vertical lines as targets. Participants were asked to perform a forced-choice task to judge targets' positions. The present study examined whether the magnitude of the repulsion effect and the attraction effect would differ (Experiment 1), whether the two effects would interact (Experiment 2), and whether the location or the dynamic shift of attentional focus would determine the distortions effects (Experiment 3). The results showed that the effect size of the attraction effect was slightly larger than the repulsion effect and the preceding and following cues have independent influences on the perceived positions. The repulsion effect was caused by the location of attnetion and the attraction effect was due to the dynamic shift of attentional focus, suggesting that the underlying mechanisms for the retrospective attraction effect might be different from those for the repulsion effect.

  19. Mislocalization of visual stimuli: independent effects of static and dynamic attention.

    Directory of Open Access Journals (Sweden)

    Sung-en Chien

    Full Text Available Shifts of visual attention cause systematic distortions of the perceived locations of visual objects around the focus of attention. In the attention repulsion effect, the perceived location of a visual target is shifted away from an attention-attracting cue when the cue is presented before the target. Recently it has been found that, if the visual cue is presented after the target, the perceived location of the target shifts toward the location of the following cue. One unanswered question is whether a single mechanism underlies both attentional repulsion and attraction effects. We presented participants with two disks at diagonal locations as visual cues and two vertical lines as targets. Participants were asked to perform a forced-choice task to judge targets' positions. The present study examined whether the magnitude of the repulsion effect and the attraction effect would differ (Experiment 1, whether the two effects would interact (Experiment 2, and whether the location or the dynamic shift of attentional focus would determine the distortions effects (Experiment 3. The results showed that the effect size of the attraction effect was slightly larger than the repulsion effect and the preceding and following cues have independent influences on the perceived positions. The repulsion effect was caused by the location of attnetion and the attraction effect was due to the dynamic shift of attentional focus, suggesting that the underlying mechanisms for the retrospective attraction effect might be different from those for the repulsion effect.

  20. Attention in a bayesian framework

    DEFF Research Database (Denmark)

    Whiteley, Louise Emma; Sahani, Maneesh

    2012-01-01

    The behavioral phenomena of sensory attention are thought to reflect the allocation of a limited processing resource, but there is little consensus on the nature of the resource or why it should be limited. Here we argue that a fundamental bottleneck emerges naturally within Bayesian models...... of perception, and use this observation to frame a new computational account of the need for, and action of, attention - unifying diverse attentional phenomena in a way that goes beyond previous inferential, probabilistic and Bayesian models. Attentional effects are most evident in cluttered environments......, and include both selective phenomena, where attention is invoked by cues that point to particular stimuli, and integrative phenomena, where attention is invoked dynamically by endogenous processing. However, most previous Bayesian accounts of attention have focused on describing relatively simple experimental...

  1. 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.

  2. [Attention deficit hyperactivity disorder].

    Science.gov (United States)

    Cunill, Ruth; Castells, Xavier

    2015-04-20

    Attention deficit hyperactivity disorder (ADHD) is one of the most common childhood psychiatric disorders and can persist into the adulthood. ADHD has important social, academic and occupational consequences. ADHD diagnosis is based on the fulfillment of several clinical criteria, which can vary depending on the diagnostic system used. The clinical presentation can show great between-patient variability and it has been related to a dysfunction in the fronto-striatal and meso-limbic circuits. Recent investigations support a model in which multiple genetic and environmental factors interact to create a neurobiological susceptibility to develop the disorder. However, no clear causal association has yet been identified. Although multimodal treatment including both pharmacological and psychosocial interventions is usually recommended, no convincing evidence exists to support this recommendation. Pharmacological treatment has fundamentally shown to improve ADHD symptoms in the short term, while efficacy data for psychosocial interventions are scarce and inconsistent. Yet, drug treatment is increasingly popular and the last 2 decades have witnessed a sharp increase in the prescription of anti-ADHD medications coinciding with the marketing of new drugs to treat ADHD. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  3. Visual attention: The past 25 years

    National Research Council Canada - National Science Library

    Carrasco, Marisa

    2011-01-01

    This review focuses on covert attention and how it alters early vision. I explain why attention is considered a selective process, the constructs of covert attention, spatial endogenous and exogenous attention, and feature-based attention...

  4. Modulation of auditory attention by training: evidence from dichotic listening.

    Science.gov (United States)

    Soveri, Anna; Tallus, Jussi; Laine, Matti; Nyberg, Lars; Bäckman, Lars; Hugdahl, Kenneth; Tuomainen, Jyrki; Westerhausen, René; Hämäläinen, Heikki

    2013-01-01

    We studied the effects of training on auditory attention in healthy adults with a speech perception task involving dichotically presented syllables. Training involved bottom-up manipulation (facilitating responses from the harder-to-report left ear through a decrease of right-ear stimulus intensity), top-down manipulation (focusing attention on the left-ear stimuli through instruction), or their combination. The results showed significant training-related effects for top-down training. These effects were evident as higher overall accuracy rates in the forced-left dichotic listening (DL) condition that sets demands on attentional control, as well as a response shift toward left-sided reports in the standard DL task. Moreover, a transfer effect was observed in an untrained auditory-spatial attention task involving bilateral stimulation where top-down training led to a relatively stronger focus on left-sided stimuli. Our results indicate that training of attentional control can modulate the allocation of attention in the auditory space in adults. Malleability of auditory attention in healthy adults raises the issue of potential training gains in individuals with attentional deficits.

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

    Science.gov (United States)

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

    2015-06-01

    Socially anxious individuals tend to shift their attention away from external socially threatening cues and instead become highly self-focused. Such heightened self-focused attention has been suggested to be involved in the development and maintenance of social anxiety disorder. This study used functional magnetic resonance imaging to investigate the neural correlates of self-focused attention in 16 high socially anxious (HSA) and 16 low socially anxious (LSA) individuals. Participants were instructed to focus their attention either inwardly or outwardly during a simulated social situation. Results indicate hyperactivation of medial prefrontal cortex (mPFC), temporo-parietal junction (TPJ) and temporal pole during inward vs outward attention in HSA compared with LSA participants. Furthermore, activation of mPFC, right anterior insula, TPJ and posterior cingulate cortex was positively correlated with the trait of self-focused attention in HSA subjects. Results highlight the prominent role of the mPFC and other cortical structures in abnormal self-focused attention in social anxiety. Finally, findings for the insula suggest increased processing of bodily states that is related to the amount of habitual self-focused attention in social anxiety. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

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

    Science.gov (United States)

    Caruana, Nathan; McArthur, Genevieve; Woolgar, Alexandra; Brock, Jon

    2017-01-01

    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.

  7. 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.

  8. Developmental evolution facilitates rapid adaptation.

    Science.gov (United States)

    Lin, Hui; Kazlauskas, Romas J; Travisano, Michael

    2017-11-21

    Developmental evolution has frequently been identified as a mode for rapid adaptation, but direct observations of the selective benefits and associated mechanisms of developmental evolution are necessarily challenging to obtain. Here we show rapid evolution of greatly increased rates of dispersal by developmental changes when populations experience stringent selection. Replicate populations of the filamentous fungus Trichoderma citrinoviride underwent 85 serial transfers, under conditions initially favoring growth but not dispersal. T. citrinoviride populations shifted away from multicellular growth toward increased dispersal by producing one thousand times more single-celled asexual conidial spores, three times sooner than the ancestral genotype. Conidia of selected lines also germinated fifty percent faster. Gene expression changed substantially between the ancestral and selected fungi, especially for spore production and growth, demonstrating rapid evolution of tight regulatory control for down-regulation of growth and up-regulation of conidia production between 18 and 24 hours of growth. These changes involved both developmentally fixed and plastic changes in gene expression, showing that complex developmental changes can serve as a mechanism for rapid adaptation.

  9. 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 ...

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

    OpenAIRE

    Yoshiyuki Hirano; Minoru Onozuka

    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 ...

  11. Disorders of attention: a frontier in neuropsychology.

    Science.gov (United States)

    Geschwind, N

    1982-06-25

    There is an extensive behavioural neurological literature on so-called unilateral attentional disorders, but a striking paucity of papers on global disorders of attention, i.e. confusional states. However, confusional states are distinctive because: (1) they are the most common disturbance of the higher functions in clinical practice, by orders of magnitude; (2)they are the only disturbance of the higher functions from which all normal subjects have suffered; (3) they have characteristic clinical manifestations; (4) they are frequently misdiagnosed as progressive dementias, aphasia, memory disorders, and psychoses; (5) they are the only disturbance of the higher functions that commonly cause patients to produce statement that appear to be extremely witty; (6) they can be readily studied experimentally; (7) they are the most common cause of unconcern with or denial of illness. There are almost certainly several different forms of confusional state depending on the aetiology, the rate of development, the age, and the anatomical systems involved, but little classification has yet been carried on. Confusional states are most simply defined as disorders in which there is a loss of the normal coherence of thought or action. Among the striking clinical features are: (1) failure to pay attention, excessive distractibility, or failure to shift attention; (2) paramnesias, i.e. distortions of memory; (3) reduplicative phenomena, 'wild' paraphasias with 'propagation' of error, alterations of mood in many different directions; (4) isolated or predominant disturbance of writing (the most common cause of pur agraphia); (5) unconcern with or denial of illness; (6) apparently playful behaviour. While confusional states are usually attributed to 'global involvement of the brain' as a result of metabolic or toxic disorder, there are in fact many cases produced by focal infarctions inthe right hemisphere, which, in the experience of my department, is one of the commonest effects of

  12. Spatial working memory maintenance: does attention play a role? A visual search study.

    Science.gov (United States)

    Chan, Louis K H; Hayward, William G; Theeuwes, Jan

    2009-10-01

    Recent studies have proposed that a common mechanism may underlie spatial attention and spatial working memory. One proposal is that spatial working memory is maintained by attention-based rehearsal [Awh, E., Jonides, J., & Reuter-Lorenz, P. A. (1998). Rehearsal in spatial working memory. Journal of Experimental Psychology: Human Perception and Performance, 24(3), 780-790], and so a spatial attention shift during the retention interval of a spatial location should impair its memory performance. In the present study, participants engaged in single-item, parallel or serial search tasks while remembering a spatial location. Although memory tended to bias all searches, the need for an attentional shift during the retention interval impaired memory performance only in single-item search, but not in other searches. These findings suggest that previous evidence for the attention-based rehearsal account does not generalize to visual search. Results are discussed with regard to the relationship between spatial attention and spatial working memory.

  13. Selective Age Effects on Visual Attention and Motor Attention during a Cued Saccade Task

    Directory of Open Access Journals (Sweden)

    Wendy E. Huddleston

    2014-01-01

    Full Text Available Objective. Visual information is often used to guide purposeful movement. However, older adults have impaired responses to visual information, leading to increased risk for injuries and potential loss of independence. We evaluated distinct visual and motor attention contributions to a cued saccade task to determine the extent to which aging selectively affects these processes. Methods. Nineteen healthy young (18–28 years and 20 older (60–90 years participants performed a cued saccade task under two conditions. We challenged motor attention by changing the number of possible saccade targets (1 or 6. Results. Older adults had difficulty in inhibiting unwanted eye movements and had greater eye movement inaccuracy in the hard condition when compared to the younger adults and to the easy condition. Also, an inverse relation existed between performance on the visual and motor components of the task in older adults, unlike younger adults. Conclusions. Older adults demonstrated difficulty in both inhibiting irrelevant saccade targets and selecting correct saccade endpoints during more complex tasks. The shift in relations among attention measures between the younger and older participants may indicate a need to prioritize attentional resources with age. These changes may impact an older adult’s ability to function in complex environments.

  14. Tree-species range shifts in a changing climate: detecting, modeling, assisting

    Science.gov (United States)

    Louis R. Iverson; Donald. McKenzie

    2013-01-01

    In these times of rapidly changing climate, the science of detecting and modeling shifts in the ranges of tree species is advancing of necessity. We briefly review the current state of the science on several fronts. First, we review current and historical evidence for shifting ranges and migration. Next, we review two broad categories of methods, focused on the spatial...

  15. Socio-economic perspectives on shifting cultivation landscapes in Northern Laos

    DEFF Research Database (Denmark)

    Heinimann, Andreas; Hett, Cornelia; Hurni, Kaspar

    2013-01-01

    Despite the rapid agricultural transition that has occurred in the past decade, shifting cultivation remains a widespread agricultural practice in the northern uplands of Lao PDR. Little information is available on the basic socio-economic situation and respective possible patterns in shifting...

  16. Social modulators of social attention

    OpenAIRE

    Dalmaso, Mario

    2014-01-01

    Social attention refers to the ability, which generally characterizes human beings as well as other animal species, to orient attentional resources in response to spatial cues provided by other individuals. These spatial cues are typically represented by gaze direction, head direction, and body orientation. This thesis focused mainly on the role that some social variables play in modulating this ability. In Chapter 1, the concept of social attention and its relevance in regulating social i...

  17. Attention, Media, Value and Economics

    OpenAIRE

    Aigrain, Philippe

    1997-01-01

    Building on the debate about the "attention economy" initiated by Michael Goldhaber and Rishab Aiyer Ghosh, I introduce the notion of valuing process, i.e. the process by which potential value can be translated in an economy. I show that the valuing processes applicable to attention depend on the nature of the media through which attention can be given and looked for. From there, I claim that the integration between attention and action, and the creation of a related literacy are the keys to ...

  18. 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.

  19. Training attentional control in infancy

    National Research Council Canada - National Science Library

    Wass, Sam; Porayska-Pomsta, Kaska; Johnson, Mark H

    2011-01-01

    .... Relative to an active control group, and following only a relatively short training period, posttraining assessments revealed improvements in cognitive control and sustained attention, reduced...

  20. 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.

  1. 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.

  2. Paying Attention to Attention: New Economies for Learning

    Science.gov (United States)

    de Castell, Suzanne; Jenson, Jennifer

    2004-01-01

    Challenging formal education's traditional monopoly over the mass-scale acculturation of youth, the technological infrastructure of the new economy brings in its wake a new attentional economy in which any connected adult or child owns and controls a full economic share of her or his own attention. For youth who have never known the text-bound…

  3. Visual attention: The past 25 years

    OpenAIRE

    Carrasco, Marisa

    2011-01-01

    This review focuses on covert attention and how it alters early vision. I explain why attention is considered a selective process, the constructs of covert attention, spatial endogenous and exogenous attention, and feature-based attention. I explain how in the last 25 years research on attention has characterized the effects of covert attention on spatial filters and how attention influences the selection of stimuli of interest. This review includes the effects of spatial attention on discrim...

  4. The production of information in the attention economy.

    Science.gov (United States)

    Ciampaglia, Giovanni Luca; Flammini, Alessandro; Menczer, Filippo

    2015-05-19

    Online traces of human activity offer novel opportunities to study the dynamics of complex knowledge exchange networks, in particular how emergent patterns of collective attention determine what new information is generated and consumed. Can we measure the relationship between demand and supply for new information about a topic? We propose a normalization method to compare attention bursts statistics across topics with heterogeneous distribution of attention. Through analysis of a massive dataset on traffic to Wikipedia, we find that the production of new knowledge is associated to significant shifts of collective attention, which we take as proxy for its demand. This is consistent with a scenario in which allocation of attention toward a topic stimulates the demand for information about it, and in turn the supply of further novel information. However, attention spikes only for a limited time span, during which new content has higher chances of receiving traffic, compared to content created later or earlier on. Our attempt to quantify demand and supply of information, and our finding about their temporal ordering, may lead to the development of the fundamental laws of the attention economy, and to a better understanding of social exchange of knowledge information networks.

  5. Attentional ability among survivors of leukaemia treated without cranial irradiation.

    Science.gov (United States)

    Rodgers, J; Marckus, R; Kearns, P; Windebank, K

    2003-02-01

    Previous research has indicated that children who have received treatment for leukaemia which includes cranial irradiation exhibit deficits in their ability to focus attention. It has been suggested that the use of cranial irradiation may have a role to play in long term sequelae. To investigate neuropsychological functioning among children treated for leukaemia without cranial irradiation. In a cross sectional study, 17 leukaemic patients and their sibling controls were assessed using a neuropsychological model of attention. All were treated on the UKALL XI protocol and none had received cranial irradiation. Participants completed the Arithmetic subtest and Digit Span subtest of the Weschler Intelligence Scale for Children-Revised to assess focus-encode elements of attention; the Coding subtest and the Speed of Information subtest of the BAS to assess focus-execute aspects of attention; the VIGIL computerised battery to assess sustain elements of attention; and the Wisconsin Card Sorting test to assess the ability to shift attention. These children did not exhibit the deficits witnessed in previous cohorts, and were performing at comparable levels to their controls on all measures of attention These findings suggest that children who have received treatment for leukaemia without the use of cranial irradiation do not show the neuropsychological insult found in earlier treatment groups.

  6. Sustained Attention in Real Classroom Settings: An EEG Study

    Directory of Open Access Journals (Sweden)

    Li-Wei Ko

    2017-07-01

    Full Text Available Sustained attention is a process that enables the maintenance of response persistence and continuous effort over extended periods of time. Performing attention-related tasks in real life involves the need to ignore a variety of distractions and inhibit attention shifts to irrelevant activities. This study investigates electroencephalography (EEG spectral changes during a sustained attention task within a real classroom environment. Eighteen healthy students were instructed to recognize as fast as possible special visual targets that were displayed during regular university lectures. Sorting their EEG spectra with respect to response times, which indicated the level of visual alertness to randomly introduced visual stimuli, revealed significant changes in the brain oscillation patterns. The results of power-frequency analysis demonstrated a relationship between variations in the EEG spectral dynamics and impaired performance in the sustained attention task. Across subjects and sessions, prolongation of the response time was preceded by an increase in the delta and theta EEG powers over the occipital region, and decrease in the beta power over the occipital and temporal regions. Meanwhile, implementation of the complex attention task paradigm into a real-world classroom setting makes it possible to investigate specific mutual links between brain activities and factors that cause impaired behavioral performance, such as development and manifestation of classroom mental fatigue. The findings of the study set a basis for developing a system capable of estimating the level of visual attention during real classroom activities by monitoring changes in the EEG spectra.

  7. Measuring and modeling attentional dwell time.

    Science.gov (United States)

    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus

    2012-12-01

    Attentional dwell time (AD) defines our inability to perceive spatially separate events when they occur in rapid succession. In the standard AD paradigm, subjects should identify two target stimuli presented briefly at different peripheral locations with a varied stimulus onset asynchrony (SOA). The AD effect is seen as a long-lasting impediment in reporting the second target, culminating at SOAs of 200-500 ms. Here, we present the first quantitative computational model of the effect--a theory of temporal visual attention. The model is based on the neural theory of visual attention (Bundesen, Habekost, & Kyllingsbæk, Psychological Review, 112, 291-328 2005) and introduces the novel assumption that a stimulus retained in visual short-term memory takes up visual processing-resources used to encode stimuli into memory. Resources are thus locked and cannot process subsequent stimuli until the stimulus in memory has been recoded, which explains the long-lasting AD effect. The model is used to explain results from two experiments providing detailed individual data from both a standard AD paradigm and an extension with varied exposure duration of the target stimuli. Finally, we discuss new predictions by the model.

  8. Doppler Shift Oscillations from a Hot Line Observed by IRIS

    Science.gov (United States)

    Li, D.; Ning, Z. J.; Huang, Y.; Chen, N.-H.; Zhang, Q. M.; Su, Y. N.; Su, W.

    2017-11-01

    We present a detailed investigation of the Doppler shift oscillations in a hot loop during an M7.1 flare on 2014 October 27 observed by the Interface Region Imaging Spectrograph. The periodic oscillations are observed in the Doppler shift of Fe xxi 1354.09 Å (log T˜ 7.05), and the dominant period is about 3.1 minutes. However, such 3.1 minute oscillations are not found in the line-integrated intensity of Fe xxi 1354.09 Å, AIA EUV fluxes, or microwave emissions. Solar Dynamics Observatory/AIA and Hinode/XRT imaging observations indicate that the Doppler shift oscillations locate at the hot loop-top region (≥11 MK). Moreover, the differential emission measure results show that the temperature is increasing rapidly when the Doppler shift oscillates, but the number density does not exhibit the corresponding increases nor oscillations, implying that the flare loop is likely to oscillate in an incompressible mode. All of these facts suggest that the Doppler shift oscillations at the shorter period are most likely the standing kink oscillations in a flare loop. Meanwhile, a longer period of about 10 minutes is identified in the time series of Doppler shift and line-integrated intensity, GOES SXR fluxes, and AIA EUV light curves, indicating the periodic energy release in this flare, which may be caused by a slow mode wave.

  9. Masking T1 Difficulty: Processing Time and the Attentional Blink

    Science.gov (United States)

    Visser, Troy A. W.

    2007-01-01

    When observers are presented with 2 targets in rapid succession, identification of the 1st is highly accurate, whereas identification of the 2nd is impaired at brief intertarget intervals (i.e., 200-500 ms). This 2nd-target deficit is known as the attentional blink (AB). According to bottleneck models, the AB arises because attending to the 1st…

  10. When Do Additional Distractors Reduce the Attentional Blink?

    Science.gov (United States)

    Kawahara, Jun-ichiro

    2009-01-01

    When 2 targets are embedded in a rapid serial visual presentation stream of distractors, perception of the second target is impaired when the intertarget lag is relatively short (less than 500 ms). Stimuli concurrently presented with the stream can affect this phenomenon, which is called attentional blink (AB). Previous studies have yielded…

  11. Viewpoint Costs Occur during Consolidation: Evidence from the Attentional Blink

    Science.gov (United States)

    Dux, Paul E.; Harris, Irina M.

    2007-01-01

    Do the viewpoint costs incurred when naming rotated familiar objects arise during initial identification or during consolidation? To answer this question we employed an attentional blink (AB) task where two target objects appeared amongst a rapid stream of distractor objects. Our assumption was that while both targets and distractors undergo…

  12. Self-Referenced Processing, Neurodevelopment and Joint Attention in Autism

    Science.gov (United States)

    Mundy, Peter; Gwaltney, Mary; Henderson, Heather

    2010-01-01

    This article describes a parallel and distributed processing model (PDPM) of joint attention, self-referenced processing and autism. According to this model, autism involves early impairments in the capacity for rapid, integrated processing of self-referenced (proprioceptive and interoceptive) and other-referenced (exteroceptive) information.…

  13. Visual attention: a rhythmic process?

    Science.gov (United States)

    VanRullen, Rufin

    2013-12-16

    Vision involves constant exploration of the environment by eye movements. Recent evidence suggests that a rhythmic form of exploration also occurs under covert attention, in the absence of eye movements. Sustained attention naturally fluctuates, with a periodicity in the theta (4-8 Hz) frequency range. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. 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…

  15. 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…

  16. Temporal course of position shift for a peripheral target.

    Science.gov (United States)

    Yamada, Yuki; Miura, Kayo; Kawabe, Takahiro

    2011-05-11

    When a target is presented near a leading cue stimulus, the perceived location of the target is displaced from the cue (attentional repulsion). On the other hand, a memorized target is sometimes mislocalized toward the cue (attentional attraction). The present study aimed at clarifying the temporal relationship between attentional repulsion and attentional attraction. We used a relative judgment task wherein observers judged whether the horizontal location of the target circle was displaced leftward or rightward from the location of a vertically separated probe disk. In Experiments 1 and 2, the stimulus-onset asynchrony (SOA) between the target and the probe was manipulated from 0 ms to 2000 ms. Repulsive and attractive position shifts were observed at short and long target-probe SOAs, respectively. In Experiment 3, we found that both the cue-target SOA and the target-probe SOA governed the repulsion and attraction in different ways. The results suggest that attentional repulsion and attentional attraction occur at different visual processing stages.

  17. shift

    African Journals Online (AJOL)

    during the course of an academic year at the University of Witwatersrand following recent reforms in training and assessment methods Method: All fifth ... Assessment of Psychiatry in medical education at the. University of Witwatersrand ... or two examiners, to assess mainly clinical competence; multiple-choice questions ...

  18. 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

  19. Isolating event-related potential components associated with voluntary control of visuo-spatial attention.

    Science.gov (United States)

    McDonald, John J; Green, Jessica J

    2008-08-28

    Attention-directing cues presented at fixation evoke several lateralized event-related potential (ERP) components prior to the onset of visual targets. These components have been associated with the control of visuo-spatial attention, but the neuro-cognitive operations and neural generators of the components are still largely unknown. Here, we isolated cue-elicited ERP activity in different ways to home in on different neuro-cognitive operations and to gain a better understanding about the possible neuroanatomical sources of the cue-elicited ERP activities. To isolate lateralized cue-ERP activity, we compared shift-left and shift-right cue ERPs to shift-up cue ERPs. To measure all of the ERP activity related to attentional control, including spatially nonspecific activity that is removed in the process of isolating lateralized cue-ERP components, we compared shift-cue ERPs to neutral-cue (i.e., no-shift) ERPs. Isolated lateralized-ERP activity was seen in the contralateral-occipital lobe in the early phase of the cue-target interval and in the ipsilateral-occipital lobe in the late phase. The later, ipsilateral activity indicates that the late directing attention positivity (LDAP) reflected processing of the to-be-ignored location. The neutral-cue isolation revealed a shift-related positivity over posterior scalp regions and a shift-related negativity over more anterior scalp regions. The spatio-temporal sequence of shift-related activity observed on the scalp, together with estimates of distributed source activity underlying the shift-related ERP components, indicated that frontal and parietal regions of cortex participated in the control of attention and led to pre-target biasing in visual cortical areas.

  20. The shifting foundations of nursing.

    Science.gov (United States)

    Law, Kate; Aranda, Kay

    2010-08-01

    In this paper we argue that the concerns generated by the development of Foundation Degrees and the Assistant and Associate Practitioner roles have rekindled some of the unresolved debates regarding the status and identity of nursing and nurses. Through the application of the sociological theories of professionalisation and nostalgia we have identified the shifting and unresolved nature of nursing. We argue that these theories continue to have resonance in the current climate of change and 'upskilling' of the health care workforce and argue, that the shifts illuminated are perhaps so significant as to demonstrate that we have entered a post-nursing era. Copyright 2009 Elsevier Ltd. All rights reserved.

  1. 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.

  2. 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...

  3. 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.

  4. 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.

  5. Assessing the Attention Levels of Students by Using a Novel Attention Aware System Based on Brainwave Signals

    Science.gov (United States)

    Chen, Chih-Ming; Wang, Jung-Ying; Yu, Chih-Ming

    2017-01-01

    Rapid progress in information and communication technologies (ICTs) has fueled the popularity of e-learning. However, an e-learning environment is limited in that online instructors cannot monitor immediately whether students remain focus during online autonomous learning. Therefore, this study tries to develop a novel attention aware system (AAS)…

  6. Right anterior insula hypoactivity during anticipation of homeostatic shifts in major depressive disorder.

    Science.gov (United States)

    Strigo, Irina A; Matthews, Scott C; Simmons, Alan N

    2010-04-01

    To use functional magnetic resonance imaging (fMRI) to examine how shifts in homeostatic state affect anticipatory insular activity in major depressive disorder (MDD). An intact ability to mount preparatory emotional, cognitive, and bodily responses to anticipated environmental change is necessary for adaptive responding. Although abnormal insula activity during aversive anticipation has been observed in individuals with MDD, the extent to which shifts in homeostatic state during anticipation affect insular activity in MDD subjects has not been reported. Cued hot and warm stimuli were delivered as subjects either passively viewed a fixation cross or performed an attentional task during fMRI. The task was designed so that anticipatory brain activation related to the following three types of shifts could be measured: 1) anticipatory shifts in stimulus intensity; 2) anticipatory shifts in cognitive demand; and 3) dual anticipatory shifts (i.e., shifts in both stimulus intensity and cognitive demand). Brain activation related to each of these three contrasts was compared between 15 (12 females) unmedicated subjects with current MDD and 17 (10 females) age- and education-comparable healthy control (HC) subjects. MDD vs. HC subjects showed lower right anterior insula activity related to anticipatory shifts in stimulus intensity, and altered brain activation during anticipatory shifts in cognitive demand and dual anticipatory shifts. These results indicate that MDD individuals show altered brain responses to shifts in homeostatic state during anticipation, and may suggest that MDD is associated with an impaired ability to effectively prepare for changes in the environment.

  7. 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

  8. 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

  9. 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.

  10. 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...

  11. The Shift Needed for Sustainability

    Science.gov (United States)

    Smith, Peter A. C.; Sharicz, Carol

    2011-01-01

    Purpose: The purpose of this action research is to begin to assess to what extent organizations have in practice begun to make the shift towards triple bottom line (TBL) sustainability. Design/methodology/approach: A definition of TBL sustainability is provided, and key elements of TBL sustainability considered necessary to success are identified…

  12. Shift Work: Improving Daytime Sleep

    Science.gov (United States)

    ... Good daytime sleep is possible, though, if shift work is a necessary part of your work life. To promote better sleep during the day: ... Take naps. Napping late in the day before work might help you make up your sleep debt. ...

  13. Cognitive control and attentional functions.

    Science.gov (United States)

    Mackie, Melissa-Ann; Van Dam, Nicholas T; Fan, Jin

    2013-08-01

    Cognitive control is essential to flexible, goal-directed behavior under uncertainty, yet its underlying mechanisms are not clearly understood. Because attentional functions are known to allocate mental resources and prioritize the information to be processed, we propose that the attentional functions of alerting, orienting, and executive control and the interactions among them contribute to cognitive control in the service of uncertainty reduction. To test this hypothesis, we examined the relationship between cognitive control and attentional functions. We used the Majority Function Task (MFT) to manipulate uncertainty in order to evoke cognitive control along with the Revised Attention Network Test (ANT-R) to measure the efficiency and the interactions of attentional functions. A backwards, stepwise regression model revealed that performance on the MFT could be significantly predicted by attentional functions and their interactions as measured by the ANT-R. These results provide preliminary support for our theory that the attentional functions are involved in the implementation of cognitive control as required to reduce uncertainty, though further investigation is needed. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. 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.

  15. Rewards teach visual selective attention.

    Science.gov (United States)

    Chelazzi, Leonardo; Perlato, Andrea; Santandrea, Elisa; Della Libera, Chiara

    2013-06-07

    Visual selective attention is the brain function that modulates ongoing processing of retinal input in order for selected representations to gain privileged access to perceptual awareness and guide behavior. Enhanced analysis of currently relevant or otherwise salient information is often accompanied by suppressed processing of the less relevant or salient input. Recent findings indicate that rewards exert a powerful influence on the deployment of visual selective attention. Such influence takes different forms depending on the specific protocol adopted in the given study. In some cases, the prospect of earning a larger reward in relation to a specific stimulus or location biases attention accordingly in order to maximize overall gain. This is mediated by an effect of reward acting as a type of incentive motivation for the strategic control of attention. In contrast, reward delivery can directly alter the processing of specific stimuli by increasing their attentional priority, and this can be measured even when rewards are no longer involved, reflecting a form of reward-mediated attentional learning. As a further development, recent work demonstrates that rewards can affect attentional learning in dissociable ways depending on whether rewards are perceived as feedback on performance or instead are registered as random-like events occurring during task performance. Specifically, it appears that visual selective attention is shaped by two distinct reward-related learning mechanisms: one requiring active monitoring of performance and outcome, and a second one detecting the sheer association between objects in the environment (whether attended or ignored) and the more-or-less rewarding events that accompany them. Overall this emerging literature demonstrates unequivocally that rewards "teach" visual selective attention so that processing resources will be allocated to objects, features and locations which are likely to optimize the organism's interaction with the

  16. 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.

  17. [Neuropsychological approach to visual attention].

    Science.gov (United States)

    Suzuki, Kyoko

    2007-01-01

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

  18. 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.

  19. Shifts in historical streamflow extremes in the Colorado River Basin

    OpenAIRE

    Kurt C. Solander; Katrina E. Bennett; Richard S. Middleton

    2017-01-01

    The global phenomenon of climate change-induced shifts in precipitation leading to “wet regions getting wetter” and “dry regions getting drier” has been widely studied. However, the propagation of these changes in atmospheric moisture within stream channels is not a direct relationship due to differences in the timing of how changing precipitation patterns interact with various land surfaces. Streamflow is of particular interest in the Colorado River Basin (CRB) due to the region’s rapidly gr...

  20. Early vision and visual attention

    Directory of Open Access Journals (Sweden)

    Gvozdenović Vasilije P.

    2003-01-01

    Full Text Available The question whether visual perception is spontaneous, sudden or is running through several phases, mediated by higher cognitive processes, was raised ever since the early work of Gestalt psychologists. In the early 1980s, Treisman proposed the feature integration theory of attention (FIT, based on the findings of neuroscience. Soon after publishing her theory a new scientific approach appeared investigating several visual perception phenomena. The most widely researched were the key constructs of FIT, like types of visual search and the role of the attention. The following review describes the main studies of early vision and visual attention.

  1. Dimensions of Attention Associated With the Microstructure of Corona Radiata White Matter.

    Science.gov (United States)

    Stave, Elise A; De Bellis, Michael D; Hooper, Steven R; Woolley, Donald P; Chang, Suk Ki; Chen, Steven D

    2017-04-01

    Mirsky proposed a model of attention that included these dimensions: focus/execute, sustain, stabilize, encode, and shift. The neural correlates of these dimensions were investigated within corona radiata subregions in healthy youth. Diffusion tensor imaging and neuropsychological assessments were conducted in 79 healthy, right-handed youth aged 4-17 years. Diffusion tensor imaging maps were analyzed using standardized parcellation methods. Partial Pearson correlations between neuropsychological standardized scores, representing these attention dimensions, and diffusion tensor imaging measures of corona radiata subregions were calculated after adjusting for gender and IQ. Significant correlations were found between the focus/execute, sustain, stabilize, and shift dimensions and imaging metrics in hypothesized corona radiata subregions. Results suggest that greater microstructural white matter integrity of the corona radiata is partly associated with attention across 4 attention dimensions. Findings suggest that white matter microstructure of the corona radiata is a neural correlate of several, but not all, attention dimensions.

  2. 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.

  3. Functional_Category Shift, with particular attention to Classifying, Qualifying and Localizing Modifiers in the NP

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    Published in Book of Abstracts of the 48th Annual meeting of SOCIETAS LINGUISTICA EUROPAEA. Leiden University (the Netherlands), 2-5 Sept 2015. This talk is concerned with functional categories, where ‘functional’ should be understood in the sense of the Prague School of Linguistics, whose members...... were seeking to understand what jobs the various components of an actual linguistic expression are doing (cf. Sampson 1980). Compared to formal and semantic categories, functional categories (as defined here) have played a rather marginal role in linguistics. In the tentative typology of functional...... categories proposed below, linguistic forms and constructions are classified on the basis of various kinds of interpersonal (discourse, communicative) acts.      Interpersonal acts minimally include SPEECH ACTS (Austin 1962), THETICAL ACTS (FDG: ‘subsidiary discourse acts’; Kaltenböck et al. 2011...

  4. A shift in perspective: Decentering through mindful attention to imagined stressful events

    NARCIS (Netherlands)

    Lebois, Lauren A M; Papies, Esther K|info:eu-repo/dai/nl/304832766; 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

  5. 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.

  6. 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

    Cognitive deficits represent a core symptom cluster in schizophrenia that are thought to reflect developmental dysregulations within a neural system involving the ventral hippocampus (VH), nucleus accumbens (NAC), and prefrontal cortex (PFC). The present experiments determined the cognitive effects...

  7. 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…

  8. 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.

  9. Tips for Beginners: Attention Getters.

    Science.gov (United States)

    Moldavan, Carla

    1993-01-01

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

  10. Visual attention in posterior stroke

    DEFF Research Database (Denmark)

    Fabricius, Charlotte; Petersen, Anders; Iversen, Helle K

    Objective: Impaired visual attention is common following strokes in the territory of the middle cerebral artery, particularly in the right hemisphere. However, attentional effects of more posterior lesions are less clear. The aim of this study was to characterize visual processing speed...... and apprehension span following posterior cerebral artery (PCA) stroke. We also relate these attentional parameters to visual word recognition, as previous studies have suggested that reduced visual speed and span may explain pure alexia. Methods: Nine patients with MR-verified focal lesions in the PCA......-territory (four left PCA; four right PCA; one bilateral, all >1 year post stroke) were compared to 25 controls using single case statistics. Visual attention was characterized by a whole report paradigm allowing for hemifield-specific speed and span measurements. We also characterized visual field defects...

  11. Attention Deficit Hyperactivity Disorder (ADHD)

    Science.gov (United States)

    ... NIH About Mission The NIH Director Organization Budget History NIH Almanac Public Involvement Outreach & Education Visitor Information RePORT NIH Fact Sheets Home > Attention Deficit Hyperactivity Disorder (ADHD) Small Text Medium Text Large Text ...

  12. 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.

  13. 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.

  14. Do graphemes attract spatial attention in grapheme-color synesthesia?

    Science.gov (United States)

    Volberg, G; Chockley, A S; Greenlee, M W

    2017-05-01

    Grapheme-color synesthetes perceive concurrent colors for some objectively achromatic graphemes (inducers). Using oscillatory responses in the electroencephalogram, we tested the hypothesis that inducers automatically attract spatial attention and, thus, favor a conscious experience of color. Achromatic inducers and real-colored non-inducers were presented to the left or to the right visual hemifield and orientation judgments were required for subsequently presented Gabor patches. The graphemes were irrelevant for the task so that the related brain response was purely stimulus-driven. Synesthetes (n =12), but not an equal number of controls, showed an early theta power increase for inducers presented to the right compared to the left hemifield, with sources in left fusiform gyrus. Alpha power asymmetries indicative of shifts of spatial attention were not observed. Together, synesthetes showed an increased responsiveness to inducers in grapheme processing areas. However, contrary to our hypothesis, inducers did not attract spatial attention in synesthetes. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2012-02-01

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

  16. Visual Selective Attention in Mice.

    Science.gov (United States)

    Wang, Lupeng; Krauzlis, Richard J

    2018-02-08

    Visual selective attention is a fundamental cognitive ability that allows us to process relevant visual stimuli while ignoring irrelevant distracters and has been extensively studied in human and non-human primate subjects. Mice have emerged as a powerful animal model for studying aspects of the visual system but have not yet been shown to exhibit visual selective attention. Differences in the organization of the visual systems of primates and mice raise the possibility that selective visual attention might not be present in mice, at least not in the forms that are well established in primates. Here, we tested for selective visual attention in mice by using three behavioral paradigms adapted from classic studies of attention. In a Posner-style cueing task, a spatial cue indicated the probable location of the relevant visual event, and we found that accuracy was higher and reaction times were shorter on validly cued trials. In a cue versus no-cue task, an informative spatial cue was provided on half the trials, and mice had higher accuracy and shorter reaction times with spatial cues and also lower detection thresholds measured from psychometric curves. In a filter task, the spatial cue indicated the location of the relevant visual event, and we found that mice could be trained to ignore irrelevant but otherwise identical visual events at uncued locations. Together, these results demonstrate that mice exhibit visual selective attention, paving the way to use classic attention paradigms in mice to study the genetic and neuronal circuit mechanisms of selective attention. Published by Elsevier Ltd.

  17. Developmental trajectories of regulating attentional selection over time

    Directory of Open Access Journals (Sweden)

    Sabine eHeim

    2012-08-01

    Full Text Available Adaptive behavior in learning environments requires both the maintenance of an attentional focus on a task-set and suppression of distracting stimuli. This may be especially difficult when the competing information is more appealing than the target event. The aptitude to pay attention and resist distraction has often been noted as an important prerequisite of successful acquisition of intellectual abilities in children. This focused review draws on research that highlights interindividual differences in the temporal dynamics of attentional engagement and disengagement under competition, and their relation with age and cognitive/academic skills. Although basic strategies of attention control are present in very young children, the more refined ability to manage attentional resources over time in an economic and adaptive fashion appears during early school years, dramatically improves until the early teen years, and continues to develop into late adolescence. Across studies, parameters of attention control over time predict specific aspects of academic performance, rather than general intellectual ability. We conclude that the ability to strategically regulate the dynamic allocation of attention at rapid rates may represent an important element of cognitive and academic development.

  18. 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

  19. Gating of attentional effort through the central thalamus.

    Science.gov (United States)

    Schiff, N D; Shah, S A; Hudson, A E; Nauvel, T; Kalik, S F; Purpura, K P

    2013-02-01

    The central thalamus plays an important role in the regulation of arousal and allocation of attentional resources in the performance of even simple tasks. To assess the contribution of central thalamic neurons to short-term adjustments of attentional effort, we analyzed 166 microelectrode recordings obtained from two rhesus monkeys performing a visuomotor simple reaction time task with a variable foreperiod. Multiunit responses showed maintained firing rate elevations during the variable delay period of the task in ∼24% of recording sites. Simultaneously recorded local field potentials demonstrated significant decreases in power at ∼10-20 Hz and increases in power at 30-100 Hz during the delay period when compared against precue baselines. Comparison of the spectral power of local field potentials during the delay period of correct and incorrect trials showed that, during incorrect trials, similar, but reduced, shifts of spectral power occurred within the same frequency bands. Sustained performance of even simple tasks requires regulation of arousal and attention that combine in the concept of "attentional effort". Our findings suggest that central thalamic neurons regulate task performance through brief changes in firing rates and spectral power changes during task-relevant short-term shifts of attentional effort. Increases in attentional effort may be reflected in changes within the central thalamic local populations, where correct task performance associates with more robust maintenance of firing rates during the delay period. Such ongoing fluctuations of central thalamic activity likely reflect a mix of influences, including variations in moment-to-moment levels of motivation, arousal, and availability of cognitive resources.

  20. Morningness/eveningness and the synchrony effect for spatial attention.

    Science.gov (United States)

    Dorrian, Jillian; McLean, Benjamin; Banks, Siobhan; Loetscher, Tobias

    2017-02-01

    There is evidence that a decrease in alertness is associated with a rightward shift of attention. Alertness fluctuates throughout the day and peak times differ between individuals. Some individuals feel most alert in the morning; others in the evening. Our aim was to investigate the influence of morningness/eveningness and time of testing on spatial attention. It was predicted that attention would shift rightwards when individuals were tested at their non-optimal time as compared to tests at peak times. A crowdsourcing internet marketplace, Amazon Mechanical Turk (AMT) was used to collect data. Given questions surrounding the quality of data drawn from such virtual environments, this study also investigated the sensitivity of data to demonstrate known effects from the literature. Five-hundred and thirty right-handed participants took part between 6 am and 11 pm. Participants answered demographic questions, completed a question from the Horne and Östberg Morningness/Eveningness Scale, and performed a spatial attentional task (landmark task). For the landmark task, participants indicated whether the left or right segment of each of 72 pre-bisected lines was longer (longer side counterbalanced). Response bias was calculated by subtracting the 'number of left responses' from the 'number of right responses', and dividing by the number of trials. Negative values indicate a leftward attentional bias, and positive values a rightward bias. Well-supported relationships between variables were reflected in the dataset. Controlling for age, there was a significant interaction between morningness/eveningness and time of testing (morning=6 am-2.30 pm, evening=2.30 pm-11 pm) (pattention from peak to off-peak times of testing for those identifying as morning types, but not evening types. Findings support the utility of crowdsourcing internet marketplaces as data collection vehicles for research. Results also suggest that the deployment of spatial attention is modulated by an

  1. Examining the locus of the attentional attraction effect.

    Science.gov (United States)

    Chow, Amy; Gozli, Davood G; Pratt, Jay

    2014-11-01

    Our spatial perception is not always veridical. Indeed, systematic distortions in localization have been found to result from orienting of attention. Distorted localization is inferred from tasks wherein the subject reports the location of centrally presented parallel (vernier) line stimuli. Particularly, prior to the presentation of the lines, a shift of attention toward peripheral cues produces a mislocalization of the line stimuli away from the cues (termed the attentional repulsion effect [ARE]). However, if the shift of attention is induced after target presentation, by reversing the order of stimulus presentation, a substantial mislocalization toward the cues (attentional attraction effect [AAE]) is found. The purpose of this study was to identify whether the AAE arises from the modulation in the same processes as the ARE. While an interocular presentation of cues to one eye and vernier lines to the other was previously shown to eliminate the ARE, the AAE persists across both the interocular and monocular conditions (both the cues and vernier lines are presented to the same eye). Considering Ono and Watanabe's (2011) suggestion that memory traces may be involved in generating the AAE, this prospect was examined by having participants delay their response for a short (100 ms) or long (1,000 ms) period of time. The magnitude of AAE was larger with a longer delay, consistent with the involvement of visual memory. Next, to directly examine the role of spatial working memory, the attentional attraction task was embedded within either a spatial memory task (remembering the locations of one or three squares) or a color memory task (remembering the color of one or three squares). Only high spatial memory load reduced the magnitude of AAE. Our results suggest the AAE relies on changes to different visual processes than does the ARE and involves spatial working memory.

  2. Neural basis of superior performance of action videogame players in an attention-demanding task

    National Research Council Canada - National Science Library

    Mishra, Jyoti; Zinni, Marla; Bavelier, Daphne; Hillyard, Steven A

    2011-01-01

    ...) and from non-videogame players (NVGPs) during an attention-demanding task. Participants were presented with a multi-stimulus display consisting of rapid sequences of alphanumeric stimuli presented at rates...

  3. Critical appraisal of omega-3 fatty acids in attention-deficit/hyperactivity disorder treatment

    NARCIS (Netherlands)

    Konigs, A.; Kiliaan, A.J.

    2016-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. The classical treatment of ADHD where stimulant medication is used has revealed severe side effects and intolerance. Consequently, the demand to search for alternative treatment has increased rapidly. When

  4. VP Anaphors and Object Shift

    DEFF Research Database (Denmark)

    Ørsnes, Bjarne

    2013-01-01

    The article discusses the placement of the VP anaphor det ‘it’ as a complement of verbs selecting VP complements in Danish. With verbs that only allow a VP complement, the VP anaphor must be in SpecCP regardless of its information structure properties. If SpecCP is occupied by an operator......, the anaphor can be in situ, but it cannot shift. With verbs that allow its VP complement to alternate with an NP complement, the VP anaphor can be in SpecCP, shifted or in situ according to the information structural properties of the anaphor. Only if SpecCP is occupied by an operator, must a topical anaphor...

  5. Effect of attention control on sustained attention during induced anxiety.

    Science.gov (United States)

    Grillon, Christian; Robinson, Oliver J; Mathur, Ambika; Ernst, Monique

    2016-01-01

    Anxiety has wide-reaching and complex effects on cognitive performance. Although it can intrude on cognition and interfere with performance, it can also facilitate information processing and behavioural responses. In a previous study, we showed that anxiety induced by threat of shock facilitates performance on the Sustained Attention to Response Task, a vigilance test, which probes response inhibition to infrequent nogo stimuli. The present study sought to identify factors that may have contributed to such improved performance, including on- and off-task thinking (assessed with thought probes) and individual differences in attention control, as measured with the Attention Control Scale. Replicating our prior finding, we showed that shock threat significantly reduced errors of commission on the nogo trials. However, we extended this finding in demonstrating that this effect was driven by subjects with low attention control. We therefore confirm that anxiety increases inhibitory control of prepotent responses--a mechanism which is adaptive under threat--and show that this effect is greater in those who rely more upon such prepotent responding, i.e., those with low attentional control.

  6. Visual field meridians modulate the reallocation of object-based attention.

    Science.gov (United States)

    Barnas, Adam J; Greenberg, Adam S

    2016-10-01

    Object-based attention (OBA) enhances processing within the boundaries of a selected object. Larger OBA effects have been observed for horizontal compared to vertical rectangles, which were eliminated when controlling for attention shifts across the visual field meridians. We aimed to elucidate the modulatory role of the meridians on OBA. We hypothesized that the contralateral organization of visual cortex accounts for these differences in OBA prioritization. Participants viewed "L"-shaped objects and, following a peripheral cue at the object vertex, detected the presence of a target at the cued location (valid), or at a non-cued location (invalid) offset either horizontally or vertically. In Experiment 1, the single displayed object contained components crossing both meridians. In Experiment 2, one cued object and one non-cued object were displayed such that both crossed the meridians. In Experiment 3, one cued object was sequestered into one screen quadrant, with its vertex either near or far from fixation. Results from Experiments 1 and 2 revealed a horizontal shift advantage (faster RTs for horizontal shifts across the vertical meridian compared to vertical shifts across the horizontal meridian), regardless of whether shifts take place within a cued object (Experiment 1) or between objects (Experiment 2). Results from Experiment 3 revealed no difference between horizontal and vertical shifts for objects that were positioned far from fixation, although the horizontal shift advantage reappeared for objects near fixation. These findings suggest a critical modulatory role of visual field meridians in the efficiency of reorienting object-based attention.

  7. Hadronic shift in pionic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Hennebach, M.; Gotta, D. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Anagnostopoulos, D.F. [University of Ioannina, Department of Materials Science and Engineering, Ioannina (Greece); Dax, A.; Liu, Y.W.; Markushin, V.E.; Simons, L.M. [Paul Scherrer Institut, Laboratory for Particle Physics, Villigen (Switzerland); Fuhrmann, H.; Gruber, A.; Hirtl, A.; Zmeskal, J. [Austrian Academy of Sciences, Stefan Meyer Institute for Subatomic Physics, Vienna (Austria); Indelicato, P. [UPMC Univ. Paris 06, Laboratoire Kastler Brossel, Sorbonne Universites, Paris (France); CNRS, Laboratoire Kastler Brossel, Paris (France); Departement de Physique de l' Ecole Normale Superieure, Laboratoire Kastler Brossel, Paris (France); Manil, B. [UPMC Univ. Paris 06, Laboratoire Kastler Brossel, Sorbonne Universites, Paris (France); Rusi el Hassani, A.J. [Universite Abdelmalek Essaadi, Faculte des Sciences et Techniques, Tanger (Morocco); Trassinelli, M. [Sorbonne Universites, Institut des NanoSciences de Paris, Paris (France); CNRS, Institut des NanoSciences de Paris, Paris (France)

    2014-12-01

    The hadronic shift in pionic hydrogen has been redetermined to be ε {sub 1s} = 7.086 ± 0.007(stat) ± 0.006(sys) eV by X-ray spectroscopy of ground-state transitions applying various energy calibration schemes. The experiment was performed at the high-intensity low-energy pion beam of the Paul Scherrer Institut by using the cyclotron trap and an ultimate-resolution Bragg spectrometer with bent crystals. (orig.)

  8. Into the Era of shifts

    DEFF Research Database (Denmark)

    Dencik, Lars

    2005-01-01

    Globalization and new communication technologies shape new increasingly unpredictable living conditions. Societies as individuals face a world og growing predictive impotence. Traditions loose their power as guides for maneuvering - where traditions was reflection will be. At the same time peoples......, life styles, experiences and sexuality. Even thougts and feelings.In the era of shifts we shall be living with ever more design in an ever less designed world....

  9. 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.

  10. 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.

  11. 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.

  12. Does mindfulness meditation improve attention in attention deficit hyperactivity disorder?

    Science.gov (United States)

    Modesto-Lowe, Vania; Farahmand, Pantea; Chaplin, Margaret; Sarro, Lauren

    2015-01-01

    Attention deficit hyperactivity disorder (ADHD) manifests by high levels of inattention, impulsiveness and hyperactivity. ADHD starts in childhood and results in impairments that continue into adulthood. While hyperactivity declines over time, inattention and executive function difficulties persist, leading to functional deficits. Adolescents and adults with ADHD have pervasive impairment in interpersonal and family relationships. They may develop addiction, delinquent behavior and comorbid psychiatric disorders. Despite advances in diagnosis and treatment, persistent residual symptoms are common, highlighting the need for novel treatment strategies. Mindfulness training, derived from Eastern meditation practices, may improve self-regulation of attention. It may also be a useful strategy to augment standard ADHD treatments and may be used as a potential tool to reduce impairments in patients with residual symptoms of ADHD. Clinically, this would manifest by an increased ability to suppress task-unrelated thoughts and distractions resulting in improved attention, completion of tasks and potential improvement in occupational and social function. PMID:26740931

  13. Residual Attention Network for Image Classification

    OpenAIRE

    Wang, Fei; Jiang, Mengqing; Qian, Chen; Yang, Shuo; Li, Cheng; Zhang, Honggang; Wang, Xiaogang; Tang, Xiaoou

    2017-01-01

    In this work, we propose "Residual Attention Network", a convolutional neural network using attention mechanism which can incorporate with state-of-art feed forward network architecture in an end-to-end training fashion. Our Residual Attention Network is built by stacking Attention Modules which generate attention-aware features. The attention-aware features from different modules change adaptively as layers going deeper. Inside each Attention Module, bottom-up top-down feedforward structure ...

  14. Influence of attentional load on spatial attention in acquired and developmental disorders of attention.

    Science.gov (United States)

    Bellgrove, Mark A; Eramudugolla, Ranmalee; Newman, Daniel P; Vance, Alasdair; Mattingley, Jason B

    2013-05-01

    Converging evidence suggests that right-hemisphere dominant spatial attention systems can be modulated by non-spatial processes such as attentional capacity. The severity of neglect in right-hemisphere stroke patients for example, is correlated with impairments in non-lateralized attention. Evidence also suggests the coexistence of lateralized inattention and reduced capacity in developmental disorders of attention, such as attention deficit hyperactivity disorder (ADHD), which is marked by cognitive impairments suggestive of right hemisphere dysfunction. These lines of evidence argue against a coincident damage hypothesis and suggest instead a direct modulation of spatial attention by non-spatial processes. Here we sought experimental evidence for this relationship in both acquired and developmental disorders of attention. Six adult stroke patients with focal right brain injury and 19 children with ADHD were studied in comparison to control groups of both healthy older adults and typically developing children. The participants were required to detect transient, unilateral visual targets while simultaneously monitoring a stream of alphanumeric characters at fixation. Load at fixation was manipulated by asking participants either to ignore the central stream and focus on the peripheral detection task (no report condition), or to monitor the central stream for a probe item that was defined by either a unique feature (low load condition) or a conjunction of features (high load condition). As expected, in all participants greater load at fixation slowed responses to peripheral targets. Crucially, in right brain injured patients but not older healthy adults left target detection was slowed significantly more than central and right target detection. A qualitatively similar pattern was seen in children with ADHD, but not in typically developing children. The imposition of load at fixation slowed responses to left compared with right targets, and this response time

  15. Attention trees and semantic paths

    Science.gov (United States)

    Giusti, Christian; Pieroni, Goffredo G.; Pieroni, Laura

    2007-02-01

    In the last few decades several techniques for image content extraction, often based on segmentation, have been proposed. It has been suggested that under the assumption of very general image content, segmentation becomes unstable and classification becomes unreliable. According to recent psychological theories, certain image regions attract the attention of human observers more than others and, generally, the image main meaning appears concentrated in those regions. Initially, regions attracting our attention are perceived as a whole and hypotheses on their content are formulated; successively the components of those regions are carefully analyzed and a more precise interpretation is reached. It is interesting to observe that an image decomposition process performed according to these psychological visual attention theories might present advantages with respect to a traditional segmentation approach. In this paper we propose an automatic procedure generating image decomposition based on the detection of visual attention regions. A new clustering algorithm taking advantage of the Delaunay- Voronoi diagrams for achieving the decomposition target is proposed. By applying that algorithm recursively, starting from the whole image, a transformation of the image into a tree of related meaningful regions is obtained (Attention Tree). Successively, a semantic interpretation of the leaf nodes is carried out by using a structure of Neural Networks (Neural Tree) assisted by a knowledge base (Ontology Net). Starting from leaf nodes, paths toward the root node across the Attention Tree are attempted. The task of the path consists in relating the semantics of each child-parent node pair and, consequently, in merging the corresponding image regions. The relationship detected in this way between two tree nodes generates, as a result, the extension of the interpreted image area through each step of the path. The construction of several Attention Trees has been performed and partial

  16. Attention

    Science.gov (United States)

    Montessori, Maria

    2016-01-01

    "The Advanced Montessori Method, Volume 1" was published in 1918 in English and is considered a seminal work along with "The Montessori Method." In the foreword to this book, Mario Montessori writes: "...the refulgent figure of the child, Dr. Montessori pointed out, who had found his own path to mental health, who…

  17. Elevated salivary cortisol levels as a result of sleep deprivation in a shift worker.

    Science.gov (United States)

    Lac, G; Chamoux, A

    2003-03-01

    This paper reports a case from a group of 63 shift-workers for whom adaptation to shift-work was evaluated through measurement of salivary cortisol levels. Workers' saliva was sampled and cortisol levels measured at intervals of 2 h during morning, evening and night shifts. For one subject among the 63, very high values of cortisol (an approximately 6-fold increase) were observed for the morning (M) shift, but with normal values found for evening (E) and night (N) shifts. Individual mean and peak cortisol values were 48.4 and 67.8 nmol/l against group mean and peak cortisol values of 8.9 and 11.0 nmol/l. Retrospective questioning showed that this subject was healthy and there were no indicators of long-term stress. This cortisol rise was deduced to be caused by sleep deprivation as a result of rapidly rotating shift patterns.

  18. 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.

  19. Modelling of Attentional Dwell Time

    DEFF Research Database (Denmark)

    Petersen, Anders; Kyllingsbæk, Søren; Bundesen, Claus

    2009-01-01

    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 between 200 to 500 ms after the first. This phenome......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 between 200 to 500 ms after the first....... This phenomenon is known as attentional dwell time (e.g. Duncan, Ward, Shapiro, 1994). All Previous studies of the attentional dwell time have looked at data averaged across subjects. In contrast, we have succeeded in running subjects for 3120 trials which has given us reliable data for modelling data from...... individual subjects. Our new model is based on the Theory of Visual Attention (TVA; Bundesen, 1990). TVA has previously been successful in explaining results from experiments where stimuli are presented simultaneously in the spatial domain (e.g. whole report and partial report) but has not yet been extended...

  20. Towards the automated localisation of targets in rapid image-sifting by collaborative brain-computer interfaces.

    Directory of Open Access Journals (Sweden)

    Ana Matran-Fernandez

    Full Text Available The N2pc is a lateralised Event-Related Potential (ERP that signals a shift of attention towards the location of a potential object of interest. We propose a single-trial target-localisation collaborative Brain-Computer Interface (cBCI that exploits this ERP to automatically approximate the horizontal position of targets in aerial images. Images were presented by means of the rapid serial visual presentation technique at rates of 5, 6 and 10 Hz. We created three different cBCIs and tested a participant selection method in which groups are formed according to the similarity of participants' performance. The N2pc that is elicited in our experiments contains information about the position of the target along the horizontal axis. Moreover, combining information from multiple participants provides absolute median improvements in the area under the receiver operating characteristic curve of up to 21% (for groups of size 3 with respect to single-user BCIs. These improvements are bigger when groups are formed by participants with similar individual performance, and much of this effect can be explained using simple theoretical models. Our results suggest that BCIs for automated triaging can be improved by integrating two classification systems: one devoted to target detection and another to detect the attentional shifts associated with lateral targets.

  1. The Effect of Attention on Neuronal Responses to High and Low Contrast Stimuli

    Science.gov (United States)

    Lee, Joonyeol

    2010-01-01

    It remains unclear how attention affects the tuning of individual neurons in visual cerebral cortex. Some observations suggest that attention preferentially enhances responses to low contrast stimuli, whereas others suggest that attention proportionally affects responses to all stimuli. Resolving how attention affects responses to different stimuli is essential for understanding the mechanism by which it acts. To explore the effects of attention on stimuli of different contrasts, we recorded from individual neurons in the middle temporal visual area (MT) of rhesus monkeys while shifting their attention between preferred and nonpreferred stimuli within their receptive fields. This configuration results in robust attentional modulation that makes it possible to readily distinguish whether attention acts preferentially on low contrast stimuli. We found no evidence for greater enhancement of low contrast stimuli. Instead, the strong attentional modulations were well explained by a model in which attention proportionally enhances responses to stimuli of all contrasts. These data, together with observations on the effects of attention on responses to other stimulus dimensions, suggest that the primary effect of attention in visual cortex may be to simply increase the strength of responses to all stimuli by the same proportion. PMID:20538780

  2. The influence of shift work on cognitive functions and oxidative stress.

    Science.gov (United States)

    Özdemir, Pınar Güzel; Selvi, Yavuz; Özkol, Halil; Aydın, Adem; Tülüce, Yasin; Boysan, Murat; Beşiroğlu, Lütfullah

    2013-12-30

    Shift work influences health, performance, activity, and social relationships, and it causes impairment in cognitive functions. In this study, we investigated the effects of shift work on participants' cognitive functions in terms of memory, attention, and learning, and we measured the effects on oxidative stress. Additionally, we investigated whether there were significant relationships between cognitive functions and whole blood oxidant/antioxidant status of participants. A total of 90 health care workers participated in the study, of whom 45 subjects were night-shift workers. Neuropsychological tests were administered to the participants to assess cognitive function, and blood samples were taken to detect total antioxidant capacity and total oxidant status at 08:00. Differences in anxiety, depression, and chronotype characteristics between shift work groups were not significant. Shift workers achieved significantly lower scores on verbal memory, attention-concentration, and the digit span forward sub-scales of the Wechsler Memory Scale-Revised (WMS-R), as well as on the immediate memory and total learning sub-scales of the Auditory Verbal Learning Test (AVLT). Oxidative stress parameters were significantly associated with some types of cognitive function, including attention-concentration, recognition, and long-term memory. These findings suggest that night shift work may result in significantly poorer cognitive performance, particularly working memory. © 2013 Elsevier Ireland Ltd. All rights reserved.

  3. Complexities in Understanding Attentional Functioning among Children with Fetal Alcohol Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Kimberly eLane

    2014-03-01

    Full Text Available Parental reports of attention problems and clinical symptomatology of ADHD among children with fetal alcohol syndrome disorder (FASD were assessed in relation to performance on standardized subtests of attantional control/shifting and selective attention from the Test of Everyday Attention for Children (TEA-Ch; Manly et al., 1998. The participants included 14 children with FASD with a mean CA of 11.7 years and a mean MA of 9.7 years, and 14 typically developing (TD children with no reported history of prenatal exposure to alcohol or attention problems with a mean CA of 8.4 years and a mean MA of 9.6 years. The children with FASD were rated by their caregivers as having clinically significant attention difficulties for their developmental age. The reported symptomatology for the majority of the children with FASD were consistent with a diagnosis of ADHD, combined type, and only one child had a score within the average range. These reports are consistent with the finding here that the children with FASD demonstrated difficulties on the Creature Counting subtest of attentional control/shifting, but inconsistent with the finding that they outperformed the TD children on the Map Mission subtest of selective attention. These findings are considered within the context of the complexity in understanding attentional functioning among children with FASD and discrepancies across sources of information and components of attention.

  4. Reconsideration on the neuropsychological assessment for cognitive dysfunctions in discrimination shift learning paradigm : From the view point of Kendler's level theory

    OpenAIRE

    橋本, 優花里; 利島, 保

    2003-01-01

    The visual discrimination shift learning task has been used to assess the attentional set-shifting deficits instead of Wisconsin Card Sorting Test (WCST). From a developmental psychological point of view, the discrimination shift learning tasks has been used to investigate developmental changes of learning on the basis of various developmental studies. Kendler (1995) has been proposed the level theory to explain cognitive process that governs discrimination shift learning. This theory suggest...

  5. Out of Sight, out of Mind: The Attentional Blink Can Eliminate Synaesthetic Colours

    Science.gov (United States)

    Rich, Anina N.; Mattingley, Jason B.

    2010-01-01

    Mechanisms of selective attention exert a powerful influence on visual perception. We examined whether attentional selection is necessary for generation of the vivid colours experienced by individuals with grapheme-colour synaesthesia. Twelve synaesthetes and matched controls viewed rapid serial displays of nonsense characters within which were…

  6. Blink and Shrink: The Effect of the Attentional Blink on Spatial Processing

    Science.gov (United States)

    Olivers, Christian N. L.

    2004-01-01

    The detection or discrimination of the second of 2 targets in a rapid serial visual presentation (RSVP) task is often temporarily impaired-a phenomenon termed the attentional blink. This study demonstrated that the attentional blink also affects localization performance. Spatial cues pointed out the possible target positions in a subsequent visual…

  7. Resting EEG in Alpha and Beta Bands Predicts Individual Differences in Attentional Blink Magnitude

    Science.gov (United States)

    MacLean, Mary H.; Arnell, Karen M.; Cote, Kimberly A.

    2012-01-01

    Accuracy for a second target (T2) is reduced when it is presented within 500 ms of a first target (T1) in a rapid serial visual presentation (RSVP)--an attentional blink (AB). There are reliable individual differences in the magnitude of the AB. Recent evidence has shown that the attentional approach that an individual typically adopts during a…

  8. The Role of the Magnocellular and Parvocellular Pathways in the Attentional Blink

    Science.gov (United States)

    Nieuwenhuis, Sander; Jepma, Marieke; La Fors, Sabrina; Olivers, Christian N. L.

    2008-01-01

    The attentional blink refers to the transient impairment in perceiving the 2nd of two targets presented in close temporal proximity in a rapid serial visual presentation (RSVP) stream. The purpose of this study was to examine the effect on human attentional-blink performance of disrupting the function of the magnocellular pathway--a major…

  9. Modulation of Attentional Blink with Emotional Faces in Typical Development and in Autism Spectrum Disorders

    Science.gov (United States)

    Yerys, Benjamin E.; Ruiz, Ericka; Strang, John; Sokoloff, Jennifer; Kenworthy, Lauren; Vaidya, Chandan J.

    2013-01-01

    Background: The attentional blink (AB) phenomenon was used to assess the effect of emotional information on early visual attention in typically developing (TD) children and children with autism spectrum disorders (ASD). The AB effect is the momentary perceptual unawareness that follows target identification in a rapid serial visual processing…

  10. Blink and shrink: The effect of the attentional blink on spatial processing.

    NARCIS (Netherlands)

    Olivers, C.N.L.

    2004-01-01

    The detection or discrimination of the second of 2 targets in a rapid serial visual presentation (RSVP) task is often temporarily impaired - a phenomenon termed the attentional blink. This study demonstrated that the attentional blink also affects localization performance. Spatial cues pointed out

  11. The role of the magnocellular and parvocellular pathways in the attentional blink

    NARCIS (Netherlands)

    Nieuwenhuis, S.; Jepma, C.J.; La Fors, S; Olivers, C.N.L.

    2008-01-01

    The attentional blink refers to the transient impairment in perceiving the 2nd of two targets presented in close temporal proximity in a rapid serial visual presentation (RSVP) stream. The purpose of this study was to examine the effect on human attentional-blink performance of disrupting the

  12. Different Attentional Blink Tasks Reflect Distinct Information Processing Limitations: An Individual Differences Approach

    Science.gov (United States)

    Kelly, Ashleigh J.; Dux, Paul E.

    2011-01-01

    To study the temporal dynamics and capacity-limits of attentional selection and encoding, researchers often employ the attentional blink (AB) phenomenon: subjects' impaired ability to report the second of two targets in a rapid serial visual presentation (RSVP) stream that appear within 200-500 ms of one another. The AB has now been the subject of…

  13. The Role of the Magnocellular Visual Pathway in the Attentional Blink

    Science.gov (United States)

    Stuart, Geoffrey W.; Lambeth, Sandra E.; Day, Ross H.; Gould, Ian C.; Castles, Anne E.

    2012-01-01

    Visual attention has temporal limitations. In the attentional blink (AB) a stream of stimuli such as letters or digits are presented to a participant on a computer monitor at a rapid rate. Embedded in the stream are two targets that the participant must try to identify. Identification of the second target is severely impaired if it is presented…

  14. The early development of visual attention and its implications for social and cognitive development

    NARCIS (Netherlands)

    Hunnius, S.

    2007-01-01

    Looking behavior plays a crucial role in the daily life of an infant and forms the basis for cognitive and social development. The infant's visual attentional systems undergo rapid development during the first few months of life. During the last decennia, the study of visual attentional development

  15. The impact of negative attentional set upon target processing in RSVP : An ERP study

    NARCIS (Netherlands)

    Zhang, Dexuan; Zhou, Xiaolin; Martens, Sander

    2009-01-01

    This study investigates whether the negative attentional set, a form of top-down attentional bias, can be set up on a trial-by-trial basis and impair online target processing in an RSVP (Rapid Serial Visual Presentation) task in which two targets are to be identified. Using the N2pc (N2 posterior

  16. Components of Attention in Synesthesia

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik; Nordfang, Maria; Pedersen, Michael Nygaard

    2013-01-01

    One of the most common forms of synesthesia is between colors and graphemes (Colizoli, Murre, & Rouw, 2012). Numerous studies have investigated different aspects of attention and synesthesia, e.g. effects of Stroop-like interference by colors that are incongruent with the synesthetic experience....... Here we attempt to isolate how speci¿ c components of attention are affected by grapheme-color synesthesia. Eight carefully screened healthy participants with synesthesia reported the letters in brie¿ y presented, post-masked arrays of letters and digits. On half the trials, the letters and digits were...... presented in colors congruent with the synesthetic experience. On the other half of the trials, the letters and digits were presented in colors that were incongruent with the synesthetic experience. Components of attention were estimated separately for congruent and incongruent trials by ¿ tting the data...

  17. Attention in the predictive mind.

    Science.gov (United States)

    Ransom, Madeleine; Fazelpour, Sina; Mole, Christopher

    2017-01-01

    It has recently become popular to suggest that cognition can be explained as a process of Bayesian prediction error minimization. Some advocates of this view propose that attention should be understood as the optimization of expected precisions in the prediction-error signal (Clark, 2013, 2016; Feldman & Friston, 2010; Hohwy, 2012, 2013). This proposal successfully accounts for several attention-related phenomena. We claim that it cannot account for all of them, since there are certain forms of voluntary attention that it cannot accommodate. We therefore suggest that, although the theory of Bayesian prediction error minimization introduces some powerful tools for the explanation of mental phenomena, its advocates have been wrong to claim that Bayesian prediction error minimization is 'all the brain ever does'. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Supramodal Executive Control of Attention

    Directory of Open Access Journals (Sweden)

    ALFREDO eSPAGNA

    2015-02-01

    Full Text Available The human attentional system can be subdivided into three functional networks of alerting, orienting, and executive control. Although these networks have been extensively studied in the visuospatial modality, whether the same mechanisms are deployed across different sensory modalities remains unclear. In this study we used the attention network test for visuospatial modality, in addition to two auditory variants with spatial and frequency manipulations to examine cross-modal correlations between network functions. Results showed that among the visual and auditory tasks the effects of executive control, but not effects of alerting and orienting were significantly correlated. These findings suggest that while alerting and orienting functions rely more upon modality specific processes, the executive control of attention coordinates complex behavior via supramodal mechanisms.

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

    National Research Council Canada - National Science Library

    Hirano, Yoshiyuki; Onozuka, Minoru

    2015-01-01

    .... These findings support the concept that chewing is strongly associated with cognitive function such as learning and memory and keeping and increasing attention [5]. This relationship between chewing and cognitive functions was empirically estimated a long time ago. In 1939, Hollingworth [6] reported that chewing increased relaxation and the performance of cognitive ...

  20. Mindful Movement and Skilled Attention

    Directory of Open Access Journals (Sweden)

    Dav eClark

    2015-06-01

    Full Text Available Bodily movement has long been employed as a foundation for cultivating mental skills such as attention, self-control or mindfulness, with recent studies documenting the positive impacts of mindful movement training, such as yoga and tai chi. A parallel mind-body connection has also been observed in many developmental disorders. We elaborate a spectrum of mindfulness by considering ADHD, in which deficient motor control correlates with impaired (disinhibited behavioral control contributing to defining features of excessive distractibility and impulsivity. These data provide evidence for an important axis of variation for wellbeing, in which skillful cognitive control covaries with a capacity for skillful movement. We review empirical and theoretical literature on attention, cognitive control, mind wandering, mindfulness and skill learning, endorsing a model of skilled attention in which motor plans, attention, and executive goals are seen as mutually co-defining aspects of skilled behavior that are linked by reciprocal inhibitory and excitatory connections. Thus, any movement training should engage higher-order inhibition and selection and develop a repertoire of rehearsed procedures that coordinate goals, attention and motor plans. However, we propose that mindful movement practice may improve the functional quality of rehearsed procedures, cultivating a transferrable skill of attention. We adopt Langer’s spectrum of mindful learning that spans from mindlessness to engagement with the details of the present task and contrast this with the mental attitudes cultivated in standard mindfulness meditation. We particularly follow Feldenkrais’ suggestion that mindful learning of skills for organizing the body in movement might transfer to other forms of mental activity. The results of mindful movement training should be observed in multiple complementary measures, and may have tremendous potential benefit for individuals with ADHD and other

  1. Mindful movement and skilled attention.

    Science.gov (United States)

    Clark, Dav; Schumann, Frank; Mostofsky, Stewart H

    2015-01-01

    Bodily movement has long been employed as a foundation for cultivating mental skills such as attention, self-control or mindfulness, with recent studies documenting the positive impacts of mindful movement training, such as yoga and tai chi. A parallel "mind-body connection" has also been observed in many developmental disorders. We elaborate a spectrum of mindfulness by considering ADHD, in which deficient motor control correlates with impaired (disinhibited) behavioral control contributing to defining features of excessive distractibility and impulsivity. These data provide evidence for an important axis of variation for wellbeing, in which skillful cognitive control covaries with a capacity for skillful movement. We review empirical and theoretical literature on attention, cognitive control, mind wandering, mindfulness and skill learning, endorsing a model of skilled attention in which motor plans, attention, and executive goals are seen as mutually co-defining aspects of skilled behavior that are linked by reciprocal inhibitory and excitatory connections. Thus, any movement training should engage "higher-order" inhibition and selection and develop a repertoire of rehearsed procedures that coordinate goals, attention and motor plans. However, we propose that mindful movement practice may improve the functional quality of rehearsed procedures, cultivating a transferrable skill of attention. We adopt Langer's spectrum of mindful learning that spans from "mindlessness" to engagement with the details of the present task and contrast this with the mental attitudes cultivated in standard mindfulness meditation. We particularly follow Feldenkrais' suggestion that mindful learning of skills for organizing the body in movement might transfer to other forms of mental activity. The results of mindful movement training should be observed in multiple complementary measures, and may have tremendous potential benefit for individuals with ADHD and other populations.

  2. Action experience changes attention to kinematic cues

    Directory of Open Access Journals (Sweden)

    Courtney eFilippi

    2016-02-01

    Full Text Available The current study used remote corneal reflection eye-tracking to examine the relationship between motor experience and action anticipation in 13-month-old infants. To measure online anticipation of actions infants watched videos where the actor’s hand provided kinematic information (in its orientation about the type of object that the actor was going to reach for. The actor’s hand orientation either matched the orientation of a rod (congruent cue or did not match the orientation of the rod (incongruent cue. To examine relations between motor experience and action anticipation, we used a 2 (reach first vs. observe first x 2 (congruent kinematic cue vs. incongruent kinematic cue between-subjects design. We show that 13-month-old infants in the observe first condition spontaneously generate rapid online visual predictions to congruent hand orientation cues and do not visually anticipate when presented incongruent cues. We further demonstrate that the speed that these infants generate predictions to congruent motor cues is correlated with their own ability to pre-shape their hands. Finally, we demonstrate that following reaching experience, infants generate rapid predictions to both congruent and incongruent hand shape cues—suggesting that short-term experience changes attention to kinematics.

  3. 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.

  4. Geometric phase shifting digital holography.

    Science.gov (United States)

    Jackin, Boaz Jessie; Narayanamurthy, C S; Yatagai, Toyohiko

    2016-06-01

    A new phase shifting digital holographic technique using a purely geometric phase in Michelson interferometric geometry is proposed. The geometric phase in the system does not depend upon either optical path length or wavelength, unlike dynamic phase. The amount of geometric phase generated is controllable through a rotating wave plate. The new approach has unique features and major advantages in holographic measurement of transparent and reflecting three-dimensional (3D) objects. Experimental results on surface shape measurement and imaging of 3D objects are presented using the proposed method.

  5. 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

    Theoretical investigations of a single, straight, vibrating, fluid-conveying pipe have resulted in simple analytical expressions for the approximate prediction of the spatial shift in vibration phase. The expressions have lead to hypotheses for real Coriolis flowmeters (CFMs). To test these......, 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...

  6. 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,...

  7. Task-Shifting and Quality of HIV Testing Services: Experiences from a National Reference Hospital in Zambia.

    Directory of Open Access Journals (Sweden)

    Sheila Mwangala

    Full Text Available With new testing technologies, task-shifting and rapid scale-up of HIV testing services in high HIV prevalence countries, assuring quality of HIV testing is paramount. This study aimed to explore various cadres of providers' experiences in providing HIV testing services and their understanding of elements that impact on quality of service in Zambia.Sixteen in-depth interviews and two focus group discussions were conducted with HIV testing service providers including lay counselors, nurses and laboratory personnel at purposively selected HIV testing sites at a national reference hospital in Lusaka. Qualitative content analysis was adopted for data analysis.Lay counselors and nurses reported confidentiality and privacy to be greatly compromised due to limited space in both in- and out-patient settings. Difficulties in upholding consent were reported in provider-initiated testing in in-patient settings. The providers identified non-adherence to testing procedures, high workload and inadequate training and supervision as key elements impacting on quality of testing. Difficulties related to testing varied by sub-groups of providers: lay counselors, in finger pricking and obtaining adequate volumes of specimen; non-laboratory providers in general, in interpreting invalid, false-negative and false-positive results. The providers had been participating in a recently established national HIV quality assurance program, i.e. proficiency testing, but rarely received site supervisory visits.Task-shifting coupled with policy shifts in service provision has seriously challenged HIV testing quality, protection of confidentiality and the process of informed consent. Ways to better protect confidentiality and informed consent need careful attention. Training, supervision and quality assurance need strengthening tailored to the needs of the different cadres of providers.

  8. [Investigation of the actual conditions of hospital nurses working on three rotating shifts: questionnaire results of shift work schedules, feelings of sleep and fatigue, and depression].

    Science.gov (United States)

    Matsumoto, M; Kamata, S; Naoe, H; Mutoh, F; Chiba, S

    1996-01-01

    These studies were performed to clarify (1) the actual conditions concerning rotating shift schedules of nurses in Japanese university and college hospitals and to evaluate (2) some aspects of the physical and mental health, and (3) sleep profile of hospital nurses working on counter-clockwise shift rotation. Two questionnaire surveys and the OSA sleep inventory (OSA) were carried out. The subjects in the study (1) were a total of 80 nursing directors in university and college hospitals. The questionnaire covered 4 categories, such as the schedule most frequently adopted and reasons for using the schedule. The questionnaires were returned by 67 directors (83.8%). The subjects in the study (2) were 189 nurses working on three-shift work schedules at Asahikawa Medical College Hospital. The items in the questionnaire covered 7 categories, as follows: 1) feeling of sleep after each shift (8 items); 2) feeling of fatigue after each shift (30 items); 3) physical symptoms; 4) inter-personal problems; 5) all the items on Zung's self-rating depression scale (SDS); 6) all the items on the Horne and Ostberg morningness-eveningness questionnaire; and 7) 24 items on the Maudsley personality inventory. The questionnaires were returned by 156 nurses (82.5%), whose mean age and duration of shift-work employment were 27.2 +/- 5.1 and 5.0 +/- 4.3 years (mean +/- SD), respectively. For 152 nurses (97.4%) of those returning the questionnaire, the working schedule consisted of 2 consecutive night shifts and 2 consecutive evening shifts, following a variable number of day shifts (rapid and counterclockwise shift rotation). The subjects in the study (3) were 8 healthy nurses working on above-mentioned three rotating shifts at the psychiatric ward of Asahikawa Medical College Hospital, whose mean age was 29.4 +/- 5.8 years (mean +/- SD). All the subjects recorded their sleep-logs and underwent OSA everyday for 30 consecutive days. Of the 240 OSA data, 95 data (16 after day shift, 17 after

  9. 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.

  10. Testing a dynamic-field account of interactions between spatial attention and spatial working memory.

    Science.gov (United States)

    Johnson, Jeffrey S; Spencer, John P

    2016-05-01

    Studies examining the relationship between spatial attention and spatial working memory (SWM) have shown that discrimination responses are faster for targets appearing at locations that are being maintained in SWM, and that location memory is impaired when attention is withdrawn during the delay. These observations support the proposal that sustained attention is required for successful retention in SWM: If attention is withdrawn, memory representations are likely to fail, increasing errors. In the present study, this proposal was reexamined in light of a neural-process model of SWM. On the basis of the model's functioning, we propose an alternative explanation for the observed decline in SWM performance when a secondary task is performed during retention: SWM representations drift systematically toward the location of targets appearing during the delay. To test this explanation, participants completed a color discrimination task during the delay interval of a spatial-recall task. In the critical shifting-attention condition, the color stimulus could appear either toward or away from the midline reference axis, relative to the memorized location. We hypothesized that if shifting attention during the delay leads to the failure of SWM representations, there should be an increase in the variance of recall errors, but no change in directional errors, regardless of the direction of the shift. Conversely, if shifting attention induces drift of SWM representations-as predicted by the model-systematic changes in the patterns of spatial-recall errors should occur that would depend on the direction of the shift. The results were consistent with the latter possibility-recall errors were biased toward the locations of discrimination targets appearing during the delay.

  11. Testing a Dynamic Field Account of Interactions between Spatial Attention and Spatial Working Memory

    Science.gov (United States)

    Johnson, Jeffrey S.; Spencer, John P.

    2016-01-01

    Studies examining the relationship between spatial attention and spatial working memory (SWM) have shown that discrimination responses are faster for targets appearing at locations that are being maintained in SWM, and that location memory is impaired when attention is withdrawn during the delay. These observations support the proposal that sustained attention is required for successful retention in SWM: if attention is withdrawn, memory representations are likely to fail, increasing errors. In the present study, this proposal is reexamined in light of a neural process model of SWM. On the basis of the model's functioning, we propose an alternative explanation for the observed decline in SWM performance when a secondary task is performed during retention: SWM representations drift systematically toward the location of targets appearing during the delay. To test this explanation, participants completed a color-discrimination task during the delay interval of a spatial recall task. In the critical shifting attention condition, the color stimulus could appear either toward or away from the memorized location relative to a midline reference axis. We hypothesized that if shifting attention during the delay leads to the failure of SWM representations, there should be an increase in the variance of recall errors but no change in directional error, regardless of the direction of the shift. Conversely, if shifting attention induces drift of SWM representations—as predicted by the model—there should be systematic changes in the pattern of spatial recall errors depending on the direction of the shift. Results were consistent with the latter possibility—recall errors were biased toward the location of discrimination targets appearing during the delay. PMID:26810574

  12. The role of attention processes in facial affect recognition in schizophrenia.

    Science.gov (United States)

    Tsotsi, Stella; Bozikas, Vassilis P; Kosmidis, Mary H

    2015-01-01

    Studies investigating the involvement of attention processes in facial affect recognition (FAR) have been contradictory, with some suggesting a generalised cognitive deficit, whereas others a specialised deficit in affect recognition. Given the ubiquity of both attention and emotion perception deficits in schizophrenia, we examined whether specific attentional processes, in fact, mediate FAR. Patients with schizophrenia (n = 38) and healthy controls (n = 24) performed tests assessing FAR and attention processes, specifically, visual attention (Trail Making Test A), sustained attention/inhibition (Rapid Visual Processing subtest; Cambridge Automated Neuropsychological Test Battery), and attention to details in facial features (AFF). AFF and FAR were assessed with newly devised experimental procedures. Hierarchical multiple regression analyses showed a similar pattern of association between attention processes and FAR in both participant groups with respect to all attention processes investigated, predicting FAR accuracy. Additionally, visual attention predicted accuracy in happiness, disgust and surprise, whereas AFF predicted accuracy in anger and fear. Regarding FAR processing speed, no attention process predicted participants' performance on correct responses; AFF response speed predicted participants' FAR response speed, but only on incorrect responses. The present findings highlight the role of attentional processes in emotion recognition, as deficits in the former were predictive of impairments in the latter. Furthermore, AFF appears to be involved in the discrimination of negatively valenced facial expressions. The lack of association between attentional processes and FAR processing speed, particularly regarding correct responses, might reflect the differential pattern of activation of cortical and subcortical structures involved in these cognitive processes.

  13. Attention as foraging for information and reward

    National Research Council Canada - National Science Library

    Sanjay G Manohar; Masud eHusain

    2013-01-01

    What is the purpose of attention? One avenue of research has led to the proposal that attention might be crucial for gathering information about the environment, while other lines of study have demonstrated attention's role...

  14. Attention as foraging for information and value

    National Research Council Canada - National Science Library

    Manohar, Sanjay G; Husain, Masud

    2013-01-01

    What is the purpose of attention? One avenue of research has led to the proposal that attention might be crucial for gathering information about the environment, while other lines of study have demonstrated how attention may play...

  15. Attention span during lectures: 8 seconds, 10 minutes, or more?

    Science.gov (United States)

    Bradbury, Neil A

    2016-12-01

    In the current climate of curriculum reform, the traditional lecture has come under fire for its perceived lack of effectiveness. Indeed, several institutions have reduced their lectures to 15 min in length based upon the "common knowledge" and "consensus" that there is a decline in students' attention 10-15 min into lectures. A review of the literature on this topic reveals many discussions referring to prior studies but scant few primary investigations. Alarmingly, the most often cited source for a rapid decline in student attention during a lecture barely discusses student attention at all. Of the studies that do attempt to measure attention, many suffer from methodological flaws and subjectivity in data collection. Thus, the available primary data do not support the concept of a 10- to 15-min attention limit. Interestingly, the most consistent finding from a literature review is that the greatest variability in student attention arises from differences between teachers and not from the teaching format itself. Certainly, even the most interesting material can be presented in a dull and dry fashion, and it is the job of the instructor to enhance their teaching skills to provide not only rich content but also a satisfying lecture experience for the students. Copyright © 2016 the American Physiological Society.

  16. Deficits in reflexive covert attention following cerebellar injury.

    Directory of Open Access Journals (Sweden)

    Christopher eStriemer

    2015-08-01

    Full Text Available Traditionally the cerebellum has been known for its important role in coordinating motor output. Over the past fifteen years numerous studies have indicated that the cerebellum plays a role in a variety of cognitive functions including working memory, language, perceptual functions, and emotion. In addition, recent work suggests that regions of the cerebellum involved in eye movements also play a role in controlling covert visual attention. Here we investigated whether regions of the cerebellum that are not strictly tied to the control of eye movements might also contribute to covert attention. To address this question we examined the effects of circumscribed cerebellar lesions on reflexive covert attention in a group of patients (n=11 without any gross motor or oculomotor deficits, and compared their performance to a group of age-matched controls (n=11. Results indicated that the traditional RT advantage for validly cued targets was significantly smaller at the shortest (50ms SOA for cerebellar patients compared to controls. Critically, a lesion overlap analysis indicated that this deficit in the rapid deployment of attention was linked to damage in Crus I and Crus II of the lateral cerebellum. Importantly, both cerebellar regions have connections to non-motor regions of the prefrontal and posterior parietal cortices – regions important for controlling visuospatial attention. Together, these data provide converging evidence that both lateral and midline regions of the cerebellum play an important role in the control of reflexive covert visual attention.

  17. Deficits in reflexive covert attention following cerebellar injury.

    Science.gov (United States)

    Striemer, Christopher L; Cantelmi, David; Cusimano, Michael D; Danckert, James A; Schweizer, Tom A

    2015-01-01

    Traditionally the cerebellum has been known for its important role in coordinating motor output. Over the past 15 years numerous studies have indicated that the cerebellum plays a role in a variety of cognitive functions including working memory, language, perceptual functions, and emotion. In addition, recent work suggests that regions of the cerebellum involved in eye movements also play a role in controlling covert visual attention. Here we investigated whether regions of the cerebellum that are not strictly tied to the control of eye movements might also contribute to covert attention. To address this question we examined the effects of circumscribed cerebellar lesions on reflexive covert attention in a group of patients (n = 11) without any gross motor or oculomotor deficits, and compared their performance to a group of age-matched controls (n = 11). Results indicated that the traditional RT advantage for validly cued targets was significantly smaller at the shortest (50 ms) SOA for cerebellar patients compared to controls. Critically, a lesion overlap analysis indicated that this deficit in the rapid deployment of attention was linked to damage in Crus I and Crus II of the lateral cerebellum. Importantly, both cerebellar regions have connections to non-motor regions of the prefrontal and posterior parietal cortices-regions important for controlling visuospatial attention. Together, these data provide converging evidence that both lateral and midline regions of the cerebellum play an important role in the control of reflexive covert visual attention.

  18. Paradigm shifts in corneal transplantation.

    Science.gov (United States)

    Tan, Donald T H; Anshu, Arundhati; Mehta, Jodhbir S

    2009-04-01

    Conventional corneal transplantation, in the form of penetrating keratoplasty (PK), involves full-thickness replacement of the cornea, and is a highly successful procedure. However, the cornea is anatomically a multi-layered structure. Pathology may only affect individual layers of the cornea, hence selective lamellar surgical replacement of only the diseased corneal layers whilst retaining unaffected layers represents a new paradigm shift in the field. Recent advancements in surgical techniques and instrumentation have resulted in several forms of manual, microkeratome and femto-second laser-assisted lamellar transplantation procedures. Anterior lamellar keratoplasty (ALK) aims at replacing only diseased or scarred corneal stroma, whilst retaining the unaffected corneal endothelial layer, thus obviating the risk of endothelial allograft rejection. Posterior lamellar keratoplasty/endothelial keratoplasty (PLK/EK) involves the replacement of the dysfunctional endothelial cell layer only. Whilst significant technical and surgical challenges are involved in performing lamellar micro-dissection of a tissue which is only 0.5 mm thick, the benefits of a more controlled surgical procedure and improved graft survival rates have resulted in a shift away from conventional PK. This review details the current advances in emerging lamellar corneal surgical procedures and highlights the main advantages and disadvantages of these new lamellar corneal procedures.

  19. 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

  20. 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.