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Sample records for adaptive attention processes

  1. Effects of Crowding and Attention on High-Levels of Motion Processing and Motion Adaptation

    PubMed Central

    Pavan, Andrea; Greenlee, Mark W.

    2015-01-01

    The motion after-effect (MAE) persists in crowding conditions, i.e., when the adaptation direction cannot be reliably perceived. The MAE originating from complex moving patterns spreads into non-adapted sectors of a multi-sector adapting display (i.e., phantom MAE). In the present study we used global rotating patterns to measure the strength of the conventional and phantom MAEs in crowded and non-crowded conditions, and when attention was directed to the adapting stimulus and when it was diverted away from the adapting stimulus. The results show that: (i) the phantom MAE is weaker than the conventional MAE, for both non-crowded and crowded conditions, and when attention was focused on the adapting stimulus and when it was diverted from it, (ii) conventional and phantom MAEs in the crowded condition are weaker than in the non-crowded condition. Analysis conducted to assess the effect of crowding on high-level of motion adaptation suggests that crowding is likely to affect the awareness of the adapting stimulus rather than degrading its sensory representation, (iii) for high-level of motion processing the attentional manipulation does not affect the strength of either conventional or phantom MAEs, neither in the non-crowded nor in the crowded conditions. These results suggest that high-level MAEs do not depend on attention and that at high-level of motion adaptation the effects of crowding are not modulated by attention. PMID:25615577

  2. Prism Adaptation Alters Electrophysiological Markers of Attentional Processes in the Healthy Brain.

    PubMed

    Martín-Arévalo, Elisa; Laube, Inga; Koun, Eric; Farnè, Alessandro; Reilly, Karen T; Pisella, Laure

    2016-01-20

    Neglect patients typically show a rightward attentional orienting bias and a strong disengagement deficit, such that they are especially slow in responding to left-sided targets after right-sided cues (Posner et al., 1984). Prism adaptation (PA) can reduce diverse debilitating neglect symptoms and it has been hypothesized that PA's effects are so generalized that they might be mediated by attentional mechanisms (Pisella et al., 2006; Redding and Wallace, 2006). In neglect patients, performance on spatial attention tasks improves after rightward-deviating PA (Jacquin-Courtois et al., 2013). In contrast, in healthy subjects, although there is evidence that leftward-deviating PA induces neglect-like performance on some visuospatial tasks, behavioral studies of spatial attention tasks have mostly yielded negative results (Morris et al., 2004; Bultitude et al., 2013). We hypothesized that these negative behavioral findings might reflect the limitations of behavioral measures in healthy subjects. Here we exploited the sensitivity of event-related potentials to test the hypothesis that electrophysiological markers of attentional processes in the healthy human brain are affected by PA. Leftward-deviating PA generated asymmetries in attentional orienting (reflected in the cue-locked N1) and in attentional disengagement for invalidly cued left targets (reflected in the target-locked P1). This is the first electrophysiological demonstration that leftward-deviating PA in healthy subjects mimics attentional patterns typically seen in neglect patients. Significance statement: Prism adaptation (PA) is a promising tool for ameliorating many deficits in neglect patients and inducing neglect-like behavior in healthy subjects. The mechanisms underlying PA's effects are poorly understood but one hypothesis suggests that it acts by modulating attention. To date, however, there has been no successful demonstration of attentional modulation in healthy subjects. We provide the first

  3. ERP evidence of adaptive changes in error processing and attentional control during rhythm synchronization learning.

    PubMed

    Padrão, Gonçalo; Penhune, Virginia; de Diego-Balaguer, Ruth; Marco-Pallares, Josep; Rodriguez-Fornells, Antoni

    2014-10-15

    The ability to detect and use information from errors is essential during the acquisition of new skills. There is now a wealth of evidence about the brain mechanisms involved in error processing. However, the extent to which those mechanisms are engaged during the acquisition of new motor skills remains elusive. Here we examined rhythm synchronization learning across 12 blocks of practice in musically naïve individuals and tracked changes in ERP signals associated with error-monitoring and error-awareness across distinct learning stages. Synchronization performance improved with practice, and performance improvements were accompanied by dynamic changes in ERP components related to error-monitoring and error-awareness. Early in learning, when performance was poor and the internal representations of the rhythms were weaker we observed a larger error-related negativity (ERN) following errors compared to later learning. The larger ERN during early learning likely results from greater conflict between competing motor responses, leading to greater engagement of medial-frontal conflict monitoring processes and attentional control. Later in learning, when performance had improved, we observed a smaller ERN accompanied by an enhancement of a centroparietal positive component resembling the P3. This centroparietal positive component was predictive of participant's performance accuracy, suggesting a relation between error saliency, error awareness and the consolidation of internal templates of the practiced rhythms. Moreover, we showed that during rhythm learning errors led to larger auditory evoked responses related to attention orientation which were triggered automatically and which were independent of the learning stage. The present study provides crucial new information about how the electrophysiological signatures related to error-monitoring and error-awareness change during the acquisition of new skills, extending previous work on error processing and cognitive

  4. Encoding attentional states during visuomotor adaptation.

    PubMed

    Im, Hee Yeon; Bédard, Patrick; Song, Joo-Hyun

    2015-01-01

    We recently showed that visuomotor adaptation acquired under attentional distraction is better recalled under a similar level of distraction compared to no distraction. This paradoxical effect suggests that attentional state (e.g., divided or undivided) is encoded as an internal context during visuomotor learning and should be reinstated for successful recall (Song & Bédard, 2015). To investigate if there is a critical temporal window for encoding attentional state in visuomotor memory, we manipulated whether participants performed the secondary attention-demanding task concurrently in the early or late phase of visuomotor learning. Recall performance was enhanced when the attentional states between recall and the early phase of visuomotor learning were consistent. However, it reverted to untrained levels when tested under the attentional state of the late-phase learning. This suggests that attentional state is primarily encoded during the early phase of learning before motor errors decrease and reach an asymptote. Furthermore, we demonstrate that when divided and undivided attentional states were mixed during visuomotor adaptation, only divided attention was encoded as an internal cue for memory retrieval. Therefore, a single attentional state appears to be primarily integrated with visuomotor memory while motor error reduction is in progress during learning. PMID:26114683

  5. Attention modulates emotional expression processing.

    PubMed

    Wronka, Eligiusz; Walentowska, Wioleta

    2011-08-01

    To investigate the time course of emotional expression processing, we recorded ERPs to facial stimuli. The first task was to discriminate emotional expressions. Enhanced negativity of the face-specific N170 was elicited by emotional as opposed to neutral faces, followed by the occipital negativity (240-340 ms poststimulus). The second task was to classify face gender. Here, N170 was unaffected by the emotional expression. However, emotional expression effect was expressed in the anterior positivity (160-250 ms poststimulus) and subsequent occipital negativity (240-340 ms poststimulus). Results support the thesis that structural encoding relevant to gender recognition and simultaneous expression analysis are independent processes. Attention modulates facial emotion processing 140-185 ms poststimulus. Involuntary differentiation of facial expression was observed later (160-340 ms poststimulus), suggesting unintentional attention capture. PMID:21332489

  6. Pre-attentive and attentive processing of French vowels.

    PubMed

    Deguchi, Chizuru; Chobert, Julie; Brunellière, Angèle; Nguyen, Noël; Colombo, Lucia; Besson, Mireille

    2010-12-17

    This study aimed at investigating the effects of acoustic distance and of speaker variability on the pre-attentive and attentive perception of French vowels by French adult speakers. The electroencephalogram (EEG) was recorded while participants watched a silent movie (Passive condition) and discriminated deviant vowels (Active condition). The auditory sequence included 4 French vowels, /u/ (standard) and /o/, /y/ and /ø/ as deviants, produced by 3 different speakers. As the vowel /o/ is closer to /u/ than the other deviants in acoustic distance, we predicted smaller mismatch negativity (MMN) and smaller N1 component, as well as higher error rate and longer reaction times. Results were in line with these predictions. Moreover, the MMN was elicited by all deviant vowels independently of speaker variability. By contrast, the Vowel by Speaker interaction was significant in the Active listening condition thereby showing that subtle within-category differences are processed at the attentive level. These results suggest that while vowels are categorized pre-attentively according to phonemic representations and independently of speaker variability, participants are sensitive to between-speaker differences when they focus attention on vowel processing. PMID:20920484

  7. Holistic Processing from Learned Attention to Parts

    PubMed Central

    Chua, Kao-Wei; Richler, Jennifer J.; Gauthier, Isabel

    2016-01-01

    Attention helps us focus on what is most relevant to our goals, and prior work shows that aspects of attention can be learned. Learned inattention to parts can abolish holistic processing of faces, but it is unknown whether learned attention to parts is sufficient to cause a change from part-based to holistic processing with objects. Here, we trained subjects to individuate non-face objects (Greebles) from two categories, Ploks and Glips. Diagnostic information was in complementary halves for the two categories. Holistic processing was then tested with Plok-Glip composites that combined the kind of part that was diagnostic or non-diagnostic during training. Exposure to Greeble parts resulted in general failures of selective attention for non-diagnostic composites, but face-like holistic processing was only observed for diagnostic composites. These results demonstrate a novel link between learned attentional control and the acquisition of holistic processing. PMID:25775049

  8. Temporal Processing, Attention, and Learning Disorders

    ERIC Educational Resources Information Center

    Landerl, Karin; Willburger, Edith

    2010-01-01

    In a large sample (N = 439) of literacy impaired and unimpaired elementary school children the predictions of the temporal processing theory of dyslexia were tested while controlling for (sub)clininal attentional deficits. Visual and Auditory Temporal Order Judgement were administered as well as three subtests of a standardized attention test. The…

  9. Accuracy of Information Processing under Focused Attention.

    ERIC Educational Resources Information Center

    Bastick, Tony

    This paper reports the results of an experiment on the accuracy of information processing during attention focused arousal under two conditions: single estimation and double estimation. The attention of 187 college students was focused by a task requiring high level competition for a monetary prize ($10) under severely limited time conditions. The…

  10. Do social utility judgments influence attentional processing?

    PubMed

    Shore, Danielle M; Heerey, Erin A

    2013-10-01

    Research shows that social judgments influence decision-making in social environments. For example, judgments about an interaction partners' trustworthiness affect a variety of social behaviors and decisions. One mechanism by which social judgments may influence social decisions is by biasing the automatic allocation of attention toward certain social partners, thereby shaping the information people acquire. Using an attentional blink paradigm, we investigate how trustworthiness judgments alter the allocation of attention to social stimuli in a set of two experiments. The first experiment investigates trustworthiness judgments based solely on a social partner's facial appearance. The second experiment examines the effect of trustworthiness judgments based on experienced behavior. In the first, strong appearance-based judgments (positive and negative) enhanced stimulus recognizability but did not alter the size of the attentional blink, suggesting that appearance-based social judgments enhance face memory but do not affect pre-attentive processing. However, in the second experiment, in which judgments were based on behavioral experience rather than appearance, positive judgments enhanced pre-attentive processing of trustworthy faces. This suggests that a stimulus's potential benefits, rather than its disadvantages, shape the automatic distribution of attentional resources. These results have implications for understanding how appearance- and behavior-based social cues shape attention distribution in social environments. PMID:23887150

  11. Does Involuntary Attentional Capture Curtail Stimulus Processing

    NASA Technical Reports Server (NTRS)

    Remington, Roger W.; McLean, John P.; Folk, Charles L.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    Under certain conditions uninformative visual cues at non-target locations increase target RTs. The typical explanation is that visual attention has been involuntarily summoned to the cued location and is unavailable when needed at the target location. Here we present evidence that capture has not just oriented attention away from the target location, but has lead to the processing of stimuli at the location of the uninformative cue.

  12. Attention to individual identities modulates face processing.

    PubMed

    Ruz, María; Aranda, Clara; Sarmiento, Beatriz R; Sanabria, Daniel

    2015-05-01

    The ability of attention to apply in a flexible manner to several types of information at various stages of processing has been studied extensively. However, the susceptibility of these effects to the nature of the idiosyncratic items being attended is less understood. In the current study, we used symbolic cues to orient the attention of participants to the subsequent appearance of the face of a famous person (the former king of Spain) or an unfamiliar face. These were matched in perceptual characteristics. Behavioral effects showed that face-specific attention optimized response speed in an orthogonal task when the target matched the cue (valid trials) compared to when it did not (invalid trials). According to topographical analyses of the electrophysiological data, the famous and unfamiliar faces engaged dissociable brain circuits in two different temporal windows, from 144 to 300 ms after target processing, and at a later 456-492 ms epoch. In addition, orienting attention to specific faces modulated the perceptual stages reflected in the P1 and N170 potentials but with a different laterality pattern that depended on the familiarity of the faces. Whereas only attention to the famous face enhanced the P1 potential at left posterior electrodes, with no corresponding effect for the unfamiliar face at this stage, the N170 was modulated at left posterior sites for the famous item and at right homologous electrodes for the unfamiliar face. Intermediate processing stages, previously linked to facial identity processing indexed by the P2 and N2 potentials, reflected item familiarity but were not affected by the cueing manipulation. At the P3 level, attention influenced again item processing but did so in an equivalent manner for the famous and unfamiliar face. Our results, showing that identity-specific attention modulates perceptual stages of facial processing at different locations depending on idiosyncratic stimulus familiarity, may inform comparison of studies

  13. Limited attention facilitates coherent motion processing.

    PubMed

    Motoyoshi, Isamu; Ishii, Taichi; Kamachi, Miyuki G

    2015-01-01

    It has been suggested that sensitivities for visual motion are typically impaired by poor attention. Here, we show that limited attention paradoxically improves performance on a global motion detection task. Psychophysical experiments revealed that deliberately attending to an irrelevant stimulus enhanced sensitivity for detecting coherent motion in random-dot kinematograms but did not affect contrast and velocity sensitivity for local luminance motion. Subsequent experiments further demonstrated that the dual task reduced sensitivity for detecting spatial modulations in local motion direction and induced illusory motion assimilation. Additional measurements confirmed that the secondary task had no effect when attentional load was extremely high or when motion stimuli were presented peripherally. These results may be explained by the idea that limited attention dynamically expands the spatial extent of motion integration by reducing center-surround interactions at high-level motion processing. PMID:26327254

  14. Attentional Processing of Letter Strings by Children.

    PubMed

    Leclercq, Virginie; Siéroff, Eric

    2016-01-01

    Reading a letter string requires attentional orienting toward the beginning of the string (left-dominant orientation), followed by orienting along the string. These attentional-orienting processes differ according to the lexicality of the letter string: Sequential processes apply when reading nonwords or pseudowords, while words can be processed more globally. The aim of this study was to evaluate the development of these attentional processes involved in reading. We conducted two experiments in 6- (first grade), 7- (second grade), and 9-year-old (fourth grade) children, using a procedure that required the detection of a letter (Experiment 1) or a nonletter (Experiment 2) target in a string of five characters. The target character could occur in the second (left) or fourth (right) position in the string. Results showed an advantage for left nonletter targets as early as age 6 and of left letter targets as early as age 7. In 6-year-olds, only good readers detected a left letter target faster than a right letter target; others detected a right letter target faster. Thus, dominant orienting toward the beginning of the letter string is not fully developed in children before the second year of reading. A possibility is that beginning readers have difficulties inhibiting an attention-orienting bias toward the right visual field in linguistic tasks. The results also showed that the lexicality effect on these attentional processes develops gradually until the fourth year of reading. We believe that the procedure used in this study will be very valuable for evaluating attentional difficulties during reading acquisition. PMID:25386702

  15. Attention as a Bayesian inference process

    NASA Astrophysics Data System (ADS)

    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.

  16. Errors Disrupt Subsequent Early Attentional Processes

    PubMed Central

    Van der Borght, Liesbet; Schevernels, Hanne; Burle, Boris; Notebaert, Wim

    2016-01-01

    It has been demonstrated that target detection is impaired following an error in an unrelated flanker task. These findings support the idea that the occurrence or processing of unexpected error-like events interfere with subsequent information processing. In the present study, we investigated the effect of errors on early visual ERP components. We therefore combined a flanker task and a visual discrimination task. Additionally, the intertrial interval between both tasks was manipulated in order to investigate the duration of these negative after-effects. The results of the visual discrimination task indicated that the amplitude of the N1 component, which is related to endogenous attention, was significantly decreased following an error, irrespective of the intertrial interval. Additionally, P3 amplitude was attenuated after an erroneous trial, but only in the long-interval condition. These results indicate that low-level attentional processes are impaired after errors. PMID:27050303

  17. Spatial attention modulates early face processing.

    PubMed

    Feng, Wenfeng; Martinez, Antigona; Pitts, Michael; Luo, Yue-Jia; Hillyard, Steven A

    2012-12-01

    It is widely reported that inverting a face dramatically affects its recognition. Previous studies have shown that face inversion increases the amplitude and delays the latency of the face-specific N170 component of the event-related potential (ERP) and also enhances the amplitude of the occipital P1 component (latency 100-132 ms). The present study investigates whether these effects of face inversion can be modulated by visual spatial attention. Participants viewed two streams of visual stimuli, one to the left and one to the right of fixation. One stream consisted of a sequence of alphanumeric characters at 6.67 Hz, and the other stream consisted of a series of upright and inverted images of faces and houses presented in randomized order. The participants' task was to attend selectively to one or the other of the streams (during different blocks) in order to detect infrequent target stimuli. ERPs elicited by inverted faces showed larger P1 amplitudes compared to upright faces, but only when the faces were attended. In contrast, the N170 amplitude was larger to inverted than to upright faces only when the faces were not attended. The N170 peak latency was delayed to inverted faces regardless of attention condition. These inversion effects were face specific, as similar effects were absent for houses. These results suggest that early stages of face-specific processing can be enhanced by attention, but when faces are not attended the onset of face-specific processing is delayed until the latency range of the N170. PMID:23017595

  18. Treating Attention in Mild Aphasia: Evaluation of Attention Process Training-II

    ERIC Educational Resources Information Center

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

    2006-01-01

    This study examined whether attention processing training-II [Sohlberg, M. M., Johnson, L., Paule, L., Raskin, S. A., & Mateer, C. A. (2001). "Attention Process Training-II: A program to address attentional deficits for persons with mild cognitive dysfunction" (2nd ed.). Wake Forest, NC: Lash & Associates.; APT-II], when applied in the context of…

  19. The role of attention in visual processing.

    PubMed Central

    Maunsell, John H R; Cook, Erik P

    2002-01-01

    Attention to a visual stimulus typically increases the responses of cortical neurons to that stimulus. Because many studies have shown a close relationship between the performance of individual neurons and behavioural performance of animal subjects, it is important to consider how attention affects this relationship. Measurements of behavioural and neuronal performance taken from rhesus monkeys while they performed a motion detection task with two attentional states show that attention alters the relationship between behaviour and neuronal response. Notably, attention affects the relationship differently in different cortical visual areas. This indicates that a close relationship between neuronal and behavioural performance on a given task persists over changes in attentional state only within limited regions of visual cortex. PMID:12217174

  20. Variability of Attention Processes in ADHD: Observations from the Classroom

    ERIC Educational Resources Information Center

    Rapport, Mark D.; Kofler, Michael J.; Alderson, R. Matt; Timko, Thomas M., Jr.; DuPaul, George J.

    2009-01-01

    Objective: Classroom- and laboratory-based efforts to study the attentional problems of children with ADHD are incongruent in elucidating attentional deficits; however, none have explored within- or between-minute variability in the classroom attentional processing in children with ADHD. Method: High and low attention groups of ADHD children…

  1. Adapted Physical Education: Self-Control and Attention

    ERIC Educational Resources Information Center

    Cratty, Bryant J.

    2004-01-01

    Hyperactivity and impulsivity, as well as poor attention in its various forms, are encountered much more often in atypical populations, including those with learning disabilities. Many children with disabilities display attentional difficulties or some kind of lethargic, dreamy state. These problems are amenable to treatment by physical educators…

  2. Allocation of Attention and the Locus of Adaptation to Displaced Vision

    ERIC Educational Resources Information Center

    Kelso, J. A. Scott; And Others

    1975-01-01

    This article examined the effect of allocation of attention on adaptation to displacement when proprioception and vision conflict and considered whether more effective procedures to insure that attention is directed in the prescribed manner would cause adaptation to be confined strictly to the unattended modality. (Author/RK)

  3. Robotic Attention Processing And Its Application To Visual Guidance

    NASA Astrophysics Data System (ADS)

    Barth, Matthew; Inoue, Hirochika

    1988-03-01

    This paper describes a method of real-time visual attention processing for robots performing visual guidance. This robot attention processing is based on a novel vision processor, the multi-window vision system that was developed at the University of Tokyo. The multi-window vision system is unique in that it only processes visual information inside local area windows. These local area windows are quite flexible in their ability to move anywhere on the visual screen, change their size and shape, and alter their pixel sampling rate. By using these windows for specific attention tasks, it is possible to perform high speed attention processing. The primary attention skills of detecting motion, tracking an object, and interpreting an image are all performed at high speed on the multi-window vision system. A basic robotic attention scheme using the attention skills was developed. The attention skills involved detection and tracking of salient visual features. The tracking and motion information thus obtained was utilized in producing the response to the visual stimulus. The response of the attention scheme was quick enough to be applicable to the real-time vision processing tasks of playing a video 'pong' game, and later using an automobile driving simulator. By detecting the motion of a 'ball' on a video screen and then tracking the movement, the attention scheme was able to control a 'paddle' in order to keep the ball in play. The response was faster than that of a human's, allowing the attention scheme to play the video game at higher speeds. Further, in the application to the driving simulator, the attention scheme was able to control both direction and velocity of a simulated vehicle following a lead car. These two applications show the potential of local visual processing in its use for robotic attention processing.

  4. Spatial Attention Enhances Perceptual Processing of Single-Element Displays

    NASA Technical Reports Server (NTRS)

    Bacon, William; Johnston, James C.; Remington, Roger W.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    Shiu and Pashler (1993) reported that precueing masked, single-element displays had negligible effects on identification accuracy. They argued that spatial attention does not actually enhance stimulus perceptibility, but only reduces decision noise. Alternatively, such negative results may arise if cues are sub-optimal, or if masks place an insufficient premium on timely deployment of attention. We report results showing that valid cueing enhances processing of even single-element displays. Spatial attention does indeed enhance perceptual processes.

  5. Attention-dependent brief adaptation to contour orientation: a high-level aftereffect for convexity?

    PubMed

    Suzuki, S

    2001-12-01

    In contrast to the abundant literature investigating how orientation coding depends on edges defined by various image features, relatively little is known about how coding of orientation might also depend on the two distinct functional roles that oriented edges commonly play. Oriented lines can delineate outline contours of a figure or they can form texture. The results of five experiments using orientation aftereffects measured with brief tests (27 ms, backward masked; adapt-to-test interval=201 ms) provided evidence that brief stimuli (<135 ms) selectively adapt coding of contour-line orientation rather than coding of line-texture orientation. Furthermore, parametric results revealed that the rapidly adapting aftereffects for contour orientation are characterized by (1) broad orientation tuning (peaking at +/-30 degrees to +/-50 degrees from test orientation), (2) indifference as to how the contours are defined (e.g. bright lines, high-pass-filtered lines, faint lines generated by the spatial inhomogeneity of visual sensitivity), (3) rapid saturation at low contrast energy, (4) strong modulation by selective attention, and (5) relative size tolerance. These characteristics appear to parallel those of cells in the high end of the visual form processing pathway (such as inferotemporal cortex). It is thus suggested that the rapidly adapting contour orientation aftereffects reported here may be mediated by high-level neural units that encode global configurations of orientation (e.g. convexity and concavity). PMID:11738454

  6. Study Of Adaptive-Array Signal Processing

    NASA Technical Reports Server (NTRS)

    Satorius, Edgar H.; Griffiths, Lloyd

    1990-01-01

    Report describes study of adaptive signal-processing techniques for suppression of mutual satellite interference in mobile (on ground)/satellite communication system. Presents analyses and numerical simulations of performances of two approaches to signal processing for suppression of interference. One approach, known as "adaptive side lobe canceling", second called "adaptive temporal processing".

  7. Attention and information processing in schizophrenia.

    PubMed

    Hemsley, D R

    1976-06-01

    The performance of 20 acute schizophrenics and 10 depressives, matched for age, verbal intelligence, and pre-morbid functioning, was assessed on a choice reaction-time card-sorting task. Stimulus and response uncertainty were varied independently, and there were two main conditions, distraction and no distraction. The schizophrenics were slower than the depressives over all the functions examined in the study. Schizophrenics were significantly more affected by increases in response uncertainty than the depressives. Although there was a tendency for the schizophrenic group to be more affected by distraction and by increasing stimulus uncertainty, these differences were not significant. There was no significant interaction between the effects of stimulus and response uncertainty, nor between the effects of distraction and stimulus uncertainty. The effects of distraction increased with increasing response uncertainty. The results are discussed in relation to two models of information processing, suggested by Broadbent (1971) and by Sternberg (1969). Such models allow a more detailed examination of the cognitive abnormalities found in schizophrenia. PMID:938824

  8. Attentional Processes in Young Children with Congenital Visual Impairment

    ERIC Educational Resources Information Center

    Tadic, Valerie; Pring, Linda; Dale, Naomi

    2009-01-01

    The study investigated attentional processes of 32 preschool children with congenital visual impairment (VI). Children with profound visual impairment (PVI) and severe visual impairment (SVI) were compared to a group of typically developing sighted children in their ability to respond to adult directed attention in terms of establishing,…

  9. Shallow Processing and Attention Capture in Written and Spoken Discourse

    ERIC Educational Resources Information Center

    Sanford, Alison J. S.; Sanford, Anthony J.; Molle, Jo; Emmott, Catherine

    2006-01-01

    Processing of discourse seems to be far from uniform with much evidence indicating that it can be quite shallow. The question is then what modulates depth of processing? A range of discourse devices exist that we believe may lead to more detailed processing of language input (Attention Capturers), thus serving as modulators of processing enabling…

  10. Deployment of spatial attention without moving the eyes is boosted by oculomotor adaptation

    PubMed Central

    Habchi, Ouazna; Rey, Elodie; Mathieu, Romain; Urquizar, Christian; Farnè, Alessandro; Pélisson, Denis

    2015-01-01

    Vertebrates developed sophisticated solutions to select environmental visual information, being capable of moving attention without moving the eyes. A large body of behavioral and neuroimaging studies indicate a tight coupling between eye movements and spatial attention. The nature of this link, however, remains highly debated. Here, we demonstrate that deployment of human covert attention, measured in stationary eye conditions, can be boosted across space by changing the size of ocular saccades to a single position via a specific adaptation paradigm. These findings indicate that spatial attention is more widely affected by oculomotor plasticity than previously thought. PMID:26300755

  11. Preferential processing of tactile events under conditions of divided attention

    PubMed Central

    Hanson, James V. M.; Whitaker, David; Heron, James

    2012-01-01

    Differences in transduction and transmission latencies of visual, auditory and tactile events cause corresponding differences in simple reaction time. As reaction time is usually measured in unimodal blocks, it is unclear whether such latency differences also apply when observers monitor multiple sensory channels. We investigate this by comparing reaction time when attention is focussed on a single modality, and when attention is divided between multiple modalities. Results show that tactile reaction time is unaffected by dividing attention, whilst visual and auditory reaction times are significantly and asymmetrically increased. These findings show that tactile information is processed preferentially by the nervous system under conditions of divided attention, and suggest that tactile events may be processed pre-attentively. PMID:19738497

  12. Attentional control of the processing of neural and emotional stimuli.

    PubMed

    Pessoa, Luiz; Kastner, Sabine; Ungerleider, Leslie G

    2002-12-01

    A typical scene contains many different objects that compete for neural representation due to the limited processing capacity of the visual system. At the neural level, competition among multiple stimuli is evidenced by the mutual suppression of their visually evoked responses and occurs most strongly at the level of the receptive field. The competition among multiple objects can be biased by both bottom-up sensory-driven mechanisms and top-down influences, such as selective attention. Functional brain imaging studies reveal that biasing signals due to selective attention can modulate neural activity in visual cortex not only in the presence but also in the absence of visual stimulation. Although the competition among stimuli for representation is ultimately resolved within visual cortex, the source of top-down biasing signals likely derives from a distributed network of areas in frontal and parietal cortex. Competition suggests that once attentional resources are depleted, no further processing is possible. Yet, existing data suggest that emotional stimuli activate brain regions "automatically," largely immune from attentional control. We tested the alternative possibility, namely, that the neural processing of stimuli with emotional content is not automatic and instead requires some degree of attention. Our results revealed that, contrary to the prevailing view, all brain regions responding differentially to emotional faces, including the amygdala, did so only when sufficient attentional resources were available to process the faces. Thus, similar to the processing of other stimulus categories, the processing of facial expression is under top-down control. PMID:12433381

  13. Thalamic Circuit Mechanisms Link Sensory Processing in Sleep and Attention

    PubMed Central

    Chen, Zhe; Wimmer, Ralf D.; Wilson, Matthew A.; Halassa, Michael M.

    2016-01-01

    The correlation between sleep integrity and attentional performance is normally interpreted as poor sleep causing impaired attention. Here, we provide an alternative explanation for this correlation: common thalamic circuits regulate sensory processing across sleep and attention, and their disruption may lead to correlated dysfunction. Using multi-electrode recordings in mice, we find that rate and rhythmicity of thalamic reticular nucleus (TRN) neurons are predictive of their functional organization in sleep and suggestive of their participation in sensory processing across states. Surprisingly, TRN neurons associated with spindles in sleep are also associated with alpha oscillations during attention. As such, we propose that common thalamic circuit principles regulate sensory processing in a state-invariant manner and that in certain disorders, targeting these circuits may be a more viable therapeutic strategy than considering individual states in isolation. PMID:26778969

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

    ERIC Educational Resources Information Center

    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.…

  15. The time course of attentional modulation on emotional conflict processing.

    PubMed

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

    2016-06-01

    Cognitive conflict resolution is critical to human survival in a rapidly changing environment. However, emotional conflict processing seems to be particularly important for human interactions. This study examined whether the time course of attentional modulation on emotional conflict processing was different from cognitive conflict processing during a flanker task. Results showed that emotional N200 and P300 effects, similar to colour conflict processing, appeared only during the relevant task. However, the emotional N200 effect preceded the colour N200 effect, indicating that emotional conflict can be identified earlier than cognitive conflict. Additionally, a significant emotional N100 effect revealed that emotional valence differences could be perceived during early processing based on rough aspects of input. The present data suggest that emotional conflict processing is modulated by top-down attention, similar to cognitive conflict processing (reflected by N200 and P300 effects). However, emotional conflict processing seems to have more time advantages during two different processing stages. PMID:25809920

  16. Attention alters orientation processing in the human lateral geniculate nucleus.

    PubMed

    Ling, Sam; Pratte, Michael S; Tong, Frank

    2015-04-01

    Orientation selectivity is a cornerstone property of vision, commonly believed to emerge in the primary visual cortex. We found that reliable orientation information could be detected even earlier, in the human lateral geniculate nucleus, and that attentional feedback selectively altered these orientation responses. This attentional modulation may allow the visual system to modify incoming feature-specific signals at the earliest possible processing site. PMID:25730671

  17. Attention alters orientation processing in the human lateral geniculate nucleus

    PubMed Central

    Ling, Sam; Pratte, Michael; Tong, Frank

    2015-01-01

    Orientation selectivity is a cornerstone property of vision, commonly believed to emerge in the primary visual cortex (V1). Here, we demonstrate that reliable orientation information can be detected even earlier, in the human lateral geniculate nucleus (LGN), and that attentional feedback selectively alters these orientation responses. This attentional modulation may allow the visual system to modify incoming feature-specific signals at the earliest possible processing site. PMID:25730671

  18. Attentional Processes in Children's Overt and Relational Aggression

    ERIC Educational Resources Information Center

    Arsenault, Darin J.; Foster, Sharon L.

    2012-01-01

    This study examined attention and memory processes assumed by the social information-processing model to be biased in aggressive children. We also explored whether similar biases were associated with overt and relational aggression. A total of 96 fourth through sixth graders saw videos of overtly and relationally aggressive child actors and…

  19. Investigations in adaptive processing of multispectral data

    NASA Technical Reports Server (NTRS)

    Kriegler, F. J.; Horwitz, H. M.

    1973-01-01

    Adaptive data processing procedures are applied to the problem of classifying objects in a scene scanned by multispectral sensor. These procedures show a performance improvement over standard nonadaptive techniques. Some sources of error in classification are identified and those correctable by adaptive processing are discussed. Experiments in adaptation of signature means by decision-directed methods are described. Some of these methods assume correlation between the trajectories of different signature means; for others this assumption is not made.

  20. The contributions of memory and attention processes to cognitive abilities.

    PubMed

    Rockstroh, S; Schweizer, K

    2001-01-01

    In two experiments, the contributions of memory and attention processes to the cognitive abilities of reasoning and perceptual speed were investigated. Two measures of speed of information retrieval from long-term and short-term memory (Posner paradigm, Sternberg paradigm) and two attention measures (continuous attention test, attention switching test) were included in the first experiment (N = 220). The memory tests led to correlations with the measures of cognitive abilities, whereas the attention test did not. The same tests as well as one additional memory test and one attention test (working memory test, test of covert orientation) were administered in the second experiment (N = 116). Again, the memory tests led to the larger correlations with the measures of cognitive abilities. Two components were obtained in components analysis, of which the first was characterized by high loadings of the memory tests and the second by high loadings of the attention tests. Only the memory component contributed to the prediction of cognitive abilities. PMID:11277445

  1. Children's Attentional Processing of Mother and Proximity Seeking

    PubMed Central

    2015-01-01

    Attachment expectations regarding the availability of mother as a source for support are supposed to influence distressed children’s support seeking behavior. Because research is needed to better understand the mechanisms related to support seeking behavior, this study tested the hypothesis that the cognitive processing of mother-related information is linked to proximity and support seeking behavior. Uncertainty in maternal support has been shown to be characterized by a biased attentional encoding of mother, reducing the breadth of children’s attentional field around her. We investigated whether this attentional bias is related to how long distressed children wait before seeking their mother’s proximity. Thirty-three children (9-11 years) participated in this study that consisted of experimental tasks to measure attentional breadth and to observe proximity seeking behavior and of questionnaires to measure confidence in maternal support and experienced distress. Results suggested that distressed children with a more narrow attentional field around their mother wait longer to seek her proximity. Key Message: These findings provide a first support for the hypothesis that the attentional processing of mother is related to children’s attachment behavior. PMID:25927921

  2. Disgust-specific modulation of early attention processes.

    PubMed

    van Hooff, Johanna C; van Buuringen, Melanie; El M'rabet, Ihsane; de Gier, Margot; van Zalingen, Lilian

    2014-10-01

    Although threatening images are known to attract and keep our attention, little is known about the existence of emotion-specific attention effects. In this study (N=46), characteristics of an anticipated, disgust-specific effect were investigated by means of a covert orienting paradigm incorporating pictures that were either disgust-evoking, fear-evoking, happiness-evoking or neutral. Attention adhesion to these pictures was measured by the time necessary to identify a peripheral target, presented 100, 200, 500, or 800 ms after picture onset. Main results showed that reaction times were delayed for targets following the disgust-evoking pictures by 100 and 200 ms, suggesting that only these pictures temporarily grabbed hold of participants' attention. These delays were similar for ignore- and attend-instructions, and they were not affected by the participants' anxiety levels or disgust sensitivity. The disgust-specific influence on early attention processes thus appeared very robust, occurring in the majority of participants and without contribution of voluntary- and strategic-attention processes. In contrast, a smaller and less reliable effect of all emotional (arousing) pictures was present in the form of delayed responding in the 100 ms cue-target interval. This effect was more transitory and apparent only in participants with relatively high state-anxiety scores. Practical and theoretical consequences of these findings are discussed. PMID:25226546

  3. Understanding Attention to Adaptive Hints in Educational Games: An Eye-Tracking Study

    ERIC Educational Resources Information Center

    Conati, Cristina; Jaques, Natasha; Muir, Mary

    2013-01-01

    This paper presents a user study that investigates the factors affecting student attention to user-adaptive hints during interaction with an educational computer game. The study focuses on Prime Climb, an educational game designed to provide individualized support for learning number factorization skills in the form of textual hints based on a…

  4. Towards incorporating affective computing to virtual rehabilitation; surrogating attributed attention from posture for boosting therapy adaptation

    NASA Astrophysics Data System (ADS)

    Rivas, Jesús J.; Heyer, Patrick; Orihuela-Espina, Felipe; Sucar, Luis Enrique

    2015-01-01

    Virtual rehabilitation (VR) is a novel motor rehabilitation therapy in which the rehabilitation exercises occurs through interaction with bespoken virtual environments. These virtual environments dynamically adapt their activity to match the therapy progress. Adaptation should be guided by the cognitive and emotional state of the patient, none of which are directly observable. Here, we present our first steps towards inferring non-observable attentional state from unobtrusively observable seated posture, so that this knowledge can later be exploited by a VR platform to modulate its behaviour. The space of seated postures was discretized and 648 pictures of acted representations were exposed to crowd-evaluation to determine attributed state of attention. A semi-supervised classifier based on Na¨ıve Bayes with structural improvement was learnt to unfold a predictive relation between posture and attributed attention. Internal validity was established following a 2×5 cross-fold strategy. Following 4959 votes from crowd, classification accuracy reached a promissory 96.29% (µ±σ = 87.59±6.59) and F-measure reached 82.35% (µ ± σ = 69.72 ± 10.50). With the afforded rate of classification, we believe it is safe to claim posture as a reliable proxy for attributed attentional state. It follows that unobtrusively monitoring posture can be exploited for guiding an intelligent adaptation in a virtual rehabilitation platform. This study further helps to identify critical aspects of posture permitting inference of attention.

  5. Neural processing of reward magnitude under varying attentional demands.

    PubMed

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

    2011-04-01

    Central to the organization of behavior is the ability to represent the magnitude of a prospective reward and the costs related to obtaining it. Therein, reward-related neural activations are discounted in dependence of the effort required to resolve a given task. Varying attentional demands of the task might however affect reward-related neural activations. Here we employed fMRI to investigate the neural representation of expected values during a monetary incentive delay task with varying attentional demands. Following a cue, indicating at the same time the difficulty (hard/easy) and the reward magnitude (high/low) of the upcoming trial, subjects performed an attention task and subsequently received feedback about their monetary reward. Consistent with previous results, activity in anterior-cingulate, insular/orbitofrontal and mesolimbic regions co-varied with the anticipated reward-magnitude, but also with the attentional requirements of the task. These activations occurred contingent on action-execution and resembled the response time pattern of the subjects. In contrast, cue-related activations, signaling the forthcoming task-requirements, were only observed within attentional control structures. These results suggest that anticipated reward-magnitude and task-related attentional demands are concurrently processed in partially overlapping neural networks of anterior-cingulate, insular/orbitofrontal, and mesolimbic regions. PMID:21295019

  6. Unintentionality of affective attention across visual processing stages

    PubMed Central

    Uusberg, Andero; Uibo, Helen; Kreegipuu, Kairi; Tamm, Maria; Raidvee, Aire; Allik, Jüri

    2013-01-01

    Affective attention involves bottom-up perceptual selection that prioritizes motivationally significant stimuli. To clarify the extent to which this process is automatic, we investigated the dependence of affective attention on the intention to process emotional meaning. Affective attention was manipulated by presenting affective images with variable arousal and intentionality by requiring participants to make affective and non-affective evaluations. Polytomous rather than binary decisions were required from the participants in order to elicit relatively deep emotional processing. The temporal dynamics of prioritized processing were assessed using early posterior negativity (EPN, 175–300 ms) as well as P3-like (P3, 300–500 ms) and slow wave (SW, 500–1500 ms) portions of the late positive potential. All analyzed components were differentially sensitive to stimulus categories suggesting that they indeed reflect distinct stages of motivational significance encoding. The intention to perceive emotional meaning had no effect on EPN, an additive effect on P3, and an interactive effect on SW. We concluded that affective attention went from completely unintentional during the EPN to partially unintentional during P3 and SW where top-down signals, respectively, complemented and modulated bottom-up differences in stimulus prioritization. The findings were interpreted in light of two-stage models of visual perception by associating the EPN with large-capacity initial relevance detection and the P3 as well as SW with capacity-limited consolidation and elaboration of affective stimuli. PMID:24421772

  7. Optical Profilometers Using Adaptive Signal Processing

    NASA Technical Reports Server (NTRS)

    Hall, Gregory A.; Youngquist, Robert; Mikhael, Wasfy

    2006-01-01

    A method of adaptive signal processing has been proposed as the basis of a new generation of interferometric optical profilometers for measuring surfaces. The proposed profilometers would be portable, hand-held units. Sizes could be thus reduced because the adaptive-signal-processing method would make it possible to substitute lower-power coherent light sources (e.g., laser diodes) for white light sources and would eliminate the need for most of the optical components of current white-light profilometers. The adaptive-signal-processing method would make it possible to attain scanning ranges of the order of decimeters in the proposed profilometers.

  8. Surprise? Early visual novelty processing is not modulated by attention

    PubMed Central

    Tarbi, Elise C.; Sun, Xue; Holcomb, Phillip J.; Daffner, Kirk R.

    2010-01-01

    This study investigated the influence of direction of attention on the early detection of visual novelty, as indexed by the anterior N2. The anterior N2 was measured in young subjects (n=32) under an Attend and Ignore condition. Subjects were presented standard, target/rare, and perceptually novel visual stimuli under both conditions, but under the Ignore condition, attention was directed towards an auditory n-back task. The size of the anterior N2 to novel stimuli did not differ between conditions and was significantly larger than the anterior N2 to all other stimulus types. Furthermore, under the Ignore condition, the anterior N2 to visual novel stimuli was not affected by the level of difficulty of the auditory n-back task (3-back vs. 2-back). Our findings suggest that the early processing of visual novelty, as measured by the size of the anterior N2, is not strongly modulated by direction of attention. PMID:20880260

  9. Oscillatory synchrony as a mechanism of attentional processing.

    PubMed

    Gregoriou, Georgia G; Paneri, Sofia; Sapountzis, Panagiotis

    2015-11-11

    The question of how the brain selects which stimuli in our visual field will be given priority to enter into perception, to guide our actions and to form our memories has been a matter of intense research in studies of visual attention. Work in humans and animal models has revealed an extended network of areas involved in the control and maintenance of attention. For many years, imaging studies in humans constituted the main source of a systems level approach, while electrophysiological recordings in non-human primates provided insight into the cellular mechanisms of visual attention. Recent technological advances and the development of sophisticated analytical tools have allowed us to bridge the gap between the two approaches and assess how neuronal ensembles across a distributed network of areas interact in visual attention tasks. A growing body of evidence suggests that oscillatory synchrony plays a crucial role in the selective communication of neuronal populations that encode the attended stimuli. Here, we discuss data from theoretical and electrophysiological studies, with more emphasis on findings from humans and non-human primates that point to the relevance of oscillatory activity and synchrony for attentional processing and behavior. These findings suggest that oscillatory synchrony in specific frequencies reflects the biophysical properties of specific cell types and local circuits and allows the brain to dynamically switch between different spatio-temporal patterns of activity to achieve flexible integration and selective routing of information along selected neuronal populations according to behavioral demands. This article is part of a Special Issue entitled SI: Prediction and Attention. PMID:25712615

  10. Evolution of attention mechanisms for early visual processing

    NASA Astrophysics Data System (ADS)

    Müller, Thomas; Knoll, Alois

    2011-03-01

    Early visual processing as a method to speed up computations on visual input data has long been discussed in the computer vision community. The general target of a such approaches is to filter nonrelevant information from the costly higher-level visual processing algorithms. By insertion of this additional filter layer the overall approach can be speeded up without actually changing the visual processing methodology. Being inspired by the layered architecture of the human visual processing apparatus, several approaches for early visual processing have been recently proposed. Most promising in this field is the extraction of a saliency map to determine regions of current attention in the visual field. Such saliency can be computed in a bottom-up manner, i.e. the theory claims that static regions of attention emerge from a certain color footprint, and dynamic regions of attention emerge from connected blobs of textures moving in a uniform way in the visual field. Top-down saliency effects are either unconscious through inherent mechanisms like inhibition-of-return, i.e. within a period of time the attention level paid to a certain region automatically decreases if the properties of that region do not change, or volitional through cognitive feedback, e.g. if an object moves consistently in the visual field. These bottom-up and top-down saliency effects have been implemented and evaluated in a previous computer vision system for the project JAST. In this paper an extension applying evolutionary processes is proposed. The prior vision system utilized multiple threads to analyze the regions of attention delivered from the early processing mechanism. Here, in addition, multiple saliency units are used to produce these regions of attention. All of these saliency units have different parameter-sets. The idea is to let the population of saliency units create regions of attention, then evaluate the results with cognitive feedback and finally apply the genetic mechanism

  11. The influence of scopolamine on motor control and attentional processes

    PubMed Central

    Bestaven, Emma; Kambrun, Charline; Guehl, Dominique; Cazalets, Jean-René

    2016-01-01

    Background: Motion sickness may be caused by a sensory conflict between the visual and the vestibular systems. Scopolamine, known to be the most effective therapy to control the vegetative symptoms of motion sickness, acts on the vestibular nucleus and potentially the vestibulospinal pathway, which may affect balance and motor tasks requiring both attentional process and motor balance. The aim of this study was to explore the effect of scopolamine on motor control and attentional processes. Methods: Seven subjects were evaluated on four different tasks before and after a subcutaneous injection of scopolamine (0.2 mg): a one-minute balance test, a subjective visual vertical test, a pointing task and a galvanic vestibular stimulation with EMG recordings. Results: The results showed that the reaction time and the movement duration were not modified after the injection of scopolamine. However, there was an increase in the center of pressure displacement during the balance test, a decrease in EMG muscle response after galvanic vestibular stimulation and an alteration in the perception of verticality. Discussion: These results confirm that low doses of scopolamine such as those prescribed to avoid motion sickness have no effect on attentional processes, but that it is essential to consider the responsiveness of each subject. However, scopolamine did affect postural control and the perception of verticality. In conclusion, the use of scopolamine to prevent motion sickness must be considered carefully because it could increase imbalances in situations when individuals are already at risk of falling (e.g., sailing, parabolic flight). PMID:27169000

  12. Adaptive filtering in biological signal processing.

    PubMed

    Iyer, V K; Ploysongsang, Y; Ramamoorthy, P A

    1990-01-01

    The high dependence of conventional optimal filtering methods on the a priori knowledge of the signal and noise statistics render them ineffective in dealing with signals whose statistics cannot be predetermined accurately. Adaptive filtering methods offer a better alternative, since the a priori knowledge of statistics is less critical, real time processing is possible, and the computations are less expensive for this approach. Adaptive filtering methods compute the filter coefficients "on-line", converging to the optimal values in the least-mean square (LMS) error sense. Adaptive filtering is therefore apt for dealing with the "unknown" statistics situation and has been applied extensively in areas like communication, speech, radar, sonar, seismology, and biological signal processing and analysis for channel equalization, interference and echo canceling, line enhancement, signal detection, system identification, spectral analysis, beamforming, modeling, control, etc. In this review article adaptive filtering in the context of biological signals is reviewed. An intuitive approach to the underlying theory of adaptive filters and its applicability are presented. Applications of the principles in biological signal processing are discussed in a manner that brings out the key ideas involved. Current and potential future directions in adaptive biological signal processing are also discussed. PMID:2180633

  13. The role of spatial attention in visual word processing

    NASA Technical Reports Server (NTRS)

    Mccann, Robert S.; Folk, Charles L.; Johnston, James C.

    1992-01-01

    Subjects made lexical decisions on a target letter string presented above or below fixation. In Experiments 1 and 2, target location was cued 100 ms in advance of target onset. Responses were faster on validly than on invalidly cued trials. In Experiment 3, the target was sometimes accompanied by irrelevant stimuli on the other side of fixation; in such cases, responses were slowed (a spatial filtering effect). Both cuing and filtering effects on response time were additive with effects of word frequency and lexical status (words vs. nonwords). These findings are difficult to reconcile with claims that spatial attention is less involved in processing familiar words than in unfamiliar words and nonwords. The results can be reconciled with a late-selection locus of spatial attention only with difficulty, but are easily explained by early-selection models.

  14. Processes in Language Acquisition: The Roles of Gender, Attention, and Maternal Encouragement of Attention over Time

    ERIC Educational Resources Information Center

    Karrass, Jan; Braungart-Rieker, Julia M.; Mullins, Jennifer; Lefever, Jennifer Burke

    2002-01-01

    This longitudinal study including 87 infant-mother dyads examined the relation between infant temperamental attention, maternal encouragement of attention, language, and the effects of gender. At ages 0;4, 0;8, and 1;0, global attention was assessed from Rothbart's (1981) IBQ; manipulative exploration was assessed with the Bayley (1969) IBR; and…

  15. Divided Attention and Processes Underlying Sense of Agency

    PubMed Central

    Wen, Wen; Yamashita, Atsushi; Asama, Hajime

    2016-01-01

    Sense of agency refers to the subjective feeling of controlling events through one’s behavior or will. Sense of agency results from matching predictions of one’s own actions with actual feedback regarding the action. Furthermore, when an action involves a cued goal, performance-based inference contributes to sense of agency. That is, if people achieve their goal, they would believe themselves to be in control. Previous studies have shown that both action-effect comparison and performance-based inference contribute to sense of agency; however, the dominance of one process over the other may shift based on task conditions such as the presence or absence of specific goals. In this study, we examined the influence of divided attention on these two processes underlying sense of agency in two conditions. In the experimental task, participants continuously controlled a moving dot for 10 s while maintaining a string of three or seven digits in working memory. We found that when there was no cued goal (no-cued-goal condition), sense of agency was impaired by high cognitive load. Contrastingly, when participants controlled the dot based on a cued goal (cued-goal-directed condition), their sense of agency was lower than in the no-cued-goal condition and was not affected by cognitive load. The results suggest that the action-effect comparison process underlying sense of agency requires attention. On the other hand, the weaker influence of divided attention in the cued-goal-directed condition could be attributed to the dominance of performance-based inference, which is probably automatic. PMID:26858680

  16. Tufted capuchins (Cebus apella) adapt their communicative behaviour to human's attentional states.

    PubMed

    Defolie, Charlotte; Malassis, Raphaëlle; Serre, Marion; Meunier, Hélène

    2015-05-01

    Animal communication has become a widely studied field of research, especially because of the associated debates on the origin of human language. Due to their phylogenetic proximity with humans, non-human primates represent a suitable model to investigate the precursors of language. This study focuses on the perception of the attentional states of others, an important prerequisite to intentional communication. We investigated whether capuchins (Cebus apella) produce a learnt pointing gesture towards a hidden and unreachable food reward as a function of the attentional status of the human experimenter. For that purpose, we tested five subjects that we first trained to indicate by a pointing gesture towards the human partner the position of a reward hidden by an assistant. Then, capuchins were tested in two experimental conditions randomly ordered. In the first condition-motivation trial-the experimenter was attentive to the subject gestures and rewarded him immediately when it pointed towards the baited cylinder. During the second condition-test trial-the experimenter adopted one of the following attention states and the subject was rewarded after 10 s has elapsed, regardless of the subject's behaviour. Five attentional states were tested: (1) experimenter absent, (2) experimenter back to the monkey, (3) experimenter's head away, (4) experimenter watching above the monkey, and (5) experimenter watching the monkey face. Our results reveal a variation in our subjects' communicative behaviours with a discrimination of the different postural clues (body and head orientation) available in our experimental conditions. This study suggests that capuchins can flexibly use a communicative gesture to adapt to the attentional state of their partner and provides evidence that acquired communicative gestures of monkeys might be used intentionally. PMID:25630371

  17. Neural Adaptation Effects in Conceptual Processing

    PubMed Central

    Marino, Barbara F. M.; Borghi, Anna M.; Gemmi, Luca; Cacciari, Cristina; Riggio, Lucia

    2015-01-01

    We investigated the conceptual processing of nouns referring to objects characterized by a highly typical color and orientation. We used a go/no-go task in which we asked participants to categorize each noun as referring or not to natural entities (e.g., animals) after a selective adaptation of color-edge neurons in the posterior LV4 region of the visual cortex was induced by means of a McCollough effect procedure. This manipulation affected categorization: the green-vertical adaptation led to slower responses than the green-horizontal adaptation, regardless of the specific color and orientation of the to-be-categorized noun. This result suggests that the conceptual processing of natural entities may entail the activation of modality-specific neural channels with weights proportional to the reliability of the signals produced by these channels during actual perception. This finding is discussed with reference to the debate about the grounded cognition view. PMID:26264031

  18. Saccade adaptation in young people diagnosed with Attention Deficit Hyperactivity Disorder Combined Type.

    PubMed

    Connolly, Amanda J; Rinehart, Nicole J; Fielding, Joanne

    2016-10-01

    Growing evidence suggests Attention Deficit Hyperactivity Disorder (ADHD) often co-occurs with Autism Spectrum Disorder (ASD), and a better understanding of the nature of their overlap, including at a neurobiological level, is needed. Research has implicated cerebellar-networks as part of the neural-circuitry disrupted in ASD, but little research has been carried out to investigate this in ADHD. We investigated cerebellar integrity using a double-step saccade adaptation paradigm in a group of male children age 8-15 (n=12) diagnosed with ADHD-Combined Type (-CT). Their performance was compared to a group of age and IQ-matched typically developing (TD) controls (n=12). Parent reported symptoms of ADHD-CT and ASD were measured, along with motor proficiency (Movement ABC-2). We found, on average, the adaptation of saccade gain was reduced for the ADHD-CT group compared to the TD group. Greater saccadic gain change (adaptation) was also positively correlated with higher Movement ABC-2 total and balance scores among the ADHD-CT participants. These differences suggest cerebellar networks underlying saccade adaptation may be disrupted in young people with ADHD-CT. Though our findings require further replication with larger samples, they suggest further research into cerebellar dysfunction in ADHD-CT, and as a point of neurobiological overlap with ASD, may be warranted. PMID:27393248

  19. Adaptive deployment of spatial and feature-based attention before saccades

    PubMed Central

    White, Alex L.; Rolfs, Martin; Carrasco, Marisa

    2012-01-01

    What you see depends not only on where you are looking but also on where you will look next. The pre-saccadic attention shift is an automatic enhancement of visual sensitivity at the target of the next saccade. We investigated whether and how perceptual factors independent of the oculomotor plan modulate pre-saccadic attention within and across trials. Observers made saccades to one (the target) of six patches of moving dots and discriminated a brief luminance pulse (the probe) that appeared at an unpredictable location. Sensitivity to the probe was always higher at the target’s location (spatial attention), and this attention effect was stronger if the previous probe appeared at the previous target’s location. Furthermore, sensitivity was higher for probes moving in directions similar to the target’s direction (feature-based attention), but only when the previous probe moved in the same direction as the previous target. Therefore, implicit cognitive processes permeate pre-saccadic attention, so that–contingent on recent experience–it flexibly distributes resources to potentially relevant locations and features. PMID:23147690

  20. Adoption: biological and social processes linked to adaptation.

    PubMed

    Grotevant, Harold D; McDermott, Jennifer M

    2014-01-01

    Children join adoptive families through domestic adoption from the public child welfare system, infant adoption through private agencies, and international adoption. Each pathway presents distinctive developmental opportunities and challenges. Adopted children are at higher risk than the general population for problems with adaptation, especially externalizing, internalizing, and attention problems. This review moves beyond the field's emphasis on adoptee-nonadoptee differences to highlight biological and social processes that affect adaptation of adoptees across time. The experience of stress, whether prenatal, postnatal/preadoption, or during the adoption transition, can have significant impacts on the developing neuroendocrine system. These effects can contribute to problems with physical growth, brain development, and sleep, activating cascading effects on social, emotional, and cognitive development. Family processes involving contact between adoptive and birth family members, co-parenting in gay and lesbian adoptive families, and racial socialization in transracially adoptive families affect social development of adopted children into adulthood. PMID:24016275

  1. Post-perceptual processing during the attentional blink is modulated by inter-trial task expectancies

    PubMed Central

    Sy, Jocelyn L.; Elliott, James C.; Giesbrecht, Barry

    2013-01-01

    The selective processing of goal-relevant information depends on an attention system that can flexibly adapt to changing task demands and expectations. Evidence from visual search tasks indicates that the perceptual selectivity of attention increases when the bottom-up demands of the task increase and when the expectations about task demands engendered by trial history are violated. Evidence from studies of the attentional blink (AB), which measures the temporal dynamics of attention, also indicates that perceptual selectivity during the AB is increased if the bottom-up task demands are increased. The present work tested whether expectations about task demands engendered by trial history also modulate perceptual selectivity during the AB. Two experiments tested the extent to which inter-trial switches in task demands reduced post-perceptual processing of targets presented during the AB. Experiment 1 indexed post-perceptual processing using the event-related potential (ERP) technique to isolate the context sensitive N400 ERP component evoked by words presented during the AB. Experiment 2 indexed post-perceptual processing using behavioral performance to determine the extent to which personal names survive the AB. The results of both experiments revealed that both electrophysiological (Exp. 1) and behavioral (Exp. 2) indices of post-perceptual processing were attenuated when consecutive trials differed in terms of their perceptual demands. The results are consistent with the notion that the selectivity of attention during the AB is modulated not only by within-trial task demands, but also can be flexibly determined by trial-by-trial expectations. PMID:24115924

  2. Altered salience processing in attention deficit hyperactivity disorder.

    PubMed

    Tegelbeckers, Jana; Bunzeck, Nico; Duzel, Emrah; Bonath, Björn; Flechtner, Hans-Henning; Krauel, Kerstin

    2015-06-01

    Attentional problems in patients with attention deficit hyperactivity disorder (ADHD) have often been linked with deficits in cognitive control. Whether these deficits are associated with increased sensitivity to external salient stimuli remains unclear. To address this issue, we acquired functional brain images (fMRI) in 38 boys with and without ADHD (age: 11-16 years). To differentiate the effects of item novelty, contextual rareness and task relevance, participants performed a visual oddball task including four stimulus categories: a frequent standard picture (62.5%), unique novel pictures (12.5%), one repeated rare picture (12.5%), and a target picture (12.5%) that required a specific motor response. As a main finding, we can show considerable overlap in novelty-related BOLD responses between both groups, but only healthy participants showed neural deactivation in temporal as well as frontal regions in response to novel pictures. Furthermore, only ADHD patients, but not healthy controls, engaged wide parts of the novelty network when processing the rare but familiar picture. Our results provide first evidence that ADHD patients show enhanced neural activity in response to novel but behaviorally irrelevant stimuli as well as reduced habituation to familiar items. These findings suggest an inefficient use of neuronal resources in children with ADHD that could be closely linked to increased distractibility. PMID:25648705

  3. A Novel Approach for Adaptive Signal Processing

    NASA Technical Reports Server (NTRS)

    Chen, Ya-Chin; Juang, Jer-Nan

    1998-01-01

    Adaptive linear predictors have been used extensively in practice in a wide variety of forms. In the main, their theoretical development is based upon the assumption of stationarity of the signals involved, particularly with respect to the second order statistics. On this basis, the well-known normal equations can be formulated. If high- order statistical stationarity is assumed, then the equivalent normal equations involve high-order signal moments. In either case, the cross moments (second or higher) are needed. This renders the adaptive prediction procedure non-blind. A novel procedure for blind adaptive prediction has been proposed and considerable implementation has been made in our contributions in the past year. The approach is based upon a suitable interpretation of blind equalization methods that satisfy the constant modulus property and offers significant deviations from the standard prediction methods. These blind adaptive algorithms are derived by formulating Lagrange equivalents from mechanisms of constrained optimization. In this report, other new update algorithms are derived from the fundamental concepts of advanced system identification to carry out the proposed blind adaptive prediction. The results of the work can be extended to a number of control-related problems, such as disturbance identification. The basic principles are outlined in this report and differences from other existing methods are discussed. The applications implemented are speech processing, such as coding and synthesis. Simulations are included to verify the novel modelling method.

  4. Attentional Resource Allocation in Visuotactile Processing Depends on the Task, But Optimal Visuotactile Integration Does Not Depend on Attentional Resources

    PubMed Central

    Wahn, Basil; König, Peter

    2016-01-01

    Humans constantly process and integrate sensory input from multiple sensory modalities. However, the amount of input that can be processed is constrained by limited attentional resources. A matter of ongoing debate is whether attentional resources are shared across sensory modalities, and whether multisensory integration is dependent on attentional resources. Previous research suggested that the distribution of attentional resources across sensory modalities depends on the the type of tasks. Here, we tested a novel task combination in a dual task paradigm: Participants performed a self-terminated visual search task and a localization task in either separate sensory modalities (i.e., haptics and vision) or both within the visual modality. Tasks considerably interfered. However, participants performed the visual search task faster when the localization task was performed in the tactile modality in comparison to performing both tasks within the visual modality. This finding indicates that tasks performed in separate sensory modalities rely in part on distinct attentional resources. Nevertheless, participants integrated visuotactile information optimally in the localization task even when attentional resources were diverted to the visual search task. Overall, our findings suggest that visual search and tactile localization partly rely on distinct attentional resources, and that optimal visuotactile integration is not dependent on attentional resources. PMID:27013994

  5. Attentional Resource Allocation in Visuotactile Processing Depends on the Task, But Optimal Visuotactile Integration Does Not Depend on Attentional Resources.

    PubMed

    Wahn, Basil; König, Peter

    2016-01-01

    Humans constantly process and integrate sensory input from multiple sensory modalities. However, the amount of input that can be processed is constrained by limited attentional resources. A matter of ongoing debate is whether attentional resources are shared across sensory modalities, and whether multisensory integration is dependent on attentional resources. Previous research suggested that the distribution of attentional resources across sensory modalities depends on the the type of tasks. Here, we tested a novel task combination in a dual task paradigm: Participants performed a self-terminated visual search task and a localization task in either separate sensory modalities (i.e., haptics and vision) or both within the visual modality. Tasks considerably interfered. However, participants performed the visual search task faster when the localization task was performed in the tactile modality in comparison to performing both tasks within the visual modality. This finding indicates that tasks performed in separate sensory modalities rely in part on distinct attentional resources. Nevertheless, participants integrated visuotactile information optimally in the localization task even when attentional resources were diverted to the visual search task. Overall, our findings suggest that visual search and tactile localization partly rely on distinct attentional resources, and that optimal visuotactile integration is not dependent on attentional resources. PMID:27013994

  6. Contrast Adaptation Implies Two Spatiotemporal Channels but Three Adapting Processes

    ERIC Educational Resources Information Center

    Langley, Keith; Bex, Peter J.

    2007-01-01

    The contrast gain control model of adaptation predicts that the effects of contrast adaptation correlate with contrast sensitivity. This article reports that the effects of high contrast spatiotemporal adaptors are maximum when adapting around 19 Hz, which is a factor of two or more greater than the peak in contrast sensitivity. To explain the…

  7. Coping and adaptation process during puerperium

    PubMed Central

    Muñoz de Rodríguez, Lucy; Ruiz de Cárdenas, Carmen Helena

    2012-01-01

    Introduction: The puerperium is a stage that produces changes and adaptations in women, couples and family. Effective coping, during this stage, depends on the relationship between the demands of stressful or difficult situations and the recourses that the puerperal individual has. Roy (2004), in her Middle Range Theory about the Coping and Adaptation Processing, defines Coping as the ''behavioral and cognitive efforts that a person makes to meet the environment demands''. For the puerperal individual, the correct coping is necessary to maintain her physical and mental well being, especially against situations that can be stressful like breastfeeding and return to work. According to Lazarus and Folkman (1986), a resource for coping is to have someone who receives emotional support, informative and / or tangible. Objective: To review the issue of women coping and adaptation during the puerperium stage and the strategies that enhance this adaptation. Methods: search and selection of database articles: Cochrane, Medline, Ovid, ProQuest, Scielo, and Blackwell Synergy. Other sources: unpublished documents by Roy, published books on Roy´s Model, Websites from of international health organizations. Results: the need to recognize the puerperium as a stage that requires comprehensive care is evident, where nurses must be protagonist with the care offered to women and their families, considering the specific demands of this situation and recourses that promote effective coping and the family, education and health services. PMID:24893059

  8. Modeling attention in associative learning: two processes or one?

    PubMed

    Le Pelley, M E; Haselgrove, Mark; Esber, Guillem R

    2012-09-01

    Certain studies of associative learning show that attention is more substantial to cues that have a history of being predictive of an outcome than to cues that are irrelevant. At the same time, other studies show that attention is more substantial to cues whose outcomes are uncertain than to cues whose outcomes are predictable. This has led to the suggestion of there being two kinds of attention in associative learning: one based upon a mechanism that allocates attention to a cue on the basis of its predictiveness, the other based upon a mechanism that allocates attention to a cue on the basis of its prediction error (e.g., Le Pelley, Quarterly Journal of Experimental Psychology, 57B, 193-243, 2004). As an alternative, it has been demonstrated that the effects of both predictiveness and uncertainty can be accounted for with only one kind of attention: one that emphasizes the role of prediction (Esber & Haselgrove, Proceedings of the Royal Society B, 278, 2553-2561, 2011). Here, we consider the alternative: whether the effects of predictiveness and uncertainty can be reconciled with a model of learning that emphasizes the role of prediction error (Pearce, Kaye, & Hall, 1982). Simulations of this model reveal that, in many cases, it too is able to account for the influence of predictiveness and uncertainty in associative learning. PMID:22927002

  9. Less Efficient Neural Processing Related to Irregular Sleep and Less Sustained Attention in Toddlers

    PubMed Central

    Hoyniak, Caroline P.; Petersen, Isaac T.; McQuillan, Maureen E.; Staples, Angela D.; Bates, John E.

    2015-01-01

    The current study used event-related potentials to examine a candidate process through which sleep difficulties affect attentional processing in toddlers. Fifteen toddlers participated in an auditory Oddball Task while neurophysiological data were collected. Sleep deficits were assessed using actigraphs, and attention was examined with a sustained attention task. A P3-like component was elicited from the toddlers, and longer target P3 latencies were associated with poorer sustained attention and irregular sleep. Findings suggest that irregular sleep is associated with less efficient attentional processing as reflected by the P3 component, and that longer target P3 latencies are associated with poorer sustained attention. PMID:26151613

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

    PubMed Central

    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. 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 produces 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. PMID:24723897

  11. Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS)

    NASA Technical Reports Server (NTRS)

    Masek, Jeffrey G.

    2006-01-01

    The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) project is creating a record of forest disturbance and regrowth for North America from the Landsat satellite record, in support of the carbon modeling activities. LEDAPS relies on the decadal Landsat GeoCover data set supplemented by dense image time series for selected locations. Imagery is first atmospherically corrected to surface reflectance, and then change detection algorithms are used to extract disturbance area, type, and frequency. Reuse of the MODIS Land processing system (MODAPS) architecture allows rapid throughput of over 2200 MSS, TM, and ETM+ scenes. Initial ("Beta") surface reflectance products are currently available for testing, and initial continental disturbance products will be available by the middle of 2006.

  12. On the Nonautomaticity of Visual Word Processing: Electrophysiological Evidence That Word Processing Requires Central Attention

    ERIC Educational Resources Information Center

    Lien, Mei-Ching; Ruthruff, Eric; Cornett, Logan; Goodin, Zachary; Allen, Philip A.

    2008-01-01

    The present study used event-related potentials (ERPs) to determine the degree to which people can process words while devoting central attention to another task. Experiments 1-4 measured the N400 effect, which is sensitive to the degree of mismatch between a word and the current semantic context. Experiment 5 measured the P3 difference between…

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

    ERIC Educational Resources Information Center

    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…

  14. Family-Peer Linkages: The Mediational Role of Attentional Processes

    ERIC Educational Resources Information Center

    Social Development, 2009

    2009-01-01

    The goal of this study was to examine the role of attention regulation as a mediator between parent-child relationships and peer social skills. Using the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development data set, mother-child and father-child relationships measured at 54 months and…

  15. Crossmodal Object-Based Attention: Auditory Objects Affect Visual Processing

    ERIC Educational Resources Information Center

    Turatto, M.; Mazza, V.; Umilta, C.

    2005-01-01

    According to the object-based view, visual attention can be deployed to ''objects'' or perceptual units, regardless of spatial locations. Recently, however, the notion of object has also been extended to the auditory domain, with some authors suggesting possible interactions between visual and auditory objects. Here we show that task-irrelevant…

  16. Knowledge as process: Contextually-cued attention and early word learning

    PubMed Central

    Smith, Linda B.; Colunga, Eliana; Yoshida, Hanako

    2010-01-01

    Learning depends on attention. The processes that cue attention in the moment dynamically integrate learned regularities and immediate contextual cues. This paper reviews the extensive literature on cued attention and attentional learning in the adult literature and proposes that these fundamental processes are likely significant mechanisms of change in cognitive development. The value of this idea is illustrated using phenomena in children novel word learning. PMID:21116438

  17. Adaptation of photosynthetic processes to stress.

    PubMed

    Berry, J A

    1975-05-01

    I have focused on examples of plant adaptations to environmental conditions that range from adjustments in the allocation of metabolic resources and modification of structural components to entirely separate mechanisms. The result of these modifications is more efficient performance under the stresses typically encountered in the plants' native habitats. Such adaptations, for reasons which are not entirely clear, often lead to poorer performance in other environmental conditions. This situation may be a fundamental basis for the tendency toward specialization among plants native to specific niches or habitats. The evolutionary mechanisms that have resulted in these specializations are very large-scale processes. It seems reasonable to suppose that the plants native to particular habitats are relatively efficient in terms of the limitations imposed by those habitats, and that the adaptive mechanisms these plants possess are, compared to those which have evolved in competing organisms, the most succesful biological means of coping with the environmental stresses encountered. I believe that we can learn from nature and utilize the adaptive mechanisms of these plants in agriculture to replace in part our present reliance on resources and energy to modify the environment for plant growth. By analogy with natural systems, improved resource utilization will require specialization and greater knowledge of the limitations of a particular environment and plant genotype. For example, the cultural conditions, plant architecture, and physiological responses necessary to achieve high water use efficiency from our crop species with C(4) photosynthesis probably differ from those required to achieve maximum total growth. Also, efforts to control water application to eliminate waste carry with them the risk that the crop could be injured by inadequate water. Thus, greater demands would be placed on the crop physiologist, the plant breeder, and the farmer. Planting and appropriate

  18. The time-course of threat processing in children: a temporal dissociation between selective attention and behavioral interference.

    PubMed

    Wolters, Lidewij H; de Haan, Else; Vervoort, Leentje; Hogendoorn, Sanne M; Boer, Frits; Prins, Pier J M

    2012-05-01

    Although selective attention to threatening information is an adaptive mechanism, exaggerated attention to threat may be related to anxiety disorders. However, studies examining threat processing in children have obtained mixed findings. In the present study, the time-course of attentional bias for threat and behavioral interference was analyzed in a community sample of 8-18-year-old children (N=33) using a pictorial dot probe task. Threatening and neutral stimuli were shown during 17 ms (masked), 500 ms, and 1250 ms. Results provide preliminary evidence of an automatic attentional bias for threat at 17 ms that persists during later, more controlled stages of information processing (500 and 1250 ms). Furthermore, participants showed a delayed response to threat-containing trials relative to neutral trials in the 500 and 1250 ms condition, which may indicate interference by threat. Together, these results suggest that an attentional bias for threat precedes behavioral interference in children. Furthermore, results indicate that performance in daily life can be temporarily interrupted by the processing of threatening information. In addition, results of earlier studies into selective attention in children using tasks based on behavioral responses may have been confounded by interference effects of threat. For future studies, we recommend to take behavioral interference into account. PMID:21623478

  19. The Urban Adaptation and Adaptation Process of Urban Migrant Children: A Qualitative Study

    ERIC Educational Resources Information Center

    Liu, Yang; Fang, Xiaoyi; Cai, Rong; Wu, Yang; Zhang, Yaofang

    2009-01-01

    This article employs qualitative research methods to explore the urban adaptation and adaptation processes of Chinese migrant children. Through twenty-one in-depth interviews with migrant children, the researchers discovered: The participant migrant children showed a fairly high level of adaptation to the city; their process of urban adaptation…

  20. Linearly-Constrained Adaptive Signal Processing Methods

    NASA Astrophysics Data System (ADS)

    Griffiths, Lloyd J.

    1988-01-01

    In adaptive least-squares estimation problems, a desired signal d(n) is estimated using a linear combination of L observation values samples xi (n), x2(n), . . . , xL-1(n) and denoted by the vector X(n). The estimate is formed as the inner product of this vector with a corresponding L-dimensional weight vector W. One particular weight vector of interest is Wopt which minimizes the mean-square between d(n) and the estimate. In this context, the term `mean-square difference' is a quadratic measure such as statistical expectation or time average. The specific value of W which achieves the minimum is given by the prod-uct of the inverse data covariance matrix and the cross-correlation between the data vector and the desired signal. The latter is often referred to as the P-vector. For those cases in which time samples of both the desired and data vector signals are available, a variety of adaptive methods have been proposed which will guarantee that an iterative weight vector Wa(n) converges (in some sense) to the op-timal solution. Two which have been extensively studied are the recursive least-squares (RLS) method and the LMS gradient approximation approach. There are several problems of interest in the communication and radar environment in which the optimal least-squares weight set is of interest and in which time samples of the desired signal are not available. Examples can be found in array processing in which only the direction of arrival of the desired signal is known and in single channel filtering where the spectrum of the desired response is known a priori. One approach to these problems which has been suggested is the P-vector algorithm which is an LMS-like approximate gradient method. Although it is easy to derive the mean and variance of the weights which result with this algorithm, there has never been an identification of the corresponding underlying error surface which the procedure searches. The purpose of this paper is to suggest an alternative

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

    ERIC Educational Resources Information Center

    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).…

  2. Dynamic Motivational Processing of Antimarijuana Messages: Coactivation Begets Attention

    ERIC Educational Resources Information Center

    Wang, Zheng; Solloway, Tyler; Tchernev, John M.; Barker, Bethany

    2012-01-01

    In the theoretical framework of dynamic motivational activation, this study reveals the dynamics of antimarijuana public service announcement (PSA) processing, especially the processing of co-occurring positive and negative content. It specifies the important role of endogenous feedback dynamics of the information processing system and teases them…

  3. Reduced beamset adaptive matched field processing

    NASA Astrophysics Data System (ADS)

    Tracey, Brian; Turaga, Srinivas; Lee, Nigel

    2003-04-01

    Matched field processing (MFP) offers the possibility of improved towed array performance at endfire through range/depth discrimination of contacts. One challenge is that arrays with limited vertical aperture can often resolve only a small number of multipath arrivals. This paper explores ways to capture the array resolution by re-parametrizing the set of MFP replicas. A reduced beamset can be created by performing a singular value decomposition on the MFP replica set. Alternatively, clustering techniques can be used to generate MFP cell families, or regions of similar response. These parametrizations are applied to adaptive MFP algorithms to show speed and performance gains. The use of cell families/regions instead of individual MFP cells also provides a framework for increasing the robustness of MFP by defocusing the MFP beamforming operation. The techniques are demonstrated for shallow-water towed array scenarios. [Work sponsored by DARPA-ATO under Air Force Contract No. F19628-00-C-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the Department of Defense. Approved for Public Release, Distribution Unlimited.

  4. Flood adaptive traits and processes: an overview.

    PubMed

    Voesenek, Laurentius A C J; Bailey-Serres, Julia

    2015-04-01

    Unanticipated flooding challenges plant growth and fitness in natural and agricultural ecosystems. Here we describe mechanisms of developmental plasticity and metabolic modulation that underpin adaptive traits and acclimation responses to waterlogging of root systems and submergence of aerial tissues. This includes insights into processes that enhance ventilation of submerged organs. At the intersection between metabolism and growth, submergence survival strategies have evolved involving an ethylene-driven and gibberellin-enhanced module that regulates growth of submerged organs. Opposing regulation of this pathway is facilitated by a subgroup of ethylene-response transcription factors (ERFs), which include members that require low O₂ or low nitric oxide (NO) conditions for their stabilization. These transcription factors control genes encoding enzymes required for anaerobic metabolism as well as proteins that fine-tune their function in transcription and turnover. Other mechanisms that control metabolism and growth at seed, seedling and mature stages under flooding conditions are reviewed, as well as findings demonstrating that true endurance of submergence includes an ability to restore growth following the deluge. Finally, we highlight molecular insights obtained from natural variation of domesticated and wild species that occupy different hydrological niches, emphasizing the value of understanding natural flooding survival strategies in efforts to stabilize crop yields in flood-prone environments. PMID:25580769

  5. Category-selective attention modulates unconscious processes in the middle occipital gyrus.

    PubMed

    Tu, Shen; Qiu, Jiang; Martens, Ulla; Zhang, Qinglin

    2013-06-01

    Many studies have revealed the top-down modulation (spatial attention, attentional load, etc.) on unconscious processing. However, there is little research about how category-selective attention could modulate the unconscious processing. In the present study, using functional magnetic resonance imaging (fMRI), the results showed that category-selective attention modulated unconscious face/tool processing in the middle occipital gyrus (MOG). Interestingly, MOG effects were of opposed direction for face and tool processes. During unconscious face processing, activation in MOG decreased under the face-selective attention compared with tool-selective attention. This result was in line with the predictive coding theory. During unconscious tool processing, however, activation in MOG increased under the tool-selective attention compared with face-selective attention. The different effects might be ascribed to an interaction between top-down category-selective processes and bottom-up processes in the partial awareness level as proposed by Kouider, De Gardelle, Sackur, and Dupoux (2010). Specifically, we suppose an "excessive activation" hypothesis. PMID:23518233

  6. Adaptive, predictive controller for optimal process control

    SciTech Connect

    Brown, S.K.; Baum, C.C.; Bowling, P.S.; Buescher, K.L.; Hanagandi, V.M.; Hinde, R.F. Jr.; Jones, R.D.; Parkinson, W.J.

    1995-12-01

    One can derive a model for use in a Model Predictive Controller (MPC) from first principles or from experimental data. Until recently, both methods failed for all but the simplest processes. First principles are almost always incomplete and fitting to experimental data fails for dimensions greater than one as well as for non-linear cases. Several authors have suggested the use of a neural network to fit the experimental data to a multi-dimensional and/or non-linear model. Most networks, however, use simple sigmoid functions and backpropagation for fitting. Training of these networks generally requires large amounts of data and, consequently, very long training times. In 1993 we reported on the tuning and optimization of a negative ion source using a special neural network[2]. One of the properties of this network (CNLSnet), a modified radial basis function network, is that it is able to fit data with few basis functions. Another is that its training is linear resulting in guaranteed convergence and rapid training. We found the training to be rapid enough to support real-time control. This work has been extended to incorporate this network into an MPC using the model built by the network for predictive control. This controller has shown some remarkable capabilities in such non-linear applications as continuous stirred exothermic tank reactors and high-purity fractional distillation columns[3]. The controller is able not only to build an appropriate model from operating data but also to thin the network continuously so that the model adapts to changing plant conditions. The controller is discussed as well as its possible use in various of the difficult control problems that face this community.

  7. Modular and Adaptive Control of Sound Processing

    NASA Astrophysics Data System (ADS)

    van Nort, Douglas

    parameters. In this view, desired gestural dynamics and sonic response are achieved through modular construction of mapping layers that are themselves subject to parametric control. Complementing this view of the design process, the work concludes with an approach in which the creation of gestural control/sound dynamics are considered in the low-level of the underlying sound model. The result is an adaptive system that is specialized to noise-based transformations that are particularly relevant in an electroacoustic music context. Taken together, these different approaches to design and evaluation result in a unified framework for creation of an instrumental system. The key point is that this framework addresses the influence that mapping structure and control dynamics have on the perceived feel of the instrument. Each of the results illustrate this using either top-down or bottom-up approaches that consider musical control context, thereby pointing to the greater potential for refined sonic articulation that can be had by combining them in the design process.

  8. Cueing Complex Animations: Does Direction of Attention Foster Learning Processes?

    ERIC Educational Resources Information Center

    Lowe, Richard; Boucheix, Jean-Michel

    2011-01-01

    The time course of learners' processing of a complex animation was studied using a dynamic diagram of a piano mechanism. Over successive repetitions of the material, two forms of cueing (standard colour cueing and anti-cueing) were administered either before or during the animated segment of the presentation. An uncued group and two other control…

  9. Executive Function Predicts Adaptive Behavior in Children with Histories of Heavy Prenatal Alcohol Exposure and Attention Deficit/Hyperactivity Disorder

    PubMed Central

    Ware, Ashley L.; Crocker, Nicole; O’Brien, Jessica W.; Deweese, Benjamin N.; Roesch, Scott C.; Coles, Claire D.; Kable, Julie A.; May, Philip A.; Kalberg, Wendy O.; Sowell, Elizabeth R.; Jones, Kenneth Lyons; Riley, Edward P.; Mattson, Sarah N.

    2011-01-01

    Purpose of Study Prenatal exposure to alcohol often results in disruption to discrete cognitive and behavioral domains, including executive function (EF) and adaptive functioning. In the current study, the relation between these two domains was examined in children with histories of heavy prenatal alcohol exposure, non-exposed children with a diagnosis of attention-deficit/hyperactivity disorder (ADHD), and typically developing controls. Methods As part of a multisite study, three groups of children (8-18y, M = 12.10) were tested: children with histories of heavy prenatal alcohol exposure (ALC, N=142), non-exposed children with ADHD (ADHD, N=82), and typically developing controls (CON, N=133) who did not have ADHD or a history of prenatal alcohol exposure. Children completed subtests of the Delis-Kaplan Executive Function System (D-KEFS) and their primary caregivers completed the Vineland Adaptive Behavior Scales-II (VABS). Data were analyzed using regression analyses. Results Analyses showed that EF measures were predictive of adaptive abilities and significant interactions between D-KEFS measures and group were present. For the ADHD group, the relation between adaptive abilities and EF was more general, with three of the four EF measures showing a significant relation with adaptive score. In contrast, for the ALC group, this relation was specific to the nonverbal EF measures. In the CON group, performance on EF tasks did not predict adaptive scores over the influence of age. Conclusion These results support prior research in ADHD suggesting that EF deficits are predictive of poorer adaptive behavior and extend this finding to include children with heavy prenatal exposure to alcohol. However, the relation between EF and adaptive ability differed by group, suggesting unique patterns of abilities in these children. These results provide enhanced understanding of adaptive deficits in these populations, as well as demonstrate the ecological validity of laboratory

  10. Interactions between voluntary and involuntary attention modulate the quality and temporal dynamics of visual processing.

    PubMed

    Grubb, Michael A; White, Alex L; Heeger, David J; Carrasco, Marisa

    2015-04-01

    Successfully navigating a dynamic environment requires the efficient distribution of finite neural resources. Voluntary (endogenous) covert spatial attention selectively allocates those processing resources to goal-relevant locations in the visual scene in the absence of eye movements. However, the allocation of spatial attention is not always voluntary; abrupt onsets in the visual periphery automatically enhance processing of nearby stimuli (exogenous attention). In dynamic environments, exogenous events and internal goals likely compete to determine the distribution of attention, but how such competition is resolved is not well understood. To investigate how exogenous events interact with the concurrent allocation of voluntary attention, we used a speed-accuracy trade-off (SAT) procedure. SAT conjointly measures the rate of information accrual and asymptotic discriminability, allowing us to measure how attentional interactions unfold over time during stimulus processing. We found that both types of attention sped information accrual and improved discriminability. However, focusing endogenous attention at the target location reduced the effects of exogenous cues on the rate of information accrual and rendered negligible their effects on asymptotic discriminability. We verified the robustness of these findings in four additional experiments that targeted specific, critical response delays. In conclusion, the speed and quality of visual processing depend conjointly on internally and externally driven attentional states, but it is possible to voluntarily diminish distraction by irrelevant events in the periphery. PMID:25117089

  11. Attention to Faces Modulates Early Face Processing during Low but not High Face Discriminability

    PubMed Central

    Sreenivasan, Kartik K.; Goldstein, Jonathan M.; Lustig, Audrey G.; Rivas, Luis R.; Jha, Amishi P.

    2010-01-01

    In the present study, we investigated if attention to faces results in sensory gain modulation. Participants were cued to attend to faces or scenes in superimposed face-scene images while face discriminability was parametrically manipulated across images. The face-sensitive N170 event-related potential component was used as a measure of early face processing. Attention to faces modulated N170 amplitude, but only when faces were not highly discriminable. Additionally, directing attention to faces modulated later processing (~230–300 msec) for all discriminability levels. These results demonstrate that attention to faces can modulate perceptual processing of faces at multiple stages of processing, including early sensory levels. Critically, the early attentional benefit is present only when the “face signal” (i.e., the perceptual quality of the face) in the environment is suboptimal. PMID:19429962

  12. Cannabinoid Modulation of Functional Connectivity within Regions Processing Attentional Salience

    PubMed Central

    Bhattacharyya, Sagnik; Falkenberg, Irina; Martin-Santos, Rocio; Atakan, Zerrin; Crippa, Jose A; Giampietro, Vincent; Brammer, Mick; McGuire, Philip

    2015-01-01

    There is now considerable evidence to support the hypothesis that psychotic symptoms are the result of abnormal salience attribution, and that the attribution of salience is largely mediated through the prefrontal cortex, the striatum, and the hippocampus. Although these areas show differential activation under the influence of delta-9-tetrahydrocannabinol (delta-9-THC) and cannabidiol (CBD), the two major derivatives of cannabis sativa, little is known about the effects of these cannabinoids on the functional connectivity between these regions. We investigated this in healthy occasional cannabis users by employing event-related functional magnetic resonance imaging (fMRI) following oral administration of delta-9-THC, CBD, or a placebo capsule. Employing a seed cluster-based functional connectivity analysis that involved using the average time series from each seed cluster for a whole-brain correlational analysis, we investigated the effect of drug condition on functional connectivity between the seed clusters and the rest of the brain during an oddball salience processing task. Relative to the placebo condition, delta-9-THC and CBD had opposite effects on the functional connectivity between the dorsal striatum, the prefrontal cortex, and the hippocampus. Delta-9-THC reduced fronto-striatal connectivity, which was related to its effect on task performance, whereas this connection was enhanced by CBD. Conversely, mediotemporal-prefrontal connectivity was enhanced by delta-9-THC and reduced by CBD. Our results suggest that the functional integration of brain regions involved in salience processing is differentially modulated by single doses of delta-9-THC and CBD and that this relates to the processing of salient stimuli. PMID:25249057

  13. Cannabinoid modulation of functional connectivity within regions processing attentional salience.

    PubMed

    Bhattacharyya, Sagnik; Falkenberg, Irina; Martin-Santos, Rocio; Atakan, Zerrin; Crippa, Jose A; Giampietro, Vincent; Brammer, Mick; McGuire, Philip

    2015-05-01

    There is now considerable evidence to support the hypothesis that psychotic symptoms are the result of abnormal salience attribution, and that the attribution of salience is largely mediated through the prefrontal cortex, the striatum, and the hippocampus. Although these areas show differential activation under the influence of delta-9-tetrahydrocannabinol (delta-9-THC) and cannabidiol (CBD), the two major derivatives of cannabis sativa, little is known about the effects of these cannabinoids on the functional connectivity between these regions. We investigated this in healthy occasional cannabis users by employing event-related functional magnetic resonance imaging (fMRI) following oral administration of delta-9-THC, CBD, or a placebo capsule. Employing a seed cluster-based functional connectivity analysis that involved using the average time series from each seed cluster for a whole-brain correlational analysis, we investigated the effect of drug condition on functional connectivity between the seed clusters and the rest of the brain during an oddball salience processing task. Relative to the placebo condition, delta-9-THC and CBD had opposite effects on the functional connectivity between the dorsal striatum, the prefrontal cortex, and the hippocampus. Delta-9-THC reduced fronto-striatal connectivity, which was related to its effect on task performance, whereas this connection was enhanced by CBD. Conversely, mediotemporal-prefrontal connectivity was enhanced by delta-9-THC and reduced by CBD. Our results suggest that the functional integration of brain regions involved in salience processing is differentially modulated by single doses of delta-9-THC and CBD and that this relates to the processing of salient stimuli. PMID:25249057

  14. Blinded by fear? Prior exposure to fearful faces enhances attentional processing of task-irrelevant stimuli.

    PubMed

    Berggren, Nick; Derakshan, Nazanin

    2013-01-01

    Threatening information has been shown to both capture attention and enhance sensory processing. Recent evidence has also suggested that exposure to fearful stimuli may enhance perceptual processing of subsequently presented information, as well as increase attentional capacity. However, these results are inconsistent with other findings that fearful stimuli reduce task-irrelevant distraction and improve selective attention. Here, we investigated the effect of prior exposure to fearful faces on performance in the Eriksen flanker task. Across experiments, fearful cues led to increased task-irrelevant distraction for items positioned across visual space, in contrast to other emotional expressions and inverted face items, and under conditions of attentional load. Findings support the view that fearful images enhance attentional capacity, allowing one to attend to as much visual information as possible when danger is implied. Conflicting findings on the effect of fear and selective attention are discussed. PMID:23510073

  15. Distributed Cortical Phase Synchronization in the EEG Reveals Parallel Attention and Working Memory Processes Involved in the Attentional Blink.

    PubMed

    Glennon, Mark; Keane, Michael A; Elliott, Mark A; Sauseng, Paul

    2016-05-01

    Attentional blink (AB) describes a visuo-perceptual phenomenon in which the second of 2 targets within a rapid serial visual presentation stream is not detected. There are several cognitive models attempting to explain the fundamentals of this information processing bottleneck. Here, we used electroencephalographic recordings and the analysis of interregional phase synchronization of rhythmical brain activity to investigate the neural bases of the AB. By investigating the time course of interregional phase synchronization separately for trials in which participants failed to report the second target correctly (AB trials) and trials in which no AB occurred, and by clustering interregional connections based on their functional similarity, it was possible to define several distinct cortical networks. Analyzing these networks comprising phase synchronization-over a large spectrum of brain frequencies from theta to gamma activity-it was possible to identify neural correlates for cognitive subfunctions involved in the AB, such as the encoding of targets into working memory, tuning of attentional filters, and the recruitment of general cognitive resources. This parallel activation of functionally distinct neural processes substantiates the eligibility of several cognitive models on the AB. PMID:25750255

  16. Adaptation Processes in Chinese: Word Formation.

    ERIC Educational Resources Information Center

    Pasierbsky, Fritz

    The typical pattern of Chinese word formation is to have native material adapt to changed circumstances. The Chinese language neither borrows nor lends words, but it does occasionally borrow concepts. The larger cultural pattern in which this occurs is that the Chinese culture borrows, if necessary, but ensures that the act of borrowing does not…

  17. Adaptive mesh refinement for stochastic reaction-diffusion processes

    SciTech Connect

    Bayati, Basil; Chatelain, Philippe; Koumoutsakos, Petros

    2011-01-01

    We present an algorithm for adaptive mesh refinement applied to mesoscopic stochastic simulations of spatially evolving reaction-diffusion processes. The transition rates for the diffusion process are derived on adaptive, locally refined structured meshes. Convergence of the diffusion process is presented and the fluctuations of the stochastic process are verified. Furthermore, a refinement criterion is proposed for the evolution of the adaptive mesh. The method is validated in simulations of reaction-diffusion processes as described by the Fisher-Kolmogorov and Gray-Scott equations.

  18. A systematic process for adaptive concept exploration

    NASA Astrophysics Data System (ADS)

    Nixon, Janel Nicole

    several common challenges to the creation of quantitative modeling and simulation environments. Namely, a greater number of alternative solutions imply a greater number of design variables as well as larger ranges on those variables. This translates to a high-dimension combinatorial problem. As the size and dimensionality of the solution space gets larger, the number of physically impossible solutions within that space greatly increases. Thus, the ratio of feasible design space to infeasible space decreases, making it much harder to not only obtain a good quantitative sample of the space, but to also make sense of that data. This is especially the case in the early stages of design, where it is not practical to dedicate a great deal of resources to performing thorough, high-fidelity analyses on all the potential solutions. To make quantitative analyses feasible in these early stages of design, a method is needed that allows for a relatively sparse set of information to be collected quickly and efficiently, and yet, that information needs to be meaningful enough with which to base a decision. The method developed to address this need uses a Systematic Process for Adaptive Concept Exploration (SPACE). In the SPACE method, design space exploration occurs in a sequential fashion; as data is acquired, the sampling scheme adapts to the specific problem at hand. Previously gathered data is used to make inferences about the nature of the problem so that future samples can be taken from the more interesting portions of the design space. Furthermore, the SPACE method identifies those analyses that have significant impacts on the relationships being modeled, so that effort can be focused on acquiring only the most pertinent information. The SPACE method uses a four-part sampling scheme to efficiently uncover the parametric relationships between the design variables and responses. Step 1 aims to identify the location of infeasible space within the region of interest using an initial

  19. The pupil response is sensitive to divided attention during speech processing.

    PubMed

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

    2014-06-01

    Dividing attention over two streams of speech strongly decreases performance compared to focusing on only one. How divided attention affects cognitive processing load as indexed with pupillometry during speech recognition has so far not been investigated. In 12 young adults the pupil response was recorded while they focused on either one or both of two sentences that were presented dichotically and masked by fluctuating noise across a range of signal-to-noise ratios. In line with previous studies, the performance decreases when processing two target sentences instead of one. Additionally, dividing attention to process two sentences caused larger pupil dilation and later peak pupil latency than processing only one. This suggests an effect of attention on cognitive processing load (pupil dilation) during speech processing in noise. PMID:24709275

  20. Evidence against a Central Bottleneck during the Attentional Blink: Multiple Channels for Configural and Featural Processing

    ERIC Educational Resources Information Center

    Awh, Edward; Serences, John; Laurey, Paul; Dhaliwal, Harpreet; van der Jagt, Thomas; Dassonville, Paul

    2004-01-01

    When a visual target is identified, there is a period of several hundred milliseconds when the processing of subsequent targets is impaired, a phenomenon labeled the attentional blink (AB). The emerging consensus is that the identification of a visual target temporarily occupies a limited attentional resource that is essential for all visual…

  1. Auditory Working Memory Load Impairs Visual Ventral Stream Processing: Toward a Unified Model of Attentional Load

    ERIC Educational Resources Information Center

    Klemen, Jane; Buchel, Christian; Buhler, Mira; Menz, Mareike M.; Rose, Michael

    2010-01-01

    Attentional interference between tasks performed in parallel is known to have strong and often undesired effects. As yet, however, the mechanisms by which interference operates remain elusive. A better knowledge of these processes may facilitate our understanding of the effects of attention on human performance and the debilitating consequences…

  2. Infant responding to joint attention, executive processes, and self-regulation in preschool children.

    PubMed

    Vaughan Van Hecke, Amy; Mundy, Peter; Block, Jessica J; Delgado, Christine E F; Parlade, Meaghan V; Pomares, Yuly B; Hobson, Jessica A

    2012-04-01

    Infant joint attention is related to behavioral and social outcomes, as well as language in childhood. Recent research and theory suggests that the relations between joint attention and social-behavioral outcomes may reflect the role of executive self-regulatory processes in the development of joint attention. To test this hypothesis two studies were conducted. The first, cross-sectional study examined the development of responding to joint attention (RJA) skill in terms of increasing executive efficiency of responding between 9 and 18 months of age. The results indicated that development of RJA was characterized by a decreased latency to shift attention in following another person's gaze and head turn, as well as an increase in the proportion of correct RJA responses exhibited by older infants. The second study examined the longitudinal relations between 12-month measures of responding to joint attention and 36-month attention regulation in a delay of gratification task. The results indicated that responding to joint attention at 12-months was significantly related to children's use of three types of self-regulation behaviors while waiting for a snack reward at 36 months of age. These observations are discussed in light of a developmental theory of attention regulation and joint attention in infancy. PMID:22206892

  3. Adaptive Diagrams: Handing Control over to the Learner to Manage Split-Attention Online

    ERIC Educational Resources Information Center

    Agostinho, Shirley; Tindall-Ford, Sharon; Roodenrys, Kylie

    2013-01-01

    Based on cognitive load theory, it is well known that when studying a diagram that includes explanatory text, optimal learning occurs when the text is physically positioned close to the diagram as it eliminates the need for learners to split their attention between the two sources of information. What is not known is the effect on learning when…

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

    PubMed Central

    Kiefer, Markus

    2012-01-01

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

  5. Deficits in attentional processing of fearful facial expressions in schizophrenic patients

    PubMed Central

    Liu, Yunzhe; Zhang, Dandan; Zhao, Yanli; Tan, Shuping; Luo, Yuejia

    2016-01-01

    Impaired attentional processing of negative facial expressions is prominent in schizophrenia and has been shown to be associated with patients’ social dysfunctions. However, little is known about when and which specific attention deficits influence social functions. Given the dynamic feature of attention, it is necessary to investigate the attention deficits in negative emotional processing unfolding in time. The current study used event-related potentials (ERPs) to investigate the temporal dynamics of attention deficits in emotion perception and their potential relationship with emotional/social impairments in neuroleptic naive schizophrenic patients. Two specific attention deficits were identified and were found to be associated with emotional/social impairments. More specifically, the deficit in orienting attention (evidenced with the reduced P1 amplitude) was correlated with expressive deficits, while the deficit in executive control of attention (evidenced with the reduced P3 amplitude) was correlated with avolition/asociality. Together, these findings may provide novel insights into the core pathophysiological processes and offer objective biomarkers for specific emotional/social impairments in schizophrenia. It is also hoped that this study helps to bridge the gap between basic cognitive deficits and relative high-level social dysfunctions in schizophrenic patients. PMID:27586404

  6. Deficits in attentional processing of fearful facial expressions in schizophrenic patients.

    PubMed

    Liu, Yunzhe; Zhang, Dandan; Zhao, Yanli; Tan, Shuping; Luo, Yuejia

    2016-01-01

    Impaired attentional processing of negative facial expressions is prominent in schizophrenia and has been shown to be associated with patients' social dysfunctions. However, little is known about when and which specific attention deficits influence social functions. Given the dynamic feature of attention, it is necessary to investigate the attention deficits in negative emotional processing unfolding in time. The current study used event-related potentials (ERPs) to investigate the temporal dynamics of attention deficits in emotion perception and their potential relationship with emotional/social impairments in neuroleptic naive schizophrenic patients. Two specific attention deficits were identified and were found to be associated with emotional/social impairments. More specifically, the deficit in orienting attention (evidenced with the reduced P1 amplitude) was correlated with expressive deficits, while the deficit in executive control of attention (evidenced with the reduced P3 amplitude) was correlated with avolition/asociality. Together, these findings may provide novel insights into the core pathophysiological processes and offer objective biomarkers for specific emotional/social impairments in schizophrenia. It is also hoped that this study helps to bridge the gap between basic cognitive deficits and relative high-level social dysfunctions in schizophrenic patients. PMID:27586404

  7. [Aging and cognitive slowing: example of attentional processes--evaluation procedures and related questions].

    PubMed

    Eusop, E; Sebban, C; Piette, F

    2001-01-01

    Slowing is generally associated to ageing. It appears in motor's functions and in cognitive tasks. What is the real nature of this slowing? Is it a general slowing concerning every cognitive processes with the same scale or is this slowing specific of only processes. Or, at least, is it of different magnitude for each cognitive processes? The aim of this paper is to present the state of this debate from results obtained in studies orientated toward attentional processes. Attention allows us to adapt oneself to environment that require in one hand selective mechanisms for pertinence events and in other hand inhibitory mechanisms for interferences. To evaluate these mechanisms priming and cueing procedures are used. Using primes (semantic or conceptual) results in shorter reaction time than for conditions without prime. In some experimental conditions, negative primes can be observed which results for longer reaction time. In these procedures, we need to be careful to the SOA's value (Stimulus Onset Asynchrony) (it represents the time between the end of the prime or cue presentation and the beginning of the stimulus presentation). The longer is the SOA, the shorter is the reaction time increase with a SOA between 200 ms and 400 ms. In these procedures, we now have to understand in the field of information processing what causes this reaction time modification. In other words, increase of reaction time with SOA could be explain increase of all stages of treatment or may be also the consequence of some abolition's of stages? In attentional procedures, we have to consider the automatic or controlled nature of cognitive processes. In target research tasks that implies selective attention, several authors have showed a distinction between automatic and controlled processing. Time to detect prompts increase generally with the distractor number excepted when the prompt is prominent for the subject (because of physical or emotional characteristics). In this second case, the

  8. Adaptive Processes in Thalamus and Cortex Revealed by Silencing of Primary Visual Cortex during Contrast Adaptation.

    PubMed

    King, Jillian L; Lowe, Matthew P; Stover, Kurt R; Wong, Aimee A; Crowder, Nathan A

    2016-05-23

    Visual adaptation illusions indicate that our perception is influenced not only by the current stimulus but also by what we have seen in the recent past. Adaptation to stimulus contrast (the relative luminance created by edges or contours in a scene) induces the perception of the stimulus fading away and increases the contrast detection threshold in psychophysical tests [1, 2]. Neural correlates of contrast adaptation have been described throughout the visual system including the retina [3], dorsal lateral geniculate nucleus (dLGN) [4, 5], primary visual cortex (V1) [6], and parietal cortex [7]. The apparent ubiquity of adaptation at all stages raises the question of how this process cascades across brain regions [8]. Focusing on V1, adaptation could be inherited from pre-cortical stages, arise from synaptic depression at the thalamo-cortical synapse [9], or develop locally, but what is the weighting of these contributions? Because contrast adaptation in mouse V1 is similar to classical animal models [10, 11], we took advantage of the optogenetic tools available in mice to disentangle the processes contributing to adaptation in V1. We disrupted cortical adaptation by optogenetically silencing V1 and found that adaptation measured in V1 now resembled that observed in dLGN. Thus, the majority of adaptation seen in V1 neurons arises through local activity-dependent processes, with smaller contributions from dLGN inheritance and synaptic depression at the thalamo-cortical synapse. Furthermore, modeling indicates that divisive scaling of the weakly adapted dLGN input can predict some of the emerging features of V1 adaptation. PMID:27112300

  9. Modulation of early cortical processing during divided attention to non-contiguous locations.

    PubMed

    Frey, Hans-Peter; Schmid, Anita M; Murphy, Jeremy W; Molholm, Sophie; Lalor, Edmund C; Foxe, John J

    2014-05-01

    We often face the challenge of simultaneously attending to multiple non-contiguous regions of space. There is ongoing debate as to how spatial attention is divided under these situations. Whereas, for several years, the predominant view was that humans could divide the attentional spotlight, several recent studies argue in favor of a unitary spotlight that rhythmically samples relevant locations. Here, this issue was addressed by the use of high-density electrophysiology in concert with the multifocal m-sequence technique to examine visual evoked responses to multiple simultaneous streams of stimulation. Concurrently, we assayed the topographic distribution of alpha-band oscillatory mechanisms, a measure of attentional suppression. Participants performed a difficult detection task that required simultaneous attention to two stimuli in contiguous (undivided) or non-contiguous parts of space. In the undivided condition, the classic pattern of attentional modulation was observed, with increased amplitude of the early visual evoked response and increased alpha amplitude ipsilateral to the attended hemifield. For the divided condition, early visual responses to attended stimuli were also enhanced, and the observed multifocal topographic distribution of alpha suppression was in line with the divided attention hypothesis. These results support the existence of divided attentional spotlights, providing evidence that the corresponding modulation occurs during initial sensory processing time-frames in hierarchically early visual regions, and that suppressive mechanisms of visual attention selectively target distracter locations during divided spatial attention. PMID:24606564

  10. Modulation of early cortical processing during divided attention to non-contiguous locations

    PubMed Central

    Frey, Hans-Peter; Schmid, Anita M.; Murphy, Jeremy W.; Molholm, Sophie; Lalor, Edmund C.; Foxe, John J.

    2015-01-01

    We often face the challenge of simultaneously attending to multiple non-contiguous regions of space. There is ongoing debate as to how spatial attention is divided under these situations. While for several years the predominant view was that humans could divide the attentional spotlight, several recent studies argue in favor of a unitary spotlight that rhythmically samples relevant locations. Here, this issue was addressed using high-density electrophysiology in concert with the multifocal m-sequence technique to examine visual evoked responses to multiple simultaneous streams of stimulation. Concurrently, we assayed the topographic distribution of alpha-band oscillatory mechanisms, a measure of attentional suppression. Participants performed a difficult detection task that required simultaneous attention to two stimuli in contiguous (undivided) or non-contiguous parts of space. In the undivided condition, the classical pattern of attentional modulation was observed, with increased amplitude of the early visual evoked response and increased alpha amplitude ipsilateral to the attended hemifield. For the divided condition, early visual responses to attended stimuli were also enhanced and the observed multifocal topographic distribution of alpha suppression was in line with the divided attention hypothesis. These results support the existence of divided attentional spotlights, providing evidence that the corresponding modulation occurs during initial sensory processing timeframes in hierarchically early visual regions and that suppressive mechanisms of visual attention selectively target distracter locations during divided spatial attention. PMID:24606564

  11. Intermodal auditory, visual, and tactile attention modulates early stages of neural processing

    PubMed Central

    Karns, Christina M.; Knight, Robert T.

    2011-01-01

    We used event-related potentials (ERPs) and gamma band oscillatory responses (GBRs) to examine whether intermodal attention operates early in the auditory, visual, and tactile modalities. To control for the effects of spatial attention, we spatially coregistered all stimuli and varied the attended modality across counterbalanced blocks in an intermodal selection task. In each block participants selectively responded to either auditory, visual, or vibrotactile stimuli from the stream of intermodal events. Auditory and visual ERPs were modulated at the latencies of early cortical processing, but attention manifested later for tactile ERPs. For ERPs, auditory processing was modulated at the latency of the Na (29 ms) which indexes early cortical or thalamocortical processing and the subsequent P1 (90 ms) ERP components. Visual processing was modulated at the latency of the early phase of the C1 (62-72 ms) thought to be generated in primary visual cortex and the subsequent P1 and N1 (176 ms). Tactile processing was modulated at the latency of the N160 (165 ms) likely generated in secondary association cortex. Intermodal attention enhanced early sensory GBRs for all three modalities: auditory (onset 57 ms), visual (onset 47 ms) and tactile (onset 27 ms). Together, these results suggest that intermodal attention enhances neural processing relatively early in the sensory stream independent from differential effects of spatial and intramodal selective attention. PMID:18564047

  12. Adaptive Constructive Processes and the Future of Memory

    ERIC Educational Resources Information Center

    Schacter, Daniel L.

    2012-01-01

    Memory serves critical functions in everyday life but is also prone to error. This article examines adaptive constructive processes, which play a functional role in memory and cognition but can also produce distortions, errors, and illusions. The article describes several types of memory errors that are produced by adaptive constructive processes…

  13. Adaptation to Work: An Exploration of Processes and Outcomes.

    ERIC Educational Resources Information Center

    Ashley, William L.; And Others

    A study of adaptation to work as both a process and an outcome was conducted. The study was conducted by personal interview that probed adaptation with respect to work's organizational, performance, interpersonal, responsibility, and affective aspects; and by questionnaire using the same aspects. The population studied consisted of persons without…

  14. Adaptive, Emotional, and Family Functioning of Children With Obsessive-Compulsive Disorder and Comorbid Attention Deficit Hyperactivity Disorder

    PubMed Central

    Sukhodolsky, Denis G.; do Rosario-Campos, Maria C.; Scahill, Lawrence; Katsovich, Lily; Pauls, David L.; Peterson, Bradley S.; King, Robert A.; Lombroso, Paul J.; Findley, Diane B.; Leckman, James F.

    2008-01-01

    Objective The purpose of the study was to examine adaptive, emotional, and family functioning in a well-characterized group of children and adolescents with obsessive-compulsive disorder (OCD) and to evaluate the influence of comorbid attention deficit hyperactivity disorder (ADHD) on the levels of impairment in various functional domains. Method The study group included 287 children and adolescents (191 boys, 96 girls) ages 7–18 years. Fifty-six subjects had a diagnosis of OCD only, 43 had both OCD and ADHD, 95 had ADHD, and 93 were unaffected comparison children. Best estimate DSM-IV diagnoses were assigned on the basis of structured interviews and clinical ratings. The children's functioning was evaluated with a comprehensive battery of well-established, standardized measures, including the Vineland Adaptive Behavior Scales, parents' ratings of social and family functioning, and children's self-reports of emotional adjustment. Results The children with OCD only were more impaired than were unaffected comparison subjects in most areas of adaptive functioning and emotional adjustment. Children with OCD plus ADHD had additional difficulties in social functioning, school problems, and self-reported depression. Impairment in daily living skills, reduced number of activities, and self-reported anxiety were uniquely associated with the diagnosis of OCD. Family dysfunction was associated with ADHD but not with OCD. Conclusions Children and adolescents with OCD are impaired in multiple domains of adaptive and emotional functioning. When comorbid ADHD is present, there is an additional burden on social, school, and family functioning. PMID:15930061

  15. Revisiting attentional processing of non-emotional cues in social anxiety: A specific impairment for the orienting network of attention.

    PubMed

    Heeren, Alexandre; Maurage, Pierre; Philippot, Pierre

    2015-07-30

    People with social anxiety disorder (SAD) exhibit an attentional bias for threat (AB). Nevertheless, the focus on AB for emotional stimuli has led to neglect the exploration of basic attention deficits for non-emotional material among SAD patients. This study aimed to investigate the integrity of the attentional system in SAD. The Attention Network Test was used to precisely explore attentional deficits, and centrally the differential deficit across the three attentional networks, namely alerting (allowing to achieve and maintain a state of alertness), orienting (allowing to select information from sensory input by engaging or disengaging attention to one stimulus among others and/or shifting the attentional resources from one stimulation to another), and executive control (involving the top-down control of attention and allowing to resolve response conflicts). Twenty-five patients with SAD were compared to 25 matched controls. SAD patients exhibited a specific impairment for the orienting network (p < 0.001) but preserved performance for the alerting and executive networks. Complementary analyses revealed that this impairment may result from a faster attentional engagement to task-irrelevant material. The orienting impairment was highly correlated with the intensity of the social anxiety symptoms, but did not correlate either with trait-anxiety, state-anxiety, or depressive symptoms. PMID:25957649

  16. Adaptive Noise Suppression Using Digital Signal Processing

    NASA Technical Reports Server (NTRS)

    Kozel, David; Nelson, Richard

    1996-01-01

    A signal to noise ratio dependent adaptive spectral subtraction algorithm is developed to eliminate noise from noise corrupted speech signals. The algorithm determines the signal to noise ratio and adjusts the spectral subtraction proportion appropriately. After spectra subtraction low amplitude signals are squelched. A single microphone is used to obtain both eh noise corrupted speech and the average noise estimate. This is done by determining if the frame of data being sampled is a voiced or unvoiced frame. During unvoice frames an estimate of the noise is obtained. A running average of the noise is used to approximate the expected value of the noise. Applications include the emergency egress vehicle and the crawler transporter.

  17. Effects of Methylphenidate (Ritalin) on Auditory Performance in Children with Attention and Auditory Processing Disorders.

    ERIC Educational Resources Information Center

    Tillery, Kim L.; Katz, Jack; Keller, Warren D.

    2000-01-01

    A double-blind, placebo-controlled study examined effects of methylphenidate (Ritalin) on auditory processing in 32 children with both attention deficit hyperactivity disorder and central auditory processing (CAP) disorder. Analyses revealed that Ritalin did not have a significant effect on any of the central auditory processing measures, although…

  18. Adaptive Memory: Is Survival Processing Special?

    ERIC Educational Resources Information Center

    Nairne, James S.; Pandeirada, Josefa N. S.

    2008-01-01

    Do the operating characteristics of memory continue to bear the imprints of ancestral selection pressures? Previous work in our laboratory has shown that human memory may be specially tuned to retain information processed in terms of its survival relevance. A few seconds of survival processing in an incidental learning context can produce recall…

  19. Assessing new dimensions of attentional functions in children prenatally exposed to environmental contaminants using an adapted Posner paradigm.

    PubMed

    Ethier, Audrey-Anne; Muckle, Gina; Jacobson, Sandra W; Ayotte, Pierre; Jacobson, Joseph L; Saint-Amour, Dave

    2015-01-01

    Chronic exposure to methylmercury (MeHg), lead (Pb) and polychlorinated biphenyls (PCBs) has been associated with a range of attention deficits in children, but it is not known whether selective spatial attention is also altered. We modified the classic Posner paradigm, which assesses visuospatial attention, to also assess vigilance and impulsivity. This paradigm is based on the well-documented findings that a target will be detected more quickly if a visual cue indicates beforehand where it will appear, and more slowly if the cue indicates a false spatial location. In our task, visual distractors were introduced, in addition to the classic Posner trials, to assess impulsivity, and a central smiley face, whose eye-movement cued the location of the targets, to measure spatial attention. This task was administered to 27 school-age Inuit children (mean age = 11.2 years) from Nunavik (Arctic Quebec, Canada), in which pre- and postnatal exposures to environmental contaminants had been documented from birth. After controlling for the impact of confounding variables, multivariable regressions revealed that prenatal exposures to PCBs and Pb were significantly associated with greater inattention and impulsivity, respectively, while current exposure to Pb was significantly associated with longer reaction times. Although a significant correlation was observed between cord blood PCB concentration and decreased visuospatial performance, no significant association was found after adjustment for confounders. No effect was found for Hg exposures. These results suggest that our adapted Posner paradigm is sensitive in detecting a range of attention deficits in children exposed to environmental contaminants; implications for future studies are discussed. PMID:26235045

  20. Spatial attention does not modulate holistic face processing, even when multiple faces are present.

    PubMed

    Norman, Liam J; Tokarev, Alexander

    2014-01-01

    The perception of faces is often considered to be unique in comparison with that of other objects in the world. The fact that faces are processed not by their constituent components but by the spatial configuration between those components (holistic face processing--HFP) is often used to support this. Despite two decades of research, however, there is no consensus as to whether or not HFP is a process that is subject to attentional modulation. Here, in two experiments, we used a method to direct spatial attention not previously used in studies of HFP--an exogenous spatial cue--as it offers a robust, rapid, and involuntary method of directing attention. In one experiment we demonstrate that the degree of HFP afforded to a face is not reduced when attention is directed away from that face. In a second experiment we replicate this finding even when the face is simultaneously flanked by other faces--a condition under which a face-specific processing module would, hypothetically, be more sensitive to attentional guidance. These results add to the argument that HFP is carried out independently of attention. PMID:25669051

  1. Brief Report: Joint Attention and Information Processing in Children with Higher Functioning Autism Spectrum Disorders.

    PubMed

    Mundy, Peter; Kim, Kwanguk; McIntyre, Nancy; Lerro, Lindsay; Jarrold, William

    2016-07-01

    Theory suggests that information processing during joint attention may be atypical in children with Autism Spectrum Disorder (ASD). This hypothesis was tested in a study of school-aged children with higher functioning ASD and groups of children with symptoms of ADHD or typical development. The results indicated that the control groups displayed significantly better recognition memory for pictures studied in an initiating joint attention (IJA) rather than responding to joint attention (RJA) condition. This effect was not evident in the ASD group. The ASD group also recognized fewer pictures from the IJA condition than controls, but not the RJA condition. Atypical information processing may be a marker of the continued effects of joint attention disturbance in school aged children with ASD. PMID:27062035

  2. Positive Affect Processing and Joint Attention in Infants at High Risk for Autism: An Exploratory Study.

    PubMed

    Key, Alexandra P; Ibanez, Lisa V; Henderson, Heather A; Warren, Zachary; Messinger, Daniel S; Stone, Wendy L

    2015-12-01

    Few behavioral indices of risk for autism spectrum disorders (ASD) are present before 12 months, and potential biomarkers remain largely unexamined. This prospective study of infant siblings of children with ASD (n = 16) and low-risk comparison infants (n = 15) examined group differences in event-related potentials (ERPs) indexing processing of facial positive affect (N290/P400, Nc) at 9 months and their relation to joint attention at 15 months. Group differences were most pronounced for subtle facial expressions, in that the low-risk group exhibited relatively longer processing (P400 latency) and greater attention resource allocation (Nc amplitude). Exploratory analyses found associations between ERP responses and later joint attention, suggesting that attention to positive affect cues may support the development of other social competencies. PMID:25056131

  3. Attentional modulation of neural processing of shape, color, and velocity in humans

    SciTech Connect

    Corbetta, M.; Miezin, F.M.; Dobmeyer, S.; Shulman, G.L.; Petersen, S.E. )

    1990-06-22

    Positron emission tomography (PET) was used to measure changes in regional cerebral blood flow of normal subjects, while they were discriminating different attributes (shape, color, and velocity) of the same set of visual stimuli. Psychophysical evidence indicated that the sensitivity for discriminating subtle stimulus changes was higher when subjects focused attention on one attribute than when they divided attention among several attributes. Correspondingly, attention enhanced the activity of different regions of extrastriate visual cortex that appear to be specialized for processing information related to the selected attribute.

  4. Attentional processing of faces in ASD: a Dot-Probe study.

    PubMed

    Moore, David J; Heavey, Lisa; Reidy, John

    2012-10-01

    The present study used the Dot-Probe paradigm to explore attentional allocation to faces compared with non-social images in high-functioning individuals with autism spectrum disorder (ASD) and typically developing controls. There was no evidence of attentional bias in either group when stimuli were presented at individually calculated sub-threshold levels. However, at supra-threshold presentation (200 ms), a face bias was found for control participants but not for those with ASD. These results add to evidence of reduced social interest in ASD, relative to controls, and further demonstrate when atypical social processing arises in the attentional time course. PMID:22278029

  5. Alterations of attention and emotional processing following childhood-onset damage to the prefrontal cortex

    PubMed Central

    Sánchez-Navarro, Juan P.; Driscoll, David; Anderson, Steven W.; Tranel, Daniel; Bechara, Antoine; Buchanan, Tony W.

    2015-01-01

    The prefrontal cortex (PFC), especially the medial sector, plays a crucial role in emotional processing. Damage to this region results in impaired processing of emotional information, perhaps due to an inability to initiate and maintain attention toward emotional materials, a process that is normally automatic. Childhood onset damage to the PFC impairs emotional processing more than adult-onset PFC damage. The aim of this work was to study the involvement of the PFC in attention to emotional stimuli, and to explore how age at lesion onset affects this involvement. To address these issues, we studied both the emotional and attentional modulation of the startle reflex. Our sample was composed of 4 patients with childhood-onset PFC damage, 6 patients with adult-onset PFC damage, and 10 healthy comparison participants. Subjects viewed 54 affective pictures; acoustic startle probes were presented at 300 ms after picture onset in 18 pictures (as an index of attentional modulation) and at 3,800 ms after picture onset in 18 pictures (as an index of emotional modulation). Childhood-onset PFC patients did not show attentional or emotional modulation of the response, in contrast to adult-onset PFC damage and comparison participants. Early-onset damage to the PFC results, therefore, in more severe dysfunction in the processing of affective stimuli than adult-onset PFC damage, perhaps reflecting limited plasticity in the neural systems that support these processes. PMID:24377423

  6. Sensory Processing Subtypes in Autism: Association with Adaptive Behavior

    ERIC Educational Resources Information Center

    Lane, Alison E.; Young, Robyn L.; Baker, Amy E. Z.; Angley, Manya T.

    2010-01-01

    Children with autism are frequently observed to experience difficulties in sensory processing. This study examined specific patterns of sensory processing in 54 children with autistic disorder and their association with adaptive behavior. Model-based cluster analysis revealed three distinct sensory processing subtypes in autism. These subtypes…

  7. Selective attention modulates high-frequency activity in the face-processing network.

    PubMed

    Müsch, Kathrin; Hamamé, Carlos M; Perrone-Bertolotti, Marcela; Minotti, Lorella; Kahane, Philippe; Engel, Andreas K; Lachaux, Jean-Philippe; Schneider, Till R

    2014-11-01

    Face processing depends on the orchestrated activity of a large-scale neuronal network. Its activity can be modulated by attention as a function of task demands. However, it remains largely unknown whether voluntary, endogenous attention and reflexive, exogenous attention to facial expressions equally affect all regions of the face-processing network, and whether such effects primarily modify the strength of the neuronal response, the latency, the duration, or the spectral characteristics. We exploited the good temporal and spatial resolution of intracranial electroencephalography (iEEG) and recorded from depth electrodes to uncover the fast dynamics of emotional face processing. We investigated frequency-specific responses and event-related potentials (ERP) in the ventral occipito-temporal cortex (VOTC), ventral temporal cortex (VTC), anterior insula, orbitofrontal cortex (OFC), and amygdala when facial expressions were task-relevant or task-irrelevant. All investigated regions of interest (ROI) were clearly modulated by task demands and exhibited stronger changes in stimulus-induced gamma band activity (50-150 Hz) when facial expressions were task-relevant. Observed latencies demonstrate that the activation is temporally coordinated across the network, rather than serially proceeding along a processing hierarchy. Early and sustained responses to task-relevant faces in VOTC and VTC corroborate their role for the core system of face processing, but they also occurred in the anterior insula. Strong attentional modulation in the OFC and amygdala (300 msec) suggests that the extended system of the face-processing network is only recruited if the task demands active face processing. Contrary to our expectation, we rarely observed differences between fearful and neutral faces. Our results demonstrate that activity in the face-processing network is susceptible to the deployment of selective attention. Moreover, we show that endogenous attention operates along the whole

  8. Establishment of Joint Attention in Dyads Involving Hearing Mothers of Deaf and Hearing Children, and Its Relation to Adaptive Social Behavior

    ERIC Educational Resources Information Center

    Nowakowski, Matilda E.; Tasker, Susan L.; Schmidt, Louis A.

    2009-01-01

    Mounting evidence points to joint attention as a mediating variable in children's adaptive behavior. Joint attention in interactions between hearing mothers and congenitally deaf (n = 27) and hearing (n = 29) children, ages 18-36 months, was examined. All deaf children had severe to profound hearing loss. Mother-child interactions were coded for…

  9. Metabolic Adaptation Processes That Converge to Optimal Biomass Flux Distributions

    PubMed Central

    Altafini, Claudio; Facchetti, Giuseppe

    2015-01-01

    In simple organisms like E.coli, the metabolic response to an external perturbation passes through a transient phase in which the activation of a number of latent pathways can guarantee survival at the expenses of growth. Growth is gradually recovered as the organism adapts to the new condition. This adaptation can be modeled as a process of repeated metabolic adjustments obtained through the resilencings of the non-essential metabolic reactions, using growth rate as selection probability for the phenotypes obtained. The resulting metabolic adaptation process tends naturally to steer the metabolic fluxes towards high growth phenotypes. Quite remarkably, when applied to the central carbon metabolism of E.coli, it follows that nearly all flux distributions converge to the flux vector representing optimal growth, i.e., the solution of the biomass optimization problem turns out to be the dominant attractor of the metabolic adaptation process. PMID:26340476

  10. Sleep deprivation influences some but not all processes of supervisory attention

    NASA Technical Reports Server (NTRS)

    Jennings, J. R.; Monk, T. H.; van der Molen, M. W.

    2003-01-01

    Does one night of sleep deprivation alter processes of supervisory attention in general or only a specific subset of such processes? Twenty college-aged volunteers, half female, performed a choice reaction time task. A cue indicated that compatible (e.g., right button, right-pointing arrow) or incompatible (e.g., left button, right-pointing arrow) responses were to be given to a stimulus that followed 50 or 500 ms later. The paradigm assessed response inhibition, task-shifting skill, and task strategy-processes inherent in supervisory attention. Performance, along with heart rate, was assessed for 12 hr following normal sleep or a night of complete sleep deprivation. Sleep deprivation altered neither preparation for task shifting nor response inhibition. The ability to use preparatory bias to speed performance did decrease with sleep deprivation. Sleep deprivation appears to selectively affect this supervisory attention process, which is perceived as an active effort to cope with a challenging task.

  11. Action video games and improved attentional control: Disentangling selection- and response-based processes.

    PubMed

    Chisholm, Joseph D; Kingstone, Alan

    2015-10-01

    Research has demonstrated that experience with action video games is associated with improvements in a host of cognitive tasks. Evidence from paradigms that assess aspects of attention has suggested that action video game players (AVGPs) possess greater control over the allocation of attentional resources than do non-video-game players (NVGPs). Using a compound search task that teased apart selection- and response-based processes (Duncan, 1985), we required participants to perform an oculomotor capture task in which they made saccades to a uniquely colored target (selection-based process) and then produced a manual directional response based on information within the target (response-based process). We replicated the finding that AVGPs are less susceptible to attentional distraction and, critically, revealed that AVGPs outperform NVGPs on both selection-based and response-based processes. These results not only are consistent with the improved-attentional-control account of AVGP benefits, but they suggest that the benefit of action video game playing extends across the full breadth of attention-mediated stimulus-response processes that impact human performance. PMID:25772554

  12. Spatial Attention Effects during Conscious and Nonconscious Processing of Visual Features and Objects

    ERIC Educational Resources Information Center

    Tapia, Evelina; Breitmeyer, Bruno G.; Jacob, Jane; Broyles, Elizabeth C.

    2013-01-01

    Flanker congruency effects were measured in a masked flanker task to assess the properties of spatial attention during conscious and nonconscious processing of form, color, and conjunctions of these features. We found that (1) consciously and nonconsciously processed colored shape distractors (i.e., flankers) produce flanker congruency effects;…

  13. An Exploratory Study of Planning, Attention, Simultaneous, and Successive Cognitive Processes.

    ERIC Educational Resources Information Center

    Naglieri, Jack A.; And Others

    1989-01-01

    Examined factorial validity of tasks designed to measure cognitive processing in each of Luria's three functional units. Fourth and fifth graders (N=112) were administered nine experimental tasks chosen or developed according to theoretical components of planning, attention, simultaneous, and successive processes. Obtained general support for…

  14. Double Take: Parallel Processing by the Cerebral Hemispheres Reduces Attentional Blink

    ERIC Educational Resources Information Center

    Scalf, Paige E.; Banich, Marie T.; Kramer, Arthur F.; Narechania, Kunjan; Simon, Clarissa D.

    2007-01-01

    Recent data have shown that parallel processing by the cerebral hemispheres can expand the capacity of visual working memory for spatial locations (J. F. Delvenne, 2005) and attentional tracking (G. A. Alvarez & P. Cavanagh, 2005). Evidence that parallel processing by the cerebral hemispheres can improve item identification has remained elusive.…

  15. On adaptive robustness approach to Anti-Jam signal processing

    NASA Astrophysics Data System (ADS)

    Poberezhskiy, Y. S.; Poberezhskiy, G. Y.

    An effective approach to exploiting statistical differences between desired and jamming signals named adaptive robustness is proposed and analyzed in this paper. It combines conventional Bayesian, adaptive, and robust approaches that are complementary to each other. This combining strengthens the advantages and mitigates the drawbacks of the conventional approaches. Adaptive robustness is equally applicable to both jammers and their victim systems. The capabilities required for realization of adaptive robustness in jammers and victim systems are determined. The employment of a specific nonlinear robust algorithm for anti-jam (AJ) processing is described and analyzed. Its effectiveness in practical situations has been proven analytically and confirmed by simulation. Since adaptive robustness can be used by both sides in electronic warfare, it is more advantageous for the fastest and most intelligent side. Many results obtained and discussed in this paper are also applicable to commercial applications such as communications in unregulated or poorly regulated frequency ranges and systems with cognitive capabilities.

  16. Do I have my attention? Speed of processing advantages for the self-face are not driven by automatic attention capture.

    PubMed

    Keyes, Helen; Dlugokencka, Aleksandra

    2014-01-01

    We respond more quickly to our own face than to other faces, but there is debate over whether this is connected to attention-grabbing properties of the self-face. In two experiments, we investigate whether the self-face selectively captures attention, and the attentional conditions under which this might occur. In both experiments, we examined whether different types of face (self, friend, stranger) provide differential levels of distraction when processing self, friend and stranger names. In Experiment 1, an image of a distractor face appeared centrally - inside the focus of attention - behind a target name, with the faces either upright or inverted. In Experiment 2, distractor faces appeared peripherally - outside the focus of attention - in the left or right visual field, or bilaterally. In both experiments, self-name recognition was faster than other name recognition, suggesting a self-referential processing advantage. The presence of the self-face did not cause more distraction in the naming task compared to other types of face, either when presented inside (Experiment 1) or outside (Experiment 2) the focus of attention. Distractor faces had different effects across the two experiments: when presented inside the focus of attention (Experiment 1), self and friend images facilitated self and friend naming, respectively. This was not true for stranger stimuli, suggesting that faces must be robustly represented to facilitate name recognition. When presented outside the focus of attention (Experiment 2), no facilitation occurred. Instead, we report an interesting distraction effect caused by friend faces when processing strangers' names. We interpret this as a "social importance" effect, whereby we may be tuned to pick out and pay attention to familiar friend faces in a crowd. We conclude that any speed of processing advantages observed in the self-face processing literature are not driven by automatic attention capture. PMID:25338170

  17. Orienting attention to visual or verbal/auditory imagery differentially impairs the processing of visual stimuli.

    PubMed

    Villena-González, Mario; López, Vladimir; Rodríguez, Eugenio

    2016-05-15

    When attention is oriented toward inner thoughts, as spontaneously occurs during mind wandering, the processing of external information is attenuated. However, the potential effects of thought's content regarding sensory attenuation are still unknown. The present study aims to assess if the representational format of thoughts, such as visual imagery or inner speech, might differentially affect the sensory processing of external stimuli. We recorded the brain activity of 20 participants (12 women) while they were exposed to a probe visual stimulus in three different conditions: executing a task on the visual probe (externally oriented attention), and two conditions involving inward-turned attention i.e. generating inner speech and performing visual imagery. Event-related potentials results showed that the P1 amplitude, related with sensory response, was significantly attenuated during both task involving inward attention compared with external task. When both representational formats were compared, the visual imagery condition showed stronger attenuation in sensory processing than inner speech condition. Alpha power in visual areas was measured as an index of cortical inhibition. Larger alpha amplitude was found when participants engaged in an internal thought contrasted with the external task, with visual imagery showing even more alpha power than inner speech condition. Our results show, for the first time to our knowledge, that visual attentional processing to external stimuli during self-generated thoughts is differentially affected by the representational format of the ongoing train of thoughts. PMID:26876471

  18. Auditory global-local processing: effects of attention and musical experience.

    PubMed

    Ouimet, Tia; Foster, Nicholas E V; Hyde, Krista L

    2012-10-01

    In vision, global (whole) features are typically processed before local (detail) features ("global precedence effect"). However, the distinction between global and local processing is less clear in the auditory domain. The aims of the present study were to investigate: (i) the effects of directed versus divided attention, and (ii) the effect musical training on auditory global-local processing in 16 adult musicians and 16 non-musicians. Participants were presented with short nine-tone melodies, each comprised of three triplet sequences (three-tone units). In a "directed attention" task, participants were asked to focus on either the global or local pitch pattern and had to determine if the pitch pattern went up or down. In a "divided attention" task, participants judged whether the target pattern (up or down) was present or absent. Overall, global structure was perceived faster and more accurately than local structure. The global precedence effect was observed regardless of whether attention was directed to a specific level or divided between levels. Musicians performed more accurately than non-musicians overall, but non-musicians showed a more pronounced global advantage. This study provides evidence for an auditory global precedence effect across attention tasks, and for differences in auditory global-local processing associated with musical experience. PMID:23039447

  19. The Automatic Conservative: Ideology-Based Attentional Asymmetries in the Processing of Valenced Information

    PubMed Central

    Carraro, Luciana; Castelli, Luigi; Macchiella, Claudia

    2011-01-01

    Research has widely explored the differences between conservatives and liberals, and it has been also recently demonstrated that conservatives display different reactions toward valenced stimuli. However, previous studies have not yet fully illuminated the cognitive underpinnings of these differences. In the current work, we argued that political ideology is related to selective attention processes, so that negative stimuli are more likely to automatically grab the attention of conservatives as compared to liberals. In Experiment 1, we demonstrated that negative (vs. positive) information impaired the performance of conservatives, more than liberals, in an Emotional Stroop Task. This finding was confirmed in Experiment 2 and in Experiment 3 employing a Dot-Probe Task, demonstrating that threatening stimuli were more likely to attract the attention of conservatives. Overall, results support the conclusion that people embracing conservative views of the world display an automatic selective attention for negative stimuli. PMID:22096486

  20. Attention processes in children with movement difficulties, reading difficulties or both.

    PubMed

    Cruddace, S A; Riddell, P M

    2006-10-01

    Reading difficulties (RD) and movement difficulties (MD) co-occur more often in clinical populations than expected for independent disorders. In this study, we investigated the pattern of association between attentional processes, RD and MD in a population of 9 year old school children. Children were screened to identify index groups with RD, MD or both, plus a control group. These groups were then tested on a battery of cognitive attention assessments (TEA-Ch). Results confirmed that the occurrence of RD and MD was greater than would be predicted for independent disorders. Additionally, children with MD, whether or not combined with RD, had poor performance on all attention measures when compared with typically developing children. Children with RD only, were no poorer on measures of attention than typical children. The results are discussed with respect to approaches proposed to account for the co-occurrence of disorders. PMID:17029026

  1. Does Attention Play a Role in Dynamic Receptive Field Adaptation to Changing Acoustic Salience in A1?

    PubMed Central

    Fritz, Jonathan; Elhilali, Mounya; David, Stephen; Shamma, Shihab

    2007-01-01

    Acoustic filter properties of A1 neurons can dynamically adapt to stimulus statistics, classical conditioning, instrumental learning and the changing auditory attentional focus. We have recently developed an experimental paradigm that allows us to view cortical receptive field plasticity on-line as the animal meets different behavioral challenges by attending to salient acoustic cues and changing its cortical filters to enhance performance. We propose that attention is the key trigger that initiates a cascade of events leading to the dynamic receptive field changes that we observe. In our paradigm, ferrets were initially trained, using conditioned avoidance training techniques, to discriminate between background noise stimuli (temporally orthogonal ripple combinations) and foreground tonal target stimuli. They learned to generalize the task for a wide variety of distinct background and foreground target stimuli. We recorded cortical activity in the awake behaving animal and computed on-line spectrotemporal receptive fields (STRFs) of single neurons in A1. We observed clear, predictable task-related changes in STRF shape while the animal performed spectral tasks (including single tone and multi-tone detection, and two-tone discrimination) with different tonal targets. A different set of task-related changes occurred when the animal performed temporal tasks (including gap detection and click-rate discrimination). Distinctive cortical STRF changes may constitute a “task-specific signature”. These spectral and temporal changes in cortical filters occur quite rapidly, within 2 minutes of task onset, and fade just as quickly after task completion, or in some cases, persisted for hours. The same cell could multiplex by differentially changing its receptive field in different task conditions. On-line dynamic task-related changes, as well as persistent plastic changes, were observed at a single-unit, multi-unit and population level. Auditory attention is likely to be

  2. Prism adaptation reverses the local processing bias in patients with right temporo-parietal junction lesions

    PubMed Central

    Rafal, Robert D.; List, Alexandra

    2009-01-01

    Lesions to the right temporo-parietal cortex commonly result in hemispatial neglect. Lesions to the same area are also associated with hyperattention to local details of a scene and difficulty perceiving the global structure. This local processing bias is an important factor contributing to neglect and may contribute to the higher prevalence of the disorder following right compared with left hemisphere strokes. In recent years, visuomotor adaptation to rightward-shifting prisms has been introduced as a promising treatment for hemispatial neglect. Explanations for these improvements have generally described a leftward realignment of attention, however, the present investigation provides evidence that prism adaptation reduces the local processing bias. Five patients with right temporal-parietal junction lesions were asked to identify the global or local levels of hierarchical figures before and after visuomotor adaptation to rightward-shifting prisms. Prior to prism adaptation the patients had difficulty ignoring the local elements when identifying the global component. Following prism adaptation, however, this pattern was reversed, with greater global interference during local level identification. The results suggest that prism adaptation may improve non-spatially lateralized deficits that contribute to the neglect syndrome. PMID:19416951

  3. Adaptive constructive processes and the future of memory

    PubMed Central

    Schacter, Daniel L.

    2013-01-01

    Memory serves critical functions in everyday life, but is also prone to error. This article examines adaptive constructive processes, which play a functional role in memory and cognition but can also produce distortions, errors, or illusions. The article describes several types of memory errors that are produced by adaptive constructive processes, and focuses in particular on the process of imagining or simulating events that might occur in one’s personal future. Simulating future events relies on many of the same cognitive and neural processes as remembering past events, which may help to explain why imagination and memory can be easily confused. The article considers both pitfalls and adaptive aspects of future event simulation in the context of research on planning, prediction, problem solving, mind-wandering, prospective and retrospective memory, coping and positivity bias, and the interconnected set of brain regions known as the default network. PMID:23163437

  4. Sequential sampling model for multiattribute choice alternatives with random attention time and processing order

    PubMed Central

    Diederich, Adele; Oswald, Peter

    2014-01-01

    A sequential sampling model for multiattribute binary choice options, called multiattribute attention switching (MAAS) model, assumes a separate sampling process for each attribute. During the deliberation process attention switches from one attribute consideration to the next. The order in which attributes are considered as well for how long each attribute is considered—the attention time—influences the predicted choice probabilities and choice response times. Several probability distributions for the attention time with different variances are investigated. Depending on the time and order schedule the model predicts a rich choice probability/choice response time pattern including preference reversals and fast errors. Furthermore, the difference between finite and infinite decision horizons for the attribute considered last is investigated. For the former case the model predicts a probability p0 > 0 of not deciding within the available time. The underlying stochastic process for each attribute is an Ornstein-Uhlenbeck process approximated by a discrete birth-death process. All predictions are also true for the widely applied Wiener process. PMID:25249963

  5. Attention fine-tunes auditory-motor processing of speech sounds.

    PubMed

    Möttönen, Riikka; van de Ven, Gido M; Watkins, Kate E

    2014-03-12

    The earliest stages of cortical processing of speech sounds take place in the auditory cortex. Transcranial magnetic stimulation (TMS) studies have provided evidence that the human articulatory motor cortex contributes also to speech processing. For example, stimulation of the motor lip representation influences specifically discrimination of lip-articulated speech sounds. However, the timing of the neural mechanisms underlying these articulator-specific motor contributions to speech processing is unknown. Furthermore, it is unclear whether they depend on attention. Here, we used magnetoencephalography and TMS to investigate the effect of attention on specificity and timing of interactions between the auditory and motor cortex during processing of speech sounds. We found that TMS-induced disruption of the motor lip representation modulated specifically the early auditory-cortex responses to lip-articulated speech sounds when they were attended. These articulator-specific modulations were left-lateralized and remarkably early, occurring 60-100 ms after sound onset. When speech sounds were ignored, the effect of this motor disruption on auditory-cortex responses was nonspecific and bilateral, and it started later, 170 ms after sound onset. The findings indicate that articulatory motor cortex can contribute to auditory processing of speech sounds even in the absence of behavioral tasks and when the sounds are not in the focus of attention. Importantly, the findings also show that attention can selectively facilitate the interaction of the auditory cortex with specific articulator representations during speech processing. PMID:24623783

  6. Interests shape how adolescents pay attention: the interaction of motivation and top-down attentional processes in biasing sensory activations to anticipated events.

    PubMed

    Banerjee, Snigdha; Frey, Hans-Peter; Molholm, Sophie; Foxe, John J

    2015-03-01

    The voluntary allocation of attention to environmental inputs is a crucial mechanism of healthy cognitive functioning, and is probably influenced by an observer's level of interest in a stimulus. For example, an individual who is passionate about soccer but bored by botany will obviously be more attentive at a soccer match than an orchid show. The influence of monetary rewards on attention has been examined, but the impact of more common motivating factors (i.e. the level of interest in the materials under observation) remains unclear, especially during development. Here, stimulus sets were designed based on survey measures of the level of interest of adolescent participants in several item classes. High-density electroencephalography was recorded during a cued spatial attention task in which stimuli of high or low interest were presented in separate blocks. The motivational impact on performance of a spatial attention task was assessed, along with event-related potential measures of anticipatory top-down attention. As predicted, performance was improved for the spatial target detection of high interest items. Further, the impact of motivation was observed in parieto-occipital processes associated with anticipatory top-down spatial attention. The anticipatory activity over these regions was also increased for high vs. low interest stimuli, irrespective of the direction of spatial attention. The results also showed stronger anticipatory attentional and motivational modulations over the right vs. left parieto-occipital cortex. These data suggest that motivation enhances top-down attentional processes, and can independently shape activations in sensory regions in anticipation of events. They also suggest that attentional functions across hemispheres may not fully mature until late adolescence. PMID:25546318

  7. Emotional communication in the context of joint attention for food stimuli: effects on attentional and affective processing.

    PubMed

    Soussignan, Robert; Schaal, Benoist; Boulanger, Véronique; Garcia, Samuel; Jiang, Tao

    2015-01-01

    Guided by distinct theoretical frameworks (the embodiment theories, shared-signal hypothesis, and appraisal theories), we examined the effects of gaze direction and emotional expressions (joy, disgust, and neutral) of virtual characters on attention orienting and affective reactivity of participants while they were engaged in joint attention for food stimuli contrasted by preference (disliked, moderately liked, and liked). The participants were exposed to videos of avatars looking at food and displaying facial expressions with their gaze directed either toward the food only or toward the food and participants consecutively. We recorded eye-tracking responses, heart rate, facial electromyography (zygomatic, corrugator, and levator labii regions), and food wanting/liking. The avatars' joy faces increased the participants' zygomatic reactions and food liking, with mutual eye contact boosting attentional responses. Eye contact also fostered disgust reactions to disliked food, regardless of the avatars' expressions. The findings show that joint attention for food accompanied by face-to-face emotional communication elicits differential attentional and affective responses. The findings appear consistent with the appraisal theories of emotion. PMID:25541512

  8. Attentional effects on orientation judgements are dependent on memory consolidation processes.

    PubMed

    Haskell, Christie; Anderson, Britt

    2016-11-01

    Are the effects of memory and attention on perception synergistic, antagonistic, or independent? Tested separately, memory and attention have been shown to affect the accuracy of orientation judgements. When multiple stimuli are presented sequentially versus simultaneously, error variance is reduced. When a target is validly cued, precision is increased. What if they are manipulated together? We combined memory and attention manipulations in an orientation judgement task to answer this question. Two circular gratings were presented sequentially or simultaneously. On some trials a brief luminance cue preceded the stimuli. Participants were cued to report the orientation of one of the two gratings by rotating a response grating. We replicated the finding that error variance is reduced on sequential trials. Critically, we found interacting effects of memory and attention. Valid cueing reduced the median, absolute error only when two stimuli appeared together and improved it to the level of performance on uncued sequential trials, whereas invalid cueing always increased error. This effect was not mediated by cue predictiveness; however, predictive cues reduced the standard deviation of the error distribution, whereas nonpredictive cues reduced "guessing". Our results suggest that, when the demand on memory is greater than a single stimulus, attention is a bottom-up process that prioritizes stimuli for consolidation. Thus attention and memory are synergistic. PMID:26595533

  9. Attention to language: Novel MEG paradigm for registering involuntary language processing in the brain

    PubMed Central

    Shtyrov, Yury; Smith, Marie L.; Horner, Aidan J.; Henson, Richard; Nathan, Pradeep J.; Bullmore, Edward T.; Pulvermüller, Friedemann

    2012-01-01

    Previous research indicates that, under explicit instructions to listen to spoken stimuli or in speech-oriented behavioural tasks, the brain’s responses to senseless pseudowords are larger than those to meaningful words; the reverse is true in non-attended conditions. These differential responses could be used as a tool to trace linguistic processes in the brain and their interaction with attention. However, as previous studies relied on explicit instructions to attend or ignore the stimuli, a technique for automatic attention modulation (i.e., not dependent on explicit instruction) would be more advantageous, especially when cooperation with instructions may not be guaranteed (e.g., neurological patients, children etc). Here we present a novel paradigm in which the stimulus context automatically draws attention to speech. In a non-attend passive auditory oddball sequence, rare words and pseudowords were presented among frequent non-speech tones of variable frequency and length. The low percentage of spoken stimuli guarantees an involuntary attention switch to them. The speech stimuli, in turn, could be disambiguated as words or pseudowords only in their end, at the last phoneme, after the attention switch would have already occurred. Our results confirmed that this paradigm can indeed be used to induce automatic shifts of attention to spoken input. At ∼250 ms after the stimulus onset, a P3a-like neuromagnetic deflection was registered to spoken (but not tone) stimuli indicating an involuntary attention shift. Later, after the word-pseudoword divergence point, we found a larger oddball response to pseudowords than words, best explained by neural processes of lexical search facilitated through increased attention. Furthermore, we demonstrate a breakdown of this orderly pattern of neurocognitive processes as a result of sleep deprivation. The new paradigm may thus be an efficient way to assess language comprehension processes and their dynamic interaction with

  10. Dynamic analysis of neural encoding by point process adaptive filtering.

    PubMed

    Eden, Uri T; Frank, Loren M; Barbieri, Riccardo; Solo, Victor; Brown, Emery N

    2004-05-01

    Neural receptive fields are dynamic in that with experience, neurons change their spiking responses to relevant stimuli. To understand how neural systems adapt their representations of biological information, analyses of receptive field plasticity from experimental measurements are crucial. Adaptive signal processing, the well-established engineering discipline for characterizing the temporal evolution of system parameters, suggests a framework for studying the plasticity of receptive fields. We use the Bayes' rule Chapman-Kolmogorov paradigm with a linear state equation and point process observation models to derive adaptive filters appropriate for estimation from neural spike trains. We derive point process filter analogues of the Kalman filter, recursive least squares, and steepest-descent algorithms and describe the properties of these new filters. We illustrate our algorithms in two simulated data examples. The first is a study of slow and rapid evolution of spatial receptive fields in hippocampal neurons. The second is an adaptive decoding study in which a signal is decoded from ensemble neural spiking activity as the receptive fields of the neurons in the ensemble evolve. Our results provide a paradigm for adaptive estimation for point process observations and suggest a practical approach for constructing filtering algorithms to track neural receptive field dynamics on a millisecond timescale. PMID:15070506

  11. Adaptation.

    PubMed

    Broom, Donald M

    2006-01-01

    The term adaptation is used in biology in three different ways. It may refer to changes which occur at the cell and organ level, or at the individual level, or at the level of gene action and evolutionary processes. Adaptation by cells, especially nerve cells helps in: communication within the body, the distinguishing of stimuli, the avoidance of overload and the conservation of energy. The time course and complexity of these mechanisms varies. Adaptive characters of organisms, including adaptive behaviours, increase fitness so this adaptation is evolutionary. The major part of this paper concerns adaptation by individuals and its relationships to welfare. In complex animals, feed forward control is widely used. Individuals predict problems and adapt by acting before the environmental effect is substantial. Much of adaptation involves brain control and animals have a set of needs, located in the brain and acting largely via motivational mechanisms, to regulate life. Needs may be for resources but are also for actions and stimuli which are part of the mechanism which has evolved to obtain the resources. Hence pigs do not just need food but need to be able to carry out actions like rooting in earth or manipulating materials which are part of foraging behaviour. The welfare of an individual is its state as regards its attempts to cope with its environment. This state includes various adaptive mechanisms including feelings and those which cope with disease. The part of welfare which is concerned with coping with pathology is health. Disease, which implies some significant effect of pathology, always results in poor welfare. Welfare varies over a range from very good, when adaptation is effective and there are feelings of pleasure or contentment, to very poor. A key point concerning the concept of individual adaptation in relation to welfare is that welfare may be good or poor while adaptation is occurring. Some adaptation is very easy and energetically cheap and

  12. Acoustic Noise Alters Selective Attention Processes as Indicated by Direct Current (DC) Brain Potential Changes

    PubMed Central

    Trimmel, Karin; Schätzer, Julia; Trimmel, Michael

    2014-01-01

    Acoustic environmental noise, even of low to moderate intensity, is known to adversely affect information processing in animals and humans via attention mechanisms. In particular, facilitation and inhibition of information processing are basic functions of selective attention. Such mechanisms can be investigated by analyzing brain potentials under conditions of externally directed attention (intake of environmental information) versus internally directed attention (rejection of environmental stimuli and focusing on memory/planning processes). This study investigated brain direct current (DC) potential shifts—which are discussed to represent different states of cortical activation—of tasks that require intake and rejection of environmental information under noise. It was hypothesized that without background noise rejection tasks would show more positive DC potential changes compared to intake tasks and that under noise both kinds of tasks would show positive DC shifts as an expression of cortical inhibition caused by noise. DC potential shifts during intake and rejection tasks were analyzed at 16 standard locations in 45 persons during irrelevant speech or white noise vs. control condition. Without noise, rejection tasks were associated with more positive DC potential changes compared to intake tasks. During background noise, however, this difference disappeared and both kinds of tasks led to positive DC shifts. Results suggest—besides some limitations—that noise modulates selective attention mechanisms by switching to an environmental information processing and noise rejection mode, which could represent a suggested “attention shift”. Implications for fMRI studies as well as for public health in learning and performance environments including susceptible persons are discussed. PMID:25264675

  13. Shared and distinct factors driving attention and temporal processing across modalities

    PubMed Central

    Berry, Anne S.; Li, Xu; Lin, Ziyong; Lustig, Cindy

    2013-01-01

    In addition to the classic finding that “sounds are judged longer than lights,” the timing of auditory stimuli is often more precise and accurate than is the timing of visual stimuli. In cognitive models of temporal processing, these modality differences are explained by positing that auditory stimuli more automatically capture and hold attention, more efficiently closing an attentional switch that allows the accumulation of pulses marking the passage of time (Block & Zakay, 1997; Meck, 1991; Penney, 2003). However, attention is a multifaceted construct, and there has been little attempt to determine which aspects of attention may be related to modality effects. We used visual and auditory versions of the Continuous Temporal Expectancy Task (CTET; O'Connell et al., 2009) a timing task previously linked to behavioral and electrophysiological measures of mind-wandering and attention lapses, and tested participants with or without the presence of a video distractor. Performance in the auditory condition was generally superior to that in the visual condition, replicating standard results in the timing literature. The auditory modality was also less affected by declines in sustained attention indexed by declines in performance over time. In contrast, distraction had an equivalent impact on performance in the two modalities. Analysis of individual differences in performance revealed further differences between the two modalities: Poor performance in the auditory condition was primarily related to boredom whereas poor performance in the visual condition was primarily related to distractibility. These results suggest that: 1) challenges to different aspects of attention reveal both modality-specific and nonspecific effects on temporal processing, and 2) different factors drive individual differences when testing across modalities. PMID:23978664

  14. Applying statistical process control to the adaptive rate control problem

    NASA Astrophysics Data System (ADS)

    Manohar, Nelson R.; Willebeek-LeMair, Marc H.; Prakash, Atul

    1997-12-01

    Due to the heterogeneity and shared resource nature of today's computer network environments, the end-to-end delivery of multimedia requires adaptive mechanisms to be effective. We present a framework for the adaptive streaming of heterogeneous media. We introduce the application of online statistical process control (SPC) to the problem of dynamic rate control. In SPC, the goal is to establish (and preserve) a state of statistical quality control (i.e., controlled variability around a target mean) over a process. We consider the end-to-end streaming of multimedia content over the internet as the process to be controlled. First, at each client, we measure process performance and apply statistical quality control (SQC) with respect to application-level requirements. Then, we guide an adaptive rate control (ARC) problem at the server based on the statistical significance of trends and departures on these measurements. We show this scheme facilitates handling of heterogeneous media. Last, because SPC is designed to monitor long-term process performance, we show that our online SPC scheme could be used to adapt to various degrees of long-term (network) variability (i.e., statistically significant process shifts as opposed to short-term random fluctuations). We develop several examples and analyze its statistical behavior and guarantees.

  15. Prism adaptation in virtual and natural contexts: Evidence for a flexible adaptive process.

    PubMed

    Veilleux, Louis-Nicolas; Proteau, Luc

    2015-01-01

    Prism exposure when aiming at a visual target in a virtual condition (e.g., when the hand is represented by a video representation) produces no or only small adaptations (after-effects), whereas prism exposure in a natural condition produces large after-effects. Some researchers suggested that this difference may arise from distinct adaptive processes, but other studies suggested a unique process. The present study reconciled these conflicting interpretations. Forty participants were divided into two groups: One group used visual feedback of their hand (natural context), and the other group used computer-generated representational feedback (virtual context). Visual feedback during adaptation was concurrent or terminal. All participants underwent laterally displacing prism perturbation. The results showed that the after-effects were twice as large in the "natural context" than in the "virtual context". No significant differences were observed between the concurrent and terminal feedback conditions. The after-effects generalized to untested targets and workspace. These results suggest that prism adaptation in virtual and natural contexts involves the same process. The smaller after-effects in the virtual context suggest that the depth of adaptation is a function of the degree of convergence between the proprioceptive and visual information that arises from the hand. PMID:25338188

  16. Using Hazard Functions to Assess Changes in Processing Capacity in an Attentional Cuing Paradigm

    ERIC Educational Resources Information Center

    Wenger, Michael J.; Gibson, Bradley S.

    2004-01-01

    Processing capacity-defined as the relative ability to perform mental work in a unit of time-is a critical construct in cognitive psychology and is central to theories of visual attention. The unambiguous use of the construct, experimentally and theoretically, has been hindered by both conceptual confusions and the use of measures that are at best…

  17. Executive Processes in Appearance-Reality Tasks: The Role of Inhibition of Attention and Symbolic Representation

    ERIC Educational Resources Information Center

    Bialystok, Ellen; Senman, Lili

    2004-01-01

    Two studies addressed the role of representation ability and control of attention on solutions to an appearance-reality task based on two types of objects, real and representational. In Study 1, 67 preschool children (3-, 4-, and 5-year-olds) solved appearancereality problems and executive processing tasks. There was an interaction between object…

  18. Striatal Sensitivity during Reward Processing in Attention-Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Paloyelis, Yannis; Mehta, Mitul A.; Faraone, Stephen V.; Asherson, Philip; Kuntsi, Jonna

    2012-01-01

    Objective: Attention-deficit/hyperactivity disorder (ADHD) has been linked to deficits in the dopaminergic reward-processing circuitry; yet, existing evidence is limited, and the influence of genetic variation affecting dopamine signaling remains unknown. We investigated striatal responsivity to rewards in ADHD combined type (ADHD-CT) using…

  19. Attentional modulations of the early and later stages of the neural processing of visual completion

    PubMed Central

    Wu, Xiang; Zhou, Liang; Qian, Cheng; Gan, Lingyu; Zhang, Daren

    2015-01-01

    The brain effortlessly recognizes objects even when the visual information belonging to an object is widely separated, as well demonstrated by the Kanizsa-type illusory contours (ICs), in which a contour is perceived despite the fragments of the contour being separated by gaps. Such large-range visual completion has long been thought to be preattentive, whereas its dependence on top-down influences remains unclear. Here, we report separate modulations by spatial attention and task relevance on the neural activities in response to the ICs. IC-sensitive event-related potentials that were localized to the lateral occipital cortex were modulated by spatial attention at an early processing stage (130–166 ms after stimulus onset) and modulated by task relevance at a later processing stage (234–290 ms). These results not only demonstrate top-down attentional influences on the neural processing of ICs but also elucidate the characteristics of the attentional modulations that occur in different phases of IC processing. PMID:25666450

  20. Attention and Semantic Processing during Speech: An fMRI Study

    ERIC Educational Resources Information Center

    Rama, Pia; Relander-Syrjanen, Kristiina; Carlson, Synnove; Salonen, Oili; Kujala, Teija

    2012-01-01

    This fMRI study was conducted to investigate whether language semantics is processed even when attention is not explicitly directed to word meanings. In the "unattended" condition, the subjects performed a visual detection task while hearing semantically related and unrelated word pairs. In the "phoneme" condition, the subjects made phoneme…

  1. Brief Report: Joint Attention and Information Processing in Children with Higher Functioning Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Mundy, Peter; Kim, Kwanguk; McIntyre, Nancy; Lerro, Lindsay; Jarrold, William

    2016-01-01

    Theory suggests that information processing during joint attention may be atypical in children with Autism Spectrum Disorder (ASD). This hypothesis was tested in a study of school-aged children with higher functioning ASD and groups of children with symptoms of ADHD or typical development. The results indicated that the control groups displayed…

  2. Listening Processes: Attention, Understanding, Evaluation. What Research Says to the Teacher.

    ERIC Educational Resources Information Center

    Friedman, Paul G.

    This review of the research on listening offers general guidelines to help teachers be more effective listeners and to help them teach their students more effective listening skills. The process of listening is discussed according to three components, attentiveness, understanding, and evaluation, which are viewed as occurring sequentially,…

  3. Gender Differences in Planning, Attention, Simultaneous, and Successive (PASS) Cognitive Processes and Achievement.

    ERIC Educational Resources Information Center

    Naglieri, Jack A.; Rojahn, Johannes

    2001-01-01

    Examined 1,100 boys and 1,100 girls who matched the U.S. population using the Planning, Attention, Simultaneous, Successive (PASS) cognitive-processing theory, built on the neuropsychological work of A.R. Luria (1973). Results illustrate that the PASS theory offers a useful way to examine gender differences in cognitive performance. (BF)

  4. Temporal Context in Speech Processing and Attentional Stream Selection: A Behavioral and Neural Perspective

    ERIC Educational Resources Information Center

    Golumbic, Elana M. Zion; Poeppel, David; Schroeder, Charles E.

    2012-01-01

    The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the "Cocktail Party" effect. Yet, the neural mechanisms underlying on-line…

  5. The timing of face selectivity and attentional modulation in visual processing.

    PubMed

    Okazaki, Y; Abrahamyan, A; Stevens, C J; Ioannides, A A

    2008-04-01

    Despite the complete imprint of a visual scene on the retina, the brain selects particular items for further processing. However, there is considerable debate about when and where the first attentional effects take hold in the cortex. We examined the timing of face specificity and attentional influences in the primary/secondary visual cortex (V1/V2) and in the fusiform gyrus (FG) in two experiments using magnetoencephalography (MEG). In experiment 1, using a passive viewing task, we identified three components in response to "Face," "Hand," and "Shoe" stimuli bilaterally in the FG: M(FG)100, M(FG)170, and M(FG)200-all showing a stronger preference for faces. The timing of these three activations of the FG is consistent with earlier studies claiming distinct stages of processing of visual stimuli in the first 300 ms. In experiment 2, subjects performed a gender-discrimination task on either faces or hands, drawing attention to only one of the two object categories. In addition to the previously identified three components in FG, here we found object-selective attentional enhancement first appearing in V1/V2 at around 170 ms, and then in FG at around 200 ms, i.e. concurrent with the third component. No attentional effects were evident on the first or second magnetoencephalography components. These findings may indicate that the visual input for an object is first encoded and matched to an attended "cue" object held in mind. When the attended and encoded objects match, a third stage involving attentive processing is enhanced. PMID:18355971

  6. Selective attention modulates early human evoked potentials during emotional face-voice processing.

    PubMed

    Ho, Hao Tam; Schröger, Erich; Kotz, Sonja A

    2015-04-01

    Recent findings on multisensory integration suggest that selective attention influences cross-sensory interactions from an early processing stage. Yet, in the field of emotional face-voice integration, the hypothesis prevails that facial and vocal emotional information interacts preattentively. Using ERPs, we investigated the influence of selective attention on the perception of congruent versus incongruent combinations of neutral and angry facial and vocal expressions. Attention was manipulated via four tasks that directed participants to (i) the facial expression, (ii) the vocal expression, (iii) the emotional congruence between the face and the voice, and (iv) the synchrony between lip movement and speech onset. Our results revealed early interactions between facial and vocal emotional expressions, manifested as modulations of the auditory N1 and P2 amplitude by incongruent emotional face-voice combinations. Although audiovisual emotional interactions within the N1 time window were affected by the attentional manipulations, interactions within the P2 modulation showed no such attentional influence. Thus, we propose that the N1 and P2 are functionally dissociated in terms of emotional face-voice processing and discuss evidence in support of the notion that the N1 is associated with cross-sensory prediction, whereas the P2 relates to the derivation of an emotional percept. Essentially, our findings put the integration of facial and vocal emotional expressions into a new perspective-one that regards the integration process as a composite of multiple, possibly independent subprocesses, some of which are susceptible to attentional modulation, whereas others may be influenced by additional factors. PMID:25269113

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

    ERIC Educational Resources Information Center

    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,…

  8. Meditation Increases the Depth of Information Processing and Improves the Allocation of Attention in Space

    PubMed Central

    van Leeuwen, Sara; Singer, Wolf; Melloni, Lucia

    2012-01-01

    During meditation, practitioners are required to center their attention on a specific object for extended periods of time. When their thoughts get diverted, they learn to quickly disengage from the distracter. We hypothesized that learning to respond to the dual demand of engaging attention on specific objects and disengaging quickly from distracters enhances the efficiency by which meditation practitioners can allocate attention. We tested this hypothesis in a global-to-local task while measuring electroencephalographic activity from a group of eight highly trained Buddhist monks and nuns and a group of eight age and education matched controls with no previous meditation experience. Specifically, we investigated the effect of attentional training on the global precedence effect, i.e., faster detection of targets on a global than on a local level. We expected to find a reduced global precedence effect in meditation practitioners but not in controls, reflecting that meditators can more quickly disengage their attention from the dominant global level. Analysis of reaction times confirmed this prediction. To investigate the underlying changes in brain activity and their time course, we analyzed event-related potentials. Meditators showed an enhanced ability to select the respective target level, as reflected by enhanced processing of target level information. In contrast with control group, which showed a local target selection effect only in the P1 and a global target selection effect in the P3 component, meditators showed effects of local information processing in the P1, N2, and P3 and of global processing for the N1, N2, and P3. Thus, meditators seem to display enhanced depth of processing. In addition, meditation altered the uptake of information such that meditators selected target level information earlier in the processing sequence than controls. In a longitudinal experiment, we could replicate the behavioral effects, suggesting that meditation modulates

  9. Meditation increases the depth of information processing and improves the allocation of attention in space.

    PubMed

    van Leeuwen, Sara; Singer, Wolf; Melloni, Lucia

    2012-01-01

    During meditation, practitioners are required to center their attention on a specific object for extended periods of time. When their thoughts get diverted, they learn to quickly disengage from the distracter. We hypothesized that learning to respond to the dual demand of engaging attention on specific objects and disengaging quickly from distracters enhances the efficiency by which meditation practitioners can allocate attention. We tested this hypothesis in a global-to-local task while measuring electroencephalographic activity from a group of eight highly trained Buddhist monks and nuns and a group of eight age and education matched controls with no previous meditation experience. Specifically, we investigated the effect of attentional training on the global precedence effect, i.e., faster detection of targets on a global than on a local level. We expected to find a reduced global precedence effect in meditation practitioners but not in controls, reflecting that meditators can more quickly disengage their attention from the dominant global level. Analysis of reaction times confirmed this prediction. To investigate the underlying changes in brain activity and their time course, we analyzed event-related potentials. Meditators showed an enhanced ability to select the respective target level, as reflected by enhanced processing of target level information. In contrast with control group, which showed a local target selection effect only in the P1 and a global target selection effect in the P3 component, meditators showed effects of local information processing in the P1, N2, and P3 and of global processing for the N1, N2, and P3. Thus, meditators seem to display enhanced depth of processing. In addition, meditation altered the uptake of information such that meditators selected target level information earlier in the processing sequence than controls. In a longitudinal experiment, we could replicate the behavioral effects, suggesting that meditation modulates

  10. Becoming a Lunari or Taiyo expert: learned attention to parts drives holistic processing of faces.

    PubMed

    Chua, Kao-Wei; Richler, Jennifer J; Gauthier, Isabel

    2014-06-01

    Faces are processed holistically, but the locus of holistic processing remains unclear. We created two novel races of faces (Lunaris and Taiyos) to study how experience with face parts influences holistic processing. In Experiment 1, subjects individuated Lunaris wherein the top, bottom, or both face halves contained diagnostic information. Subjects who learned to attend to face parts exhibited no holistic processing. This suggests that individuation only leads to holistic processing when the whole face is attended. In Experiment 2, subjects individuated both Lunaris and Taiyos, with diagnostic information in complementary face halves of the two races. Holistic processing was measured with composites made of either diagnostic or nondiagnostic face parts. Holistic processing was only observed for composites made from diagnostic face parts, demonstrating that holistic processing can occur for diagnostic face parts that were never seen together. These results suggest that holistic processing is an expression of learned attention to diagnostic face parts. PMID:24588261

  11. Neurocognitive mechanisms of gaze-expression interactions in face processing and social attention

    PubMed Central

    Graham, Reiko; LaBar, Kevin S.

    2012-01-01

    The face conveys a rich source of non-verbal information used during social communication. While research has revealed how specific facial channels such as emotional expression are processed, little is known about the prioritization and integration of multiple cues in the face during dyadic exchanges. Classic models of face perception have emphasized the segregation of dynamic versus static facial features along independent information processing pathways. Here we review recent behavioral and neuroscientific evidence suggesting that within the dynamic stream, concurrent changes in eye gaze and emotional expression can yield early independent effects on face judgments and covert shifts of visuospatial attention. These effects are partially segregated within initial visual afferent processing volleys, but are subsequently integrated in limbic regions such as the amygdala or via reentrant visual processing volleys. This spatiotemporal pattern may help to resolve otherwise perplexing discrepancies across behavioral studies of emotional influences on gaze-directed attentional cueing. Theoretical explanations of gaze-expression interactions are discussed, with special consideration of speed-of-processing (discriminability) and contextual (ambiguity) accounts. Future research in this area promises to reveal the mental chronometry of face processing and interpersonal attention, with implications for understanding how social referencing develops in infancy and is impaired in autism and other disorders of social cognition. PMID:22285906

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

    PubMed

    Keitel, Christian; Müller, Matthias M

    2016-05-01

    Our brain relies on neural mechanisms of selective attention and converging sensory processing to efficiently cope with rich and unceasing multisensory inputs. One prominent assumption holds that audio-visual synchrony can act as a strong attractor for spatial attention. Here, we tested for a similar effect of audio-visual synchrony on feature-selective attention. We presented two superimposed Gabor patches that differed in colour and orientation. On each trial, participants were cued to selectively attend to one of the two patches. Over time, spatial frequencies of both patches varied sinusoidally at distinct rates (3.14 and 3.63 Hz), giving rise to pulse-like percepts. A simultaneously presented pure tone carried a frequency modulation at the pulse rate of one of the two visual stimuli to introduce audio-visual synchrony. Pulsed stimulation elicited distinct time-locked oscillatory electrophysiological brain responses. These steady-state responses were quantified in the spectral domain to examine individual stimulus processing under conditions of synchronous versus asynchronous tone presentation and when respective stimuli were attended versus unattended. We found that both, attending to the colour of a stimulus and its synchrony with the tone, enhanced its processing. Moreover, both gain effects combined linearly for attended in-sync stimuli. Our results suggest that audio-visual synchrony can attract attention to specific stimulus features when stimuli overlap in space. PMID:26226930

  13. Temporal context in speech processing and attentional stream selection: a behavioral and neural perspective.

    PubMed

    Zion Golumbic, Elana M; Poeppel, David; Schroeder, Charles E

    2012-09-01

    The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the 'Cocktail Party' effect. Yet, the neural mechanisms underlying on-line speech decoding and attentional stream selection are not well understood. We review findings from behavioral and neurophysiological investigations that underscore the importance of the temporal structure of speech for achieving these perceptual feats. We discuss the hypothesis that entrainment of ambient neuronal oscillations to speech's temporal structure, across multiple time-scales, serves to facilitate its decoding and underlies the selection of an attended speech stream over other competing input. In this regard, speech decoding and attentional stream selection are examples of 'Active Sensing', emphasizing an interaction between proactive and predictive top-down modulation of neuronal dynamics and bottom-up sensory input. PMID:22285024

  14. Uncertainty is associated with increased selective attention and sustained stimulus processing.

    PubMed

    Dieterich, Raoul; Endrass, Tanja; Kathmann, Norbert

    2016-06-01

    Uncertainty about future threat has been found to be associated with an overestimation of threat probability and is hypothesized to elicit additional allocation of attention. We used event-related potentials to examine uncertainty-related dynamics in attentional allocation, exploiting brain potentials' high temporal resolution and sensitivity to attention. Thirty participants performed a picture-viewing task in which cues indicated the subsequent picture valence. A certain-neutral and a certain-aversive cue accurately predicted subsequent picture valence, whereas an uncertain cue did not. Participants overestimated the effective frequency of aversive pictures following the uncertain cue, both during and after the task, signifying expectancy and covariation biases, and they tended to express lower subjective valences for aversive pictures presented after the uncertain cue. Pictures elicited increased P2 and LPP amplitudes when their valence could not be predicted from the cue. For the LPP, this effect was more pronounced in response to neutral pictures. Uncertainty appears to enhance the engagement of early phasic and sustained attention for uncertainly cued targets. Thus, defensive motivation related to uncertainty about future threat elicits specific attentional dynamics implicating prioritization at various processing stages, especially for nonthreatening stimuli that tend to violate expectations. PMID:26810702

  15. Topographical Organization of Attentional, Social, and Memory Processes in the Human Temporoparietal Cortex.

    PubMed

    Igelström, Kajsa M; Webb, Taylor W; Kelly, Yin T; Graziano, Michael S A

    2016-01-01

    The temporoparietal junction (TPJ) is activated in association with a large range of functions, including social cognition, episodic memory retrieval, and attentional reorienting. An ongoing debate is whether the TPJ performs an overarching, domain-general computation, or whether functions reside in domain-specific subdivisions. We scanned subjects with fMRI during five tasks known to activate the TPJ, probing social, attentional, and memory functions, and used data-driven parcellation (independent component analysis) to isolate task-related functional processes in the bilateral TPJ. We found that one dorsal component in the right TPJ, which was connected with the frontoparietal control network, was activated in all of the tasks. Other TPJ subregions were specific for attentional reorienting, oddball target detection, or social attribution of belief. The TPJ components that participated in attentional reorienting and oddball target detection appeared spatially separated, but both were connected with the ventral attention network. The TPJ component that participated in the theory-of-mind task was part of the default-mode network. Further, we found that the BOLD response in the domain-general dorsal component had a longer latency than responses in the domain-specific components, suggesting an involvement in distinct, perhaps postperceptual, computations. These findings suggest that the TPJ performs both domain-general and domain-specific computations that reside within spatially distinct functional components. PMID:27280153

  16. Attention modulates cortical processing of pitch feedback errors in voice control.

    PubMed

    Hu, Huijing; Liu, Ying; Guo, Zhiqiang; Li, Weifeng; Liu, Peng; Chen, Shaozhen; Liu, Hanjun

    2015-01-01

    Considerable evidence has shown that unexpected alterations in auditory feedback elicit fast compensatory adjustments in vocal production. Although generally thought to be involuntary in nature, whether these adjustments can be influenced by attention remains unknown. The present event-related potential (ERP) study aimed to examine whether neurobehavioral processing of auditory-vocal integration can be affected by attention. While sustaining a vowel phonation and hearing pitch-shifted feedback, participants were required to either ignore the pitch perturbations, or attend to them with low (counting the number of perturbations) or high attentional load (counting the type of perturbations). Behavioral results revealed no systematic change of vocal response to pitch perturbations irrespective of whether they were attended or not. At the level of cortex, there was an enhancement of P2 response to attended pitch perturbations in the low-load condition as compared to when they were ignored. In the high-load condition, however, P2 response did not differ from that in the ignored condition. These findings provide the first neurophysiological evidence that auditory-motor integration in voice control can be modulated as a function of attention at the level of cortex. Furthermore, this modulatory effect does not lead to a general enhancement but is subject to attentional load. PMID:25589447

  17. Topographical Organization of Attentional, Social, and Memory Processes in the Human Temporoparietal Cortex123

    PubMed Central

    Webb, Taylor W.; Kelly, Yin T.; Graziano, Michael S. A.

    2016-01-01

    Abstract The temporoparietal junction (TPJ) is activated in association with a large range of functions, including social cognition, episodic memory retrieval, and attentional reorienting. An ongoing debate is whether the TPJ performs an overarching, domain-general computation, or whether functions reside in domain-specific subdivisions. We scanned subjects with fMRI during five tasks known to activate the TPJ, probing social, attentional, and memory functions, and used data-driven parcellation (independent component analysis) to isolate task-related functional processes in the bilateral TPJ. We found that one dorsal component in the right TPJ, which was connected with the frontoparietal control network, was activated in all of the tasks. Other TPJ subregions were specific for attentional reorienting, oddball target detection, or social attribution of belief. The TPJ components that participated in attentional reorienting and oddball target detection appeared spatially separated, but both were connected with the ventral attention network. The TPJ component that participated in the theory-of-mind task was part of the default-mode network. Further, we found that the BOLD response in the domain-general dorsal component had a longer latency than responses in the domain-specific components, suggesting an involvement in distinct, perhaps postperceptual, computations. These findings suggest that the TPJ performs both domain-general and domain-specific computations that reside within spatially distinct functional components. PMID:27280153

  18. Attention Modulates Cortical Processing of Pitch Feedback Errors in Voice Control

    PubMed Central

    Hu, Huijing; Liu, Ying; Guo, Zhiqiang; Li, Weifeng; Liu, Peng; Chen, Shaozhen; Liu, Hanjun

    2015-01-01

    Considerable evidence has shown that unexpected alterations in auditory feedback elicit fast compensatory adjustments in vocal production. Although generally thought to be involuntary in nature, whether these adjustments can be influenced by attention remains unknown. The present event-related potential (ERP) study aimed to examine whether neurobehavioral processing of auditory-vocal integration can be affected by attention. While sustaining a vowel phonation and hearing pitch-shifted feedback, participants were required to either ignore the pitch perturbations, or attend to them with low (counting the number of perturbations) or high attentional load (counting the type of perturbations). Behavioral results revealed no systematic change of vocal response to pitch perturbations irrespective of whether they were attended or not. At the level of cortex, there was an enhancement of P2 response to attended pitch perturbations in the low-load condition as compared to when they were ignored. In the high-load condition, however, P2 response did not differ from that in the ignored condition. These findings provide the first neurophysiological evidence that auditory-motor integration in voice control can be modulated as a function of attention at the level of cortex. Furthermore, this modulatory effect does not lead to a general enhancement but is subject to attentional load. PMID:25589447

  19. Behavioral training promotes multiple adaptive processes following acute hearing loss

    PubMed Central

    Keating, Peter; Rosenior-Patten, Onayomi; Dahmen, Johannes C; Bell, Olivia; King, Andrew J

    2016-01-01

    The brain possesses a remarkable capacity to compensate for changes in inputs resulting from a range of sensory impairments. Developmental studies of sound localization have shown that adaptation to asymmetric hearing loss can be achieved either by reinterpreting altered spatial cues or by relying more on those cues that remain intact. Adaptation to monaural deprivation in adulthood is also possible, but appears to lack such flexibility. Here we show, however, that appropriate behavioral training enables monaurally-deprived adult humans to exploit both of these adaptive processes. Moreover, cortical recordings in ferrets reared with asymmetric hearing loss suggest that these forms of plasticity have distinct neural substrates. An ability to adapt to asymmetric hearing loss using multiple adaptive processes is therefore shared by different species and may persist throughout the lifespan. This highlights the fundamental flexibility of neural systems, and may also point toward novel therapeutic strategies for treating sensory disorders. DOI: http://dx.doi.org/10.7554/eLife.12264.001 PMID:27008181

  20. Assessing the Process of Marital Adaptation: The Marital Coping Inventory.

    ERIC Educational Resources Information Center

    Zborowski, Lydia L.; Berman, William H.

    Studies on coping with life events identify marriage as a distinct situational stressor, in which a wide range of coping strategies specific to the marital relationship are employed. This study examined the process of martial adaptation, identified as a style of coping, in 116 married volunteers. Subjects completed a demographic questionnaire, the…

  1. Attachment and children's biased attentional processing: evidence for the exclusion of attachment-related information.

    PubMed

    Vandevivere, Eva; Braet, Caroline; Bosmans, Guy; Mueller, Sven C; De Raedt, Rudi

    2014-01-01

    Research in both infants and adults demonstrated that attachment expectations are associated with the attentional processing of attachment-related information. However, this research suffered from methodological issues and has not been validated across ages. Employing a more ecologically valid paradigm to measure attentional processes by virtue of eye tracking, the current study tested the defensive exclusion hypothesis in late childhood. According to this hypothesis, insecurely attached children are assumed to defensively exclude attachment-related information. We hypothesized that securely attached children process attachment- related neutral and emotional information in a more open manner compared to insecurely attached children. Sixty-two children (59.7% girls, 8-12 years) completed two different tasks, while eye movements were recorded: task one presented an array of neutral faces including mother and unfamiliar women and task two presented the same with happy and angry faces. Results indicated that more securely attached children looked longer at mother's face regardless of the emotional expression. Also, they tend to have more maintained attention to mother's neutral face. Furthermore, more attachment avoidance was related to a reduced total viewing time of mother's neutral, happy, and angry face. Attachment anxiety was not consistently related to the processing of mother's face. Findings support the theoretical assumption that securely attached children have an open manner of processing all attachment-related information. PMID:25061662

  2. The Information Adaptive System - A demonstration of real-time onboard image processing

    NASA Technical Reports Server (NTRS)

    Thomas, G. L.; Carney, P. C.; Meredith, B. D.

    1983-01-01

    The Information Adaptive System (IAS) program has the objective to develop and demonstrate, at the brassboard level, an architecture which can be used to perform advanced signal procesing functions on board the spacecraft. Particular attention is given to the processing of high-speed multispectral imaging data in real-time, and the development of advanced technology which could be employed for future space applications. An IAS functional description is provided, and questions of radiometric correction are examined. Problems of data packetization are considered along with data selection, a distortion coefficient processor, an adaptive system controller, an image processing demonstration system, a sensor simulator and output data buffer, a test support and demonstration controller, and IAS demonstration operating modes.

  3. Adaptive control of surface finish in automated turning processes

    NASA Astrophysics Data System (ADS)

    García-Plaza, E.; Núñez, P. J.; Martín, A. R.; Sanz, A.

    2012-04-01

    The primary aim of this study was to design and develop an on-line control system of finished surfaces in automated machining process by CNC turning. The control system consisted of two basic phases: during the first phase, surface roughness was monitored through cutting force signals; the second phase involved a closed-loop adaptive control system based on data obtained during the monitoring of the cutting process. The system ensures that surfaces roughness is maintained at optimum values by adjusting the feed rate through communication with the PLC of the CNC machine. A monitoring and adaptive control system has been developed that enables the real-time monitoring of surface roughness during CNC turning operations. The system detects and prevents faults in automated turning processes, and applies corrective measures during the cutting process that raise quality and reliability reducing the need for quality control.

  4. Electrophysiological Correlates of Aberrant Motivated Attention and Salience Processing in Unaffected Relatives of Schizophrenia Patients.

    PubMed

    Andersen, Elizabeth H; Campbell, Alana M; Schipul, Sarah E; Bellion, Carolyn M; Donkers, Franc C L; Evans, Anna M; Belger, Aysenil

    2016-01-01

    Patients with schizophrenia (SCZ) exhibit debilitating deficits in attention and affective processing, which are often resistant to treatment and associated with poor functional outcomes. Impaired orientation to task-relevant target information has been indexed by diminished P3b event-related potentials in patients, as well as their unaffected first-degree relatives, suggesting that P3b may be a vulnerability marker for schizophrenia. Despite intact affective valence processing, patients are unable to employ cognitive change strategies to reduce electrophysiological responses to aversive stimuli. Less is known about the attentional processing of emotionally salient task-irrelevant information in patients and unaffected first-degree relatives. The goal of the present study was to examine the neural correlates of salience processing, as indexed by the late positive potential (LPP), during the processing of emotionally salient distractor stimuli in 31 patients with SCZ, 28 first-degree relatives, and 47 control participants using an oddball paradigm. Results indicated that despite intact novelty detection (P3a), both SCZ and first-degree relatives demonstrated deficiencies in attentional processing, reflected in attenuated target-P3b, and aberrant motivated attention, with reduced early-LPP amplitudes for aversive stimuli relative to controls. First-degree relatives revealed a unique enhancement of the late-LPP response, possibly underlying an exaggerated evaluation of salient information and a compensatory engagement of neural circuitry. Furthermore, reduced early-LPP and target-P3b amplitudes were associated with enhanced symptom severity. These findings suggest that, in addition to P3b, LPP may be useful for monitoring clinical state. Future studies will explore the value of P3 and LPP responses as vulnerability markers for early detection and prediction of psychopathology. PMID:26251457

  5. Sustained and transient attentional processes modulate neural predictors of memory encoding in consecutive time periods

    PubMed Central

    Padovani, Tullia; Koenig, Thomas; Eckstein, Doris; Perrig, Walter J

    2013-01-01

    Memory formation is commonly thought to rely on brain activity following an event. Yet, recent research has shown that even brain activity previous to an event can predict later recollection (subsequent memory effect, SME). In order to investigate the attentional sources of the SME, event-related potentials (ERPs) elicited by task cues preceding target words were recorded in a switched task paradigm that was followed by a surprise recognition test. Stay trials, that is, those with the same task as the previous trial, were contrasted with switch trials, which included a task switch compared to the previous trial. The underlying assumption was that sustained attention would be dominant in stay trials and that transient attentional reconfiguration processes would be dominant in switch trials. To determine the SME, local and global statistics of scalp electric fields were used to identify differences between subsequently remembered and forgotten items. Results showed that the SME in stay trials occurred in a time window from 2 to 1 sec before target onset, whereas the SME in switch trials occurred subsequently, in a time window from 1 to 0 sec before target onset. Both SMEs showed a frontal negativity resembling the topography of previously reported effects, which suggests that sustained and transient attentional processes contribute to the prestimulus SME in consecutive time periods. PMID:24381815

  6. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials.

    PubMed

    Schupp, Harald T; Kirmse, Ursula; Schmälzle, Ralf; Flaisch, Tobias; Renner, Britta

    2016-01-01

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depicting a person either in an erotic pose or as a portrait. Afterwards, to activate newly-built memory traces, edited pictures were presented showing only the head region of the person. ERP recordings revealed the emotional regulation of attention by newly-formed memories. Specifically, edited pictures from the erotic compared to the portrait category elicited an early posterior negativity and late positive potential, similar to the findings observed for the original pictures. A control condition showed that the effect was dependent on newly-formed memory traces. Given the large number of new memories formed each day, they presumably make an important contribution to the regulation of attention in everyday life. PMID:27321471

  7. Stress and selective attention: the interplay of mood, cortisol levels, and emotional information processing.

    PubMed

    Ellenbogen, Mark A; Schwartzman, Alex E; Stewart, Jane; Walker, Claire-Dominique

    2002-11-01

    The effects of a stressful challenge on the processing of emotional words were examined in college students. Stress induction was achieved using a competitive computer task, where the individual either repeatedly lost or won against a confederate. Mood, attention, and cortisol were recorded during the study. There were four findings: (1) Participants in the negative stressor condition were faster to shift attention away from negative words than positive or neutral words; (2) attentional shifts away from negative words were associated with stress-induced mood lowering; (3) participants in the negative stress condition with elevated scores on the Beck Depression Inventory were slow to disengage attention from all stimuli; and (4) elevated depression scores were associated with lower cortisol change from baseline during the experimental phase, and with higher cortisol levels during the recovery phase. These findings point to information-processing strategies as a means to regulate emotion, and to atypical features of cognitive and adrenocortical function that may serve as putative risk markers of depression. PMID:12462500

  8. Selective Attention to Semantic and Syntactic Features Modulates Sentence Processing Networks in Anterior Temporal Cortex

    PubMed Central

    Rogalsky, Corianne

    2009-01-01

    Numerous studies have identified an anterior temporal lobe (ATL) region that responds preferentially to sentence-level stimuli. It is unclear, however, whether this activity reflects a response to syntactic computations or some form of semantic integration. This distinction is difficult to investigate with the stimulus manipulations and anomaly detection paradigms traditionally implemented. The present functional magnetic resonance imaging study addresses this question via a selective attention paradigm. Subjects monitored for occasional semantic anomalies or occasional syntactic errors, thus directing their attention to semantic integration, or syntactic properties of the sentences. The hemodynamic response in the sentence-selective ATL region (defined with a localizer scan) was examined during anomaly/error-free sentences only, to avoid confounds due to error detection. The majority of the sentence-specific region of interest was equally modulated by attention to syntactic or compositional semantic features, whereas a smaller subregion was only modulated by the semantic task. We suggest that the sentence-specific ATL region is sensitive to both syntactic and integrative semantic functions during sentence processing, with a smaller portion of this area preferentially involved in the later. This study also suggests that selective attention paradigms may be effective tools to investigate the functional diversity of networks involved in sentence processing. PMID:18669589

  9. Sustained and transient attentional processes modulate neural predictors of memory encoding in consecutive time periods.

    PubMed

    Padovani, Tullia; Koenig, Thomas; Eckstein, Doris; Perrig, Walter J

    2013-07-01

    Memory formation is commonly thought to rely on brain activity following an event. Yet, recent research has shown that even brain activity previous to an event can predict later recollection (subsequent memory effect, SME). In order to investigate the attentional sources of the SME, event-related potentials (ERPs) elicited by task cues preceding target words were recorded in a switched task paradigm that was followed by a surprise recognition test. Stay trials, that is, those with the same task as the previous trial, were contrasted with switch trials, which included a task switch compared to the previous trial. The underlying assumption was that sustained attention would be dominant in stay trials and that transient attentional reconfiguration processes would be dominant in switch trials. To determine the SME, local and global statistics of scalp electric fields were used to identify differences between subsequently remembered and forgotten items. Results showed that the SME in stay trials occurred in a time window from 2 to 1 sec before target onset, whereas the SME in switch trials occurred subsequently, in a time window from 1 to 0 sec before target onset. Both SMEs showed a frontal negativity resembling the topography of previously reported effects, which suggests that sustained and transient attentional processes contribute to the prestimulus SME in consecutive time periods. PMID:24381815

  10. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials

    PubMed Central

    Schupp, Harald T.; Kirmse, Ursula; Schmälzle, Ralf; Flaisch, Tobias; Renner, Britta

    2016-01-01

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depicting a person either in an erotic pose or as a portrait. Afterwards, to activate newly-built memory traces, edited pictures were presented showing only the head region of the person. ERP recordings revealed the emotional regulation of attention by newly-formed memories. Specifically, edited pictures from the erotic compared to the portrait category elicited an early posterior negativity and late positive potential, similar to the findings observed for the original pictures. A control condition showed that the effect was dependent on newly-formed memory traces. Given the large number of new memories formed each day, they presumably make an important contribution to the regulation of attention in everyday life. PMID:27321471

  11. Relationships Among Linguistic Processing Speed, Phonological Working Memory, and Attention in Children Who Stutter

    PubMed Central

    Anderson, Julie D.; Wagovich, Stacy A.

    2010-01-01

    Relatively recently, experimental studies of linguistic processing speed in children who stutter (CWS) have emerged, some of which suggest differences in performance among CWS compared to children who do not stutter (CWNS). What is not yet well understood is the extent to which underlying cognitive skills may impact performance on timed tasks of linguistic performance. The purpose of this study was to explore possible relationships between measures of linguistic processing speed and two aspects of cognition: phonological working memory and attention. Participants were 9 CWS and 14 CWNS between the ages of 3;6 and 5;2. Children participated in a computerized picture naming task (an index of linguistic processing speed) and a nonword repetition task (an index of phonological working memory). Parents completed a temperament behavior questionnaire, from which information about the children’s attentional skills was collected. Findings revealed that the groups did not differ from each other on speed of picture naming or attention; however, the CWS performed significantly worse in nonword repetition. In addition, after partialling out the effects of age, (a) for CWS only, there was a significant negative relationship between picture naming speed and nonword repetition; (b) there were no significant relationships for either group between aspects of attention and picture naming speed; and (c) only the CWNS showed a significant relationship between nonword repetition and focused attentional skills. These results underscore the need to consider the underlying skills associated with lexically-related aspects of language production when examining the task performances of CWS and CWNS. PMID:20831969

  12. I Can Read It in Your Eyes: What Eye Movements Tell Us about Visuo-Attentional Processes in Developmental Dyslexia

    ERIC Educational Resources Information Center

    Bellocchi, Stephanie; Muneaux, Mathilde; Bastien-Toniazzo, Mireille; Ducrot, Stephanie

    2013-01-01

    Most studies today agree about the link between visual-attention and oculomotor control during reading: attention seems to affect saccadic programming, that is, the position where the eyes land in a word. Moreover, recent studies show that visuo-attentional processes are strictly linked to normal and impaired reading. In particular, a large body…

  13. Frequency Adaptability and Waveform Design for OFDM Radar Space-Time Adaptive Processing

    SciTech Connect

    Sen, Satyabrata; Glover, Charles Wayne

    2012-01-01

    We propose an adaptive waveform design technique for an orthogonal frequency division multiplexing (OFDM) radar signal employing a space-time adaptive processing (STAP) technique. We observe that there are inherent variabilities of the target and interference responses in the frequency domain. Therefore, the use of an OFDM signal can not only increase the frequency diversity of our system, but also improve the target detectability by adaptively modifying the OFDM coefficients in order to exploit the frequency-variabilities of the scenario. First, we formulate a realistic OFDM-STAP measurement model considering the sparse nature of the target and interference spectra in the spatio-temporal domain. Then, we show that the optimal STAP-filter weight-vector is equal to the generalized eigenvector corresponding to the minimum generalized eigenvalue of the interference and target covariance matrices. With numerical examples we demonstrate that the resultant OFDM-STAP filter-weights are adaptable to the frequency-variabilities of the target and interference responses, in addition to the spatio-temporal variabilities. Hence, by better utilizing the frequency variabilities, we propose an adaptive OFDM-waveform design technique, and consequently gain a significant amount of STAP-performance improvement.

  14. Adaptive process control using fuzzy logic and genetic algorithms

    NASA Technical Reports Server (NTRS)

    Karr, C. L.

    1993-01-01

    Researchers at the U.S. Bureau of Mines have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by modeling the search procedures of natural genetics. FLC's are rule based systems that efficiently manipulate a problem environment by modeling the 'rule-of-thumb' strategy used in human decision making. Together, GA's and FLC's possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, and a learning element to adjust to the changes in the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented.

  15. Adaptive Process Control with Fuzzy Logic and Genetic Algorithms

    NASA Technical Reports Server (NTRS)

    Karr, C. L.

    1993-01-01

    Researchers at the U.S. Bureau of Mines have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by modeling the search procedures of natural genetics. FLC's are rule based systems that efficiently manipulate a problem environment by modeling the 'rule-of-thumb' strategy used in human decision-making. Together, GA's and FLC's possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, an analysis element to recognize changes in the problem environment, and a learning element to adjust to the changes in the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented.

  16. Epidemic processes over adaptive state-dependent networks

    NASA Astrophysics Data System (ADS)

    Ogura, Masaki; Preciado, Victor M.

    2016-06-01

    In this paper we study the dynamics of epidemic processes taking place in adaptive networks of arbitrary topology. We focus our study on the adaptive susceptible-infected-susceptible (ASIS) model, where healthy individuals are allowed to temporarily cut edges connecting them to infected nodes in order to prevent the spread of the infection. In this paper we derive a closed-form expression for a lower bound on the epidemic threshold of the ASIS model in arbitrary networks with heterogeneous node and edge dynamics. For networks with homogeneous node and edge dynamics, we show that the resulting lower bound is proportional to the epidemic threshold of the standard SIS model over static networks, with a proportionality constant that depends on the adaptation rates. Furthermore, based on our results, we propose an efficient algorithm to optimally tune the adaptation rates in order to eradicate epidemic outbreaks in arbitrary networks. We confirm the tightness of the proposed lower bounds with several numerical simulations and compare our optimal adaptation rates with popular centrality measures.

  17. Epidemic processes over adaptive state-dependent networks.

    PubMed

    Ogura, Masaki; Preciado, Victor M

    2016-06-01

    In this paper we study the dynamics of epidemic processes taking place in adaptive networks of arbitrary topology. We focus our study on the adaptive susceptible-infected-susceptible (ASIS) model, where healthy individuals are allowed to temporarily cut edges connecting them to infected nodes in order to prevent the spread of the infection. In this paper we derive a closed-form expression for a lower bound on the epidemic threshold of the ASIS model in arbitrary networks with heterogeneous node and edge dynamics. For networks with homogeneous node and edge dynamics, we show that the resulting lower bound is proportional to the epidemic threshold of the standard SIS model over static networks, with a proportionality constant that depends on the adaptation rates. Furthermore, based on our results, we propose an efficient algorithm to optimally tune the adaptation rates in order to eradicate epidemic outbreaks in arbitrary networks. We confirm the tightness of the proposed lower bounds with several numerical simulations and compare our optimal adaptation rates with popular centrality measures. PMID:27415289

  18. A pox on the mind: Disjunction of attention and memory in the processing of physical disfigurement

    PubMed Central

    Ackerman, Joshua M.; Becker, D. Vaughn; Mortensen, Chad R.; Sasaki, Takao; Neuberg, Steven L.; Kenrick, Douglas T.

    2009-01-01

    The unfavorable treatment of people with physical disfigurements is well-documented, yet little is known about basic perceptual and cognitive responses to disfigurement. Here, we identify a specialized pattern of cognitive processing consistent with the hypothesis that disfigurements act as heuristic cues to contagious disease. Disfigurements are often invariant across time and difficult to conceal, and thus observers can detect the presence of such cues without necessarily remembering the particular individuals bearing these cues. Indeed, despite the fact that disfigured faces were especially likely to hold disease-sensitive perceivers’ attention (Study 1), disfigured individuals were often confused with one another and thus not well remembered later (Study 2), revealing a disjunction of the typical relationship between elevated attention and elevated memory. We discuss the implications of our results for stigmatization of people with and without physical abnormalities and suggest the possibility that cognitive mechanisms for processing social information may be functionally tuned to the variant nature of important cues. PMID:19578547

  19. Endogenous Attention Selection during Binocular Rivalry at Early Stages of Visual Processing

    PubMed Central

    Mishra, Jyoti; Hillyard, Steven A.

    2009-01-01

    Directing attention to one of two superimposing surfaces composed of dot fields rotating in opposing directions facilitates processing of brief translations of the attended surface (Valdes-Sosa et al., 1998). Here we used ERP recordings to investigate the mechanisms of endogenous attentional selection of such competing dot surfaces under conditions of dichoptic viewing (one surface to each eye) and monocular viewing (both surfaces to one eye). Under dichoptic conditions, which induced binocular rivalry, translations of the attended surface presented to one eye elicited enhanced visual P1 and N1 ERP components relative to translations of the unattended surface presented to the other eye. In comparison, during monocular viewing the attended surface translations elicited a significantly larger N1 component in the absence of any P1 modulation. These results indicate that processing of the attended surface is biased at an earlier level in extrastriate visual cortex under conditions of inter-ocular versus intra-ocular competition. PMID:18384833

  20. Information processing in very-low-birth-weight children with and without attention deficit disorder.

    PubMed

    Potgieter, S T; de Cock, P

    2004-01-01

    Very-low-birth-weight children (16 with and 45 without attention deficit/hyperactivity disorder) were matched to term-born controls (27 with attention deficit/hyperactivity disorder and 30 without) according to age, intelligence, and social class of their parents. The children were screened for motor, visual, and mental disabilities. The general aim of the study was to evaluate information processing stages using the additive factor method of Sternberg. The tasks consisted of computerized visual-motor letter recognition and arrow detection tasks. The tasks elicited similar prolongations of response times, increases in standard deviation of the response times, and increased error rates in the four groups. We conclude that very-low-birth-weight and control children do not differ in their information processing stages. PMID:14707433

  1. Small Sample Properties of an Adaptive Filter with Application to Low Volume Statistical Process Control

    SciTech Connect

    CROWDER, STEPHEN V.

    1999-09-01

    In many manufacturing environments such as the nuclear weapons complex, emphasis has shifted from the regular production and delivery of large orders to infrequent small orders. However, the challenge to maintain the same high quality and reliability standards while building much smaller lot sizes remains. To meet this challenge, specific areas need more attention, including fast and on-target process start-up, low volume statistical process control, process characterization with small experiments, and estimating reliability given few actual performance tests of the product. In this paper we address the issue of low volume statistical process control. We investigate an adaptive filtering approach to process monitoring with a relatively short time series of autocorrelated data. The emphasis is on estimation and minimization of mean squared error rather than the traditional hypothesis testing and run length analyses associated with process control charting. We develop an adaptive filtering technique that assumes initial process parameters are unknown, and updates the parameters as more data become available. Using simulation techniques, we study the data requirements (the length of a time series of autocorrelated data) necessary to adequately estimate process parameters. We show that far fewer data values are needed than is typically recommended for process control applications. We also demonstrate the techniques with a case study from the nuclear weapons manufacturing complex.

  2. Small sample properties of an adaptive filter with application to low volume statistical process control

    SciTech Connect

    Crowder, S.V.; Eshleman, L.

    1998-08-01

    In many manufacturing environments such as the nuclear weapons complex, emphasis has shifted from the regular production and delivery of large orders to infrequent small orders. However, the challenge to maintain the same high quality and reliability standards white building much smaller lot sizes remains. To meet this challenge, specific areas need more attention, including fast and on-target process start-up, low volume statistical process control, process characterization with small experiments, and estimating reliability given few actual performance tests of the product. In this paper the authors address the issue of low volume statistical process control. They investigate an adaptive filtering approach to process monitoring with a relatively short time series of autocorrelated data. The emphasis is on estimation and minimization of mean squared error rather than the traditional hypothesis testing and run length analyses associated with process control charting. The authors develop an adaptive filtering technique that assumes initial process parameters are unknown, and updates the parameters as more data become available. Using simulation techniques, they study the data requirements (the length of a time series of autocorrelated data) necessary to adequately estimate process parameters. They show that far fewer data values are needed than is typically recommended for process control applications. And they demonstrate the techniques with a case study from the nuclear weapons manufacturing complex.

  3. Beyond pleasure and arousal: appetitive erotic stimuli modulate electrophysiological brain correlates of early attentional processing.

    PubMed

    Kuhr, Benjamin; Schomberg, Jessica; Gruber, Thomas; Quirin, Markus

    2013-03-27

    Previous studies investigating affective reactions to pictures that elicit a specific effect have mainly focused on the dimensions valence and arousal. Using an event-related picture-viewing paradigm in electroencephalography, we investigated whether erotica - that is appetitive, evolutionarily relevant stimuli - have effects on early stages of attentional processing that are distinct from those of other positive and arousing stimuli. Seventeen male students viewed arousing photos of erotic, nude women or pictures of extreme sport scenes, as well as control pictures of attractive, dressed women or daily activities. Erotic pictures differed from extreme sport pictures not only in late but also in early attentional processes, as indicated by event-related potentials appearing from 130 ms after stimulus onset (P1). The findings suggest (a) that the dimension of appetence should be considered in addition to valence and arousal when investigating psychophysiological reactions to affective-motivational stimuli and (b) that early attentional processing as mirrored by the P1 can be influenced by motivational systems. PMID:23426107

  4. Beat processing is pre-attentive for metrically simple rhythms with clear accents: an ERP study.

    PubMed

    Bouwer, Fleur L; Van Zuijen, Titia L; Honing, Henkjan

    2014-01-01

    The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN), an ERP response elicited by violations of acoustic regularity irrespective of whether subjects are attending to the stimuli. Both musicians and non-musicians were presented with a varying rhythm with a clear accent structure in which occasionally a sound was omitted. We compared the MMN response to the omission of identical sounds in different metrical positions. Most importantly, we found that omissions in strong metrical positions, on the beat, elicited higher amplitude MMN responses than omissions in weak metrical positions, not on the beat. This suggests that the detection of a beat is pre-attentive when highly beat inducing stimuli are used. No effects of musical expertise were found. Our results suggest that for metrically simple rhythms with clear accents beat processing does not require attention or musical expertise. In addition, we discuss how the use of acoustically varying stimuli may influence ERP results when studying beat processing. PMID:24870123

  5. The role of automaticity and attention in neural processes underlying empathy for happiness, sadness, and anxiety.

    PubMed

    Morelli, Sylvia A; Lieberman, Matthew D

    2013-01-01

    Although many studies have examined the neural basis of empathy, relatively little is known about how empathic processes are affected by different attentional conditions. Thus, we examined whether instructions to empathize might amplify responses in empathy-related regions and whether cognitive load would diminish the involvement of these regions. Thirty-two participants completed a functional magnetic resonance imaging session assessing empathic responses to individuals experiencing happy, sad, and anxious events. Stimuli were presented under three conditions: watching naturally, actively empathizing, and under cognitive load. Across analyses, we found evidence for a core set of neural regions that support empathic processes (dorsomedial prefrontal cortex, DMPFC; medial prefrontal cortex, MPFC; temporoparietal junction, TPJ; amygdala; ventral anterior insula, AI; and septal area, SA). Two key regions-the ventral AI and SA-were consistently active across all attentional conditions, suggesting that they are automatically engaged during empathy. In addition, watching vs. empathizing with targets was not markedly different and instead led to similar subjective and neural responses to others' emotional experiences. In contrast, cognitive load reduced the subjective experience of empathy and diminished neural responses in several regions related to empathy and social cognition (DMPFC, MPFC, TPJ, and amygdala). The results reveal how attention impacts empathic processes and provides insight into how empathy may unfold in everyday interactions. PMID:23658538

  6. The role of automaticity and attention in neural processes underlying empathy for happiness, sadness, and anxiety

    PubMed Central

    Morelli, Sylvia A.; Lieberman, Matthew D.

    2013-01-01

    Although many studies have examined the neural basis of empathy, relatively little is known about how empathic processes are affected by different attentional conditions. Thus, we examined whether instructions to empathize might amplify responses in empathy-related regions and whether cognitive load would diminish the involvement of these regions. Thirty-two participants completed a functional magnetic resonance imaging session assessing empathic responses to individuals experiencing happy, sad, and anxious events. Stimuli were presented under three conditions: watching naturally, actively empathizing, and under cognitive load. Across analyses, we found evidence for a core set of neural regions that support empathic processes (dorsomedial prefrontal cortex, DMPFC; medial prefrontal cortex, MPFC; temporoparietal junction, TPJ; amygdala; ventral anterior insula, AI; and septal area, SA). Two key regions—the ventral AI and SA—were consistently active across all attentional conditions, suggesting that they are automatically engaged during empathy. In addition, watching vs. empathizing with targets was not markedly different and instead led to similar subjective and neural responses to others' emotional experiences. In contrast, cognitive load reduced the subjective experience of empathy and diminished neural responses in several regions related to empathy and social cognition (DMPFC, MPFC, TPJ, and amygdala). The results reveal how attention impacts empathic processes and provides insight into how empathy may unfold in everyday interactions. PMID:23658538

  7. Involuntary attentional orienting in the absence of awareness speeds up early sensory processing.

    PubMed

    Schettino, Antonio; Rossi, Valentina; Pourtois, Gilles; Müller, Matthias M

    2016-01-01

    A long-standing controversy in the field of human neuroscience has revolved around the question whether attended stimuli are processed more rapidly compared to unattended stimuli. We conducted two event-related potential (ERP) experiments employing a temporal order judgment procedure in order to assess whether involuntary attention accelerates sensory processing, as indicated by latency modulations of early visual ERP components. A non-reportable exogenous cue could precede the first target with equal probability at the same (compatible) or opposite (incompatible) location. The use of non-reportable cues promoted automatic, bottom-up attentional capture, and ensured the elimination of any confounds related to the use of stimulus features that are common to both cue and target. Behavioral results confirmed involuntary exogenous orienting towards the unaware cue. ERP results showed that the N1pc, an electrophysiological measure of attentional orienting, was smaller and peaked earlier in compatible as opposed to incompatible trials, indicating cue-dependent changes in magnitude and speed of first target processing in extrastriate visual areas. Complementary Bayesian analysis confirmed the presence of this effect regardless of whether participants were actively looking for the cue (Experiment 1) or were not informed of it (Experiment 2), indicating purely automatic, stimulus-driven orienting mechanisms. PMID:26673944

  8. Age-related decline in bottom-up processing and selective attention in the very old

    PubMed Central

    Zhuravleva, T. Y.; Alperin, B. R.; Haring, A. E.; Rentz, D. M.; Holcomb, P. J.; Daffner, K. R.

    2014-01-01

    Previous research demonstrating age-related deficits in selective attention have not included old-old adults, an increasingly important group to study. The current investigation compared event-related potentials (ERPs) in 15 young-old (65–79) and 23 old-old (80–99) subjects during a color-selective attention task. Subjects responded to target letters in a specified color (Attend) while ignoring letters in a different color (Ignore) under both low and high load. There were no group differences in visual acuity, accuracy, reaction time, or latency of early ERP components. The old-old group showed a disruption in bottom-up processing, indexed by a substantially diminished posterior N1 (smaller amplitude). They also demonstrated markedly decreased modulation of bottom-up processing based on selected visual features, indexed by the posterior selection negativity (SN), with similar attenuation under both loads. In contrast, there were no group differences in frontally-mediated attentional selection, measured by the anterior selection positivity (SP). There was a robust inverse relationship between the size of the SN and SP (the smaller the SN, the larger the SP), which may represent an anteriorly-supported compensatory mechanism. In the absence of a decline in top-down modulation indexed by the SP, the diminished SN may reflect age-related degradation of early bottom-up visual processing in old-old adults. PMID:24887611

  9. Beat Processing Is Pre-Attentive for Metrically Simple Rhythms with Clear Accents: An ERP Study

    PubMed Central

    Bouwer, Fleur L.; Van Zuijen, Titia L.; Honing, Henkjan

    2014-01-01

    The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN), an ERP response elicited by violations of acoustic regularity irrespective of whether subjects are attending to the stimuli. Both musicians and non-musicians were presented with a varying rhythm with a clear accent structure in which occasionally a sound was omitted. We compared the MMN response to the omission of identical sounds in different metrical positions. Most importantly, we found that omissions in strong metrical positions, on the beat, elicited higher amplitude MMN responses than omissions in weak metrical positions, not on the beat. This suggests that the detection of a beat is pre-attentive when highly beat inducing stimuli are used. No effects of musical expertise were found. Our results suggest that for metrically simple rhythms with clear accents beat processing does not require attention or musical expertise. In addition, we discuss how the use of acoustically varying stimuli may influence ERP results when studying beat processing. PMID:24870123

  10. Rapid processing of letters, digits and symbols: what purely visual-attentional deficit in developmental dyslexia?

    PubMed

    Ziegler, Johannes C; Pech-Georgel, Catherine; Dufau, Stéphane; Grainger, Jonathan

    2010-07-01

    Visual-attentional theories of dyslexia predict deficits for dyslexic children not only for the perception of letter strings but also for non-alphanumeric symbol strings. This prediction was tested in a two-alternative forced-choice paradigm with letters, digits, and symbols. Children with dyslexia showed significant deficits for letter and digit strings but not for symbol strings. This finding is difficult to explain for visual-attentional theories of dyslexia which postulate identical deficits for letters, digits and symbols. Moreover, dyslexics showed normal W-shaped serial position functions for letter and digit strings, which suggests that their deficit is not due to an abnormally small attentional window. Finally, the size of the deficit was identical for letters and digits, which suggests that poor letter perception is not just a consequence of the lack of reading. Together then, our results show that symbols that map onto phonological codes are impaired (i.e. letters and digits), whereas symbols that do not map onto phonological codes are not impaired. This dissociation suggests that impaired symbol-sound mapping rather than impaired visual-attentional processing is the key to understanding dyslexia. PMID:20590718

  11. Thermodynamic Costs of Information Processing in Sensory Adaptation

    PubMed Central

    Sartori, Pablo; Granger, Léo; Lee, Chiu Fan; Horowitz, Jordan M.

    2014-01-01

    Biological sensory systems react to changes in their surroundings. They are characterized by fast response and slow adaptation to varying environmental cues. Insofar as sensory adaptive systems map environmental changes to changes of their internal degrees of freedom, they can be regarded as computational devices manipulating information. Landauer established that information is ultimately physical, and its manipulation subject to the entropic and energetic bounds of thermodynamics. Thus the fundamental costs of biological sensory adaptation can be elucidated by tracking how the information the system has about its environment is altered. These bounds are particularly relevant for small organisms, which unlike everyday computers, operate at very low energies. In this paper, we establish a general framework for the thermodynamics of information processing in sensing. With it, we quantify how during sensory adaptation information about the past is erased, while information about the present is gathered. This process produces entropy larger than the amount of old information erased and has an energetic cost bounded by the amount of new information written to memory. We apply these principles to the E. coli's chemotaxis pathway during binary ligand concentration changes. In this regime, we quantify the amount of information stored by each methyl group and show that receptors consume energy in the range of the information-theoretic minimum. Our work provides a basis for further inquiries into more complex phenomena, such as gradient sensing and frequency response. PMID:25503948

  12. Attention as a Process of Selection, Perception as a Process of Representation, and Phenomenal Experience as the Resulting Process of Perception Being Modulated by a Dedicated Consciousness Mechanism

    PubMed Central

    Bachmann, Talis

    2011-01-01

    Equivalence of attention and consciousness is disputed and necessity of attentional effects for conscious experience has become questioned. However, the conceptual landscape and interpretations of empirical evidence as related to this issue have remained controversial. Here I present some conceptual distinctions and research strategies potentially useful for moving forward when tackling this issue. Specifically, it is argued that we should carefully differentiate between pre-conscious processes and the processes resulting in phenomenal experience, move the emphasis from studying the effects of attention on the modality-specific and feature-specific perception to studying attentional effects on panmodal universal attributes of whatever conscious experience may be the case, and acknowledge that there is a specialized mechanism for leading to conscious experience of the pre-consciously represented contents autonomous from the mechanisms of perception, attention, memory, and cognitive control. PMID:22232612

  13. The left visual field attentional advantage: No evidence of different speeds of processing across visual hemifields.

    PubMed

    García-Pérez, Miguel A; Alcalá-Quintana, Rocío

    2015-12-01

    Temporal-order judgment (TOJ) and simultaneity judgment (SJ) tasks are used to study differences in speed of processing across sensory modalities, stimulus types, or experimental conditions. Matthews and Welch (2015) reported that observed performance in SJ and TOJ tasks is superior when visual stimuli are presented in the left visual field (LVF) compared to the right visual field (RVF), revealing an LVF advantage presumably reflecting attentional influences. Because observed performance reflects the interplay of perceptual and decisional processes involved in carrying out the tasks, analyses that separate out these influences are needed to determine the origin of the LVF advantage. We re-analyzed the data of Matthews and Welch (2015) using a model of performance in SJ and TOJ tasks that separates out these influences. Parameter estimates capturing the operation of perceptual processes did not differ between hemifields by these analyses, whereas parameter estimates capturing the operation of decisional processes differed. In line with other evidence, perceptual processing also did not differ between SJ and TOJ tasks. Thus, the LVF advantage occurs with identical speeds of processing in both visual hemifields. If attention is responsible for the LVF advantage, it does not exert its influence via prior entry. PMID:26261896

  14. Adaptive Sampling for Learning Gaussian Processes Using Mobile Sensor Networks

    PubMed Central

    Xu, Yunfei; Choi, Jongeun

    2011-01-01

    This paper presents a novel class of self-organizing sensing agents that adaptively learn an anisotropic, spatio-temporal Gaussian process using noisy measurements and move in order to improve the quality of the estimated covariance function. This approach is based on a class of anisotropic covariance functions of Gaussian processes introduced to model a broad range of spatio-temporal physical phenomena. The covariance function is assumed to be unknown a priori. Hence, it is estimated by the maximum a posteriori probability (MAP) estimator. The prediction of the field of interest is then obtained based on the MAP estimate of the covariance function. An optimal sampling strategy is proposed to minimize the information-theoretic cost function of the Fisher Information Matrix. Simulation results demonstrate the effectiveness and the adaptability of the proposed scheme. PMID:22163785

  15. Attentional demand and processing of relevant visual information during simulated driving: a MEG study.

    PubMed

    Fort, Alexandra; Martin, Robert; Jacquet-Andrieu, Armelle; Combe-Pangaud, Chantal; Foliot, Gérald; Daligault, Sébastien; Delpuech, Claude

    2010-12-01

    It is a well-known fact that attention is crucial for driving a car. This innovative study aims to assess the impact of attentional workload modulation on cerebral activity during a simulated driving task using magnetoencephalography (MEG). A car simulator equipped with a steering wheel, turn indicators, an accelerator and a brake pedal has been specifically designed to be used with MEG. Attentional demand has been modulated using a radio broadcast. During half of the driving scenarios, subjects could ignore the broadcast (simple task, ST) and during the other half, they had to actively listen to it in order to answer 3 questions (dual task, DT). Evoked magnetic responses were computed in both conditions separately for two visual stimuli of interest: traffic lights (from green to amber) and direction signs (arrows to the right or to the left) shown on boards. The cortical sources of these activities have been estimated using a minimum-norm current estimates modeling technique. Results show the activation of a large distributed network similar in ST and DT and similar for both the traffic lights and the direction signs. This network mainly involves sensory visual areas as well as parietal and frontal regions known to play a role in selective attention and motor areas. The increase of attentional demand affects the neuronal processing of relevant visual information for driving, as early as the perceptual stage. By demonstrating the feasibility of recording MEG activity during an interactive simulated driving task, this study opens new possibilities for investigating issues regarding drivers' activity. PMID:20920486

  16. [Formula: see text] and [Formula: see text] Spoken Word Processing: Evidence from Divided Attention Paradigm.

    PubMed

    Shafiee Nahrkhalaji, Saeedeh; Lotfi, Ahmad Reza; Koosha, Mansour

    2016-10-01

    The present study aims to reveal some facts concerning first language ([Formula: see text] and second language ([Formula: see text] spoken-word processing in unbalanced proficient bilinguals using behavioral measures. The intention here is to examine the effects of auditory repetition word priming and semantic priming in first and second languages of these bilinguals. The other goal is to explore the effects of attention manipulation on implicit retrieval of perceptual and conceptual properties of spoken [Formula: see text] and [Formula: see text] words. In so doing, the participants performed auditory word priming and semantic priming as memory tests in their [Formula: see text] and [Formula: see text]. In a half of the trials of each experiment, they carried out the memory test while simultaneously performing a secondary task in visual modality. The results revealed that effects of auditory word priming and semantic priming were present when participants processed [Formula: see text] and [Formula: see text] words in full attention condition. Attention manipulation could reduce priming magnitude in both experiments in [Formula: see text]. Moreover, [Formula: see text] word retrieval increases the reaction times and reduces accuracy on the simultaneous secondary task to protect its own accuracy and speed. PMID:26643309

  17. Addressing the need for adaptable decision processes within healthcare software.

    PubMed

    Miseldine, P; Taleb-Bendiab, A; England, D; Randles, M

    2007-03-01

    In the healthcare sector, where the decisions made by software aid in the direct treatment of patients, software requires high levels of assurance to ensure the correct interpretation of the tasks it is automating. This paper argues that introducing adaptable decision processes within eHealthcare initiatives can reduce software-maintenance complexity and, due to the instantaneous, distributed deployment of decision models, allow for quicker updates of current best practice, thereby improving patient care. The paper provides a description of a collection of technologies and tools that can be used to provide the required adaptation in a decision process. These tools are evaluated against two case studies that individually highlight different requirements in eHealthcare: a breast-cancer decision-support system, in partnership with several of the UK's leading cancer hospitals, and a dental triage in partnership with the Royal Liverpool Hospital which both show how the complete process flow of software can be abstracted and adapted, and the benefits that arise as a result. PMID:17365643

  18. Effect of temporal predictability on exogenous attentional modulation of feedforward processing in the striate cortex.

    PubMed

    Dassanayake, Tharaka L; Michie, Patricia T; Fulham, Ross

    2016-07-01

    Non-informative peripheral visual cues facilitate extrastriate processing of targets [as indexed by enhanced amplitude of contralateral P1 event-related potential (ERP) component] presented at the cued location as opposed to those presented at uncued locations, at short cue-target stimulus onset asynchrony (SOA). Recently, two lines of research are emerging to suggest that the locus of attentional modulation is flexible and depends on 1) perceptual load and 2) temporal predictability of visual stimuli. We aimed to examine the effect of temporal predictability on attentional modulation of feed-forward activation of the striate cortex (as indexed by the C1 ERP component) by high-perceptual-load (HPL) stimuli. We conducted two ERP experiments where exogenously-cued HPL targets were presented under two temporal predictability conditions. In Experiment 1 [high-temporal-predictability (HTP) condition], 17 healthy subjects (age 18-26years) performed a line-orientation discrimination task on HPL targets presented in the periphery of the left upper or diagonally opposite right lower visual field, validly or invalidly cued by peripheral cues. SOA was fixed at 160ms. In Experiment 2 [low-temporal-predictability (LTP) condition], (n=10, age 19-36years) we retained HPL stimuli but randomly intermixed short-SOA trials with long-SOA (1000ms) trials in the task-blocks. In Experiment 1 and the short-SOA condition of the Experiment 2, validly-cued targets elicited significantly faster reaction times and larger contralateral P1, consistent with previous literature. A significant attentional enhancement of C1 amplitude was also observed in the HTP, but not LTP condition. The findings suggest that exogenous visual attention can facilitate the earliest stage of cortical processing under HTP conditions. PMID:27114044

  19. Reactive Recruitment of Attentional Control in Math Anxiety: An ERP Study of Numeric Conflict Monitoring and Adaptation

    PubMed Central

    Suárez-Pellicioni, Macarena; Núñez-Peña, María Isabel; Colomé, Àngels

    2014-01-01

    This study uses event-related brain potentials (ERPs) to investigate the electrophysiological correlates of numeric conflict monitoring in math-anxious individuals, by analyzing whether math anxiety is related to abnormal processing in early conflict detection (as shown by the N450 component) and/or in a later, response-related stage of processing (as shown by the conflict sustained potential; Conflict-SP). Conflict adaptation effects were also studied by analyzing the effect of the previous trial’s congruence in current interference. To this end, 17 low math-anxious (LMA) and 17 high math-anxious (HMA) individuals were presented with a numerical Stroop task. Groups were extreme in math anxiety but did not differ in trait or state anxiety or in simple math ability. The interference effect of the current trial (incongruent-congruent) and the interference effect preceded by congruence and by incongruity were analyzed both for behavioral measures and for ERPs. A greater interference effect was found for response times in the HMA group than in the LMA one. Regarding ERPs, the LMA group showed a greater N450 component for the interference effect preceded by congruence than when preceded by incongruity, while the HMA group showed greater Conflict-SP amplitude for the interference effect preceded by congruence than when preceded by incongruity. Our study showed that the electrophysiological correlates of numeric interference in HMA individuals comprise the absence of a conflict adaptation effect in the first stage of conflict processing (N450) and an abnormal subsequent up-regulation of cognitive control in order to overcome the conflict (Conflict-SP). More concretely, our study shows that math anxiety is related to a reactive and compensatory recruitment of control resources that is implemented only when previously exposed to a stimuli presenting conflicting information. PMID:24918584

  20. Involvement of Norepinephrine in the Control of Activity and Attentive Processes in Animal Models of Attention Deficit Hyperactivity Disorder

    PubMed Central

    Viggiano, D.; Ruocco, L. A.; Arcieri, S.; Sadile, A. G.

    2004-01-01

    Functional and morphological studies in children affected by Attention Deficit Hyperactivity Disorder (ADHD) suggest a prefrontal cortex (PFc) dysfunction. This cortical region is regulated by subcortical systems including noradrenergic (NEergic), dopaminergic (DAergic), cholinergic, serotonergic, and histaminergic pathways. A wealth of data in humans and in animal models demonstrates altered dopamine (DA) regulation. Drugs that modulate norepinephrine (NE) transmission are also effective in ADHD patients, thus leading to the hypothesis of a NEergic disorder. This review covers the regulation of PFc functions by NE and the interaction between the NE and DA systems, as suggested by pharmacological, electrophysiological, morphological, and gene knock out (KO) studies. A negative feedback between NE and DA neurons emerges from KO studies because KO mice showing increased (NE transporter (NET) KO) or decreased (DBH and VMAT2 KO) NE levels are respectively associated with lower and higher DA levels. Locomotor activity can be generally predicted by the DA level, whereas sensitivity to amphetamines is by NE/DA balance. Some animal models of ADHD, such as spontaneously hypertensive rats (SHR), show alterations in the PFc and in the DA system. Evidence about a correlation between the NE system and hyper-locomotion activity in such animals has not yet been clarified. Therefore, this review also includes recent evidence on the behavioral effects of two NET blockers, reboxetine and atomoxetine, in two animal models of ADHD: SHR and Naples High Excitability rats. As these drugs modulate the DA level in the PFc, certain effects are likely to be due to a rebalanced DA system. We discuss the significance of the results for theories of ADHD and make suggestions for future experimentation. PMID:15303310

  1. Studying the star formation process with adaptive optics

    NASA Astrophysics Data System (ADS)

    Menard, Francois; Dougados, Catherine; Duchene, Gaspard; Bouvier, Jerome; Duvert, Gilles; Lavalley, Claudia; Monin, Jean-Louis; Beuzit, Jean-Luc

    2000-07-01

    Young Stellar Objects (YSOs) are the builders of worlds. During its infancy, a star transforms ordinary interstellar dust particles into astronomical gold: planets to say the process is complex, and largely unknown to data. Yet, violent and spectacular events of mass ejection are witnessed, disks in keplerian rotation are detected, multiple stars dancing around each other are found. These are as many traces of the stellar and planet formation process. The high angular resolution provided by adaptive optics, and the related gain in sensitivity, have allowed major breakthrough discoveries to be made in each of these specific fields and our understanding of the various physical processes involved in the formation of a star has leaped forward tremendously over the last few years. In the following, meant as a report of the progress made recently in star formation due to adaptive optics, we will describe new results obtained at optical and near- infrared wavelengths, in imaging and spectroscopic modes. Our images of accretion disks and ionized stellar jets permit direct measurements of many physical parameters and shed light into the physics of the accretion and ejection processes. Although the accretion/ejection process so fundamental to star formation is usually studied around single objects, most of young stars form as part of multiple systems. We also present our findings on how the fraction of stars in binary systems evolves with age. The implications of these results on the conditions under which these stars must have formed are discussed.

  2. Temporal Context in Speech Processing and Attentional Stream Selection: A Behavioral and Neural perspective

    PubMed Central

    Zion Golumbic, Elana M.; Poeppel, David; Schroeder, Charles E.

    2012-01-01

    The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the ‘Cocktail Party’ effect. Yet, the neural mechanisms underlying on-line speech decoding and attentional stream selection are not well understood. We review findings from behavioral and neurophysiological investigations that underscore the importance of the temporal structure of speech for achieving these perceptual feats. We discuss the hypothesis that entrainment of ambient neuronal oscillations to speech’s temporal structure, across multiple time-scales, serves to facilitate its decoding and underlies the selection of an attended speech stream over other competing input. In this regard, speech decoding and attentional stream selection are examples of ‘active sensing’, emphasizing an interaction between proactive and predictive top-down modulation of neuronal dynamics and bottom-up sensory input. PMID:22285024

  3. Self make-up: the influence of self-referential processing on attention orienting

    PubMed Central

    Zhao, Shuo; Uono, Shota; Yoshimura, Sayaka; Toichi, Motomi

    2015-01-01

    For humans, both eye gaze and arrows serve as powerful signals for orienting attention. Recent studies have shown important differences between gaze and arrows in attention orienting; however, the mechanisms underlying these differences are not known. One such mechanism may be self-referential processing. To investigate this possibility, we trained participants to associate two cues (a red and green arrow in Experiment 1A and two different faces in Experiment 1B) with distinct words (“self” and “other”). Then, we manipulated two types of sound (voice and tone) as targets to investigate whether the cueing effect to self- and other-referential cues differs in a manner similar to that reported for gaze and arrows. We found that self-, but not other-, referential cues induced an enhanced cueing effect to the voice target relative to the tone target regardless of the cue characteristic (i.e., biological or non-biological). Our results suggest that the difference between gaze and arrows in orienting attention can be explained, at least in part, by the self-referentiality of gaze. Furthermore, in Experiment 2, we found a reverse cueing pattern between gaze and arrow cues by manipulating subjects’ experiences, suggesting that differences in the self-referentiality of gaze and arrow cues are not inherent. PMID:26391177

  4. Parallel Processing of Adaptive Meshes with Load Balancing

    NASA Technical Reports Server (NTRS)

    Das, Sajal K.; Harvey, Daniel J.; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Many scientific applications involve grids that lack a uniform underlying structure. These applications are often also dynamic in nature in that the grid structure significantly changes between successive phases of execution. In parallel computing environments, mesh adaptation of unstructured grids through selective refinement/coarsening has proven to be an effective approach. However, achieving load balance while minimizing interprocessor communication and redistribution costs is a difficult problem. Traditional dynamic load balancers are mostly inadequate because they lack a global view of system loads across processors. In this paper, we propose a novel and general-purpose load balancer that utilizes symmetric broadcast networks (SBN) as the underlying communication topology, and compare its performance with a successful global load balancing environment, called PLUM, specifically created to handle adaptive unstructured applications. Our experimental results on an IBM SP2 demonstrate that the SBN-based load balancer achieves lower redistribution costs than that under PLUM by overlapping processing and data migration.

  5. Optimal and adaptive methods of processing hydroacoustic signals (review)

    NASA Astrophysics Data System (ADS)

    Malyshkin, G. S.; Sidel'nikov, G. B.

    2014-09-01

    Different methods of optimal and adaptive processing of hydroacoustic signals for multipath propagation and scattering are considered. Advantages and drawbacks of the classical adaptive (Capon, MUSIC, and Johnson) algorithms and "fast" projection algorithms are analyzed for the case of multipath propagation and scattering of strong signals. The classical optimal approaches to detecting multipath signals are presented. A mechanism of controlled normalization of strong signals is proposed to automatically detect weak signals. The results of simulating the operation of different detection algorithms for a linear equidistant array under multipath propagation and scattering are presented. An automatic detector is analyzed, which is based on classical or fast projection algorithms, which estimates the background proceeding from median filtering or the method of bilateral spatial contrast.

  6. Adaptive neural information processing with dynamical electrical synapses

    PubMed Central

    Xiao, Lei; Zhang, Dan-ke; Li, Yuan-qing; Liang, Pei-ji; Wu, Si

    2013-01-01

    The present study investigates a potential computational role of dynamical electrical synapses in neural information process. Compared with chemical synapses, electrical synapses are more efficient in modulating the concerted activity of neurons. Based on the experimental data, we propose a phenomenological model for short-term facilitation of electrical synapses. The model satisfactorily reproduces the phenomenon that the neuronal correlation increases although the neuronal firing rates attenuate during the luminance adaptation. We explore how the stimulus information is encoded in parallel by firing rates and correlated activity of neurons, and find that dynamical electrical synapses mediate a transition from the firing rate code to the correlation one during the luminance adaptation. The latter encodes the stimulus information by using the concerted, but lower neuronal firing rate, and hence is economically more efficient. PMID:23596413

  7. Adaptive-optics optical coherence tomography processing using a graphics processing unit.

    PubMed

    Shafer, Brandon A; Kriske, Jeffery E; Kocaoglu, Omer P; Turner, Timothy L; Liu, Zhuolin; Lee, John Jaehwan; Miller, Donald T

    2014-01-01

    Graphics processing units are increasingly being used for scientific computing for their powerful parallel processing abilities, and moderate price compared to super computers and computing grids. In this paper we have used a general purpose graphics processing unit to process adaptive-optics optical coherence tomography (AOOCT) images in real time. Increasing the processing speed of AOOCT is an essential step in moving the super high resolution technology closer to clinical viability. PMID:25570838

  8. Salience and Attention in Surprisal-Based Accounts of Language Processing

    PubMed Central

    Zarcone, Alessandra; van Schijndel, Marten; Vogels, Jorrig; Demberg, Vera

    2016-01-01

    The notion of salience has been singled out as the explanatory factor for a diverse range of linguistic phenomena. In particular, perceptual salience (e.g., visual salience of objects in the world, acoustic prominence of linguistic sounds) and semantic-pragmatic salience (e.g., prominence of recently mentioned or topical referents) have been shown to influence language comprehension and production. A different line of research has sought to account for behavioral correlates of cognitive load during comprehension as well as for certain patterns in language usage using information-theoretic notions, such as surprisal. Surprisal and salience both affect language processing at different levels, but the relationship between the two has not been adequately elucidated, and the question of whether salience can be reduced to surprisal / predictability is still open. Our review identifies two main challenges in addressing this question: terminological inconsistency and lack of integration between high and low levels of representations in salience-based accounts and surprisal-based accounts. We capitalize upon work in visual cognition in order to orient ourselves in surveying the different facets of the notion of salience in linguistics and their relation with models of surprisal. We find that work on salience highlights aspects of linguistic communication that models of surprisal tend to overlook, namely the role of attention and relevance to current goals, and we argue that the Predictive Coding framework provides a unified view which can account for the role played by attention and predictability at different levels of processing and which can clarify the interplay between low and high levels of processes and between predictability-driven expectation and attention-driven focus. PMID:27375525

  9. Salience and Attention in Surprisal-Based Accounts of Language Processing.

    PubMed

    Zarcone, Alessandra; van Schijndel, Marten; Vogels, Jorrig; Demberg, Vera

    2016-01-01

    The notion of salience has been singled out as the explanatory factor for a diverse range of linguistic phenomena. In particular, perceptual salience (e.g., visual salience of objects in the world, acoustic prominence of linguistic sounds) and semantic-pragmatic salience (e.g., prominence of recently mentioned or topical referents) have been shown to influence language comprehension and production. A different line of research has sought to account for behavioral correlates of cognitive load during comprehension as well as for certain patterns in language usage using information-theoretic notions, such as surprisal. Surprisal and salience both affect language processing at different levels, but the relationship between the two has not been adequately elucidated, and the question of whether salience can be reduced to surprisal / predictability is still open. Our review identifies two main challenges in addressing this question: terminological inconsistency and lack of integration between high and low levels of representations in salience-based accounts and surprisal-based accounts. We capitalize upon work in visual cognition in order to orient ourselves in surveying the different facets of the notion of salience in linguistics and their relation with models of surprisal. We find that work on salience highlights aspects of linguistic communication that models of surprisal tend to overlook, namely the role of attention and relevance to current goals, and we argue that the Predictive Coding framework provides a unified view which can account for the role played by attention and predictability at different levels of processing and which can clarify the interplay between low and high levels of processes and between predictability-driven expectation and attention-driven focus. PMID:27375525

  10. Contributions of emotional state and attention to the processing of syntactic agreement errors: evidence from P600

    PubMed Central

    Verhees, Martine W. F. T.; Chwilla, Dorothee J.; Tromp, Johanne; Vissers, Constance T. W. M.

    2015-01-01

    The classic account of language is that language processing occurs in isolation from other cognitive systems, like perception, motor action, and emotion. The central theme of this paper is the relationship between a participant’s emotional state and language comprehension. Does emotional context affect how we process neutral words? Recent studies showed that processing of word meaning – traditionally conceived as an automatic process – is affected by emotional state. The influence of emotional state on syntactic processing is less clear. One study reported a mood-related P600 modulation, while another study did not observe an effect of mood on syntactic processing. The goals of this study were: First, to clarify whether and if so how mood affects syntactic processing. Second, to shed light on the underlying mechanisms by separating possible effects of mood from those of attention on syntactic processing. Event-related potentials (ERPs) were recorded while participants read syntactically correct or incorrect sentences. Mood (happy vs. sad) was manipulated by presenting film clips. Attention was manipulated by directing attention to syntactic features vs. physical features. The mood induction was effective. Interactions between mood, attention and syntactic correctness were obtained, showing that mood and attention modulated P600. The mood manipulation led to a reduction in P600 for sad as compared to happy mood when attention was directed at syntactic features. The attention manipulation led to a reduction in P600 when attention was directed at physical features compared to syntactic features for happy mood. From this we draw two conclusions: First, emotional state does affect syntactic processing. We propose mood-related differences in the reliance on heuristics as the underlying mechanism. Second, attention can contribute to emotion-related ERP effects in syntactic language processing. Therefore, future studies on the relation between language and emotion

  11. Mental workload prediction based on attentional resource allocation and information processing.

    PubMed

    Xiao, Xu; Wanyan, Xiaoru; Zhuang, Damin

    2015-01-01

    Mental workload is an important component in complex human-machine systems. The limited applicability of empirical workload measures produces the need for workload modeling and prediction methods. In the present study, a mental workload prediction model is built on the basis of attentional resource allocation and information processing to ensure pilots' accuracy and speed in understanding large amounts of flight information on the cockpit display interface. Validation with an empirical study of an abnormal attitude recovery task showed that this model's prediction of mental workload highly correlated with experimental results. This mental workload prediction model provides a new tool for optimizing human factors interface design and reducing human errors. PMID:26406085

  12. The role of attention in processing morphologically complex spoken words: an EEG/MEG study

    PubMed Central

    Leminen, Alina; Lehtonen, Minna; Leminen, Miika; Nevalainen, Päivi; Mäkelä, Jyrki P.; Kujala, Teija

    2013-01-01

    This study determined to what extent morphological processing of spoken inflected and derived words is attention-independent. To answer these questions EEG and MEG responses were recorded from healthy participants while they were presented with spoken Finnish inflected, derived, and monomorphemic words. In the non-attended task, the participants were instructed to ignore the incoming auditory stimuli and concentrate on the silent cartoon. In the attended task, previously reported by Leminen et al. (2011), the participants were to judge the acceptability of each stimulus. Importantly, EEG and MEG responses were time-locked to the onset of critical information [suffix onset for the complex words and uniqueness point (UP) for the monomorphemic words]. Early after the critical point, word type did not interact with task: in both attended and non-attended tasks, the event-related potentials (ERPs) showed larger negativity to derived than inflected or monomorphemic words ~100 ms after the critical point. MEG source waveforms showed a similar pattern. Later than 100 ms after the critical point, there were no differences between word types in the non-attended task either in the ERP or source modeling data. However, in the attended task inflected words elicited larger responses than other words ~200 ms after the critical point. The results suggest different brain representations for derived and inflected words. The early activation after the critical point was elicited both in the non-attended and attended tasks. As this stage of word recognition was not modulated by attention, it can be concluded to reflect an automatic mapping of incoming acoustic information onto stored representations. In contrast, the later differences between word types in the attended task were not observed in the non-attended task. This indicates that later compositional processes at the (morpho)syntactic-semantic level require focused attention. PMID:23316156

  13. On Cognition, Structured Sequence Processing, and Adaptive Dynamical Systems

    NASA Astrophysics Data System (ADS)

    Petersson, Karl Magnus

    2008-11-01

    Cognitive neuroscience approaches the brain as a cognitive system: a system that functionally is conceptualized in terms of information processing. We outline some aspects of this concept and consider a physical system to be an information processing device when a subclass of its physical states can be viewed as representational/cognitive and transitions between these can be conceptualized as a process operating on these states by implementing operations on the corresponding representational structures. We identify a generic and fundamental problem in cognition: sequentially organized structured processing. Structured sequence processing provides the brain, in an essential sense, with its processing logic. In an approach addressing this problem, we illustrate how to integrate levels of analysis within a framework of adaptive dynamical systems. We note that the dynamical system framework lends itself to a description of asynchronous event-driven devices, which is likely to be important in cognition because the brain appears to be an asynchronous processing system. We use the human language faculty and natural language processing as a concrete example through out.

  14. Adaptive ocean acoustic processing for a shallow ocean experiment

    SciTech Connect

    Candy, J.V.; Sullivan, E.J.

    1995-07-19

    A model-based approach is developed to solve an adaptive ocean acoustic signal processing problem. Here we investigate the design of model-based identifier (MBID) for a normal-mode model developed from a shallow water ocean experiment and then apply it to a set of experimental data demonstrating the feasibility of this approach. In this problem we show how the processor can be structured to estimate the horizontal wave numbers directly from measured pressure sound speed thereby eliminating the need for synthetic aperture processing or a propagation model solution. Ocean acoustic signal processing has made great strides over the past decade necessitated by the development of quieter submarines and the recent proliferation of diesel powered vessels.

  15. Selective attention modulates the effect of target location probability on redundant signal processing.

    PubMed

    Chang, Ting-Yun; Little, Daniel R; Yang, Cheng-Ta

    2016-08-01

    We investigated the decision process underlying the detection of targets at multiple locations. In three experiments using the same observers, target location probability and attentional instructions were manipulated. A redundant-target detection task was conducted in which participants were required to detect a dot presented at one of two locations. When the dot appeared at the two locations with equal frequency (Experiment 1), those participants who were found to have limited to unlimited capacity were shown to adopt a parallel, self-terminating strategy. By contrast, those participants who had supercapacity were shown to process redundant targets in a coactive manner. When targets were presented with unequal probability, two participants adopted a parallel, self-terminating strategy regardless of whether they were informed the target location probability (Experiment 3) or not (Experiment 2). For the remaining two participants, the strategy changed from parallel, self-terminating to serial, self-terminating as a result of the probability instructions. In Experiments 2 and 3, all the participants were of unlimited to limited capacity. Taken together, these results suggest that target location probability differently affects the selection of a decision strategy and highlight the role of controlled attention in selecting a decision strategy. PMID:27188653

  16. [Super sweet corn hybrids adaptability for industrial processing. I freezing].

    PubMed

    Alfonzo, Braunnier; Camacho, Candelario; Ortiz de Bertorelli, Ligia; De Venanzi, Frank

    2002-09-01

    With the purpose of evaluating adaptability to the freezing process of super sweet corn sh2 hybrids Krispy King, Victor and 324, 100 cobs of each type were frozen at -18 degrees C. After 120 days of storage, their chemical, microbiological and sensorial characteristics were compared with a sweet corn su. Industrial quality of the process of freezing and length and number of rows in cobs were also determined. Results revealed yields above 60% in frozen corns. Length and number of rows in cobs were acceptable. Most of the chemical characteristics of super sweet hybrids were not different from the sweet corn assayed at the 5% significance level. Moisture content and soluble solids of hybrid Victor, as well as total sugars of hybrid 324 were statistically different. All sh2 corns had higher pH values. During freezing, soluble solids concentration, sugars and acids decreased whereas pH increased. Frozen cobs exhibited acceptable microbiological rank, with low activities of mesophiles and total coliforms, absence of psychrophiles and fecal coliforms, and an appreciable amount of molds. In conclusion, sh2 hybrids adapted with no problems to the freezing process, they had lower contents of soluble solids and higher contents of total sugars, which almost doubled the amount of su corn; flavor, texture, sweetness and appearance of kernels were also better. Hybrid Victor was preferred by the evaluating panel and had an outstanding performance due to its yield and sensorial characteristics. PMID:12448345

  17. Motion compensation for adaptive horizontal line array processing

    NASA Astrophysics Data System (ADS)

    Yang, T. C.

    2003-01-01

    Large aperture horizontal line arrays have small resolution cells and can be used to separate a target signal from an interference signal by array beamforming. High-resolution adaptive array processing can be used to place a null at the interference signal so that the array gain can be much higher than that of conventional beamforming. But these nice features are significantly degraded by the source motion, which reduces the time period under which the environment can be considered stationary from the array processing point of view. For adaptive array processing, a large number of data samples are generally required to minimize the variance of the cross-spectral density, or the covariance matrix, between the array elements. For a moving source and interference, the penalty of integrating over a large number of samples is the spread of signal and interference energy to more than one or two eigenvalues. The signal and interference are no longer clearly identified by the eigenvectors and, consequently, the ability to suppress the interference suffers. We show in this paper that the effect of source motion can be compensated for the (signal) beam covariance matrix, thus allowing integration over a large number of data samples without loss in the signal beam power. We employ an equivalent of a rotating coordinate frame to track the signal bearing change and use the waveguide invariant theory to compensate the signal range change by frequency shifting.

  18. Prediction and control of chaotic processes using nonlinear adaptive networks

    SciTech Connect

    Jones, R.D.; Barnes, C.W.; Flake, G.W.; Lee, K.; Lewis, P.S.; O'Rouke, M.K.; Qian, S.

    1990-01-01

    We present the theory of nonlinear adaptive networks and discuss a few applications. In particular, we review the theory of feedforward backpropagation networks. We then present the theory of the Connectionist Normalized Linear Spline network in both its feedforward and iterated modes. Also, we briefly discuss the theory of stochastic cellular automata. We then discuss applications to chaotic time series, tidal prediction in Venice lagoon, finite differencing, sonar transient detection, control of nonlinear processes, control of a negative ion source, balancing a double inverted pendulum and design advice for free electron lasers and laser fusion targets.

  19. Landsat ecosystem disturbance adaptive processing system (LEDAPS) algorithm description

    USGS Publications Warehouse

    Schmidt, Gail; Jenkerson, Calli; Masek, Jeffrey; Vermote, Eric; Gao, Feng

    2013-01-01

    The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) software was originally developed by the National Aeronautics and Space Administration–Goddard Space Flight Center and the University of Maryland to produce top-of-atmosphere reflectance from LandsatThematic Mapper and Enhanced Thematic Mapper Plus Level 1 digital numbers and to apply atmospheric corrections to generate a surface-reflectance product.The U.S. Geological Survey (USGS) has adopted the LEDAPS algorithm for producing the Landsat Surface Reflectance Climate Data Record.This report discusses the LEDAPS algorithm, which was implemented by the USGS.

  20. Altered attentional and perceptual processes as indexed by N170 during gaze perception in schizophrenia: Relationship with perceived threat and paranoid delusions.

    PubMed

    Tso, Ivy F; Calwas, Anita M; Chun, Jinsoo; Mueller, Savanna A; Taylor, Stephan F; Deldin, Patricia J

    2015-08-01

    Using gaze information to orient attention and guide behavior is critical to social adaptation. Previous studies have suggested that abnormal gaze perception in schizophrenia (SCZ) may originate in abnormal early attentional and perceptual processes and may be related to paranoid symptoms. Using event-related brain potentials (ERPs), this study investigated altered early attentional and perceptual processes during gaze perception and their relationship to paranoid delusions in SCZ. Twenty-eight individuals with SCZ or schizoaffective disorder and 32 demographically matched healthy controls (HCs) completed a gaze-discrimination task with face stimuli varying in gaze direction (direct, averted), head orientation (forward, deviated), and emotion (neutral, fearful). ERPs were recorded during the task. Participants rated experienced threat from each face after the task. Participants with SCZ were as accurate as, though slower than, HCs on the task. Participants with SCZ displayed enlarged N170 responses over the left hemisphere to averted gaze presented in fearful relative to neutral faces, indicating a heightened encoding sensitivity to faces signaling external threat. This abnormality was correlated with increased perceived threat and paranoid delusions. Participants with SCZ also showed a reduction of N170 modulation by head orientation (normally increased amplitude to deviated faces relative to forward faces), suggesting less integration of contextual cues of head orientation in gaze perception. The psychophysiological deviations observed during gaze discrimination in SCZ underscore the role of early attentional and perceptual abnormalities in social information processing and paranoid symptoms of SCZ. PMID:25894438

  1. Temporal processing impairment in children with attention-deficit-hyperactivity disorder.

    PubMed

    Huang, Jia; Yang, Bin-rang; Zou, Xiao-bing; Jing, Jin; Pen, Gang; McAlonan, Gráinne M; Chan, Raymond C K

    2012-01-01

    The current study aimed to investigate temporal processing in Chinese children with Attention-Deficit-Hyperactivity Disorder(ADHD) using time production, time reproduction paradigm and duration discrimination tasks. A battery of tests specifically designed to measure temporal processing was administered to 94 children with ADHD and 100 demographically matched healthy children. A multivariate analysis of variance (MANOVA) and a repeated measure MANOVA indicated that children with ADHD were impaired in time processing functions. The results of pairwise comparisons showed that the probands with a family history of ADHD performed significantly worse than those without family history in the time production tasks and the time reproduction task. Logistic regression analysis showed duration discrimination had a significant role in predicting whether the children were suffering from ADHD or not, while temporal processing had a significant role in predicting whether the ADHD children had a family history or not. This study provides further support for the existence of a generic temporal processing impairment in ADHD children and suggests that abnormalities in time processing and ADHD share some common genetic factors. PMID:22119703

  2. Neural sensitivity to social deviance predicts attentive processing of peer-group judgment.

    PubMed

    Schnuerch, Robert; Trautmann-Lengsfeld, Sina Alexa; Bertram, Mario; Gibbons, Henning

    2014-01-01

    The detection of one's deviance from social norms is an essential mechanism of individual adjustment to group behavior and, thus, for the perpetuation of norms within groups. It has been suggested that error signals in mediofrontal cortex provide the neural basis of such deviance detection, which contributes to later adjustment to the norm. In the present study, we used event-related potentials (ERPs) to demonstrate that, across participants, the strength of mediofrontal brain correlates of the detection of deviance from a peer group's norms was negatively related to attentive processing of the same group's judgments in a later task. We propose that an individual's perception of social deviance might bias basic cognitive processing during further interaction with the group. Strongly perceiving disagreement with a group could cause an individual to avoid or inhibit this group's judgments. PMID:24968861

  3. [Evenly floating attention, models and theories of the cognitive process of the psychoanalyst].

    PubMed

    König, H

    1996-04-01

    The perception process taking place in the mind of the analyst in the psycho-analytic situation is a constant oscillation between the temptation to be guided too much by theory and the dangers of trusting to feelings and intuition alone. In order to avoid the pitfalls of this Scylla and Charybdis situation and with a view to reconciling empathy and knowledge in such a way as to provide optimal access to the patient's unconscious, the author draws upon a model devised by W.R. Bion. The author claims that Bion's model, an intermedium between affect and cognition, achieves the integration of evenly suspended attention and theory-guided perception by taking account of patient's experiential objects while at the same time allowing scope for cognitive activity, a process which Bion calls "intervening phase" König then briefly recounts a case study illustrating the possibility of achieving interpretations that combine both empathy and knowledge. PMID:8685384

  4. Simulation of dynamic processes with adaptive neural networks.

    SciTech Connect

    Tzanos, C. P.

    1998-02-03

    Many industrial processes are highly non-linear and complex. Their simulation with first-principle or conventional input-output correlation models is not satisfactory, either because the process physics is not well understood, or it is so complex that direct simulation is either not adequately accurate, or it requires excessive computation time, especially for on-line applications. Artificial intelligence techniques (neural networks, expert systems, fuzzy logic) or their combination with simple process-physics models can be effectively used for the simulation of such processes. Feedforward (static) neural networks (FNNs) can be used effectively to model steady-state processes. They have also been used to model dynamic (time-varying) processes by adding to the network input layer input nodes that represent values of input variables at previous time steps. The number of previous time steps is problem dependent and, in general, can be determined after extensive testing. This work demonstrates that for dynamic processes that do not vary fast with respect to the retraining time of the neural network, an adaptive feedforward neural network can be an effective simulator that is free of the complexities introduced by the use of input values at previous time steps.

  5. Attention Modulates the Auditory Cortical Processing of Spatial and Category Cues in Naturalistic Auditory Scenes

    PubMed Central

    Renvall, Hanna; Staeren, Noël; Barz, Claudia S.; Ley, Anke; Formisano, Elia

    2016-01-01

    This combined fMRI and MEG study investigated brain activations during listening and attending to natural auditory scenes. We first recorded, using in-ear microphones, vocal non-speech sounds, and environmental sounds that were mixed to construct auditory scenes containing two concurrent sound streams. During the brain measurements, subjects attended to one of the streams while spatial acoustic information of the scene was either preserved (stereophonic sounds) or removed (monophonic sounds). Compared to monophonic sounds, stereophonic sounds evoked larger blood-oxygenation-level-dependent (BOLD) fMRI responses in the bilateral posterior superior temporal areas, independent of which stimulus attribute the subject was attending to. This finding is consistent with the functional role of these regions in the (automatic) processing of auditory spatial cues. Additionally, significant differences in the cortical activation patterns depending on the target of attention were observed. Bilateral planum temporale and inferior frontal gyrus were preferentially activated when attending to stereophonic environmental sounds, whereas when subjects attended to stereophonic voice sounds, the BOLD responses were larger at the bilateral middle superior temporal gyrus and sulcus, previously reported to show voice sensitivity. In contrast, the time-resolved MEG responses were stronger for mono- than stereophonic sounds in the bilateral auditory cortices at ~360 ms after the stimulus onset when attending to the voice excerpts within the combined sounds. The observed effects suggest that during the segregation of auditory objects from the auditory background, spatial sound cues together with other relevant temporal and spectral cues are processed in an attention-dependent manner at the cortical locations generally involved in sound recognition. More synchronous neuronal activation during monophonic than stereophonic sound processing, as well as (local) neuronal inhibitory mechanisms in

  6. Polymer Solidification and Stabilization: Adaptable Processes for Atypical Wastes

    SciTech Connect

    Jensen, C.

    2007-07-01

    Vinyl Ester Styrene (VES) and Advanced Polymer Solidification (APS{sup TM}) processes are used to solidify, stabilize, and immobilize radioactive, pyrophoric and hazardous wastes at US Department of Energy (DOE) and Department of Defense (DOD) sites, and commercial nuclear facilities. A wide range of projects have been accomplished, including in situ immobilization of ion exchange resin and carbon filter media in decommissioned submarines; underwater solidification of zirconium and hafnium machining swarf; solidification of uranium chips; impregnation of depth filters; immobilization of mercury, lead and other hazardous wastes (including paint chips and blasting media); and in situ solidification of submerged demineralizers. Discussion of the adaptability of the VES and APS{sup TM} processes is timely, given the decommissioning work at government sites, and efforts by commercial nuclear plants to reduce inventories of one-of-a-kind wastes. The VES and APS{sup TM} media and processes are highly adaptable to a wide range of waste forms, including liquids, slurries, bead and granular media; as well as metal fines, particles and larger pieces. With the ability to solidify/stabilize liquid wastes using high-speed mixing; wet sludges and solids by low-speed mixing; or bead and granular materials through in situ processing, these polymer will produce a stable, rock-hard product that has the ability to sequester many hazardous waste components and create Class B and C stabilized waste forms for disposal. Technical assessment and approval of these solidification processes and final waste forms have been greatly simplified by exhaustive waste form testing, as well as multiple NRC and CRCPD waste form approvals. (authors)

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

    PubMed

    Papera, Massimiliano; Richards, Anne

    2016-05-01

    Exogenous allocation of attentional resources allows the visual system to encode and maintain representations of stimuli in visual working memory (VWM). However, limits in the processing capacity to allocate resources can prevent unexpected visual stimuli from gaining access to VWM and thereby to consciousness. Using a novel approach to create unbiased stimuli of increasing saliency, we investigated visual processing during a visual search task in individuals who show a high or low propensity to neglect unexpected stimuli. When propensity to inattention is high, ERP recordings show a diminished amplification concomitantly with a decrease in theta band power during the N1 latency, followed by a poor target enhancement during the N2 latency. Furthermore, a later modulation in the P3 latency was also found in individuals showing propensity to visual neglect, suggesting that more effort is required for conscious maintenance of visual information in VWM. Effects during early stages of processing (N80 and P1) were also observed suggesting that sensitivity to contrasts and medium-to-high spatial frequencies may be modulated by low-level saliency (albeit no statistical group differences were found). In accordance with the Global Workplace Model, our data indicate that a lack of resources in low-level processors and visual attention may be responsible for the failure to "ignite" a state of high-level activity spread across several brain areas that is necessary for stimuli to access awareness. These findings may aid in the development of diagnostic tests and intervention to detect/reduce inattention propensity to visual neglect of unexpected stimuli. PMID:26849023

  8. Adaptive memory: enhanced location memory after survival processing.

    PubMed

    Nairne, James S; Vanarsdall, Joshua E; Pandeirada, Josefa N S; Blunt, Janell R

    2012-03-01

    Two experiments investigated whether survival processing enhances memory for location. From an adaptive perspective, remembering that food has been located in a particular area, or that potential predators are likely to be found in a given territory, should increase the chances of subsequent survival. Participants were shown pictures of food or animals located at various positions on a computer screen. The task was to rate the ease of collecting the food or capturing the animals relative to a central fixation point. Surprise retention tests revealed that people remembered the locations of the items better when the collection or capturing task was described as relevant to survival. These data extend the generality of survival processing advantages to a new domain (location memory) by means of a task that does not involve rating the relevance of words to a scenario. PMID:22004268

  9. Processing speed training increases the efficiency of attentional resource allocation in young adults.

    PubMed

    Burge, Wesley K; Ross, Lesley A; Amthor, Franklin R; Mitchell, William G; Zotov, Alexander; Visscher, Kristina M

    2013-01-01

    Cognitive training has been shown to improve performance on a range of tasks. However, the mechanisms underlying these improvements are still unclear. Given the wide range of transfer effects, it is likely that these effects are due to a factor common to a wide range of tasks. One such factor is a participant's efficiency in allocating limited cognitive resources. The impact of a cognitive training program, Processing Speed Training (PST), on the allocation of resources to a set of visual tasks was measured using pupillometry in 10 young adults as compared to a control group of a 10 young adults (n = 20). PST is a well-studied computerized training program that involves identifying simultaneously presented central and peripheral stimuli. As training progresses, the task becomes increasingly more difficult, by including peripheral distracting stimuli and decreasing the duration of stimulus presentation. Analysis of baseline data confirmed that pupil diameter reflected cognitive effort. After training, participants randomized to PST used fewer attentional resources to perform complex visual tasks as compared to the control group. These pupil diameter data indicated that PST appears to increase the efficiency of attentional resource allocation. Increases in cognitive efficiency have been hypothesized to underlie improvements following experience with action video games, and improved cognitive efficiency has been hypothesized to underlie the benefits of PST in older adults. These data reveal that these training schemes may share a common underlying mechanism of increasing cognitive efficiency in younger adults. PMID:24151461

  10. Sustained Attention is Associated with Error Processing Impairment: Evidence from Mental Fatigue Study in Four-Choice Reaction Time Task

    PubMed Central

    Xiao, Yi; Ma, Feng; Lv, Yixuan; Cai, Gui; Teng, Peng; Xu, FengGang; Chen, Shanguang

    2015-01-01

    Attention is important in error processing. Few studies have examined the link between sustained attention and error processing. In this study, we examined how error-related negativity (ERN) of a four-choice reaction time task was reduced in the mental fatigue condition and investigated the role of sustained attention in error processing. Forty-one recruited participants were divided into two groups. In the fatigue experiment group, 20 subjects performed a fatigue experiment and an additional continuous psychomotor vigilance test (PVT) for 1 h. In the normal experiment group, 21 subjects only performed the normal experimental procedures without the PVT test. Fatigue and sustained attention states were assessed with a questionnaire. Event-related potential results showed that ERN (p < 0.005) and peak (p < 0.05) mean amplitudes decreased in the fatigue experiment. ERN amplitudes were significantly associated with the attention and fatigue states in electrodes Fz, FC1, Cz, and FC2. These findings indicated that sustained attention was related to error processing and that decreased attention is likely the cause of error processing impairment. PMID:25756780

  11. Transfer of Training between Music and Speech: Common Processing, Attention, and Memory.

    PubMed

    Besson, Mireille; Chobert, Julie; Marie, Céline

    2011-01-01

    After a brief historical perspective of the relationship between language and music, we review our work on transfer of training from music to speech that aimed at testing the general hypothesis that musicians should be more sensitive than non-musicians to speech sounds. In light of recent results in the literature, we argue that when long-term experience in one domain influences acoustic processing in the other domain, results can be interpreted as common acoustic processing. But when long-term experience in one domain influences the building-up of abstract and specific percepts in another domain, results are taken as evidence for transfer of training effects. Moreover, we also discuss the influence of attention and working memory on transfer effects and we highlight the usefulness of the event-related potentials method to disentangle the different processes that unfold in the course of music and speech perception. Finally, we give an overview of an on-going longitudinal project with children aimed at testing transfer effects from music to different levels and aspects of speech processing. PMID:21738519

  12. Transfer of Training between Music and Speech: Common Processing, Attention, and Memory

    PubMed Central

    Besson, Mireille; Chobert, Julie; Marie, Céline

    2011-01-01

    After a brief historical perspective of the relationship between language and music, we review our work on transfer of training from music to speech that aimed at testing the general hypothesis that musicians should be more sensitive than non-musicians to speech sounds. In light of recent results in the literature, we argue that when long-term experience in one domain influences acoustic processing in the other domain, results can be interpreted as common acoustic processing. But when long-term experience in one domain influences the building-up of abstract and specific percepts in another domain, results are taken as evidence for transfer of training effects. Moreover, we also discuss the influence of attention and working memory on transfer effects and we highlight the usefulness of the event-related potentials method to disentangle the different processes that unfold in the course of music and speech perception. Finally, we give an overview of an on-going longitudinal project with children aimed at testing transfer effects from music to different levels and aspects of speech processing. PMID:21738519

  13. The interplay between attentional strategies and language processing in high-functioning adults with autism spectrum disorder.

    PubMed

    Koolen, Sophieke; Vissers, Constance Th W M; Hendriks, Angelique W C J; Egger, Jos I M; Verhoeven, Ludo

    2012-05-01

    This study examined the hypothesis of an atypical interaction between attention and language in ASD. A dual-task experiment with three conditions was designed, in which sentences were presented that contained errors requiring attentional focus either at (a) low level, or (b) high level, or (c) both levels of language. Speed and accuracy for error detection were measured from 16 high-functioning adults with ASD, and 16 matched controls. For controls, there was an attentional cost of dual level processing for low level performance but not for high level performance. For participants with ASD, there was an attentional cost both for low level and for high level performance. These results suggest a compensatory strategic use of attention during language processing in ASD. PMID:21691865

  14. How Attentional Systems Process Conflicting Cues. The Superiority of Social over Symbolic Orienting Revisited

    ERIC Educational Resources Information Center

    Nummenmaa, Lauri; Hietanen, Jari K.

    2009-01-01

    We investigated orienting of attention by social and symbolic cues presented inside/outside the locus of attention. Participants responded to laterally presented targets preceded by simultaneously presented gaze and arrow cues. Participants' attention was allocated to either of the cues and the other cue served as a distractor. In Experiments 1-4…

  15. Attentional Processes in Interactions between People with Profound Intellectual and Multiple Disabilities and Direct Support Staff

    ERIC Educational Resources Information Center

    Ine, Hostyn; Heleen, Neerinckx; Bea, Maes

    2011-01-01

    Few studies have examined joint attention in interactions with persons with profound intellectual and multiple disabilities (PIMD), despite its important role in high-quality interaction. The purpose of this study is to describe the attention-directing behaviours of persons with PIMD and their direct support staff and the attention episodes…

  16. Cortical State and Attention

    PubMed Central

    Harris, Kenneth D.; Thiele, Alexander

    2012-01-01

    Preface The brain continuously adapts its processing machinery to behavioural demands. To achieve this it rapidly modulates the operating mode of cortical circuits, controlling the way information is transformed and routed. This article will focus on two experimental approaches by which the control of cortical information processing has been investigated: the study of state-dependent cortical processing in rodents, and attention in the primate visual system. Both processes involve a modulation of low-frequency activity fluctuations and spiking correlation, and are mediated by common receptor systems. We suggest that selective attention involves processes similar to state change, operating at a local columnar level to enhance the representation of otherwise nonsalient features while suppressing internally generated activity patterns. PMID:21829219

  17. Adaptive phase estimation and its application in EEG analysis of word processing.

    PubMed

    Schack, B; Rappelsberger, P; Weiss, S; Möller, E

    1999-10-30

    Oscillations are a general phenomenon of neuronal activity during information processing. Mostly, widespread networks are involved in brain functioning. In order to investigate network activity coherence analysis turned out to be a useful tool for examining the functional relationship between different cortical areas. This parameter allows the investigation of synchronisation phenomena with regard to defined frequencies or frequency bands. Coherence and cross phase are closely connected spectral parameters. Coherence may be understood as a measure of phase stability. Whereas coherence describes the amount of information transfer, the corresponding phase, from which time delays can be computed, hints at the direction of information transfer. Mental processes can be very brief and coupling between different areas may be highly dynamic. For this reason a two-dimensional approach of adaptive filtering was developed to estimate coherence and phase continuously in time. Statistical and dynamic properties of instantaneous phase are discussed. In order to demonstrate the value of this method for studying higher cognitive processes the method was applied to EEG recorded during word processing. During visual presentation of abstract nouns an information transfer from visual areas to frontal association areas in the Alpha1 frequency band could be verified within the first 400 ms. The Alpha1 band predominately seems to reflect sensory processing and attentional processes. In addition to conventional coherence analyses during word processing phase estimations may yield valuable new insights into the physiological mechanisms during word processing. PMID:10598864

  18. Shifting Attention

    ERIC Educational Resources Information Center

    Ingram, Jenni

    2014-01-01

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

  19. Links between eye movement preparation and the attentional processing of tactile events: An event-related brain potential study

    PubMed Central

    Gherri, Elena; Eimer, Martin

    2009-01-01

    Objective We investigated whether the covert preparation of saccadic eye movements results in spatially specific modulations of somatosensory processing. Methods ERPs were recorded in a spatial cueing experiment where auditory cues preceded tactile stimuli delivered to the left or right hand. In the Saccade task, cues signalled that an eye movement towards the left or right hand had to be prepared. In the Covert Attention task, cues signalled the direction of a covert shift of tactile attention. Results A lateralised component previously observed during cued shifts of spatial attention (ADAN) was elicited in the cue-target interval in both tasks. The somatosensory N140 component was enhanced for tactile stimuli presented to the hand on the cued side. This modulation was present not just in the Covert Attention task, but also in the Saccade task. Longer-latency effects of spatial cueing were only present in the Covert Attention task. Conclusions Covert shifts of attention and saccade preparation have similar effects on early stages of tactile processing, suggesting that both are mediated by overlapping control processes. Significance These findings support the premotor theory of attention by demonstrating that the programming of eye movements has spatially selective effects on somatosensory processing. PMID:18786857

  20. Working Memory as Internal Attention: Toward an Integrative Account of Internal and External Selection Processes

    PubMed Central

    Kiyonaga, Anastasia; Egner, Tobias

    2012-01-01

    Working memory (WM) and attention have been studied as separate cognitive constructs, although it has long been acknowledged that attention plays an important role in controlling the activation, maintenance, and manipulation of representations in WM. WM has, conversely, been thought of as a means of maintaining representations to voluntarily guide perceptual selective attention. It has more recently been observed, however, that the contents of WM can capture visual attention, even when such internally maintained representations are irrelevant, and often disruptive, to the immediate external task. Thus the precise relationship between WM and attention remains unclear, but it appears that they may bi-directionally impact one another, whether or not internal representations are consistent with external perceptual goals. This reciprocal relationship seems, further, to be constrained by limited cognitive resources to handle demands in either maintenance or selection. We propose here that the close relationship between WM and attention may be best described as a give-and-take interdependence between attention directed toward actively maintained internal representations (traditionally considered WM) versus external perceptual stimuli (traditionally considered selective attention), underpinned by their shared reliance on a common cognitive resource. Put simply, we argue that WM and attention should no longer be considered as separate systems or concepts, but as competing and impacting one another because they rely on the same limited resource. This framework can offer an explanation for the capture of visual attention by irrelevant WM contents, as well as a straightforward account of the underspecified relationship between WM and attention. PMID:23233157

  1. Adapting the transtheoretical model of change to the bereavement process.

    PubMed

    Calderwood, Kimberly A

    2011-04-01

    Theorists currently believe that bereaved people undergo some transformation of self rather than returning to their original state. To advance our understanding of this process, this article presents an adaptation of Prochaska and DiClemente's transtheoretical model of change as it could be applied to the journey that bereaved individuals experience. This theory is unique because it addresses attitudes, intentions, and behavioral processes at each stage; it allows for a focus on a broader range of emotions than just anger and depression; it allows for the recognition of two periods of regression during the bereavement process; and it adds a maintenance stage, which other theories lack. This theory can benefit bereaved individuals directly and through the increased awareness among counselors, family, friends, employers, and society at large. This theory may also be used as a tool for bereavement programs to consider whether they are meeting clients' needs throughout the transformation change bereavement process rather than only focusing on the initial stages characterized by intense emotion. PMID:21553574

  2. Attentional and affective processing of sexual stimuli in women with hypoactive sexual desire disorder.

    PubMed

    Brauer, Marieke; van Leeuwen, Matthijs; Janssen, Erick; Newhouse, Sarah K; Heiman, Julia R; Laan, Ellen

    2012-08-01

    Hypoactive sexual desire disorder (HSDD) is the most common sexual problem in women. From an incentive motivation perspective, HSDD may be the result of a weak association between sexual stimuli and rewarding experiences. As a consequence, these stimuli may either lose or fail to acquire a positive meaning, resulting in a limited number of incentives that have the capacity to elicit a sexual response. According to current information processing models of sexual arousal, sexual stimuli automatically activate meanings and if these are not predominantly positive, processes relevant to the activation of sexual arousal and desire may be interrupted. Premenopausal U.S. and Dutch women with acquired HSDD (n = 42) and a control group of sexually functional women (n = 42) completed a single target Implicit Association Task and a Picture Association Task assessing automatic affective associations with sexual stimuli and a dot detection task measuring attentional capture by sexual stimuli. Results showed that women with acquired HSDD displayed less positive (but not more negative) automatic associations with sexual stimuli than sexually functional women. The same pattern was found for self-reported affective sex-related associations. Participants were slower to detect targets in the dot detection task that replaced sexual images, irrespective of sexual function status. As such, the findings point to the relevance of affective processing of sexual stimuli in women with HSDD, and imply that the treatment of HSDD might benefit from a stronger emphasis on the strengthening of the association between sexual stimuli and positive meaning and sexual reward. PMID:21892693

  3. Adaptive model predictive process control using neural networks

    DOEpatents

    Buescher, K.L.; Baum, C.C.; Jones, R.D.

    1997-08-19

    A control system for controlling the output of at least one plant process output parameter is implemented by adaptive model predictive control using a neural network. An improved method and apparatus provides for sampling plant output and control input at a first sampling rate to provide control inputs at the fast rate. The MPC system is, however, provided with a network state vector that is constructed at a second, slower rate so that the input control values used by the MPC system are averaged over a gapped time period. Another improvement is a provision for on-line training that may include difference training, curvature training, and basis center adjustment to maintain the weights and basis centers of the neural in an updated state that can follow changes in the plant operation apart from initial off-line training data. 46 figs.

  4. Adaptive model predictive process control using neural networks

    DOEpatents

    Buescher, Kevin L.; Baum, Christopher C.; Jones, Roger D.

    1997-01-01

    A control system for controlling the output of at least one plant process output parameter is implemented by adaptive model predictive control using a neural network. An improved method and apparatus provides for sampling plant output and control input at a first sampling rate to provide control inputs at the fast rate. The MPC system is, however, provided with a network state vector that is constructed at a second, slower rate so that the input control values used by the MPC system are averaged over a gapped time period. Another improvement is a provision for on-line training that may include difference training, curvature training, and basis center adjustment to maintain the weights and basis centers of the neural in an updated state that can follow changes in the plant operation apart from initial off-line training data.

  5. Similarities in error processing establish a link between saccade prediction at baseline and adaptation performance

    PubMed Central

    Shelhamer, Mark

    2014-01-01

    Adaptive processes are crucial in maintaining the accuracy of body movements and rely on error storage and processing mechanisms. Although classically studied with adaptation paradigms, evidence of these ongoing error-correction mechanisms should also be detectable in other movements. Despite this connection, current adaptation models are challenged when forecasting adaptation ability with measures of baseline behavior. On the other hand, we have previously identified an error-correction process present in a particular form of baseline behavior, the generation of predictive saccades. This process exhibits long-term intertrial correlations that decay gradually (as a power law) and are best characterized with the tools of fractal time series analysis. Since this baseline task and adaptation both involve error storage and processing, we sought to find a link between the intertrial correlations of the error-correction process in predictive saccades and the ability of subjects to alter their saccade amplitudes during an adaptation task. Here we find just such a relationship: the stronger the intertrial correlations during prediction, the more rapid the acquisition of adaptation. This reinforces the links found previously between prediction and adaptation in motor control and suggests that current adaptation models are inadequate to capture the complete dynamics of these error-correction processes. A better understanding of the similarities in error processing between prediction and adaptation might provide the means to forecast adaptation ability with a baseline task. This would have many potential uses in physical therapy and the general design of paradigms of motor adaptation. PMID:24598520

  6. Emotional Processing and Attention Control Impairments in Children with Anxiety: An Integrative Review of Event-Related Potentials Findings.

    PubMed

    Wauthia, Erika; Rossignol, Mandy

    2016-01-01

    Anxiety disorders in adults have been associated with biased processing of emotional information which may be due to a deficit in attentional control. This deficit leads to an hypervigilance and a selective attention toward threatening information. Event-related potentials (ERPs) have been used to study this topic in anxious adults. Similar biases have been reported in children with anxiety but researches investigating the ERPs components underpinning these biases are more scarce. However, the understanding of the neural correlates of attentional biases in anxious children seem quite important since they could play a role in the etiology and the maintenance of this disorder. This review summarizes the results of researches having used ERPs to index emotional processing and attention control in children suffering from anxiety. We will focus on the P1, indexing basic visual perceptual processing, the N2, thought to reflect cognitive control process, the P3 typically associated with response inhibition, and the late positive potential (LPP) that indicates sustained attention toward motivationally salient stimuli. We will also examine the error-related negativity (ERN) that indexes monitoring system for detecting errors. Electro-physiological studies generally reported increased amplitudes of these components in anxious children, even when they did not differ from typically developing children at a behavioral level. These results suggest diminished cognitive control that influences children's selective attention mechanisms toward threatening information. Theoretical perspectives and implications for future researches will be discussed in the framework of current models of childhood anxiety. PMID:27199802

  7. A Comparative Study of Sustained Attentional Bias on Emotional Processing in ADHD Children to Pictures with Eye-Tracking

    PubMed Central

    PISHYAREH, Ebrahim; TEHRANI-DOOST, Mehdi; MAHMOODI-GHARAIE, Javad; KHORRAMI, Anahita; RAHMDAR, Saeid Reza

    2015-01-01

    Objective ADHD children have anomalous and negative behavior especially in emotionally related fields when compared to other. Evidence indicates that attention has an impact on emotional processing. The present study evaluates the effect of emotional processing on the sustained attention of children with ADHD type C. Materials & Methods Sixty participants form two equal groups (each with 30 children) of normal and ADHD children) and each subject met the required selected criterion as either a normal or an ADHD child. Both groups were aged from 6–11-years-old. All pictures were chosen from the International Affective Picture System (IAPS) and presented paired emotional and neutral scenes in the following categories: pleasant-neutral; pleasant-unpleasant; unpleasant-neutral; and neutral–neutral. Sustained attention was evaluated based on the number and duration of total fixation and was compared between the groups with MANOVA analysis. Results The duration of sustained attention on pleasant in the pleasant-unpleasant pair was significant. Bias in duration of sustained attention on pleasant scenes in pleasant-neutral pairs is significantly different between the groups. Conclusion Such significant differences might be indicative of ADHD children deficiencies in emotional processing. It seems that the highly deep effect of emotionally unpleasant scenes to gain the focus of ADHD children’s attention is responsible for impulsiveness and abnormal processing of emotional stimuli. PMID:25767541

  8. Emotional Processing and Attention Control Impairments in Children with Anxiety: An Integrative Review of Event-Related Potentials Findings

    PubMed Central

    Wauthia, Erika; Rossignol, Mandy

    2016-01-01

    Anxiety disorders in adults have been associated with biased processing of emotional information which may be due to a deficit in attentional control. This deficit leads to an hypervigilance and a selective attention toward threatening information. Event-related potentials (ERPs) have been used to study this topic in anxious adults. Similar biases have been reported in children with anxiety but researches investigating the ERPs components underpinning these biases are more scarce. However, the understanding of the neural correlates of attentional biases in anxious children seem quite important since they could play a role in the etiology and the maintenance of this disorder. This review summarizes the results of researches having used ERPs to index emotional processing and attention control in children suffering from anxiety. We will focus on the P1, indexing basic visual perceptual processing, the N2, thought to reflect cognitive control process, the P3 typically associated with response inhibition, and the late positive potential (LPP) that indicates sustained attention toward motivationally salient stimuli. We will also examine the error-related negativity (ERN) that indexes monitoring system for detecting errors. Electro-physiological studies generally reported increased amplitudes of these components in anxious children, even when they did not differ from typically developing children at a behavioral level. These results suggest diminished cognitive control that influences children's selective attention mechanisms toward threatening information. Theoretical perspectives and implications for future researches will be discussed in the framework of current models of childhood anxiety. PMID:27199802

  9. Recasting Hope: a process of adaptation following fetal anomaly diagnosis.

    PubMed

    Lalor, Joan; Begley, Cecily M; Galavan, Eoin

    2009-02-01

    Recent decades have seen ultrasound revolutionise the management of pregnancy and its possible complications. However, somewhat less consideration has been given to the psychosocial consequences of mass screening resulting in fetal anomaly detection in low-risk populations, particularly in contexts where termination of pregnancy services are not readily accessible. A grounded theory study was conducted exploring forty-one women's experiences of ultrasound diagnosis of fetal abnormality up to and beyond the birth in the Republic of Ireland. Thirty-one women chose to continue the pregnancy and ten women accessed termination of pregnancy services outside the state. Data were collected using repeated in-depth individual interviews pre- and post-birth and analysed using the constant comparative method. Recasting Hope, the process of adaptation following diagnosis is represented temporally as four phases: 'Assume Normal', 'Shock', 'Gaining Meaning' and 'Rebuilding'. Some mothers expressed a sense of incredulity when informed of the anomaly and the 'Assume Normal' phase provides an improved understanding as to why women remain unprepared for an adverse diagnosis. Transition to phase 2, 'Shock,' is characterised by receiving the diagnosis and makes explicit women's initial reactions. Once the diagnosis is confirmed, a process of 'Gaining Meaning' commences, whereby an attempt to make sense of this ostensibly negative event begins. 'Rebuilding', the final stage in the process, is concerned with the extent to which women recover from the loss and resolve the inconsistency between their experience and their previous expectations of pregnancy in particular and beliefs in the world in general. This theory contributes to the theoretical field of thanatology as applied to the process of grieving associated with the loss of an ideal child. The framework of Recasting Hope is intended for use as a tool to assist health professionals through offering simple yet effective

  10. Unraveling the anxious mind: anxiety, worry, and frontal engagement in sustained attention versus off-task processing.

    PubMed

    Forster, Sophie; Nunez Elizalde, Anwar O; Castle, Elizabeth; Bishop, Sonia J

    2015-03-01

    Much remains unknown regarding the relationship between anxiety, worry, sustained attention, and frontal function. Here, we addressed this using a sustained attention task adapted for functional magnetic resonance imaging. Participants responded to presentation of simple stimuli, withholding responses to an infrequent "No Go" stimulus. Dorsolateral prefrontal cortex (DLPFC) activity to "Go" trials, and dorsal anterior cingulate (dACC) activity to "No Go" trials were associated with faster error-free performance; consistent with DLPFC and dACC facilitating proactive and reactive control, respectively. Trait anxiety was linked to reduced recruitment of these regions, slower error-free performance, and decreased frontal-thalamo-striatal connectivity. This indicates an association between trait anxiety and impoverished frontal control of attention, even when external distractors are absent. In task blocks where commission errors were made, greater DLPFC-precuneus and DLPFC-posterior cingulate connectivity were associated with both trait anxiety and worry, indicative of increased off-task thought. Notably, unlike trait anxiety, worry was not linked to reduced frontal-striatal-thalamo connectivity, impoverished frontal recruitment, or slowed responding during blocks without commission errors, contrary to accounts proposing a direct causal link between worry and impoverished attentional control. This leads us to propose a new model of the relationship between anxiety, worry and frontal engagement in attentional control versus off-task thought. PMID:24062316

  11. Affective processing bias in youth with primary bipolar disorder or primary attention-deficit/hyperactivity disorder.

    PubMed

    Seymour, Karen E; Kim, Kerri L; Cushman, Grace K; Puzia, Megan E; Weissman, Alexandra B; Galvan, Thania; Dickstein, Daniel P

    2015-11-01

    High rates of comorbidity and overlapping diagnostic criteria between pediatric bipolar disorder (BD) and attention-deficit/hyperactivity disorder (ADHD) contribute to diagnostic and treatment confusion. To advance what is known about both disorders, we compared effect of emotional stimuli on response control in children with primary BD, primary ADHD and typically developing controls (TDC). Participants included 7-17 year olds with either "narrow-phenotype" pediatric BD (n = 25), ADHD (n = 25) or TDC (n = 25). Groups were matched on participant age and FSIQ. The effect of emotional stimuli on response control was assessed using the Cambridge Neuropsychological Test Automated Battery Affective Go/No-Go task (CANTAB AGN). We found a group by target valence interaction on commission errors [F(2,71) = 5.34, p < 0.01, ƞ p (2) = 0.13] whereby ADHD, but not TDC participants, made more errors on negative than positive words [t(24) = -2.58, p < 0.05, r = 0.47]. In contrast, there was a nonsignificant trend for BD participants to make fewer errors on negative versus positive words compared to ADHD and TDC participants. Between-subjects effects showed that ADHD participants made more errors than TDC, but not BD participants. Our main finding advances what is known about the effect of emotional stimuli on response control in children with ADHD. Our results suggesting a positive affective processing bias in children with ADHD compliment emerging literature show that difficulties with emotional processing and regulation may be core features of ADHD. Further, given the observed pattern of results in children with ADHD compared to BD children, our behavioral results suggest the importance of examining differences in the brain-behavior mechanisms involved in affective processing in children with ADHD compared to BD children. PMID:25724546

  12. Augmenting synthetic aperture radar with space time adaptive processing

    NASA Astrophysics Data System (ADS)

    Riedl, Michael; Potter, Lee C.; Ertin, Emre

    2013-05-01

    Wide-area persistent radar video offers the ability to track moving targets. A shortcoming of the current technology is an inability to maintain track when Doppler shift places moving target returns co-located with strong clutter. Further, the high down-link data rate required for wide-area imaging presents a stringent system bottleneck. We present a multi-channel approach to augment the synthetic aperture radar (SAR) modality with space time adaptive processing (STAP) while constraining the down-link data rate to that of a single antenna SAR system. To this end, we adopt a multiple transmit, single receive (MISO) architecture. A frequency division design for orthogonal transmit waveforms is presented; the approach maintains coherence on clutter, achieves the maximal unaliased band of radial velocities, retains full resolution SAR images, and requires no increase in receiver data rate vis-a-vis the wide-area SAR modality. For Nt transmit antennas and N samples per pulse, the enhanced sensing provides a STAP capability with Nt times larger range bins than the SAR mode, at the cost of O(log N) more computations per pulse. The proposed MISO system and the associated signal processing are detailed, and the approach is numerically demonstrated via simulation of an airborne X-band system.

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

    ERIC Educational Resources Information Center

    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…

  14. Creating Joint Attentional Frames and Pointing to Evidence in the Reading and Writing Process

    ERIC Educational Resources Information Center

    Unger, John A.; Liu, Rong; Scullion, Vicki A.

    2015-01-01

    This theory-into-practice paper integrates Tomasello's concept of Joint Attentional Frames and well-known ideas related to the work of Russian psychologist, Lev Vygotsky, with more recent ideas from social semiotics. Classroom procedures for incorporating student-created Joint Attentional Frames into literacy lessons are explained by links to…

  15. Attentional Processing of Faces in ASD: A Dot-Probe Study

    ERIC Educational Resources Information Center

    Moore, David J.; Heavey, Lisa; Reidy, John

    2012-01-01

    The present study used the Dot-Probe paradigm to explore attentional allocation to faces compared with non-social images in high-functioning individuals with autism spectrum disorder (ASD) and typically developing controls. There was no evidence of attentional bias in either group when stimuli were presented at individually calculated…

  16. Electrophysiological Indices of Spatial Attention during Global/Local Processing in Good and Poor Phonological Decoders

    ERIC Educational Resources Information Center

    Matthews, Allison Jane; Martin, Frances Heritage

    2009-01-01

    Previous research suggests a relationship between spatial attention and phonological decoding in developmental dyslexia. The aim of this study was to examine differences between good and poor phonological decoders in the allocation of spatial attention to global and local levels of hierarchical stimuli. A further aim was to investigate the…

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

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

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

    2005-01-01

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

  19. Cognition, emotion, and attention.

    PubMed

    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. PMID:25307584

  20. The process of assisting behavior modification in a child with attention-deficit hyperactivity disorder.

    PubMed

    Chang, Hsin-Hsin; Chang, Ching-Sheng; Shih, Ying-Ling

    2007-06-01

    Attention Deficit Hyperactivity Disorder (ADHD) is a common psychological disease among children. The purpose of this study was to describe the process of assisting with behavior modification in a child with ADHD. The patient had undergone medical treatment for a year with no obvious effect. With the guidance of other professional people, the child's teachers and nursing instructors, the researchers proceeded with behavioral modification in conjunction with medication for another year. The medication treatment followed doctors' prescriptions, and, as regards the behavioral treatment, doctors and experts drafted and decided the content of the behavioral contract. The main basic techniques were skillful reinforcement and punishment. Then, via interviews with his parents and teachers, information was obtained that provided an understanding of the patient's condition and progress. It was found that the improvements were very significant. On the basis of the research results, the researchers submit that: (1) drug treatment combined with behavioral treatment apparently improves the daily behaviors of hyperactive children; (2) good communication with parents and psychological preparation are the most critical keys to the success of substantial behavioral improvement among hyperactive children; (3) establishment and integration of social resources, including provision of transitional parenting education solutions, and cooperation and sound interaction from school teachers, which fosters consolidated team work, are the critical factors to behavioral improvement among hyperactive children. PMID:17551896

  1. Adaptive memory: evaluating alternative forms of fitness-relevant processing in the survival processing paradigm.

    PubMed

    Sandry, Joshua; Trafimow, David; Marks, Michael J; Rice, Stephen

    2013-01-01

    Memory may have evolved to preserve information processed in terms of its fitness-relevance. Based on the assumption that the human mind comprises different fitness-relevant adaptive mechanisms contributing to survival and reproductive success, we compared alternative fitness-relevant processing scenarios with survival processing. Participants rated words for relevancy to fitness-relevant and control conditions followed by a delay and surprise recall test (Experiment 1a). Participants recalled more words processed for their relevance to a survival situation. We replicated these findings in an online study (Experiment 2) and a study using revised fitness-relevant scenarios (Experiment 3). Across all experiments, we did not find a mnemonic benefit for alternative fitness-relevant processing scenarios, questioning assumptions associated with an evolutionary account of remembering. Based on these results, fitness-relevance seems to be too wide-ranging of a construct to account for the memory findings associated with survival processing. We propose that memory may be hierarchically sensitive to fitness-relevant processing instructions. We encourage future researchers to investigate the underlying mechanisms responsible for survival processing effects and work toward developing a taxonomy of adaptive memory. PMID:23585858

  2. Adaptive Memory: Evaluating Alternative Forms of Fitness-Relevant Processing in the Survival Processing Paradigm

    PubMed Central

    Sandry, Joshua; Trafimow, David; Marks, Michael J.; Rice, Stephen

    2013-01-01

    Memory may have evolved to preserve information processed in terms of its fitness-relevance. Based on the assumption that the human mind comprises different fitness-relevant adaptive mechanisms contributing to survival and reproductive success, we compared alternative fitness-relevant processing scenarios with survival processing. Participants rated words for relevancy to fitness-relevant and control conditions followed by a delay and surprise recall test (Experiment 1a). Participants recalled more words processed for their relevance to a survival situation. We replicated these findings in an online study (Experiment 2) and a study using revised fitness-relevant scenarios (Experiment 3). Across all experiments, we did not find a mnemonic benefit for alternative fitness-relevant processing scenarios, questioning assumptions associated with an evolutionary account of remembering. Based on these results, fitness-relevance seems to be too wide-ranging of a construct to account for the memory findings associated with survival processing. We propose that memory may be hierarchically sensitive to fitness-relevant processing instructions. We encourage future researchers to investigate the underlying mechanisms responsible for survival processing effects and work toward developing a taxonomy of adaptive memory. PMID:23585858

  3. Emotion Processing Influences Working Memory Circuits in Pediatric Bipolar Disorder and Attention Deficit Hyperactivity Disorder

    PubMed Central

    Passarotti, Alessandra M.; Sweeney, John A.; Pavuluri, Mani N.

    2010-01-01

    Objective This fMRI study examined how working memory circuits are affected by face emotion processing in pediatric bipolar disorder (PBD) and attention-deficit hyperactivity disorder (ADHD). Methods Twenty-three patients with bipolar disorder, 14 patients with ADHD and 19 healthy controls (HC) (mean age = 13.36 ± 2.55) underwent an affective 2-back fMRI task with blocks of happy, angry and neutral faces. Results For angry vs neutral faces PBD patients, relative to ADHD patients, exhibited increased activation in subgenual anterior cingulate cortex (ACC) and orbitofrontal cortex, and reduced activation in dorsolateral prefrontal cortex (DLPFC) and premotor cortex. Relative to HC the PBD group showed no increased activation and reduced activation at the junction of DLPFC and ventrolateral prefrontal cortex (VLPFC). Relative to HC the ADHD patients exhibited greater activation in DLPFC and reduced activation in ventral and medial PFC, pregenual ACC, striatum and temporo-parietal regions. For happy vs neutral faces, relative to ADHD the PBD group exhibited greater activation in bilateral caudate, and relative to HC it showed increased activation in DLPFC, striatal and parietal regions, and no reduced activation. The ADHD group, compared to HC, showed no reduced activation and increased activation in regions that were under-active for the angry face condition. Conclusions Relative to the ADHD group the PBD group exhibited greater deployment of the emotion processing circuitry and reduced deployment of working memory circuitry. Commonalities across PBD and ADHD patients, relative to HC, entailed cortico-subcortical activity that is reduced under negative emotional challenge, and increased under positive emotional challenge. PMID:20855051

  4. Developmental Dyslexia: Exploring How Much Phonological and Visual Attention Span Disorders Are Linked to Simultaneous Auditory Processing Deficits

    ERIC Educational Resources Information Center

    Lallier, Marie; Donnadieu, Sophie; Valdois, Sylviane

    2013-01-01

    The simultaneous auditory processing skills of 17 dyslexic children and 17 skilled readers were measured using a dichotic listening task. Results showed that the dyslexic children exhibited difficulties reporting syllabic material when presented simultaneously. As a measure of simultaneous visual processing, visual attention span skills were…

  5. Towards a Cognitive Model of Distraction by Auditory Novelty: The Role of Involuntary Attention Capture and Semantic Processing

    ERIC Educational Resources Information Center

    Parmentier, Fabrice B. R.

    2008-01-01

    Unexpected auditory stimuli are potent distractors, able to break through selective attention and disrupt performance in an unrelated visual task. This study examined the processing fate of novel sounds by examining the extent to which their semantic content is analyzed and whether the outcome of this processing can impact on subsequent behavior.…

  6. Attentional processing of other's facial display of pain: an eye tracking study.

    PubMed

    Vervoort, Tine; Trost, Zina; Prkachin, Kenneth M; Mueller, Sven C

    2013-06-01

    The present study investigated the role of observer pain catastrophizing and personal pain experience as possible moderators of attention to varying levels of facial pain expression in others. Eye movements were recorded as a direct and continuous index of attention allocation in a sample of 35 undergraduate students while viewing slides presenting picture pairs consisting of a neutral face combined with either a low, moderate, or high expressive pain face. Initial orienting of attention was measured as latency and duration of first fixation to 1 of 2 target images (i.e., neutral face vs pain face). Attentional maintenance was measured by gaze duration. With respect to initial orienting to pain, findings indicated that participants reporting low catastrophizing directed their attention more quickly to pain faces than to neutral faces, with fixation becoming increasingly faster with increasing levels of facial pain expression. In comparison, participants reporting high levels of catastrophizing showed decreased tendency to initially orient to pain faces, fixating equally quickly on neutral and pain faces. Duration of the first fixation revealed no significant effects. With respect to attentional maintenance, participants reporting high catastrophizing and pain intensity demonstrated significantly longer gaze duration for all face types (neutral and pain expression), relative to low catastrophizing counterparts. Finally, independent of catastrophizing, higher reported pain intensity contributed to decreased attentional maintenance to pain faces vs neutral faces. Theoretical implications and further research directions are discussed. PMID:23561271

  7. Specificity of emotion-related effects on attentional processing in schizotypy

    PubMed Central

    Mohanty, Aprajita; Heller, Wendy; Koven, Nancy S.; Fisher, Joscelyn E.; Herrington, John D.; Miller, Gregory A.

    2010-01-01

    Objectives In the schizophrenia spectrum, cognitive functions such as perception, language, and attention have been shown to be adversely influenced by negative affect. The present study addressed three issues of specificity and one issue of mechanism regarding affect-related attentional disruption in schizotypy: (1) Is attentional disturbance from negative affective stimuli specific to positive (PS) but not negative schizotypy (NS)? (2) Do positive affective stimuli also foster attentional disturbance? (3) Are anxiety and depression differentially related to PS and NS? (4) Whatever the degree of specificity in these relationships, does anxiety mediate the relationship between schizotypy and attentional disturbance? Methods Nonpatient participants (N=162) provided responses on scales of schizotypy, anxiety, and depression and performed an emotional Stroop task, judging the ink color of positive, neutral, and negative words. Results PS but not NS was associated with poorer attentional performance. This attentional disturbance was specific to negative words. PS was associated with anxiety and depression, whereas NS was associated only with depression. Finally, anxiety and depression did not fully mediate the relationship between PS and attentional interference related to negative affective stimuli. Conclusions Findings of attentional disturbance in the presence of negative affective stimuli, particularly in positive schizotypy, have substantial theoretical implications. They provide a path by which the interplay of cognitive and affective phenomena could lead to the formation, maintenance, and exacerbation of positive symptoms, including delusions and hallucinations. Findings from this study also underscore the importance of examining the differential contribution of comorbid anxiety and depression to cognitive and affective function in the schizophrenia spectrum. PMID:18440784

  8. Intermarriages between Western Women and Palestinian Men: Multidirectional Adaptation Processes

    ERIC Educational Resources Information Center

    Roer-Strier, Dorit; Ezra, Dina Ben

    2006-01-01

    This article addresses cultural adaptation of Western-Palestinian intermarried couples. Using in-depth interviews, information was gathered from 16 participants, 7 Western women and 9 Palestinian men, living in Palestinian cities in the West Bank. Adaptation strategies are typified by the extent to which each spouse embraces the partner's culture.…

  9. Investigating attentional processes in depressive-like domestic horses (Equus caballus).

    PubMed

    Rochais, C; Henry, S; Fureix, C; Hausberger, M

    2016-03-01

    Some captive/domestic animals respond to confinement by becoming inactive and unresponsive to external stimuli. Human inactivity is one of the behavioural markers of clinical depression, a mental disorder diagnosed by the co-occurrence of symptoms including deficit in selective attention. Some riding horses display 'withdrawn' states of inactivity and low responsiveness to stimuli that resemble the reduced engagement with their environment of some depressed patients. We hypothesized that 'withdrawn' horses experience a depressive-like state and evaluated their level of attention by confronting them with auditory stimuli. Five novel auditory stimuli were broadcasted to 27 horses, including 12 'withdrawn' horses, for 5 days. The horses' reactions and durations of attention were recorded. Non-withdrawn horses reacted more and their attention lasted longer than that of withdrawn horses on the first day, but their durations of attention decreased over days, but those of withdrawn horses remained stable. These results suggest that the withdrawn horses' selective attention is altered, adding to already evidenced common features between this horses' state and human depression. PMID:26739514

  10. Character Decomposition and Transposition Processes in Chinese Compound Words Modulates Attentional Blink

    PubMed Central

    Cao, Hongwen; Gao, Min; Yan, Hongmei

    2016-01-01

    The attentional blink (AB) is the phenomenon in which the identification of the second of two targets (T2) is attenuated if it is presented less than 500 ms after the first target (T1). Although the AB is eliminated in canonical word conditions, it remains unclear whether the character order in compound words affects the magnitude of the AB. Morpheme decomposition and transposition of Chinese two-character compound words can provide an effective means to examine AB priming and to assess combinations of the component representations inherent to visual word identification. In the present study, we examined the processing of consecutive targets in a rapid serial visual presentation (RSVP) paradigm using Chinese two-character compound words in which the two characters were transposed to form meaningful words or meaningless combinations (reversible, transposed, or canonical words). We found that when two Chinese characters that form a compound word, regardless of their order, are presented in an RSVP sequence, the likelihood of an AB for the second character is greatly reduced or eliminated compared to when the two characters constitute separate words rather than a compound word. Moreover, the order of the report for the two characters is more likely to be reversed when the normal order of the two characters in a compound word is reversed, especially when the interval between the presentation of the two characters is extremely short. These findings are more consistent with the cognitive strategy hypothesis than the resource-limited hypothesis during character decomposition and transposition of Chinese two-character compound words. These results suggest that compound characters are perceived as a unit, rather than two separate words. The data further suggest that readers could easily understand the text with character transpositions in compound words during Chinese reading. PMID:27379003

  11. Character Decomposition and Transposition Processes in Chinese Compound Words Modulates Attentional Blink.

    PubMed

    Cao, Hongwen; Gao, Min; Yan, Hongmei

    2016-01-01

    The attentional blink (AB) is the phenomenon in which the identification of the second of two targets (T2) is attenuated if it is presented less than 500 ms after the first target (T1). Although the AB is eliminated in canonical word conditions, it remains unclear whether the character order in compound words affects the magnitude of the AB. Morpheme decomposition and transposition of Chinese two-character compound words can provide an effective means to examine AB priming and to assess combinations of the component representations inherent to visual word identification. In the present study, we examined the processing of consecutive targets in a rapid serial visual presentation (RSVP) paradigm using Chinese two-character compound words in which the two characters were transposed to form meaningful words or meaningless combinations (reversible, transposed, or canonical words). We found that when two Chinese characters that form a compound word, regardless of their order, are presented in an RSVP sequence, the likelihood of an AB for the second character is greatly reduced or eliminated compared to when the two characters constitute separate words rather than a compound word. Moreover, the order of the report for the two characters is more likely to be reversed when the normal order of the two characters in a compound word is reversed, especially when the interval between the presentation of the two characters is extremely short. These findings are more consistent with the cognitive strategy hypothesis than the resource-limited hypothesis during character decomposition and transposition of Chinese two-character compound words. These results suggest that compound characters are perceived as a unit, rather than two separate words. The data further suggest that readers could easily understand the text with character transpositions in compound words during Chinese reading. PMID:27379003

  12. Fixing our focus: Training attention to regulate emotion

    PubMed Central

    Wadlinger, Heather A.; Isaacowitz, Derek M.

    2010-01-01

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

  13. Analysis of dynamic deformation processes with adaptive KALMAN-filtering

    NASA Astrophysics Data System (ADS)

    Eichhorn, Andreas

    2007-05-01

    In this paper the approach of a full system analysis is shown quantifying a dynamic structural ("white-box"-) model for the calculation of thermal deformations of bar-shaped machine elements. The task was motivated from mechanical engineering searching new methods for the precise prediction and computational compensation of thermal influences in the heating and cooling phases of machine tools (i.e. robot arms, etc.). The quantification of thermal deformations under variable dynamic loads requires the modelling of the non-stationary spatial temperature distribution inside the object. Based upon FOURIERS law of heat flow the high-grade non-linear temperature gradient is represented by a system of partial differential equations within the framework of a dynamic Finite Element topology. It is shown that adaptive KALMAN-filtering is suitable to quantify relevant disturbance influences and to identify thermal parameters (i.e. thermal diffusivity) with a deviation of only 0,2%. As result an identified (and verified) parametric model for the realistic prediction respectively simulation of dynamic temperature processes is presented. Classifying the thermal bend as the main deformation quantity of bar-shaped machine tools, the temperature model is extended to a temperature deformation model. In lab tests thermal load steps are applied to an aluminum column. Independent control measurements show that the identified model can be used to predict the columns bend with a mean deviation (r.m.s.) smaller than 10 mgon. These results show that the deformation model is a precise predictor and suitable for realistic simulations of thermal deformations. Experiments with modified heat sources will be necessary to verify the model in further frequency spectra of dynamic thermal loads.

  14. Executive function in MCDD and PDD-NOS: a study of inhibitory control, attention regulation and behavioral adaptivity.

    PubMed

    van Rijn, Sophie; de Sonneville, Leo; Lahuis, Bertine; Pieterse, Jolijn; van Engeland, Herman; Swaab, Hanna

    2013-06-01

    A proportion of children within the autism spectrum is at risk for severe deregulation of thought, emotion and behaviour resulting in (symptoms of) psychotic disorders over the course of development. In an attempt to identify this subgroup, children with PDD-NOS, subtype MCDD (n = 24) were compared to children with PDD-NOS (n = 23) on executive function (EF) skills. Significant differences emerged, always to the disadvantage of the children with PDD-NOS, subtype MCDD on various EF measures. The findings suggest compromised attention regulation and impaired inhibitory control in children with MCDD, which may help explain high levels of thought problems which are frequently observed in these children. Our findings provide evidence for recognizing a PDD subcategory of MCDD that is of specific interest with regard to long-term developmental risks involved. PMID:23104616

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

    PubMed

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

    2016-01-01

    The present chapter first argues how having a goal for procuring alcohol or other substances leads to the development of a time-binding, dynamic, and goal oriented motivational state termed current concern, as the origin of substance-related attentional bias. Next, it discusses the importance of attentional bias in the development, continuation of, and relapsing to substance abuse. It further proceeds with a review of selective evidence from cognitive psychology that helps account for making decisions about using an addictive substance or refraining from using it. A discussion on the various brain loci that are involved in attentional bias and other kinds of cue reactivity is followed by presenting findings from neurocognitive research. Finally, from an interdisciplinary perspective, the chapter presents new trends and ideas that can be applied to addiction-related cognitive measurement and training. PMID:26806772

  16. Memantine Improves Attentional Processes in Fragile X-Associated Tremor/Ataxia Syndrome: Electrophysiological Evidence from a Randomized Controlled Trial.

    PubMed

    Yang, Jin-Chen; Rodriguez, Annette; Royston, Ashley; Niu, Yu-Qiong; Avar, Merve; Brill, Ryan; Simon, Christa; Grigsby, Jim; Hagerman, Randi J; Olichney, John M

    2016-01-01

    Progressive cognitive deficits are common in patients with fragile X-associated tremor/ataxia syndrome (FXTAS), with no targeted treatment yet established. In this substudy of the first randomized controlled trial for FXTAS, we examined the effects of NMDA antagonist memantine on attention and working memory. Data were analyzed for patients (24 in each arm) who completed both the primary memantine trial and two EEG recordings (at baseline and follow-up) using an auditory "oddball" task. Results demonstrated significantly improved attention/working memory performance after one year only for the memantine group. The event-related potential P2 amplitude elicited by non-targets was significantly enhanced in the treated group, indicating memantine-associated improvement in attentional processes at the stimulus identification/discrimination level. P2 amplitude increase was positively correlated with improvement on the behavioral measure of attention/working memory during target detection. Analysis also revealed that memantine treatment normalized the P2 habituation effect at the follow-up visit. These findings indicate that memantine may benefit attentional processes that represent fundamental components of executive function/dysfunction, thought to comprise the core cognitive deficit in FXTAS. The results provide evidence of target engagement of memantine, as well as therapeutically relevant information that could further the development of specific cognitive or disease-modifying therapies for FXTAS. PMID:26898832

  17. Memantine Improves Attentional Processes in Fragile X-Associated Tremor/Ataxia Syndrome: Electrophysiological Evidence from a Randomized Controlled Trial

    PubMed Central

    Yang, Jin-Chen; Rodriguez, Annette; Royston, Ashley; Niu, Yu-Qiong; Avar, Merve; Brill, Ryan; Simon, Christa; Grigsby, Jim; Hagerman, Randi J.; Olichney, John M.

    2016-01-01

    Progressive cognitive deficits are common in patients with fragile X-associated tremor/ataxia syndrome (FXTAS), with no targeted treatment yet established. In this substudy of the first randomized controlled trial for FXTAS, we examined the effects of NMDA antagonist memantine on attention and working memory. Data were analyzed for patients (24 in each arm) who completed both the primary memantine trial and two EEG recordings (at baseline and follow-up) using an auditory “oddball” task. Results demonstrated significantly improved attention/working memory performance after one year only for the memantine group. The event-related potential P2 amplitude elicited by non-targets was significantly enhanced in the treated group, indicating memantine-associated improvement in attentional processes at the stimulus identification/discrimination level. P2 amplitude increase was positively correlated with improvement on the behavioral measure of attention/working memory during target detection. Analysis also revealed that memantine treatment normalized the P2 habituation effect at the follow-up visit. These findings indicate that memantine may benefit attentional processes that represent fundamental components of executive function/dysfunction, thought to comprise the core cognitive deficit in FXTAS. The results provide evidence of target engagement of memantine, as well as therapeutically relevant information that could further the development of specific cognitive or disease-modifying therapies for FXTAS. PMID:26898832

  18. Predictive Power of Attention and Reading Readiness Variables on Auditory Reasoning and Processing Skills of Six-Year-Old Children

    ERIC Educational Resources Information Center

    Erbay, Filiz

    2013-01-01

    The aim of present research was to describe the relation of six-year-old children's attention and reading readiness skills (general knowledge, word comprehension, sentences, and matching) with their auditory reasoning and processing skills. This was a quantitative study based on scanning model. Research sampling consisted of 204 kindergarten…

  19. Are Children's Memory Illusions Created Differently from Those of Adults? Evidence from Levels-of-Processing and Divided Attention Paradigms

    ERIC Educational Resources Information Center

    Wimmer, Marina C.; Howe, Mark L.

    2010-01-01

    In two experiments, we investigated the robustness and automaticity of adults' and children's generation of false memories by using a levels-of-processing paradigm (Experiment 1) and a divided attention paradigm (Experiment 2). The first experiment revealed that when information was encoded at a shallow level, true recognition rates decreased for…

  20. The impact of simulated MRI scanner background noise on visual attention processes as measured by the EEG.

    PubMed

    Kobald, S Oliver; Getzmann, Stephan; Beste, Christian; Wascher, Edmund

    2016-01-01

    Environmental noise is known to affect personal well-being as well as cognitive processes. Besides daily life, environmental noise can also occur in experimental research settings, e.g. when being in a magnetic resonance scanner. Scanner background noise (SBN) might pose serious confounds for experimental findings, even when non-auditory settings are examined. In the current experiment we tested if SBN alters bottom-up and top-down related processes of selective visual attention mechanisms. Participants completed two blocks of a visual change detection task, one block in silence and one block under SBN exposure. SBN was found to decrease accuracy in measures of visual attention. This effect was modulated by the temporal occurrence of SBN. When SBN was encountered in the first block, it prevented a significant improvement of accuracy in the second block. When SBN appeared in the second block, it significantly decreased accuracy. Neurophysiological findings showed a strong frontal positivity shift only when SBN was present in the first block, suggesting an inhibitory process to counteract the interfering SBN. Common correlates of both top-down and bottom-up processes of selective visual attention were not specifically affected by SBN exposure. Further research appears necessary to entirely rule out confounds of SBN in assessing visual attention. PMID:27324456

  1. What Comes First? How Selective Attentional Processes Regulate the Activation of a Motor Routine in a Manual Search Task

    ERIC Educational Resources Information Center

    Riviere, James; Falaise, Aurelie

    2011-01-01

    An intriguing error has been observed in toddlers presented with a 3-location search task involving invisible displacements of an object, namely, the C-not-B task. In 3 experiments, the authors investigated the dynamics of the attentional focus process that is suspected to be involved in this task. In Experiment 1, 2.5-year-old children were…

  2. What Do Second Language Listeners Know about Spoken Words? Effects of Experience and Attention in Spoken Word Processing

    ERIC Educational Resources Information Center

    Trofimovich, Pavel

    2008-01-01

    With a goal of investigating psycholinguistic bases of spoken word processing in a second language (L2), this study examined L2 learners' sensitivity to phonological information in spoken L2 words as a function of their L2 experience and attentional demands of a learning task. Fifty-two Chinese learners of English who differed in amount of L2…

  3. The impact of simulated MRI scanner background noise on visual attention processes as measured by the EEG

    PubMed Central

    Kobald, S. Oliver; Getzmann, Stephan; Beste, Christian; Wascher, Edmund

    2016-01-01

    Environmental noise is known to affect personal well-being as well as cognitive processes. Besides daily life, environmental noise can also occur in experimental research settings, e.g. when being in a magnetic resonance scanner. Scanner background noise (SBN) might pose serious confounds for experimental findings, even when non-auditory settings are examined. In the current experiment we tested if SBN alters bottom-up and top-down related processes of selective visual attention mechanisms. Participants completed two blocks of a visual change detection task, one block in silence and one block under SBN exposure. SBN was found to decrease accuracy in measures of visual attention. This effect was modulated by the temporal occurrence of SBN. When SBN was encountered in the first block, it prevented a significant improvement of accuracy in the second block. When SBN appeared in the second block, it significantly decreased accuracy. Neurophysiological findings showed a strong frontal positivity shift only when SBN was present in the first block, suggesting an inhibitory process to counteract the interfering SBN. Common correlates of both top-down and bottom-up processes of selective visual attention were not specifically affected by SBN exposure. Further research appears necessary to entirely rule out confounds of SBN in assessing visual attention. PMID:27324456

  4. Basic Processes in Reading: On the Relation between Spatial Attention and Familiarity

    ERIC Educational Resources Information Center

    Risko, Evan F.; Stolz, Jennifer A.; Besner, Derek

    2011-01-01

    Two experiments combined a spatial cueing manipulation (valid vs. invalid spatial cues) with a stimulus repetition manipulation (repeated vs. nonrepeated) in order to assess the hypothesis that familiar items need less spatial attention than less familiar ones. The magnitude of the effect of cueing on reading aloud time for items that were…

  5. Electrophysiological Indices of Abnormal Error-Processing in Adolescents with Attention Deficit Hyperactivity Disorder (ADHD)

    ERIC Educational Resources Information Center

    Groom, Madeleine J.; Cahill, John D.; Bates, Alan T.; Jackson, Georgina M.; Calton, Timothy G.; Liddle, Peter F.; Hollis, Chris

    2010-01-01

    Background: Impaired cognitive control has been frequently observed in children and young people with attention deficit hyperactivity disorder (ADHD) and might underlie the excessive hyperactivity and impulsivity in this population. We investigated behavioural and electrophysiological indices relevant to one domain of cognitive control; namely…

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

    ERIC Educational Resources Information Center

    Raca, Mirko; Kidzinski, Lukasz; Dillenbourg, Pierre

    2015-01-01

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

  7. Students with Learning Disabilities and Attention Disorders: Stories of the College Choice Process

    ERIC Educational Resources Information Center

    Mercer, Kerri A.

    2012-01-01

    Although there has been legislation that has improved access for students with disabilities, many students are choosing not to pursue postsecondary education. The rate of postsecondary attendance for students with learning disabilities and attention disorders has increased, but they are still enrolling in postsecondary education less frequently…

  8. The Process of Auditory Distraction: Disrupted Attention and Impaired Recall in a Simulated Lecture Environment

    ERIC Educational Resources Information Center

    Zeamer, Charlotte; Fox Tree, Jean E.

    2013-01-01

    Literature on auditory distraction has generally focused on the effects of particular kinds of sounds on attention to target stimuli. In support of extensive previous findings that have demonstrated the special role of language as an auditory distractor, we found that a concurrent speech stream impaired recall of a short lecture, especially for…

  9. Attention Deficit/Hyperactivity Disorder: Perspectives of Participants in the Identification and Treatment Process.

    ERIC Educational Resources Information Center

    Davison, Judy C.

    2001-01-01

    Questions the rising incidence of Attention Deficit/Hyperactivity Disorder (AD/HD) diagnosis in the United States. Suggests that AD/HD is a socially constructed phenomenon rather than biologically based. Urges educators, medical personnel, and parents to take a holistic view of each child, with a serious examination of the wide range of causation…

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  11. Rapid Processing of Letters, Digits and Symbols: What Purely Visual-Attentional Deficit in Developmental Dyslexia?

    ERIC Educational Resources Information Center

    Ziegler, Johannes C.; Pech-Georgel, Catherine; Dufau, Stephane; Grainger, Jonathan

    2010-01-01

    Visual-attentional theories of dyslexia predict deficits for dyslexic children not only for the perception of letter strings but also for non-alphanumeric symbol strings. This prediction was tested in a two-alternative forced-choice paradigm with letters, digits, and symbols. Children with dyslexia showed significant deficits for letter and digit…

  12. Cueing Spatial Attention during Processing of Words and Letter Strings in Normals. Technical Report #2.

    ERIC Educational Resources Information Center

    Sieroff, Eric; Posner, Michael I.

    Work with patients with attentional deficits produced by posterior cerebral lesions has shown that such patients can identify words correctly even when they fail to report letters in nonwords contralateral to the lesion. Because of this, it has been assumed in cognitive neuropsychology that lesions do not produce new phenomena but instead provide…

  13. Electrophysiological Evidence of Atypical Motivation and Reward Processing in Children with Attention-Deficit Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Holroyd, Clay B.; Baker, Travis E.; Kerns, Kimberly A.; Muller, Ulrich

    2008-01-01

    Behavioral and neurophysiological evidence suggest that attention-deficit hyperactivity disorder (ADHD) is characterized by the impact of abnormal reward prediction error signals carried by the midbrain dopamine system on frontal brain areas that implement cognitive control. To investigate this issue, we recorded the event-related brain potential…

  14. The Influence of Strong Attentional Manipulations on the Processing of Dichotic Inputs in Right-Handers.

    ERIC Educational Resources Information Center

    Iaccino, James F.

    A study was conducted to investigate further the dichotic outcomes in right-handers as a function of sex, ear-side, and most especially stronger attentional bias. The derived prediction was: that increased focus time on the right side would produce a striking right ear advantage (REA) in either right-handed men or women, replicating the most…

  15. Effects of Spatial Configuration on Visual Attention Processes. Umea Psychological Reports No. 154.

    ERIC Educational Resources Information Center

    Brannstrom, Lauritz

    The significance of spatial factors on an initial segmentation and an active attentional phase was demonstrated by briefly exposing spatial configurations of elements, and then asking the subjects to reproduce the patterns or to search them for a target letter. The stimulus displays consisted of small o's forming different spatial configurations,…

  16. Do Problems with Information Processing Affect the Process of Psychotherapy for Adults with Learning Disabilities or Attention Deficit/Hyperactivity Disorder?

    ERIC Educational Resources Information Center

    Cosden, Merith; Patz, Sarah; Smith, Steven

    2009-01-01

    Problems in processing information can affect psychosocial functioning. Psychotherapy can be used to address psychosocial problems; however, the same information-processing problems that contribute to disabilities, such as learning disabilities (LD) or attention deficit/hyperactivity disorder (ADHD), particularly deficits in auditory processing…

  17. Motivation by potential gains and losses affects control processes via different mechanisms in the attentional network.

    PubMed

    Paschke, Lena M; Walter, Henrik; Steimke, Rosa; Ludwig, Vera U; Gaschler, Robert; Schubert, Torsten; Stelzel, Christine

    2015-05-01

    Attentional control in demanding cognitive tasks can be improved by manipulating the motivational state. Motivation to obtain gains and motivation to avoid losses both usually result in faster reaction times and stronger activation in relevant brain areas such as the prefrontal cortex, but little is known about differences in the underlying neurocognitive mechanisms of these types of motivation in an attentional control context. In the present functional magnetic resonance imaging (fMRI) study, we tested whether potential gain and loss as motivating incentives lead to overlapping or distinct neural effects in the attentional network, and whether one of these conditions is more effective than the other. A Flanker task with word stimuli as targets and distracters was performed by 115 healthy participants. Using a mixed blocked and event-related design allowed us to investigate transient and sustained motivation-related effects. Participants could either gain money (potential gain) or avoid losing money (potential loss) in different task blocks. Participants showed a congruency effect with increased reaction times for incongruent compared to congruent trials. Potential gain led to generally faster responses compared to the neutral condition and to stronger improvements than potential loss. Potential loss also led to shorter response times compared to the neutral condition, but participants improved mainly during incongruent and not during congruent trials. The event-related fMRI data revealed a main effect of congruency with increased activity in the left inferior frontal gyrus (IFG) and inferior frontal junction area (IFJ), the pre-supplementary motor area (pre-SMA), bilateral insula, intraparietal sulcus (IPS) and visual word form area (VWFA). While potential gain led to increased activity in a cluster of the IFJ and the VWFA only during incongruent trials, potential loss was linked to activity increases in these regions during incongruent and congruent trials. The

  18. Adaptivity and Autonomy Development in a Learning Personalization Process

    ERIC Educational Resources Information Center

    Verpoorten, D.

    2009-01-01

    Within the iClass (Integrated Project 507922) and Enhanced Learning Experience and Knowledge Transfer (ELEKTRA; Specific Targeted Research or Innovation Project 027986) European projects, the author was requested to harness his pedagogical knowledge to the production of educational adaptive systems. The article identifies and documents the…

  19. Individual differences in attentional bias associated with cocaine dependence are related to varying engagement of neural processing networks.

    PubMed

    Kilts, Clint D; Kennedy, Ashley; Elton, Amanda L; Tripathi, Shanti Prakash; Young, Jonathan; Cisler, Josh M; James, G Andrew

    2014-04-01

    Cocaine and other drug dependencies are associated with significant attentional bias for drug use stimuli that represents a candidate cognitive marker of drug dependence and treatment outcomes. We explored, using fMRI, the role of discrete neural processing networks in the representation of individual differences in the drug attentional bias effect associated with cocaine dependence (AB-coc) using a word counting Stroop task with personalized cocaine use stimuli (cocStroop). The cocStroop behavioral and neural responses were further compared with those associated with a negative emotional word Stroop task (eStroop) and a neutral word counting Stroop task (cStroop). Brain-behavior correlations were explored using both network-level correlation analysis following independent component analysis (ICA) and voxel-level, brain-wide univariate correlation analysis. Variation in the attentional bias effect for cocaine use stimuli among cocaine-dependent men and women was related to the recruitment of two separate neural processing networks related to stimulus attention and salience attribution (inferior frontal-parietal-ventral insula), and the processing of the negative affective properties of cocaine stimuli (frontal-temporal-cingulate). Recruitment of a sensory-motor-dorsal insula network was negatively correlated with AB-coc and suggested a regulatory role related to the sensorimotor processing of cocaine stimuli. The attentional bias effect for cocaine stimuli and for negative affective word stimuli were significantly correlated across individuals, and both were correlated with the activity of the frontal-temporal-cingulate network. Functional connectivity for a single prefrontal-striatal-occipital network correlated with variation in general cognitive control (cStroop) that was unrelated to behavioral or neural network correlates of cocStroop- or eStroop-related attentional bias. A brain-wide mass univariate analysis demonstrated the significant correlation of

  20. Individual Differences in Attentional Bias Associated with Cocaine Dependence Are Related to Varying Engagement of Neural Processing Networks

    PubMed Central

    Kilts, Clint D; Kennedy, Ashley; Elton, Amanda L; Tripathi, Shanti Prakash; Young, Jonathan; Cisler, Josh M; James, G Andrew

    2014-01-01

    Cocaine and other drug dependencies are associated with significant attentional bias for drug use stimuli that represents a candidate cognitive marker of drug dependence and treatment outcomes. We explored, using fMRI, the role of discrete neural processing networks in the representation of individual differences in the drug attentional bias effect associated with cocaine dependence (AB-coc) using a word counting Stroop task with personalized cocaine use stimuli (cocStroop). The cocStroop behavioral and neural responses were further compared with those associated with a negative emotional word Stroop task (eStroop) and a neutral word counting Stroop task (cStroop). Brain–behavior correlations were explored using both network-level correlation analysis following independent component analysis (ICA) and voxel-level, brain-wide univariate correlation analysis. Variation in the attentional bias effect for cocaine use stimuli among cocaine-dependent men and women was related to the recruitment of two separate neural processing networks related to stimulus attention and salience attribution (inferior frontal–parietal–ventral insula), and the processing of the negative affective properties of cocaine stimuli (frontal–temporal–cingulate). Recruitment of a sensory–motor–dorsal insula network was negatively correlated with AB-coc and suggested a regulatory role related to the sensorimotor processing of cocaine stimuli. The attentional bias effect for cocaine stimuli and for negative affective word stimuli were significantly correlated across individuals, and both were correlated with the activity of the frontal–temporal–cingulate network. Functional connectivity for a single prefrontal–striatal–occipital network correlated with variation in general cognitive control (cStroop) that was unrelated to behavioral or neural network correlates of cocStroop- or eStroop-related attentional bias. A brain-wide mass univariate analysis demonstrated the significant

  1. Perceiving emotions: Cueing social categorization processes and attentional control through facial expressions.

    PubMed

    Cañadas, Elena; Lupiáñez, Juan; Kawakami, Kerry; Niedenthal, Paula M; Rodríguez-Bailón, Rosa

    2016-09-01

    Individuals spontaneously categorise other people on the basis of their gender, ethnicity and age. But what about the emotions they express? In two studies we tested the hypothesis that facial expressions are similar to other social categories in that they can function as contextual cues to control attention. In Experiment 1 we associated expressions of anger and happiness with specific proportions of congruent/incongruent flanker trials. We also created consistent and inconsistent category members within each of these two general contexts. The results demonstrated that participants exhibited a larger congruency effect when presented with faces in the emotional group associated with a high proportion of congruent trials. Notably, this effect transferred to inconsistent members of the group. In Experiment 2 we replicated the effects with faces depicting true and false smiles. Together these findings provide consistent evidence that individuals spontaneously utilise emotions to categorise others and that such categories determine the allocation of attentional control. PMID:26197208

  2. Analysis of Interaction and Attention Processes in a Child With Congenital Deafblindness.

    PubMed

    Boas, Denise Cintra; Ferreira, Slie Piccolotto; de Moura, Maria Cec; Maia, Shirley Rodrigues; Amaral, Isabel

    2016-01-01

    Children with deafblindness need support to be able to understand the world and to have access to information. The authors analyzed a dyad consisting of a child with congenital deafblindness and a specialized teacher. The study included participant observations and audiovisual recordings. It was found that the child showed attention to the teacher in activities involving music and rhythm. As potential forms of nonverbal communication, the child presented vocalization, touch, body contact, body movements, facial expressions, and tears. The teacher's forms of communication were verbal, touch, visual, rhythm, and sign language. It was concluded that a significant communication partner is essential to identify, interpret, and respond to attention and communicative behaviors. Use of other forms of communication must comply with individual characteristics so that the child with deafblindness can receive information from the environment through these senses and thus be guaranteed access to the world. PMID:27477040

  3. Attention Genes

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  4. Tracking performance under time sharing conditions with a digit processing task: A feedback control theory analysis. [attention sharing effect on operator performance

    NASA Technical Reports Server (NTRS)

    Gopher, D.; Wickens, C. D.

    1975-01-01

    A one dimensional compensatory tracking task and a digit processing reaction time task were combined in a three phase experiment designed to investigate tracking performance in time sharing. Adaptive techniques, elaborate feedback devices, and on line standardization procedures were used to adjust task difficulty to the ability of each individual subject and manipulate time sharing demands. Feedback control analysis techniques were employed in the description of tracking performance. The experimental results show that when the dynamics of a system are constrained, in such a manner that man machine system stability is no longer a major concern of the operator, he tends to adopt a first order control describing function, even with tracking systems of higher order. Attention diversion to a concurrent task leads to an increase in remnant level, or nonlinear power. This decrease in linearity is reflected both in the output magnitude spectra of the subjects, and in the linear fit of the amplitude ratio functions.

  5. Casual Video Games as Training Tools for Attentional Processes in Everyday Life.

    PubMed

    Stroud, Michael J; Whitbourne, Susan Krauss

    2015-11-01

    Three experiments examined the attentional components of the popular match-3 casual video game, Bejeweled Blitz (BJB). Attentionally demanding, BJB is highly popular among adults, particularly those in middle and later adulthood. In experiment 1, 54 older adults (Mage = 70.57) and 33 younger adults (Mage = 19.82) played 20 rounds of BJB, and completed online tasks measuring reaction time, simple visual search, and conjunction visual search. Prior experience significantly predicted BJB scores for younger adults, but for older adults, both prior experience and simple visual search task scores predicted BJB performance. Experiment 2 tested whether BJB practice alone would result in a carryover benefit to a visual search task in a sample of 58 young adults (Mage = 19.57) who completed 0, 10, or 30 rounds of BJB followed by a BJB-like visual search task with targets present or absent. Reaction times were significantly faster for participants who completed 30 but not 10 rounds of BJB compared with the search task only. This benefit was evident when targets were both present and absent, suggesting that playing BJB improves not only target detection, but also the ability to quit search effectively. Experiment 3 tested whether the attentional benefit in experiment 2 would apply to non-BJB stimuli. The results revealed a similar numerical but not significant trend. Taken together, the findings suggest there are benefits of casual video game playing to attention and relevant everyday skills, and that these games may have potential value as training tools. PMID:26448498

  6. Attention in natural scenes: contrast affects rapid visual processing and fixations alike.

    PubMed

    't Hart, Bernard Marius; Schmidt, Hannah Claudia Elfriede Fanny; Klein-Harmeyer, Ingo; Einhäuser, Wolfgang

    2013-10-19

    For natural scenes, attention is frequently quantified either by performance during rapid presentation or by gaze allocation during prolonged viewing. Both paradigms operate on different time scales, and tap into covert and overt attention, respectively. To compare these, we ask some observers to detect targets (animals/vehicles) in rapid sequences, and others to freely view the same target images for 3 s, while their gaze is tracked. In some stimuli, the target's contrast is modified (increased/decreased) and its background modified either in the same or in the opposite way. We find that increasing target contrast relative to the background increases fixations and detection alike, whereas decreasing target contrast and simultaneously increasing background contrast has little effect. Contrast increase for the whole image (target + background) improves detection, decrease worsens detection, whereas fixation probability remains unaffected by whole-image modifications. Object-unrelated local increase or decrease of contrast attracts gaze, but less than actual objects, supporting a precedence of objects over low-level features. Detection and fixation probability are correlated: the more likely a target is detected in one paradigm, the more likely it is fixated in the other. Hence, the link between overt and covert attention, which has been established in simple stimuli, transfers to more naturalistic scenarios. PMID:24018728

  7. Inducing attention not to blink: auditory entrainment improves conscious visual processing.

    PubMed

    Ronconi, Luca; Pincham, Hannah L; Szűcs, Dénes; Facoetti, Andrea

    2016-09-01

    Our ability to allocate attention at different moments in time can sometimes fail to select stimuli occurring in close succession, preventing visual information from reaching awareness. This so-called attentional blink (AB) occurs when the second of two targets (T2) is presented closely after the first (T1) in a rapid serial visual presentation (RSVP). We hypothesized that entrainment to a rhythmic stream of stimuli-before visual targets appear-would reduce the AB. Experiment 1 tested the effect of auditory entrainment by presenting sounds with a regular or irregular interstimulus interval prior to a RSVP where T1 and T2 were separated by three possible lags (1, 3 and 8). Experiment 2 examined visual entrainment by presenting visual stimuli in place of auditory stimuli. Results revealed that irrespective of sensory modality, arrhythmic stimuli preceding the RSVP triggered an alerting effect that improved the T2 identification at lag 1, but impaired the recovery from the AB at lag 8. Importantly, only auditory rhythmic entrainment was effective in reducing the AB at lag 3. Our findings demonstrate that manipulating the pre-stimulus condition can reduce deficits in temporal attention characterizing the human cognitive architecture, suggesting innovative trainings for acquired and neurodevelopmental disorders. PMID:26215434

  8. Processing deficits in monitoring analog and digital displays: Implications for attentional theory and mental-state estimation research

    NASA Technical Reports Server (NTRS)

    Payne, David G.; Gunther, Virginia A. L.

    1988-01-01

    Subjects performed short term memory tasks, involving both spatial and verbal components, and a visual monitoring task involving either analog or digital display formats. These two tasks (memory vs. monitoring) were performed both singly and in conjunction. Contrary to expectations derived from multiple resource theories of attentional processes, there was no evidence that when the two tasks involved the same cognitive codes (i.e., either both spatial or both verbal/linguistics) there was more of a dual task performance decrement than when the two tasks employed different cognitive codes/processes. These results are discussed in terms of their implications for theories of attentional processes and also for research in mental state estimation.

  9. Evidence for the role of German final devoicing in pre-attentive speech processing: a mismatch negativity study.

    PubMed

    Truckenbrodt, Hubert; Steinberg, Johanna; Jacobsen, Thomas K; Jacobsen, Thomas

    2014-01-01

    Results of a mismatch negativity experiment are reported in which the pre-attentive relevance of the German phonological alternation of final devoicing (FD) is shown in two ways. The experiment employs pseudowords. (1) A deviant [vus] paired with standard /vuzə/ did not show a mismatch effect for the voicing change in /z/ versus [s] because the two can be related by FD. When standard and deviant were reversed, the two could not be related by FD and a mismatch effect for the voicing difference occurred. (2) An ill-formed deviant that violates FD, *[vuz], triggered mismatch effects that were plausibly attributed to its ill-formedness. The results show that a syllable-related process like FD is already taken into account by the processing system in early pre-attentive processing. PMID:25505433

  10. Evidence for the role of German final devoicing in pre-attentive speech processing: a mismatch negativity study

    PubMed Central

    Truckenbrodt, Hubert; Steinberg, Johanna; Jacobsen, Thomas K.; Jacobsen, Thomas

    2014-01-01

    Results of a mismatch negativity experiment are reported in which the pre-attentive relevance of the German phonological alternation of final devoicing (FD) is shown in two ways. The experiment employs pseudowords. (1) A deviant [vus] paired with standard /vuzə/ did not show a mismatch effect for the voicing change in /z/ versus [s] because the two can be related by FD. When standard and deviant were reversed, the two could not be related by FD and a mismatch effect for the voicing difference occurred. (2) An ill-formed deviant that violates FD, *[vuz], triggered mismatch effects that were plausibly attributed to its ill-formedness. The results show that a syllable-related process like FD is already taken into account by the processing system in early pre-attentive processing. PMID:25505433

  11. Altered intrinsic organisation of brain networks implicated in attentional processes in adult attention-deficit/hyperactivity disorder: a resting-state study of attention, default mode and salience network connectivity.

    PubMed

    Sidlauskaite, Justina; Sonuga-Barke, Edmund; Roeyers, Herbert; Wiersema, Jan R

    2016-06-01

    Deficits in task-related attentional engagement in attention-deficit/hyperactivity disorder (ADHD) have been hypothesised to be due to altered interrelationships between attention, default mode and salience networks. We examined the intrinsic connectivity during rest within and between these networks. Six-minute resting-state scans were obtained. Using a network-based approach, connectivity within and between the dorsal and ventral attention, the default mode and the salience networks was compared between the ADHD and control group. The ADHD group displayed hyperconnectivity between the two attention networks and within the default mode and ventral attention network. The salience network was hypoconnected to the dorsal attention network. There were trends towards hyperconnectivity within the dorsal attention network and between the salience and ventral attention network in ADHD. Connectivity within and between other networks was unrelated to ADHD. Our findings highlight the altered connectivity within and between attention networks, and between them and the salience network in ADHD. One hypothesis to be tested in future studies is that individuals with ADHD are affected by an imbalance between ventral and dorsal attention systems with the former playing a dominant role during task engagement, making individuals with ADHD highly susceptible to distraction by salient task-irrelevant stimuli. PMID:26260900

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

    PubMed

    Purmann, Sascha; Pollmann, Stefan

    2015-01-01

    To process information selectively and to continuously fine-tune selectivity of information processing are important abilities for successful goal-directed behavior. One phenomenon thought to represent this fine-tuning are conflict adaptation effects in interference tasks, i.e., reduction of interference after an incompatible trial and when incompatible trials are frequent. The neurocognitive mechanisms of these effects are currently only partly understood and results from brainimaging studies so far are mixed. In our study we validate and extend recent findings by examining adaption to recent conflict in the classical Stroop task using functional magnetic resonance imaging. Consistent with previous research we found increased activity in a fronto-parietal network comprising the medial prefrontal cortex, ventro-lateral prefrontal cortex, and posterior parietal cortex when contrasting incompatible with compatible trials. These areas have been associated with attentional processes and might reflect increased cognitive conflict and resolution thereof during incompatible trials. While carefully controlling for non-attentional sequential effects we found smaller Stroop interference after an incompatible trial (conflict adaptation effect). These behavioral conflict adaptation effects were accompanied by changes in activity in visual color-selective areas (V4, V4α), while there was no modulation by previous trial compatibility in a visual word-selective area (VWFA). Our results provide further evidence for the notion, that adaptation to recent conflict seems to be based mainly on enhancement of processing of the task-relevant information. PMID:25784868

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

    PubMed Central

    Purmann, Sascha; Pollmann, Stefan

    2015-01-01

    To process information selectively and to continuously fine-tune selectivity of information processing are important abilities for successful goal-directed behavior. One phenomenon thought to represent this fine-tuning are conflict adaptation effects in interference tasks, i.e., reduction of interference after an incompatible trial and when incompatible trials are frequent. The neurocognitive mechanisms of these effects are currently only partly understood and results from brainimaging studies so far are mixed. In our study we validate and extend recent findings by examining adaption to recent conflict in the classical Stroop task using functional magnetic resonance imaging. Consistent with previous research we found increased activity in a fronto-parietal network comprising the medial prefrontal cortex, ventro-lateral prefrontal cortex, and posterior parietal cortex when contrasting incompatible with compatible trials. These areas have been associated with attentional processes and might reflect increased cognitive conflict and resolution thereof during incompatible trials. While carefully controlling for non-attentional sequential effects we found smaller Stroop interference after an incompatible trial (conflict adaptation effect). These behavioral conflict adaptation effects were accompanied by changes in activity in visual color-selective areas (V4, V4α), while there was no modulation by previous trial compatibility in a visual word-selective area (VWFA). Our results provide further evidence for the notion, that adaptation to recent conflict seems to be based mainly on enhancement of processing of the task-relevant information. PMID:25784868

  14. Neural Adaptation and Behavioral Measures of Temporal Processing and Speech Perception in Cochlear Implant Recipients

    PubMed Central

    Zhang, Fawen; Benson, Chelsea; Murphy, Dora; Boian, Melissa; Scott, Michael; Keith, Robert; Xiang, Jing; Abbas, Paul

    2013-01-01

    The objective was to determine if one of the neural temporal features, neural adaptation, can account for the across-subject variability in behavioral measures of temporal processing and speech perception performance in cochlear implant (CI) recipients. Neural adaptation is the phenomenon in which neural responses are the strongest at the beginning of the stimulus and decline following stimulus repetition (e.g., stimulus trains). It is unclear how this temporal property of neural responses relates to psychophysical measures of temporal processing (e.g., gap detection) or speech perception. The adaptation of the electrical compound action potential (ECAP) was obtained using 1000 pulses per second (pps) biphasic pulse trains presented directly to the electrode. The adaptation of the late auditory evoked potential (LAEP) was obtained using a sequence of 1-kHz tone bursts presented acoustically, through the cochlear implant. Behavioral temporal processing was measured using the Random Gap Detection Test at the most comfortable listening level. Consonant nucleus consonant (CNC) word and AzBio sentences were also tested. The results showed that both ECAP and LAEP display adaptive patterns, with a substantial across-subject variability in the amount of adaptation. No correlations between the amount of neural adaptation and gap detection thresholds (GDTs) or speech perception scores were found. The correlations between the degree of neural adaptation and demographic factors showed that CI users having more LAEP adaptation were likely to be those implanted at a younger age than CI users with less LAEP adaptation. The results suggested that neural adaptation, at least this feature alone, cannot account for the across-subject variability in temporal processing ability in the CI users. However, the finding that the LAEP adaptive pattern was less prominent in the CI group compared to the normal hearing group may suggest the important role of normal adaptation pattern at the

  15. In Experts, underlying processes that drive visuomotor adaptation are different than in Novices

    PubMed Central

    Leukel, Christian; Gollhofer, Albert; Taube, Wolfgang

    2015-01-01

    Processes responsible for improvements in motor performance are often contrasted in an explicit and an implicit part. Explicit learning enables task success by using strategic (declarative) knowledge. Implicit learning refers to a change in motor performance without conscious effort. In this study, we tested the contribution of explicit and implicit processes in a visuomotor adaptation task in subjects with different expertise in the task they were asked to adapt. Thirty handball players (Experts) and 30 subjects without handball experience (Novices) participated. Three experiments tested visuomotor adaptation of a free throw in team handball using prismatic glasses. The difference between experiments was that in Experiment 2 and 3, contribution of explicit processes was prevented, whereas Experiment 1 allowed contribution of explicit and implicit processes. Retention was assessed in Experiment 3. There were three main findings: (i) contribution of explicit processes to adaptation was stronger in Experts than Novices (Experiment 1); (ii) adaptation took longer in Experts when preventing contribution of explicit processes (Experiment 2); and (iii) retention was stronger in Experts (Experiment 3). This study shows that learning processes involved in visuomotor adaptation change by expertise, with more involvement of explicit processes and most likely other implicit processes to adaptation in Experts. PMID:25713526

  16. Flight data processing with the F-8 adaptive algorithm

    NASA Technical Reports Server (NTRS)

    Hartmann, G.; Stein, G.; Petersen, K.

    1977-01-01

    An explicit adaptive control algorithm based on maximum likelihood estimation of parameters has been designed for NASA's DFBW F-8 aircraft. To avoid iterative calculations, the algorithm uses parallel channels of Kalman filters operating at fixed locations in parameter space. This algorithm has been implemented in NASA/DFRC's Remotely Augmented Vehicle (RAV) facility. Real-time sensor outputs (rate gyro, accelerometer and surface position) are telemetered to a ground computer which sends new gain values to an on-board system. Ground test data and flight records were used to establish design values of noise statistics and to verify the ground-based adaptive software. The software and its performance evaluation based on flight data are described

  17. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  18. Visuospatial selective attention in chickens.

    PubMed

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

    2014-05-13

    Voluntary control of attention promotes intelligent, adaptive behaviors by enabling the selective processing of information that is most relevant for making decisions. Despite extensive research on attention in primates, the capacity for selective attention in nonprimate species has never been quantified. Here we demonstrate selective attention in chickens by applying protocols that have been used to characterize visual spatial attention in primates. Chickens were trained to localize and report the vertical position of a target in the presence of task-relevant distracters. A spatial cue, the location of which varied across individual trials, indicated the horizontal, but not vertical, position of the upcoming target. Spatial cueing improved localization performance: accuracy (d') increased and reaction times decreased in a space-specific manner. Distracters severely impaired perceptual performance, and this impairment was greatly reduced by spatial cueing. Signal detection analysis with an "indecision" model demonstrated that spatial cueing significantly increased choice certainty in localizing targets. By contrast, error-aversion certainty (certainty of not making an error) remained essentially constant across cueing protocols, target contrasts, and individuals. The results show that chickens shift spatial attention rapidly and dynamically, following principles of stimulus selection that closely parallel those documented in primates. The findings suggest that the mechanisms that control attention have been conserved through evolution, and establish chickens--a highly visual species that is easily trained and amenable to cutting-edge experimental technologies--as an attractive model for linking behavior to neural mechanisms of selective attention. PMID:24753566

  19. Pre-Orthographic Character String Processing and Parietal Cortex: A Role for Visual Attention in Reading?

    ERIC Educational Resources Information Center

    Lobier, Muriel; Peyrin, Carole; Le Bas, Jean-Francois; Valdois, Sylviane

    2012-01-01

    The visual front-end of reading is most often associated with orthographic processing. The left ventral occipito-temporal cortex seems to be preferentially tuned for letter string and word processing. In contrast, little is known of the mechanisms responsible for pre-orthographic processing: the processing of character strings regardless of…

  20. The effects of sleep deprivation on divergent thinking and attention processes.

    PubMed

    Wimmer; Hoffmann; Bonato; Moffitt

    1992-12-01

    Twelve male undergraduate students were deprived of sleep for one night and were tested with a series of cognitive tasks. Their performance was compared to the performance of thirteen control subjects. Two hourly tasks and three occasional tasks were administered in order to examine cognitive performance following sleep loss. In an attempt to replicate the findings of Horne (1988a), the figural form of the Torrance Tests of Creative Thinking was administered. To explore the effects of short-term sleep deprivation on attention, the following tasks were also administered: a working memory task, a trail-making task, a vowel/consonant discrimination task, and a letter recognition task. Results of the Torrance test, trail-making task and letter recognition task revealed decreases in cognitive abilities following sleep loss, although all tasks required less than 10 minutes to administer. The results of this study suggest that cognitive measures following sleep deprivation have not been adequately explored. Results support the hypothesis that sleep serves a function of cognitive restitution, particularly in the maintenance of attentional mechanisms. PMID:10607055

  1. Adaptation as a Political Process: Adjusting to Drought and Conflict in Kenya's Drylands

    NASA Astrophysics Data System (ADS)

    Eriksen, Siri; Lind, Jeremy

    2009-05-01

    In this article, we argue that people’s adjustments to multiple shocks and changes, such as conflict and drought, are intrinsically political processes that have uneven outcomes. Strengthening local adaptive capacity is a critical component of adapting to climate change. Based on fieldwork in two areas in Kenya, we investigate how people seek to access livelihood adjustment options and promote particular adaptation interests through forming social relations and political alliances to influence collective decision-making. First, we find that, in the face of drought and conflict, relations are formed among individuals, politicians, customary institutions, and government administration aimed at retaining or strengthening power bases in addition to securing material means of survival. Second, national economic and political structures and processes affect local adaptive capacity in fundamental ways, such as through the unequal allocation of resources across regions, development policy biased against pastoralism, and competition for elected political positions. Third, conflict is part and parcel of the adaptation process, not just an external factor inhibiting local adaptation strategies. Fourth, there are relative winners and losers of adaptation, but whether or not local adjustments to drought and conflict compound existing inequalities depends on power relations at multiple geographic scales that shape how conflicting interests are negotiated locally. Climate change adaptation policies are unlikely to be successful or minimize inequity unless the political dimensions of local adaptation are considered; however, existing power structures and conflicts of interests represent political obstacles to developing such policies.

  2. Effects of Attention and Levels of Processing on Explicit and Implicit Memory Function with Interesting and Uninteresting Tasks in University Students

    NASA Astrophysics Data System (ADS)

    Mahdavian, Alireza; Kormi-Nouri, Reza

    This study aims to investigate the effect of attention and levels of processing on memory function and recalling words in two situations when students are interested in the subject and when they are not. This is an experimental study of 160 students conducted individually using a computer software. Results reveal focused attention, interest in the subject and deep processing caused the explicit memory to be at its highest level of functionality. On the contrary, shallow processing, divided attention and lack of interest in the subject plunged memory function into its lowest levels. Variables have different effects on attention, explicit and implicit memory. That is, interesting tasks with focused attention and deep processing have the highest effect on explicit memory in order. Also, interesting tasks, focused attention, respectively affect implicit memory. But level of processing does not affect implicit memory significantly.

  3. Context-Aware Design for Process Flexibility and Adaptation

    ERIC Educational Resources Information Center

    Yao, Wen

    2012-01-01

    Today's organizations face continuous and unprecedented changes in their business environment. Traditional process design tools tend to be inflexible and can only support rigidly defined processes (e.g., order processing in the supply chain). This considerably restricts their real-world applications value, especially in the dynamic and…

  4. Visual Attention Allocation Between Robotic Arm and Environmental Process Control: Validating the STOM Task Switching Model

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher; Vieanne, Alex; Clegg, Benjamin; Sebok, Angelia; Janes, Jessica

    2015-01-01

    Fifty six participants time shared a spacecraft environmental control system task with a realistic space robotic arm control task in either a manual or highly automated version. The former could suffer minor failures, whose diagnosis and repair were supported by a decision aid. At the end of the experiment this decision aid unexpectedly failed. We measured visual attention allocation and switching between the two tasks, in each of the eight conditions formed by manual-automated arm X expected-unexpected failure X monitoring- failure management. We also used our multi-attribute task switching model, based on task attributes of priority interest, difficulty and salience that were self-rated by participants, to predict allocation. An un-weighted model based on attributes of difficulty, interest and salience accounted for 96 percent of the task allocation variance across the 8 different conditions. Task difficulty served as an attractor, with more difficult tasks increasing the tendency to stay on task.

  5. The Effects of Changing Attention and Context in an Awake Offline Processing Period on Visual Long-Term Memory

    PubMed Central

    Ellmore, Timothy M.; Feng, Anna; Ng, Kenneth; Dewan, Luthfunnahar; Root, James C.

    2016-01-01

    There is accumulating evidence that sleep as well as awake offline processing is important for the transformation of new experiences into long-term memory (LTM). Yet much remains to be understood about how various cognitive factors influence the efficiency of awake offline processing. In the present study we investigated how changes in attention and context in the immediate period after exposure to new visual information influences LTM consolidation. After presentation of multiple naturalistic scenes within a working memory paradigm, recognition was assessed 30 min and 24 h later in three groups of subjects. One group of subjects engaged in a focused attention task [the Revised Attentional Network Task (R-ANT)] in the 30 min after exposure to the scenes. Another group of subjects remained in the testing room during the 30 min after scene exposure and engaged in no goal- or task-directed activities. A third group of subjects left the testing room and returned 30 min later. A signal detection analysis revealed no significant differences among the three groups in hits, false alarms, or sensitivity on the 30-min recognition task. At the 24-h recognition test, the group that performed the R-ANT made significantly fewer hits compared to the group that left the testing room and did not perform the attention ask. The group that performed the R-ANT and the group that remained in the testing room during the 30-min post-exposure interval made significantly fewer false alarms on the 24-h recognition test compared to the group that left the testing room. The group that stayed in the testing room and engaged in no goal- or task-directed activities exhibited significantly higher sensitivity (d′) compared to the group that left the testing room and the group that performed the R-ANT task. Staying in the same context after exposure to new information and resting quietly with minimal engagement of attention results in the best ability to distinguish old from novel visual stimuli

  6. Attention effects on the processing of task-relevant and task-irrelevant speech sounds and letters

    PubMed Central

    Mittag, Maria; Inauri, Karina; Huovilainen, Tatu; Leminen, Miika; Salo, Emma; Rinne, Teemu; Kujala, Teija; Alho, Kimmo

    2013-01-01

    We used event-related brain potentials (ERPs) to study effects of selective attention on the processing of attended and unattended spoken syllables and letters. Participants were presented with syllables randomly occurring in the left or right ear and spoken by different voices and with a concurrent foveal stream of consonant letters written in darker or lighter fonts. During auditory phonological (AP) and non-phonological tasks, they responded to syllables in a designated ear starting with a vowel and spoken by female voices, respectively. These syllables occurred infrequently among standard syllables starting with a consonant and spoken by male voices. During visual phonological and non-phonological tasks, they responded to consonant letters with names starting with a vowel and to letters written in dark fonts, respectively. These letters occurred infrequently among standard letters with names starting with a consonant and written in light fonts. To examine genuine effects of attention and task on ERPs not overlapped by ERPs associated with target processing or deviance detection, these effects were studied only in ERPs to auditory and visual standards. During selective listening to syllables in a designated ear, ERPs to the attended syllables were negatively displaced during both phonological and non-phonological auditory tasks. Selective attention to letters elicited an early negative displacement and a subsequent positive displacement (Pd) of ERPs to attended letters being larger during the visual phonological than non-phonological task suggesting a higher demand for attention during the visual phonological task. Active suppression of unattended speech during the AP and non-phonological tasks and during the visual phonological tasks was suggested by a rejection positivity (RP) to unattended syllables. We also found evidence for suppression of the processing of task-irrelevant visual stimuli in visual ERPs during auditory tasks involving left-ear syllables

  7. Adaptive information processing in auditory cortex. Annual report, 1 June 1987-31 May 1988

    SciTech Connect

    Weinberger, N.M.

    1988-05-31

    The fact that learning induces frequency-specific modification of receptive fields in auditory cortex implies that the functional organization of auditory (and perhaps other sensory) cortex comprises an adaptively-constituted information base. This project initiates the first systematic investigation of adaptive information processing in cerebral cortex. A major goal is to determine the circumstances under which adaptive information processing is induced by experience. This project also addresses central hypotheses about rules that govern adaptive information processing, at three levels of spatial scale: (a) parallel processing in different auditory fields: (b) modular processing in different cortical lamina within fields; (c) local processing in different neurons within the same locus within lamina. The author emphasized determining the learning circumstances under which adaptive information processing is invoked by the brain. Current studies reveal that the frequency receptive fields of neurons in the auditory cortex, and the physiologically plastic magnocellular medial geniculate nucleus, develop frequency-specific modification such that maximal shifts in tuning are at or adjacent to the signal frequency. Further, this adaptive re-tuning of neurons develops rapidly during habituation, classical conditioning, and instrumental avoidance conditioning. The generality of re-tuning has established that AIP during learning represents a general brain strategy for the acquisition and subsequent processing of information.

  8. Slow cortical potential and theta/beta neurofeedback training in adults: effects on attentional processes and motor system excitability.

    PubMed

    Studer, Petra; Kratz, Oliver; Gevensleben, Holger; Rothenberger, Aribert; Moll, Gunther H; Hautzinger, Martin; Heinrich, Hartmut

    2014-01-01

    Neurofeedback (NF) is being successfully applied, among others, in children with attention deficit/hyperactivity disorder (ADHD) and as a peak performance training in healthy subjects. However, the neuronal mechanisms mediating a successful NF training have not yet been sufficiently uncovered for both theta/beta (T/B), and slow cortical potential (SCP) training, two protocols established in NF in ADHD. In the present, randomized, controlled investigation in adults without a clinical diagnosis (n = 59), the specificity of the effects of these two NF protocols on attentional processes and motor system excitability were to be examined, focusing on the underlying neuronal mechanisms. Neurofeedback training consisted of 10 double sessions, and self-regulation skills were analyzed. Pre- and post-training assessments encompassed performance and event-related potential measures during an attention task, and motor system excitability assessed by transcranial magnetic stimulation. Some NF protocol-specific effects have been obtained. However, due to the limited sample size medium effects did not reach the level of significance. Self-regulation abilities during negativity trials of the SCP training were associated with increased contingent negative variation amplitudes, indicating improved resource allocation during cognitive preparation. Theta/beta training was associated with increased response speed and decreased target-P3 amplitudes after successful theta/beta regulation suggested reduced attentional resources necessary for stimulus evaluation. Motor system excitability effects after theta/beta training paralleled the effects of methylphenidate. Overall, our results are limited by the non-sufficiently acquired self-regulation skills, but some specific effects between good and poor learners could be described. Future studies with larger sample sizes and sufficient acquisition of self-regulation skills are needed to further evaluate the protocol-specific effects on

  9. Slow cortical potential and theta/beta neurofeedback training in adults: effects on attentional processes and motor system excitability

    PubMed Central

    Studer, Petra; Kratz, Oliver; Gevensleben, Holger; Rothenberger, Aribert; Moll, Gunther H.; Hautzinger, Martin; Heinrich, Hartmut

    2014-01-01

    Neurofeedback (NF) is being successfully applied, among others, in children with attention deficit/hyperactivity disorder (ADHD) and as a peak performance training in healthy subjects. However, the neuronal mechanisms mediating a successful NF training have not yet been sufficiently uncovered for both theta/beta (T/B), and slow cortical potential (SCP) training, two protocols established in NF in ADHD. In the present, randomized, controlled investigation in adults without a clinical diagnosis (n = 59), the specificity of the effects of these two NF protocols on attentional processes and motor system excitability were to be examined, focusing on the underlying neuronal mechanisms. Neurofeedback training consisted of 10 double sessions, and self-regulation skills were analyzed. Pre- and post-training assessments encompassed performance and event-related potential measures during an attention task, and motor system excitability assessed by transcranial magnetic stimulation. Some NF protocol-specific effects have been obtained. However, due to the limited sample size medium effects did not reach the level of significance. Self-regulation abilities during negativity trials of the SCP training were associated with increased contingent negative variation amplitudes, indicating improved resource allocation during cognitive preparation. Theta/beta training was associated with increased response speed and decreased target-P3 amplitudes after successful theta/beta regulation suggested reduced attentional resources necessary for stimulus evaluation. Motor system excitability effects after theta/beta training paralleled the effects of methylphenidate. Overall, our results are limited by the non-sufficiently acquired self-regulation skills, but some specific effects between good and poor learners could be described. Future studies with larger sample sizes and sufficient acquisition of self-regulation skills are needed to further evaluate the protocol-specific effects on

  10. Concurrent processing adaptation of aeroplastic analysis of propfans

    NASA Technical Reports Server (NTRS)

    Janetzke, David C.; Murthy, Durbha V.

    1990-01-01

    Discussed here is a study involving the adaptation of an advanced aeroelastic analysis program to run concurrently on a shared memory multiple processor computer. The program uses a three-dimensional compressible unsteady aerodynamic model and blade normal modes to calculate aeroelastic stability and response of propfan blades. The identification of the computational parallelism within the sequential code and the scheduling of the concurrent subtasks to minimize processor idle time are discussed. Processor idle time in the calculation of the unsteady aerodynamic coefficients was reduced by the simple strategy of appropriately ordering the computations. Speedup and efficiency results are presented for the calculation of the matched flutter point of an experimental propfan model. The results show that efficiencies above 70 percent can be obtained using the present implementation with 7 processors. The parallel computational strategy described here is also applicable to other aeroelastic analysis procedures based on panel methods.

  11. A single-rate context-dependent learning process underlies rapid adaptation to familiar object dynamics.

    PubMed

    Ingram, James N; Howard, Ian S; Flanagan, J Randall; Wolpert, Daniel M

    2011-09-01

    Motor learning has been extensively studied using dynamic (force-field) perturbations. These induce movement errors that result in adaptive changes to the motor commands. Several state-space models have been developed to explain how trial-by-trial errors drive the progressive adaptation observed in such studies. These models have been applied to adaptation involving novel dynamics, which typically occurs over tens to hundreds of trials, and which appears to be mediated by a dual-rate adaptation process. In contrast, when manipulating objects with familiar dynamics, subjects adapt rapidly within a few trials. Here, we apply state-space models to familiar dynamics, asking whether adaptation is mediated by a single-rate or dual-rate process. Previously, we reported a task in which subjects rotate an object with known dynamics. By presenting the object at different visual orientations, adaptation was shown to be context-specific, with limited generalization to novel orientations. Here we show that a multiple-context state-space model, with a generalization function tuned to visual object orientation, can reproduce the time-course of adaptation and de-adaptation as well as the observed context-dependent behavior. In contrast to the dual-rate process associated with novel dynamics, we show that a single-rate process mediates adaptation to familiar object dynamics. The model predicts that during exposure to the object across multiple orientations, there will be a degree of independence for adaptation and de-adaptation within each context, and that the states associated with all contexts will slowly de-adapt during exposure in one particular context. We confirm these predictions in two new experiments. Results of the current study thus highlight similarities and differences in the processes engaged during exposure to novel versus familiar dynamics. In both cases, adaptation is mediated by multiple context-specific representations. In the case of familiar object dynamics

  12. Anticipatory Emotions in Decision Tasks: Covert Markers of Value or Attentional Processes?

    ERIC Educational Resources Information Center

    Davis, Tyler; Love, Bradley C.; Maddox, W. Todd

    2009-01-01

    Anticipatory emotions precede behavioral outcomes and provide a means to infer interactions between emotional and cognitive processes. A number of theories hold that anticipatory emotions serve as inputs to the decision process and code the value or risk associated with a stimulus. We argue that current data do not unequivocally support this…

  13. A Case for Inhibition: Visual Attention Suppresses the Processing of Irrelevant Objects

    ERIC Educational Resources Information Center

    Wuhr, Peter; Frings, Christian

    2008-01-01

    The present study investigated the ability to inhibit the processing of an irrelevant visual object while processing a relevant one. Participants were presented with 2 overlapping shapes (e.g., circle and square) in different colors. The task was to name the color of the relevant object designated by shape. Congruent or incongruent color words…

  14. A common neuronal code for perceptual processes in visual cortex? Comparing choice and attentional correlates in V5/MT.

    PubMed Central

    Krug, Kristine

    2004-01-01

    In the past two decades, sensory neuroscience has moved from describing response properties to external stimuli in cerebral cortex to establishing connections between neuronal activity and sensory perception. The seminal studies by Newsome, Movshon and colleagues in the awake behaving macaque firmly link single cells in extrastriate area V5/MT and perception of motion. A decade later, extrastriate visual cortex appears awash with neuronal correlates for many different perceptual tasks. Examples are attentional signals, choice signals for ambiguous images, correlates for binocular rivalry, stereo and shape perception, and so on. These diverse paradigms are aimed at elucidating the neuronal code for perceptual processes, but it has been little studied how they directly compare or even interact. In this paper, I explore to what degree the measured neuronal signals in V5/MT for choice and attentional paradigms might reflect a common neuronal mechanism for visual perception. PMID:15306408

  15. Benefits of an external focus of attention: common coding or conscious processing?

    PubMed

    Poolton, J M; Maxwell, J P; Masters, R S W; Raab, M

    2006-01-01

    We conducted two experiments to assess the effect attentional focus has on learning a complex motor skill and subsequent performance under secondary task loading. Participants in Experiment 1 learnt a golf putting task (300 practice trials) with a single instruction to either focus on their hands (internal focus) or the movement of the putter (external focus). No group differences were evident during learning or retention. Differences between the groups were only apparent under secondary task load; the external group's performance remained robust, while the internal group suffered a drop in performance. Verbal protocols demonstrated that the internal group accumulated significantly more internal knowledge and more task-relevant knowledge in general than the external group. Experiment 2 was designed to establish whether greater internal focus knowledge or greater explicit rule build up in general was responsible for performance breakdown. Two groups were presented with a set of six internal or external rules. Again, no performance differences were found during learning or retention. During the secondary task, both groups experienced performance deterioration. It was concluded that accumulation of explicit rules to guide performance was responsible for the internal group's breakdown in performance under secondary task loading and may be responsible for some of the performance differences reported previously. PMID:16368617

  16. Impaired reward processing by anterior cingulate cortex in children with attention deficit hyperactivity disorder.

    PubMed

    Umemoto, Akina; Lukie, Carmen N; Kerns, Kimberly A; Müller, Ulrich; Holroyd, Clay B

    2014-06-01

    Decades of research have examined the neurocognitive mechanisms of cognitive control, but the motivational factors underlying task selection and performance remain to be elucidated. We recently proposed that anterior cingulate cortex (ACC) utilizes reward prediction error signals carried by the midbrain dopamine system to learn the value of tasks according to the principles of hierarchical reinforcement learning. According to this position, disruption of the ACC-dopamine interface can disrupt the selection and execution of extended, task-related behaviors. To investigate this issue, we recorded the event-related brain potential (ERP) from children with attention deficit hyperactivity disorder (ADHD), which is strongly associated with ACC-dopamine dysfunction, and from typically developing children while they navigated a simple "virtual T-maze" to find rewards. Depending on the condition, the feedback stimuli on each trial indicated that the children earned or failed to earn either money or points. We found that the reward positivity, an ERP component proposed to index the impact of dopamine-related reward signals on ACC, was significantly larger with money feedback than with points feedback for the children with ADHD, but not for the typically developing children. These results suggest that disruption of the ACC-dopamine interface may underlie the impairments in motivational control observed in childhood ADHD. PMID:24874420

  17. Stimulus-driven and knowledge-driven processes in attention to warbles

    NASA Astrophysics Data System (ADS)

    Dowling, W. Jay; Tillmann, Barbara

    2003-10-01

    Listeners identified warbles differing in amplitude-modulation rate (3-10 Hz). And measured RT while listeners maintained above 90% correct responses. After a practice session listeners identified target warbles following stimulus-driven or knowledge-driven cues. The stimulus-driven cue was a 250-ms ``beep'' at the target pitch (valid) or another pitch (invalid); the knowledge-driven cue was a midrange ``melody'' pointing to the target pitch (always valid). A 500-ms target warble followed the cue after delays of 0-500 ms (250-750 ms SOA). The listener pressed a key to indicate ``slow'' or ``fast.'' RTs were shortest at the briefest delay. In contrast to results from a memory task, RTs here were much shorter, and we found no evidence for IOR or attentional blink. Listeners began generating responses while the target was still sounding. Invalid ``beeps'' slowed responses at the briefest (but not the longer) delays; adding a valid ``beep'' to the valid ``melody'' did not speed responses.

  18. Effects of Prenatal PCB Exposure on Cognitive Processing Efficiency and Sustained Attention.

    ERIC Educational Resources Information Center

    Jacobson, Joseph L.; And Others

    1992-01-01

    In four year olds who had been exposed to polychlorinated biphenyls (PCBs) before birth, prenatal exposure was associated with less efficient visual discrimination processing and more errors in short memory scanning. Postnatal exposure was unrelated to cognitive performance. (GLR)

  19. Crossmodal semantic congruence can affect visuo-spatial processing and activity of the fronto-parietal attention networks.

    PubMed

    Mastroberardino, Serena; Santangelo, Valerio; Macaluso, Emiliano

    2015-01-01

    Previous studies have shown that multisensory stimuli can contribute to attention control. Here we investigate whether irrelevant audio-visual stimuli can affect the processing of subsequent visual targets, in the absence of any direct bottom-up signals generated by low-level sensory changes and any goal-related associations between the multisensory stimuli and the visual targets. Each trial included two pictures (cat/dog), one in each visual hemifield, and a central sound that was semantically congruent with one of the two pictures (i.e., either "meow" or "woof" sound). These irrelevant audio-visual stimuli were followed by a visual target that appeared either where the congruent or the incongruent picture had been presented (valid/invalid trials). The visual target was a Gabor patch requiring an orientation discrimination judgment, allowing us to uncouple the visual task from the audio-visual stimuli. Behaviourally we found lower performance for invalid than valid trials, but only when the task demands were high (Gabor target presented together with a Gabor distractor vs. Gabor target alone). The fMRI analyses revealed greater activity for invalid than for valid trials in the dorsal and the ventral fronto-parietal attention networks. The dorsal network was recruited irrespective of task demands, while the ventral network was recruited only when task demands were high and target discrimination required additional top-down control. We propose that crossmodal semantic congruence generates a processing bias associated with the location of congruent picture, and that the presentation of the visual target on the opposite side required updating these processing priorities. We relate the activation of the attention networks to these updating operations. We conclude that the fronto-parietal networks mediate the influence of crossmodal semantic congruence on visuo-spatial processing, even in the absence of any low-level sensory cue and any goal-driven task associations

  20. Crossmodal semantic congruence can affect visuo-spatial processing and activity of the fronto-parietal attention networks

    PubMed Central

    Mastroberardino, Serena; Santangelo, Valerio; Macaluso, Emiliano

    2015-01-01

    Previous studies have shown that multisensory stimuli can contribute to attention control. Here we investigate whether irrelevant audio–visual stimuli can affect the processing of subsequent visual targets, in the absence of any direct bottom–up signals generated by low-level sensory changes and any goal-related associations between the multisensory stimuli and the visual targets. Each trial included two pictures (cat/dog), one in each visual hemifield, and a central sound that was semantically congruent with one of the two pictures (i.e., either “meow” or “woof” sound). These irrelevant audio–visual stimuli were followed by a visual target that appeared either where the congruent or the incongruent picture had been presented (valid/invalid trials). The visual target was a Gabor patch requiring an orientation discrimination judgment, allowing us to uncouple the visual task from the audio–visual stimuli. Behaviourally we found lower performance for invalid than valid trials, but only when the task demands were high (Gabor target presented together with a Gabor distractor vs. Gabor target alone). The fMRI analyses revealed greater activity for invalid than for valid trials in the dorsal and the ventral fronto-parietal attention networks. The dorsal network was recruited irrespective of task demands, while the ventral network was recruited only when task demands were high and target discrimination required additional top–down control. We propose that crossmodal semantic congruence generates a processing bias associated with the location of congruent picture, and that the presentation of the visual target on the opposite side required updating these processing priorities. We relate the activation of the attention networks to these updating operations. We conclude that the fronto-parietal networks mediate the influence of crossmodal semantic congruence on visuo-spatial processing, even in the absence of any low-level sensory cue and any goal

  1. Double dissociation of working memory and attentional processes in smokers and non-smokers with and without nicotine.

    PubMed

    Grundey, Jessica; Amu, Rosa; Ambrus, Géza Gergely; Batsikadze, Georgi; Paulus, Walter; Nitsche, Michael A

    2015-07-01

    Nicotine has been shown to affect cortical excitability measured using transcranial magnetic stimulation in smoking and non-smoking subjects in different ways. In tobacco-deprived smokers, administration of nicotine restores compromised cortical facilitation while in non-smokers, it enhances cortical inhibition. As cortical excitability and activity are closely linked to cognitive processes, we aimed to explore whether nicotine-induced physiological alterations in non-smokers and smokers are associated with cognitive changes. Specifically, we assessed the impact of nicotine on working memory performance (n-back letter task) and on attentional processes (Stroop interference test) in healthy smokers and non-smokers. Both tasks have been shown to rely on prefrontal areas, and nicotinic receptors are relevantly involved in prefrontal function. Sixteen smoking and 16 non-smoking subjects participated in the 3-back letter task and 21 smoking and 21 non-smoking subjects in the Stroop test after the respective application of placebo or nicotine patches. The results show that working memory and attentional processes are compromised in nicotine-deprived smokers compared to non-smoking individuals. After administration of nicotine, working memory performance in smokers improved, while non-smoking subjects displayed decreased accuracy with increased number of errors. The effects have been shown to be more apparent for working memory performance than attentional processes. In summary, cognitive functions can be restored by nicotine in deprived smokers, whereas non-smokers do not gain additional benefit. The respective changes are in accordance with related effects of nicotine on cortical excitability in both groups. PMID:25721074

  2. How and When Accentuation Influences Temporally Selective Attention and Subsequent Semantic Processing during On-Line Spoken Language Comprehension: An ERP Study

    ERIC Educational Resources Information Center

    Li, Xiao-qing; Ren, Gui-qin

    2012-01-01

    An event-related brain potentials (ERP) experiment was carried out to investigate how and when accentuation influences temporally selective attention and subsequent semantic processing during on-line spoken language comprehension, and how the effect of accentuation on attention allocation and semantic processing changed with the degree of…

  3. Adaptable Particle-in-Cell Algorithms for Graphical Processing Units

    NASA Astrophysics Data System (ADS)

    Decyk, Viktor; Singh, Tajendra

    2010-11-01

    Emerging computer architectures consist of an increasing number of shared memory computing cores in a chip, often with vector (SIMD) co-processors. Future exascale high performance systems will consist of a hierarchy of such nodes, which will require different algorithms at different levels. Since no one knows exactly how the future will evolve, we have begun development of an adaptable Particle-in-Cell (PIC) code, whose parameters can match different hardware configurations. The data structures reflect three levels of parallelism, contiguous vectors and non-contiguous blocks of vectors, which can share memory, and groups of blocks which do not. Particles are kept ordered at each time step, and the size of a sorting cell is an adjustable parameter. We have implemented a simple 2D electrostatic skeleton code whose inner loop (containing 6 subroutines) runs entirely on the NVIDIA Tesla C1060. We obtained speedups of about 16-25 compared to a 2.66 GHz Intel i7 (Nehalem), depending on the plasma temperature, with an asymptotic limit of 40 for a frozen plasma. We expect speedups of about 70 for an 2D electromagnetic code and about 100 for a 3D electromagnetic code, which have higher computational intensities (more flops/memory access).

  4. Parallel Block Structured Adaptive Mesh Refinement on Graphics Processing Units

    SciTech Connect

    Beckingsale, D. A.; Gaudin, W. P.; Hornung, R. D.; Gunney, B. T.; Gamblin, T.; Herdman, J. A.; Jarvis, S. A.

    2014-11-17

    Block-structured adaptive mesh refinement is a technique that can be used when solving partial differential equations to reduce the number of zones necessary to achieve the required accuracy in areas of interest. These areas (shock fronts, material interfaces, etc.) are recursively covered with finer mesh patches that are grouped into a hierarchy of refinement levels. Despite the potential for large savings in computational requirements and memory usage without a corresponding reduction in accuracy, AMR adds overhead in managing the mesh hierarchy, adding complex communication and data movement requirements to a simulation. In this paper, we describe the design and implementation of a native GPU-based AMR library, including: the classes used to manage data on a mesh patch, the routines used for transferring data between GPUs on different nodes, and the data-parallel operators developed to coarsen and refine mesh data. We validate the performance and accuracy of our implementation using three test problems and two architectures: an eight-node cluster, and over four thousand nodes of Oak Ridge National Laboratory’s Titan supercomputer. Our GPU-based AMR hydrodynamics code performs up to 4.87× faster than the CPU-based implementation, and has been scaled to over four thousand GPUs using a combination of MPI and CUDA.

  5. Local adaptation in Trinidadian guppies alters ecosystem processes.

    PubMed

    Bassar, Ronald D; Marshall, Michael C; López-Sepulcre, Andrés; Zandonà, Eugenia; Auer, Sonya K; Travis, Joseph; Pringle, Catherine M; Flecker, Alexander S; Thomas, Steven A; Fraser, Douglas F; Reznick, David N

    2010-02-23

    Theory suggests evolutionary change can significantly influence and act in tandem with ecological forces via ecological-evolutionary feedbacks. This theory assumes that significant evolutionary change occurs over ecologically relevant timescales and that phenotypes have differential effects on the environment. Here we test the hypothesis that local adaptation causes ecosystem structure and function to diverge. We demonstrate that populations of Trinidadian guppies (Poecilia reticulata), characterized by differences in phenotypic and population-level traits, differ in their impact on ecosystem properties. We report results from a replicated, common garden mesocosm experiment and show that differences between guppy phenotypes result in the divergence of ecosystem structure (algal, invertebrate, and detrital standing stocks) and function (gross primary productivity, leaf decomposition rates, and nutrient flux). These phenotypic effects are further modified by effects of guppy density. We evaluated the generality of these effects by replicating the experiment using guppies derived from two independent origins of the phenotype. Finally, we tested the ability of multiple guppy traits to explain observed differences in the mesocosms. Our findings demonstrate that evolution can significantly affect both ecosystem structure and function. The ecosystem differences reported here are consistent with patterns observed across natural streams and argue that guppies play a significant role in shaping these ecosystems. PMID:20133670

  6. Process- and controller-adaptations determine the physiological effects of cold acclimation.

    PubMed

    Werner, Jürgen

    2008-09-01

    Experimental results on physiological effects of cold adaptation seem confusing and apparently incompatible with one another. This paper will explain that a substantial part of such a variety of results may be deduced from a common functional concept. A core/shell treatment ("model") of the thermoregulatory system is used with mean body temperature as the controlled variable. Adaptation, as a higher control level, is introduced into the system. Due to persistent stressors, either the (heat transfer) process or the controller properties (parameters) are adjusted (or both). It is convenient to call the one "process adaptation" and the other "controller adaptation". The most commonly demonstrated effect of autonomic cold acclimation is a change in the controller threshold. The analysis shows that this necessarily means a lowering of body temperature because of a lowered metabolic rate. This explains experimental results on both Europeans in the climatic chamber and Australian Aborigines in a natural environment. Exclusive autonomic process adaptation occurs in the form of a better insulation. The analysis explains why the post-adaptive steady-state can only be achieved, if the controller system reduces metabolism and why in spite of this the new state is inevitably characterized by a rise in body temperature. If both process and controller adaptations are simultaneously present, there may be not any change of body temperature at all, e.g., as demonstrated in animal experiments. Whether this kind of adaptation delivers a decrease, an increase or no change of mean body temperature, depends on the proportion of process and controller adaptation. PMID:18026979

  7. Adaptive Memory: The Evolutionary Significance of Survival Processing.

    PubMed

    Nairne, James S; Pandeirada, Josefa N S

    2016-07-01

    A few seconds of survival processing, during which people assess the relevance of information to a survival situation, produces particularly good retention. One interpretation of this benefit is that our memory systems are optimized to process and retain fitness-relevant information. Such a "tuning" may exist, in part, because our memory systems were shaped by natural selection, using a fitness-based criterion. However, recent research suggests that traditional mnemonic processes, such as elaborative processing, may play an important role in producing the empirical benefit. Boundary conditions have been demonstrated as well, leading some to dismiss evolutionary interpretations of the phenomenon. In this article, we discuss the current state of the evolutionary account and provide a general framework for evaluating evolutionary and purportedly nonevolutionary interpretations of mnemonic phenomena. We suggest that survival processing effects are best viewed within the context of a general survival optimization system, designed by nature to help organisms deal with survival challenges. An important component of survival optimization is the ability to simulate activities that help to prevent or escape from future threats which, in turn, depends in an important way on accurate retrospective remembering of survival-relevant information. PMID:27474137

  8. Student Guidance and Attention to Diversity in the Processes of Quality Assurance in Higher Education

    ERIC Educational Resources Information Center

    Ferreira, Camino; Vidal, Javier; Vieira, María José

    2014-01-01

    The main objective of this article is to analyse the importance given to student guidance and diversity in the standards and criteria used in the quality accreditation and evaluation processes in Europe and the US. Agencies selected in this study are the members of ENQA (European Association for Quality Assurance in Higher Education), EQAR…

  9. Increased Attention to the Search Process Improves the Chances of Foster Kinship Placements

    ERIC Educational Resources Information Center

    Gibson, Priscilla A.; Rinkel, Michaela

    2012-01-01

    Although child protective service (CPS) workers are mandated by social policies to conduct a search for relatives, the search process remains unclear and under scrutiny. Placing children with an appropriate relative is dependent on workers' practices and, to some extent, attitudes. Reviewing social policies that mandate the inclusion of relatives…

  10. Relationships among Linguistic Processing Speed, Phonological Working Memory, and Attention in Children Who Stutter

    ERIC Educational Resources Information Center

    Anderson, Julie D.; Wagovich, Stacy A.

    2010-01-01

    Relatively recently, experimental studies of linguistic processing speed in children who stutter (CWS) have emerged, some of which suggest differences in performance among CWS compared to children who do not stutter (CWNS). What is not yet well understood is the extent to which underlying cognitive skills may impact performance on timed tasks of…

  11. Selective Attention in Schizophrenic and Manic Psychoses: The Effect of Distraction on Information Processing

    ERIC Educational Resources Information Center

    Oltmanns, Thomas F.

    1978-01-01

    This study was designed to identify the general level of cognitive processing that is especially vulnerable to distraction in schizophrenia. Attempts to determine at what level auditory distraction interferes with schizophrenics' performance, as opposed to normals, on simple recall tasks. (Editor/RK)

  12. Positive Affect Processing and Joint Attention in Infants at High Risk for Autism: An Exploratory Study

    ERIC Educational Resources Information Center

    Key, Alexandra P.; Ibanez, Lisa V.; Henderson, Heather A.; Warren, Zachary; Messinger, Daniel S.; Stone, Wendy L.

    2015-01-01

    Few behavioral indices of risk for autism spectrum disorders (ASD) are present before 12 months, and potential biomarkers remain largely unexamined. This prospective study of infant siblings of children with ASD (n = 16) and low-risk comparison infants (n = 15) examined group differences in event-related potentials (ERPs) indexing processing of…

  13. ERP Study of Pre-Attentive Auditory Processing in Treatment-Refractory Schizophrenia

    ERIC Educational Resources Information Center

    Milovan, Denise L.; Baribeau, Jacinthe; Roth, Robert M.; Stip, Emmanuel

    2004-01-01

    Event-related potential (ERP) studies have demonstrated impaired auditory sensory processing in patients with schizophrenia, as reflected in abnormal mismatch negativity (MMN). We sought to extend this finding by evaluating MMN in 13 treatment-refractory patients with schizophrenia, and 14 age- and gender-matched healthy controls. Subjects…

  14. Foveal vs. Parafoveal Processing in Anxiety: Broadened Spatial Attention for Threat Words

    ERIC Educational Resources Information Center

    Gutierrez, Aida; Calvo, Manuel G.

    2011-01-01

    We investigated the processing of threat-related, positive, and neutral words in parafoveal and in foveal vision as a function of individual differences in trait anxiety. In a lexical-decision task, word primes were presented for 150 ms either parafoveally (2.2[degrees] away from fixation; Experiment 1) or foveally (at fixation; Experiment 3)…

  15. A multilevel examination of the relationships among training outcomes, mediating regulatory processes, and adaptive performance.

    PubMed

    Chen, Gilad; Thomas, Brian; Wallace, J Craig

    2005-09-01

    This study examined whether cognitive, affective-motivational, and behavioral training outcomes relate to posttraining regulatory processes and adaptive performance similarly at the individual and team levels of analysis. Longitudinal data were collected from 156 individuals composing 78 teams who were trained on and then performed a simulated flight task. Results showed that posttraining regulation processes related similarly to adaptive performance across levels. Also, regulation processes fully mediated the influences of self- and collective efficacy beliefs on individual and team adaptive performance. Finally, knowledge and skill more strongly and directly related to adaptive performance at the individual than the team level of analysis. Implications to theory and practice, limitations, and future directions are discussed. PMID:16162057

  16. Frontal EEG/ERP correlates of attentional processes, cortisol and motivational states in adolescents from lower and higher socioeconomic status

    PubMed Central

    D'Angiulli, Amedeo; Weinberg, Joanne; Oberlander, Tim F.; Grunau, Ruth E.; Hertzman, Clyde; Maggi, Stefania

    2012-01-01

    Event-related potentials (ERPs) and other electroencephalographic (EEG) evidence show that frontal brain areas of higher and lower socioeconomic status (SES) children are recruited differently during selective attention tasks. We assessed whether multiple variables related to self-regulation (perceived mental effort) emotional states (e.g., anxiety, stress, etc.) and motivational states (e.g., boredom, engagement, etc.) may co-occur or interact with frontal attentional processing probed in two matched-samples of fourteen lower-SES and higher-SES adolescents. ERP and EEG activation were measured during a task probing selective attention to sequences of tones. Pre- and post-task salivary cortisol and self-reported emotional states were also measured. At similar behavioural performance level, the higher-SES group showed a greater ERP differentiation between attended (relevant) and unattended (irrelevant) tones than the lower-SES group. EEG power analysis revealed a cross-over interaction, specifically, lower-SES adolescents showed significantly higher theta power when ignoring rather than attending to tones, whereas, higher-SES adolescents showed the opposite pattern. Significant theta asymmetry differences were also found at midfrontal electrodes indicating left hypo-activity in lower-SES adolescents. The attended vs. unattended difference in right midfrontal theta increased with individual SES rank, and (independently from SES) with lower cortisol task reactivity and higher boredom. Results suggest lower-SES children used additional compensatory resources to monitor/control response inhibition to distracters, perceiving also more mental effort, as compared to higher-SES counterparts. Nevertheless, stress, boredom and other task-related perceived states were unrelated to SES. Ruling out presumed confounds, this study confirms the midfrontal mechanisms responsible for the SES effects on selective attention reported previously and here reflect genuine cognitive

  17. The Adapted Dance Process: Planning, Partnering, and Performing

    ERIC Educational Resources Information Center

    Block, Betty A.; Johnson, Peggy V.

    2011-01-01

    This article contains specific planning, partnering, and performing techniques for fully integrating dancers with special needs into a dance pedagogy program. Each aspect is discussed within the context of the domains of learning. Fundamental partnering strategies are related to each domain as part of the integration process. The authors recommend…

  18. Adaptive healthcare processes for personalized emergency clinical pathways.

    PubMed

    Poulymenopoulou, M; Papakonstantinou, D; Malamateniou, F; Vassilacopoulos, G

    2014-01-01

    Pre-hospital and in-hospital emergency healthcare delivery involves a variety of activities and people that should be coordinated in order effectively to create an emergency care plan. Emergency care provided by emergency healthcare professionals can be improved by personalized emergency clinical pathways that are instances of relevant emergency clinical guidelines based on emergency case needs as well as on ambulance and hospital resource availability, while also enabling better resource use. Business Process Management Systems (BPMSs) in conjunction with semantic technologies can be used to support personalized emergency clinical pathways by incorporating clinical guidelines logic into the emergency healthcare processes at run-time according to emergency care context information (current emergency case and resource information). On these grounds, a framework is proposed that uses ontology to model knowledge on emergency case medical history, on healthcare resource availability, on relevant clinical guidelines and on process logic; this is inferred to result in the most suitable process model for the case, in line with relevant clinical guidelines. PMID:25160219

  19. Computer simulation program is adaptable to industrial processes

    NASA Technical Reports Server (NTRS)

    Schultz, F. E.

    1966-01-01

    The Reaction kinetics ablation program /REKAP/, developed to simulate ablation of various materials, provides mathematical formulations for computer programs which can simulate certain industrial processes. The programs are based on the use of nonsymmetrical difference equations that are employed to solve complex partial differential equation systems.

  20. Attentional Set-Shifting in Fragile X Syndrome

    ERIC Educational Resources Information Center

    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…

  1. Experimental Training of Children with Attention Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Piscalkiene, Viktorija

    2009-01-01

    Attention-deficit/hyperactivity disorder (AD/HD) negatively affects the cognitive and psychomotoric spheres of the pupil's social behavior and social adaptation. The review of many studies states that pupils with AD/HD achieve worse learning results because of insufficiently functioning cognitive processes, such as attention, (work) memory,…

  2. Adaptive control technique for accelerators using digital signal processing

    SciTech Connect

    Eaton, L.; Jachim, S.; Natter, E.

    1987-01-01

    The use of present Digital Signal Processing (DSP) techniques can drastically reduce the residual rf amplitude and phase error in an accelerating rf cavity. Accelerator beam loading contributes greatly to this residual error, and the low-level rf field control loops cannot completely absorb the fast transient of the error. A feedforward technique using DSP is required to maintain the very stringent rf field amplitude and phase specifications. 7 refs.

  3. The influence of negative stimulus features on conflict adaption: evidence from fluency of processing.

    PubMed

    Fritz, Julia; Fischer, Rico; Dreisbach, Gesine

    2015-01-01

    Cognitive control enables adaptive behavior in a dynamically changing environment. In this context, one prominent adaptation effect is the sequential conflict adjustment, i.e., the observation of reduced response interference on trials following conflict trials. Increasing evidence suggests that such response conflicts are registered as aversive signals. So far, however, the functional role of this aversive signal for conflict adaptation to occur has not been put to test directly. In two experiments, the affective valence of conflict stimuli was manipulated by fluency of processing (stimulus contrast). Experiment 1 used a flanker interference task, Experiment 2 a color-word Stroop task. In both experiments, conflict adaptation effects were only present in fluent, but absent in disfluent trials. Results thus speak against the simple idea that any aversive stimulus feature is suited to promote specific conflict adjustments. Two alternative but not mutually exclusive accounts, namely resource competition and adaptation-by-motivation, will be discussed. PMID:25767453

  4. The influence of negative stimulus features on conflict adaption: evidence from fluency of processing

    PubMed Central

    Fritz, Julia; Fischer, Rico; Dreisbach, Gesine

    2015-01-01

    Cognitive control enables adaptive behavior in a dynamically changing environment. In this context, one prominent adaptation effect is the sequential conflict adjustment, i.e., the observation of reduced response interference on trials following conflict trials. Increasing evidence suggests that such response conflicts are registered as aversive signals. So far, however, the functional role of this aversive signal for conflict adaptation to occur has not been put to test directly. In two experiments, the affective valence of conflict stimuli was manipulated by fluency of processing (stimulus contrast). Experiment 1 used a flanker interference task, Experiment 2 a color-word Stroop task. In both experiments, conflict adaptation effects were only present in fluent, but absent in disfluent trials. Results thus speak against the simple idea that any aversive stimulus feature is suited to promote specific conflict adjustments. Two alternative but not mutually exclusive accounts, namely resource competition and adaptation-by-motivation, will be discussed. PMID:25767453

  5. Paying attention to gender and poverty in health research: content and process issues.

    PubMed Central

    Ostlin, Piroska; Sen, Gita; George, Asha

    2004-01-01

    Despite the magnitude of the problem of health inequity within and between countries, little systematic research has been done on the social causes of ill-health. Health researchers have overwhelmingly focused on biomedical research at the level of individuals. Investigations into the health of groups and the determinants of health inequities that lie outside the control of the individual have received a much smaller share of research resources. Ignoring factors such as socioeconomic class, race and gender leads to biases in both the content and process of research. We use two such factors--poverty and gender--to illustrate how this occurs. There is a systematic imbalance in medical journals: research into diseases that predominate in the poorest regions of the world is less likely to be published. In addition, the slow recognition of women's health problems, misdirected and partial approaches to understanding women's and men's health, and the dearth of information on how gender interacts with other social determinants continue to limit the content of health research. In the research community these imbalances in content are linked to biases against researchers from poorer regions and women. Researchers from high-income countries benefit from better funding and infrastructure. Their publications dominate journals and citations, and these researchers also dominate advisory boards. The way to move forward is to correct biases against poverty and gender in research content and processes and provide increased funding and better career incentives to support equity-linked research. Journals need to address equity concerns in their published content and in the publishing process. Efforts to broaden access to research information need to be well resourced, publicized and expanded. PMID:15643794

  6. Implicit and Explicit Attention to Pictures and Words: An fMRI-Study of Concurrent Emotional Stimulus Processing.

    PubMed

    Flaisch, Tobias; Imhof, Martin; Schmälzle, Ralf; Wentz, Klaus-Ulrich; Ibach, Bernd; Schupp, Harald T

    2015-01-01

    The present study utilized functional magnetic resonance imaging (fMRI) to examine the neural processing of concurrently presented emotional stimuli under varying explicit and implicit attention demands. Specifically, in separate trials, participants indicated the category of either pictures or words. The words were placed over the center of the pictures and the picture-word compound-stimuli were presented for 1500 ms in a rapid event-related design. The results reveal pronounced main effects of task and emotion: the picture categorization task prompted strong activations in visual, parietal, temporal, frontal, and subcortical regions; the word categorization task evoked increased activation only in left extrastriate cortex. Furthermore, beyond replicating key findings regarding emotional picture and word processing, the results point to a dissociation of semantic-affective and sensory-perceptual processes for words: while emotional words engaged semantic-affective networks of the left hemisphere regardless of task, the increased activity in left extrastriate cortex associated with explicitly attending to words was diminished when the word was overlaid over an erotic image. Finally, we observed a significant interaction between Picture Category and Task within dorsal visual-associative regions, inferior parietal, and dorsolateral, and medial prefrontal cortices: during the word categorization task, activation was increased in these regions when the words were overlaid over erotic as compared to romantic pictures. During the picture categorization task, activity in these areas was relatively decreased when categorizing erotic as compared to romantic pictures. Thus, the emotional intensity of the pictures strongly affected brain regions devoted to the control of task-related word or picture processing. These findings are discussed with respect to the interplay of obligatory stimulus processing with task-related attentional control mechanisms. PMID:26733895

  7. Implicit and Explicit Attention to Pictures and Words: An fMRI-Study of Concurrent Emotional Stimulus Processing

    PubMed Central

    Flaisch, Tobias; Imhof, Martin; Schmälzle, Ralf; Wentz, Klaus-Ulrich; Ibach, Bernd; Schupp, Harald T.

    2015-01-01

    The present study utilized functional magnetic resonance imaging (fMRI) to examine the neural processing of concurrently presented emotional stimuli under varying explicit and implicit attention demands. Specifically, in separate trials, participants indicated the category of either pictures or words. The words were placed over the center of the pictures and the picture-word compound-stimuli were presented for 1500 ms in a rapid event-related design. The results reveal pronounced main effects of task and emotion: the picture categorization task prompted strong activations in visual, parietal, temporal, frontal, and subcortical regions; the word categorization task evoked increased activation only in left extrastriate cortex. Furthermore, beyond replicating key findings regarding emotional picture and word processing, the results point to a dissociation of semantic-affective and sensory-perceptual processes for words: while emotional words engaged semantic-affective networks of the left hemisphere regardless of task, the increased activity in left extrastriate cortex associated with explicitly attending to words was diminished when the word was overlaid over an erotic image. Finally, we observed a significant interaction between Picture Category and Task within dorsal visual-associative regions, inferior parietal, and dorsolateral, and medial prefrontal cortices: during the word categorization task, activation was increased in these regions when the words were overlaid over erotic as compared to romantic pictures. During the picture categorization task, activity in these areas was relatively decreased when categorizing erotic as compared to romantic pictures. Thus, the emotional intensity of the pictures strongly affected brain regions devoted to the control of task-related word or picture processing. These findings are discussed with respect to the interplay of obligatory stimulus processing with task-related attentional control mechanisms. PMID:26733895

  8. Adaptation is automatic.

    PubMed

    Samuel, A G; Kat, D

    1998-04-01

    Two experiments were used to test whether selective adaptation for speech occurs automatically or instead requires attentional resources. A control condition demonstrated the usual large identification shifts caused by repeatedly presenting an adapting sound (/wa/, with listeners identifying members of a /ba/-/wa/ test series). Two types of distractor tasks were used: (1) Subjects did a rapid series of arithmetic problems during the adaptation periods (Experiments 1 and 2), or (2) they made a series of rhyming judgments, requiring phonetic coding (Experiment 2). A control experiment (Experiment 3) demonstrated that these tasks normally impose a heavy attentional cost on phonetic processing. Despite this, for both experimental conditions, the observed adaptation effect was just as large as in the control condition. This result indicates that adaptation is automatic, operating at an early, preattentive level. The implications of these results for current models of speech perception are discussed. PMID:9599999

  9. Modeling feature-based attention as an active top-down inference process.

    PubMed

    Hamker, Fred H

    2006-01-01

    Vision is a crucial sensor. It provides a very rich collection of information about our environment. The difficulty in vision arises, since this information is not obvious in the image, it has to be constructed. Wheres earlier approaches have favored a bottom-up approach, which maps the image onto an internal representation of the world, more recent approaches search for alternatives and develop frameworks which make use of top-down connections. In these approaches vision is inherently a constructive process which makes use of a priory information. Following this line of research, a model of primate object perception is presented and used to simulate an object detection task in natural scenes. The model predicts that early responses in extrastriate visual areas are modulated by the visual goal. PMID:16843589

  10. Resting state EEG delta-beta coherence in relation to anxiety, behavioral inhibition, and selective attentional processing of threatening stimuli.

    PubMed

    Putman, Peter

    2011-04-01

    Variability in human resting state electroencephalography (EEG) may reflect emotion regulation processes (for a review, see Knyazev, 2007). For instance, it has been suggested that correlation between slow (1-3 Hz) and fast (13-30 Hz) activity (or δ-β coherence) may reflect functional synchronization between limbic and cortical brain systems. Indirect support comes from several studies reporting relationships between δ-β coherence and subjectively reported behavioral inhibition and state anxiety. The present study sought to extend this work and tested the prediction that objectively, experimentally, measured threat-selective attention should also be related to δ-β coherence. EEG frequency band power and dot probe task performance were assessed in forty healthy women and results demonstrated a negative association between delta-beta coherence and automatic, anxiety-driven attentional avoidance of threatening pictorial stimuli. These first reported objective measures for cognitive-emotional behavior obtained in relation to delta-beta coherence provide additional support for the hypothesis that this EEG parameter may reflect emotion regulation processes and supports suggestions that δ-β coherence may be a useful tool in the experimental study of affect and psychopathology. In addition, results showed an unexpected negative association between δ-β coherence and self-reported trait anxiety (but no association with behavioral inhibition). PMID:21277914

  11. Processing of affective prosody in boys suffering from attention deficit hyperactivity disorder: A near-infrared spectroscopy study.

    PubMed

    Köchel, Angelika; Schöngaßner, Florian; Feierl-Gsodam, Silke; Schienle, Anne

    2015-01-01

    Neurobiological studies on facial affect recognition have demonstrated reduced response amplitudes to anger cues in patients suffering from attention deficit hyperactivity disorder (ADHD). It is still unclear whether a similar deficit exists in the auditory domain. Therefore, this near-infrared spectroscopy study focused on neuronal correlates of affective prosody processing. Fourteen boys suffering from ADHD and fourteen healthy boys were exposed to emotionally intoned, standardized sentences of the categories anger, sadness, happiness, and to affectively neutral sentences. Relative to controls, the patients displayed a diminished activation of the right superior temporal gyrus (STG) when processing anger prosody, which was correlated with aggressive behavior. There were no group differences for the other emotions. Additionally, the ADHD group showed increased supramarginal gyrus (SMG) activation in the anger condition. This might mirror compensatory attention allocation. In summary, we identified a selectively lowered STG activation to auditory anger cues in ADHD patients. Consequently, STG recruitment during anger exposure might be used for evaluation of psychotherapy effects. PMID:25721229

  12. [Peculiarities of adaptive hemodynamic processes during high-frequency jet lung ventilation].

    PubMed

    Zislin, B D; Astakhov, A A; Pankov, N E; Kontorovich, M B

    2009-01-01

    This study concerns poorly known features of adaptive hemodynamic reactions of the heart pump function during traditional and high-frequency jet lung ventilation. Spectral analysis of slow-wave oscillations of stroke volume and left ventricular diastolic filling wave in 36 patients with craniocerebral injury and acute cerebral insufficiency showed that beneficial adaptive reactions were realized through a rise in the general spectrum power and entropy. High-frequency jet lung ventilation ensured better effect on the adaptive processes than the traditional technique. PMID:19642544

  13. Craving for alcohol and pre-attentive processing of alcohol stimuli.

    PubMed

    Ingjaldsson, Jon T; Thayer, Julian F; Laberg, Jon C

    2003-07-01

    The present study was designed to test the hypothesis of unconscious attending to alcohol-related information in alcoholics experiencing a high level of craving for alcohol. Subjects included a group of alcoholics (n=34) divided by a median split on a craving measure into two groups labeled as 'high craving' (n=18) and 'low craving' (n=16) alcoholics, and a non-alcoholic control group (n=39). The cardiovascular reactions of these groups were compared after their exposure to masked and unmasked alcohol and control stimuli. As expected the 'high craving' alcoholics showed an immediate heart rate deceleration after exposure to masked and non-consciously accessible alcohol pictures. The 'high craving' alcoholics reported a small but significant increase in difficulty resisting a drink after exposure to masked alcohol pictures. When the alcohol pictures were presented unmasked a significant increase was found in both high and low craving alcoholics on consciously expressed urges, fidgeting and reduced coping with temptation to drink. The 'high craving' alcoholics had lower tonic heart rate variability compared to the control group and the level of craving was positively associated with salivation during the exposure to all picture types. The findings generally support the psychobiological theory of craving, which suggests that the uncontrollability of the craving experience is rooted in unconscious processing of drug-related information. PMID:12853128

  14. Methylphenidate and emotional-motivational processing in attention-deficit/hyperactivity disorder.

    PubMed

    Conzelmann, Annette; Woidich, Eva; Mucha, Ronald F; Weyers, Peter; Müller, Mathias; Lesch, Klaus-Peter; Jacob, Christian P; Pauli, Paul

    2016-08-01

    In line with the assumption that emotional-motivational deficits are one core dysfunction in ADHD, in one of our previous studies we observed a reduced reactivity towards pleasant pictures in adult ADHD patients as compared to controls. This was indicated by a lack of attenuation of the startle reflex specifically during pleasant pictures in ADHD patients. The first choice medical agents in ADHD, methylphenidate (MPH), is discussed to normalize these dysfunctions. However, experimental evidence in the sense of double-blind placebo-controlled study designs is lacking. Therefore, we investigated 61 adult ADHD patients twice, one time with placebo and one time with MPH with the same experimental design as in our study previously and assessed emotion processing during the presentation of pleasant, neutral and unpleasant pictures. We obtained startle reflex data as well as valence and arousal ratings in association with the pictures. As previously shown, ADHD patients showed a diminished startle attenuation during pleasant pictures while startle potentiation during unpleasant pictures was normal. Valence and arousal ratings unsuspiciously increased with increasing pleasantness and arousal of the pictures, respectively. There were no significant influences of MPH. The study replicates that ADHD patients show a reduced reactivity towards pleasant stimuli. MPH did not normalize this dysfunction. Possibly, MPH only influences emotions during more complex behavioural tasks that involve executive functions in adults with ADHD. Our results emphasize the importance for the use of double-blind placebo-controlled designs in psychopharmacological research. PMID:26852138

  15. [Adaptability of sweet corn ears to a frozen process].

    PubMed

    Ramírez Matheus, Alejandra O; Martínez, Norelkys Maribel; de Bertorelli, Ligia O; De Venanzi, Frank

    2004-12-01

    The effects of frozen condition on the quality of three sweet corn ears (2038, 2010, 2004) and the pattern (Bonanza), were evaluated. Biometrics characteristics like ear size, ear diameter, row and kernel deep were measured as well as chemical and physical measurement in fresh and frozen states. The corn ears were frozen at -95 degrees C by 7 minutes. The yield and stability of the frozen ears were evaluated at 45 and 90 days of frozen storage (-18 degrees C). The average commercial yield as frozen corn ear for all the hybrids was 54.2%. The industry has a similar value range of 48% to 54%. The ear size average was 21.57 cm, row number was 15, ear diameter 45.54 mm and the kernel corn deep was 8.57 mm. All these measurements were found not different from commercial values found for the industry. All corn samples evaluated showed good stability despites the frozen processing and storage. Hybrid 2038 ranked higher in quality. PMID:15969270

  16. Interacting Adaptive Processes with Different Timescales Underlie Short-Term Motor Learning

    PubMed Central

    Ghazizadeh, Ali; Shadmehr, Reza

    2006-01-01

    Multiple processes may contribute to motor skill acquisition, but it is thought that many of these processes require sleep or the passage of long periods of time ranging from several hours to many days or weeks. Here we demonstrate that within a timescale of minutes, two distinct fast-acting processes drive motor adaptation. One process responds weakly to error but retains information well, whereas the other responds strongly but has poor retention. This two-state learning system makes the surprising prediction of spontaneous recovery (or adaptation rebound) if error feedback is clamped at zero following an adaptation-extinction training episode. We used a novel paradigm to experimentally confirm this prediction in human motor learning of reaching, and we show that the interaction between the learning processes in this simple two-state system provides a unifying explanation for several different, apparently unrelated, phenomena in motor adaptation including savings, anterograde interference, spontaneous recovery, and rapid unlearning. Our results suggest that motor adaptation depends on at least two distinct neural systems that have different sensitivity to error and retain information at different rates. PMID:16700627

  17. Incorporating Midbrain Adaptation to Mean Sound Level Improves Models of Auditory Cortical Processing

    PubMed Central

    Schoppe, Oliver; King, Andrew J.; Schnupp, Jan W.H.; Harper, Nicol S.

    2016-01-01

    Adaptation to stimulus statistics, such as the mean level and contrast of recently heard sounds, has been demonstrated at various levels of the auditory pathway. It allows the nervous system to operate over the wide range of intensities and contrasts found in the natural world. Yet current standard models of the response properties of auditory neurons do not incorporate such adaptation. Here we present a model of neural responses in the ferret auditory cortex (the IC Adaptation model), which takes into account adaptation to mean sound level at a lower level of processing: the inferior colliculus (IC). The model performs high-pass filtering with frequency-dependent time constants on the sound spectrogram, followed by half-wave rectification, and passes the output to a standard linear–nonlinear (LN) model. We find that the IC Adaptation model consistently predicts cortical responses better than the standard LN model for a range of synthetic and natural stimuli. The IC Adaptation model introduces no extra free parameters, so it improves predictions without sacrificing parsimony. Furthermore, the time constants of adaptation in the IC appear to be matched to the statistics of natural sounds, suggesting that neurons in the auditory midbrain predict the mean level of future sounds and adapt their responses appropriately. SIGNIFICANCE STATEMENT An ability to accurately predict how sensory neurons respond to novel stimuli is critical if we are to fully characterize their response properties. Attempts to model these responses have had a distinguished history, but it has proven difficult to improve their predictive power significantly beyond that of simple, mostly linear receptive field models. Here we show that auditory cortex receptive field models benefit from a nonlinear preprocessing stage that replicates known adaptation properties of the auditory midbrain. This improves their predictive power across a wide range of stimuli but keeps model complexity low as it

  18. Intentional action processing results from automatic bottom-up attention: An EEG-investigation into the Social Relevance Hypothesis using hypnosis.

    PubMed

    Neufeld, Eleonore; Brown, Elliot C; Lee-Grimm, Sie-In; Newen, Albert; Brüne, Martin

    2016-05-01

    Social stimuli grab our attention. However, it has rarely been investigated how variations in attention affect the processing of social stimuli, although the answer could help us uncover details of social cognition processes such as action understanding. In the present study, we examined how changes to bottom-up attention affects neural EEG-responses associated with intentional action processing. We induced an increase in bottom-up attention by using hypnosis. We recorded the electroencephalographic μ-wave suppression of hypnotized participants when presented with intentional actions in first and third person perspective in a video-clip paradigm. Previous studies have shown that the μ-rhythm is selectively suppressed both when executing and observing goal-directed motor actions; hence it can be used as a neural signal for intentional action processing. Our results show that neutral hypnotic trance increases μ-suppression in highly suggestible participants when they observe intentional actions. This suggests that social action processing is enhanced when bottom-up attentional processes are predominant. Our findings support the Social Relevance Hypothesis, according to which social action processing is a bottom-up driven attentional process, and can thus be altered as a function of bottom-up processing devoted to a social stimulus. PMID:26998562

  19. Geophysical Inversion with Adaptive Array Processing of Ambient Noise

    NASA Astrophysics Data System (ADS)

    Traer, James

    2011-12-01

    Land-based seismic observations of microseisms generated during Tropical Storms Ernesto and Florence are dominated by signals in the 0.15--0.5Hz band. Data from seafloor hydrophones in shallow water (70m depth, 130 km off the New Jersey coast) show dominant signals in the gravity-wave frequency band, 0.02--0.18Hz and low amplitudes from 0.18--0.3Hz, suggesting significant opposing wave components necessary for DF microseism generation were negligible at the site. Both storms produced similar spectra, despite differing sizes, suggesting near-coastal shallow water as the dominant region for observed microseism generation. A mathematical explanation for a sign-inversion induced to the passive fathometer response by minimum variance distortionless response (MVDR) beamforming is presented. This shows that, in the region containing the bottom reflection, the MVDR fathometer response is identical to that obtained with conventional processing multiplied by a negative factor. A model is presented for the complete passive fathometer response to ocean surface noise, interfering discrete noise sources, and locally uncorrelated noise in an ideal waveguide. The leading order term of the ocean surface noise produces the cross-correlation of vertical multipaths and yields the depth of sub-bottom reflectors. Discrete noise incident on the array via multipaths give multiple peaks in the fathometer response. These peaks may obscure the sub-bottom reflections but can be attenuated with use of Minimum Variance Distortionless Response (MVDR) steering vectors. A theory is presented for the Signal-to-Noise-Ratio (SNR) for the seabed reflection peak in the passive fathometer response as a function of seabed depth, seabed reflection coefficient, averaging time, bandwidth and spatial directivity of the noise field. The passive fathometer algorithm was applied to data from two drifting array experiments in the Mediterranean, Boundary 2003 and 2004, with 0.34s of averaging time. In the 2004

  20. Founding and processes of the International Council on Women's Health Issues: attentive partnering. The first 19 years.

    PubMed

    Noerager Stern, Phyllis

    2003-04-01

    I present a theoretical analysis and global influence of the first 19 years of the International Council on Women's Health Issues (ICOWHI). To do so, I analyzed observational, documented, and casual data using the constant comparative method of classical grounded theory. All data bits were analyzed with one another, coded, categorized, and reexamined until I discovered a central category that seemed to explain most of the social scene under study. The explanatory power of the central category, attentive partnering, is presented in terms of its applicability to the interactive relationship between participants working for a common goal, and within the cultural, temporal, social, and social structural context of the relationships. Partnering can occur wherever individuals with a common purpose assemble. The conditions under which the interactive process of attentive partnering occurs seem to be the presence of determined, persuasive leaders, who foster growth-enhancing collegial relationships. When this social system is in place, a small volunteer organization can have a global impact. PMID:12746000

  1. Modulating rest-break length induces differential recruitment of automatic and controlled attentional processes upon task reengagement.

    PubMed

    Lim, Julian; Teng, James; Wong, Kian Foong; Chee, Michael W L

    2016-07-01

    Rest breaks are commonly administered as a countermeasure to reduce on-the-job fatigue, both physical and mental. However, this practice makes the assumption that recovery from fatigue, as measured by the reversal of performance declines, is the sole effect of taking a break on behavior. Here, through administering rest breaks of differing lengths in between blocks of a mentally demanding symbol decoding task, we show that this assumption may not be strictly true. First, we replicate previous work by showing that taking a longer break leads to two correlated effects: greater immediate rebound in performance, and greater subsequent time-on-task decline. Using fMRI, we reveal that time-on-task in this paradigm is associated with increasing recruitment of fronto-parietal areas associated with top-down control, and decreasing deactivation in the default-mode network. Finally, by analyzing individual differences, we reveal a potential neural basis for our behavioral observation: greater recovery following long breaks is associated with greater activity in the putamen, an area associated with the automatic generation of motor responses, followed by greater activity in left middle frontal gyrus by the end of those task periods. Taken together, this suggests a shift in the implicit engagement of automatic and controlled attentional processing following longer breaks. This shift may be undesirable or detrimental in real-world situations where maintaining a stable level of attention over time is necessary. PMID:27039697

  2. The process of adapting a universal dating abuse prevention program to adolescents exposed to domestic violence.

    PubMed

    Foshee, Vangie A; Dixon, Kimberly S; Ennett, Susan T; Moracco, Kathryn E; Bowling, J Michael; Chang, Ling-Yin; Moss, Jennifer L

    2015-07-01

    Adolescents exposed to domestic violence are at increased risk of dating abuse, yet no evaluated dating abuse prevention programs have been designed specifically for this high-risk population. This article describes the process of adapting Families for Safe Dates (FSD), an evidenced-based universal dating abuse prevention program, to this high-risk population, including conducting 12 focus groups and 107 interviews with the target audience. FSD includes six booklets of dating abuse prevention information, and activities for parents and adolescents to do together at home. We adapted FSD for mothers who were victims of domestic violence, but who no longer lived with the abuser, to do with their adolescents who had been exposed to the violence. Through the adaptation process, we learned that families liked the program structure and valued being offered the program and that some of our initial assumptions about this population were incorrect. We identified practices and beliefs of mother victims and attributes of these adolescents that might increase their risk of dating abuse that we had not previously considered. In addition, we learned that some of the content of the original program generated negative family interactions for some. The findings demonstrate the utility of using a careful process to adapt evidence-based interventions (EBIs) to cultural sub-groups, particularly the importance of obtaining feedback on the program from the target audience. Others can follow this process to adapt EBIs to groups other than the ones for which the original EBI was designed. PMID:25287405

  3. Effects of cerebellar transcranial direct current stimulation on attentional processing of the stimulus: Evidence from an event-related potentials study.

    PubMed

    Mannarelli, Daniela; Pauletti, Caterina; De Lucia, Maria C; Delle Chiaie, Roberto; Bersani, Francesco Saverio; Spagnoli, Francesco; Minichino, Amedeo; Currà, Antonio; Trompetto, Carlo; Fattapposta, Francesco

    2016-04-01

    Attentional processing consists of a set of processes that manage the flow of information through the nervous system and appropriately allocate attentional resources to relevant stimuli. Specific networks in the frontal and parietal regions appear to be involved in attention. The cerebellum has been identified as a subcortical structure that interacts with cortical brain areas, thereby controlling attentional processes. The aim of this study was to investigate the role of the cerebellum in attentional processing of the stimulus using a P300 Novelty task. We studied the effects of transcranial Direct Current Stimulation (tDCS) delivered over the left cerebellar hemisphere in cathodal, anodal and sham sessions on the P300 components in healthy subjects. Only cathodal cerebellar tDCS significantly reduced the amplitude of the N1, N2 and P3 components for both the target and novel stimuli. Moreover, N1 latency for all the stimuli was shorter after the cathodal tDCS session than after the sham or anodal sessions. These results point to a role of the cerebellum in attentional processing of the stimulus. The cerebellum may act indirectly by regulating and managing the activation and inhibition levels of the cortical areas involved in attentional networks. PMID:26878981

  4. Deficits in Attention and Visual Processing but not Global Cognition Predict Simulated Driving Errors in Drivers Diagnosed With Mild Alzheimer's Disease.

    PubMed

    Yamin, Stephanie; Stinchcombe, Arne; Gagnon, Sylvain

    2016-06-01

    This study sought to predict driving performance of drivers with Alzheimer's disease (AD) using measures of attention, visual processing, and global cognition. Simulated driving performance of individuals with mild AD (n = 20) was contrasted with performance of a group of healthy controls (n = 21). Performance on measures of global cognitive function and specific tests of attention and visual processing were examined in relation to simulated driving performance. Strong associations were observed between measures of attention, notably the Test of Everyday Attention (sustained attention; r = -.651, P = .002) and the Useful Field of View (r = .563, P = .010), and driving performance among drivers with mild AD. The Visual Object and Space Perception Test-object was significantly correlated with the occurrence of crashes (r = .652, P = .002). Tests of global cognition did not correlate with simulated driving outcomes. The results suggest that professionals exercise caution when extrapolating driving performance based on global cognitive indicators. PMID:26655744

  5. Robust Brain-Machine Interface Design Using Optimal Feedback Control Modeling and Adaptive Point Process Filtering

    PubMed Central

    Carmena, Jose M.

    2016-01-01

    Much progress has been made in brain-machine interfaces (BMI) using decoders such as Kalman filters and finding their parameters with closed-loop decoder adaptation (CLDA). However, current decoders do not model the spikes directly, and hence may limit the processing time-scale of BMI control and adaptation. Moreover, while specialized CLDA techniques for intention estimation and assisted training exist, a unified and systematic CLDA framework that generalizes across different setups is lacking. Here we develop a novel closed-loop BMI training architecture that allows for processing, control, and adaptation using spike events, enables robust control and extends to various tasks. Moreover, we develop a unified control-theoretic CLDA framework within which intention estimation, assisted training, and adaptation are performed. The architecture incorporates an infinite-horizon optimal feedback-control (OFC) model of the brain’s behavior in closed-loop BMI control, and a point process model of spikes. The OFC model infers the user’s motor intention during CLDA—a process termed intention estimation. OFC is also used to design an autonomous and dynamic assisted training technique. The point process model allows for neural processing, control and decoder adaptation with every spike event and at a faster time-scale than current decoders; it also enables dynamic spike-event-based parameter adaptation unlike current CLDA methods that use batch-based adaptation on much slower adaptation time-scales. We conducted closed-loop experiments in a non-human primate over tens of days to dissociate the effects of these novel CLDA components. The OFC intention estimation improved BMI performance compared with current intention estimation techniques. OFC assisted training allowed the subject to consistently achieve proficient control. Spike-event-based adaptation resulted in faster and more consistent performance convergence compared with batch-based methods, and was robust to

  6. Robust Brain-Machine Interface Design Using Optimal Feedback Control Modeling and Adaptive Point Process Filtering.

    PubMed

    Shanechi, Maryam M; Orsborn, Amy L; Carmena, Jose M

    2016-04-01

    Much progress has been made in brain-machine interfaces (BMI) using decoders such as Kalman filters and finding their parameters with closed-loop decoder adaptation (CLDA). However, current decoders do not model the spikes directly, and hence may limit the processing time-scale of BMI control and adaptation. Moreover, while specialized CLDA techniques for intention estimation and assisted training exist, a unified and systematic CLDA framework that generalizes across different setups is lacking. Here we develop a novel closed-loop BMI training architecture that allows for processing, control, and adaptation using spike events, enables robust control and extends to various tasks. Moreover, we develop a unified control-theoretic CLDA framework within which intention estimation, assisted training, and adaptation are performed. The architecture incorporates an infinite-horizon optimal feedback-control (OFC) model of the brain's behavior in closed-loop BMI control, and a point process model of spikes. The OFC model infers the user's motor intention during CLDA-a process termed intention estimation. OFC is also used to design an autonomous and dynamic assisted training technique. The point process model allows for neural processing, control and decoder adaptation with every spike event and at a faster time-scale than current decoders; it also enables dynamic spike-event-based parameter adaptation unlike current CLDA methods that use batch-based adaptation on much slower adaptation time-scales. We conducted closed-loop experiments in a non-human primate over tens of days to dissociate the effects of these novel CLDA components. The OFC intention estimation improved BMI performance compared with current intention estimation techniques. OFC assisted training allowed the subject to consistently achieve proficient control. Spike-event-based adaptation resulted in faster and more consistent performance convergence compared with batch-based methods, and was robust to parameter

  7. Double dissociation of configural and featural face processing on P1 and P2 components as a function of spatial attention.

    PubMed

    Wang, Hailing; Guo, Shichun; Fu, Shimin

    2016-08-01

    Face recognition relies on both configural and featural processing. Previous research has shown that P1 is sensitive to configural face processing, but it is unclear whether any component is sensitive to featural face processing; moreover, if there is such a component, its temporal sequence relative to P1 is unknown. Thus, to avoid confounding physical stimuli differences between configural and featural face processing on ERP components, a spatial attention paradigm was employed by instructing participants to attend an image stream (faces and houses) or an alphanumeric character stream. The interaction between attention and face processing type on P1 and P2 components indicates different mechanisms of configural and featural face processing as a function of spatial attention. The steady-state visual evoked potential (SSVEP) results clearly demonstrated that participants could selectively attend to different streams of information. Importantly, configural face processing elicited a larger posterior P1 (approximately 128 ms) than featural face processing, whereas P2 (approximately 248 ms) was greater for featural than for configural face processing under attended condition. The interaction between attention and face processing type (configural vs. featural) on P1 and P2 components indicates that there are different mechanisms of configural and featural face processing operating as functions of spatial attention. While the P1 result confirms previous findings separating configural and featural face processing, the newly observed P2 finding in the present study extends this separation to a double dissociation. Therefore, configural and featural face processing are modulated differently by spatial attention, and configural face processing precedes featural face processing. PMID:27167853

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

    PubMed

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

    2016-06-01

    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. PMID:25899613

  9. Between-Person and Within-Person Associations among Processing Speed, Attention Switching and Working Memory in Younger and Older Adults

    PubMed Central

    Stawski, Robert S.; Sliwinski, Martin J.; Hofer, Scott M.

    2013-01-01

    Background/Study Context Theories of cognitive aging predict associations among processes that transpire within individuals, but are often tested by examining between-person relationships. The authors provide an empirical demonstration of how associations among measures of processing speed, attention switching, and working memory are different when considered between persons versus within persons over time. Methods A sample of 108 older adults (Mage: 80.8, range: 66–95) and 68 younger adults (Mage: 20.2, range:18–24) completed measures of processing speed, attention switching, and working memory on six occasions over a 14-day period. Multilevel modeling was used to examine processing speed and attention switching performance as predictors of working memory performance simultaneously across days (within-person) and across individuals (between-person). Results The findings indicates that simple comparison and response speed predicted working memory better than attention switching between persons, whereas attention switching predicted working memory better than simple comparison and response speed within persons over time. Furthermore, the authors did not observe strong evidence of age differences in these associations either within or between persons. Conclusion The findings of the current study suggest that processing speed is important for understanding between-person and age-related differences in working memory, whereas attention switching is more important for understanding within-person variation in working memory. The authors conclude that theories of cognitive aging should be evaluated by analysis of within-person processes, not exclusively age-related individual differences. PMID:23421639

  10. An adaptive algorithm for simulation of stochastic reaction-diffusion processes

    SciTech Connect

    Ferm, Lars Hellander, Andreas Loetstedt, Per

    2010-01-20

    We propose an adaptive hybrid method suitable for stochastic simulation of diffusion dominated reaction-diffusion processes. For such systems, simulation of the diffusion requires the predominant part of the computing time. In order to reduce the computational work, the diffusion in parts of the domain is treated macroscopically, in other parts with the tau-leap method and in the remaining parts with Gillespie's stochastic simulation algorithm (SSA) as implemented in the next subvolume method (NSM). The chemical reactions are handled by SSA everywhere in the computational domain. A trajectory of the process is advanced in time by an operator splitting technique and the timesteps are chosen adaptively. The spatial adaptation is based on estimates of the errors in the tau-leap method and the macroscopic diffusion. The accuracy and efficiency of the method are demonstrated in examples from molecular biology where the domain is discretized by unstructured meshes.

  11. Knowledge-Aided Multichannel Adaptive SAR/GMTI Processing: Algorithm and Experimental Results

    NASA Astrophysics Data System (ADS)

    Wu, Di; Zhu, Daiyin; Zhu, Zhaoda

    2010-12-01

    The multichannel synthetic aperture radar ground moving target indication (SAR/GMTI) technique is a simplified implementation of space-time adaptive processing (STAP), which has been proved to be feasible in the past decades. However, its detection performance will be degraded in heterogeneous environments due to the rapidly varying clutter characteristics. Knowledge-aided (KA) STAP provides an effective way to deal with the nonstationary problem in real-world clutter environment. Based on the KA STAP methods, this paper proposes a KA algorithm for adaptive SAR/GMTI processing in heterogeneous environments. It reduces sample support by its fast convergence properties and shows robust to non-stationary clutter distribution relative to the traditional adaptive SAR/GMTI scheme. Experimental clutter suppression results are employed to verify the virtue of this algorithm.

  12. A mixed signal ECG processing platform with an adaptive sampling ADC for portable monitoring applications.

    PubMed

    Kim, Hyejung; Van Hoof, Chris; Yazicioglu, Refet Firat

    2011-01-01

    This paper describes a mixed-signal ECG processing platform with an 12-bit ADC architecture that can adapt its sampling rate according to the input signals rate of change. This enables the sampling of ECG signals with significantly reduced data rate without loss of information. The presented adaptive sampling scheme reduces the ADC power consumption, enables the processing of ECG signals with lower power consumption, and reduces the power consumption of the radio while streaming the ECG signals. The test results show that running a CWT-based R peak detection algorithm using the adaptively sampled ECG signals consumes only 45.6 μW and it leads to 36% less overall system power consumption. PMID:22254775

  13. Moving to Capture Children's Attention: Developing a Methodology for Measuring Visuomotor Attention.

    PubMed

    Hill, Liam J B; Coats, Rachel O; Mushtaq, Faisal; Williams, Justin H G; Aucott, Lorna S; Mon-Williams, Mark

    2016-01-01

    Attention underpins many activities integral to a child's development. However, methodological limitations currently make large-scale assessment of children's attentional skill impractical, costly and lacking in ecological validity. Consequently we developed a measure of 'Visual Motor Attention' (VMA)-a construct defined as the ability to sustain and adapt visuomotor behaviour in response to task-relevant visual information. In a series of experiments, we evaluated the capability of our method to measure attentional processes and their contributions in guiding visuomotor behaviour. Experiment 1 established the method's core features (ability to track stimuli moving on a tablet-computer screen with a hand-held stylus) and demonstrated its sensitivity to principled manipulations in adults' attentional load. Experiment 2 standardised a format suitable for use with children and showed construct validity by capturing developmental changes in executive attention processes. Experiment 3 tested the hypothesis that children with and without coordination difficulties would show qualitatively different response patterns, finding an interaction between the cognitive and motor factors underpinning responses. Experiment 4 identified associations between VMA performance and existing standardised attention assessments and thereby confirmed convergent validity. These results establish a novel approach to measuring childhood attention that can produce meaningful functional assessments that capture how attention operates in an ecologically valid context (i.e. attention's specific contribution to visuomanual action). PMID:27434198

  14. [Features of brain mechanisms of regulation of the level of wakefulness, organization of cognitive functions and adaptive reactions in children with attention deficit with hyperactivity syndrome and healthy children].

    PubMed

    Iliukhina, V A; Krivoshchapova, M N; Manzhosova, G V

    2011-01-01

    In work results of research of features of infringement superslow cortical-truncal, limbic-reticular and upsegmentary mechanisms of regulation of a level of wakefulness at children of 6-7 years with a syndrome of deficiency of attention and hyperactivity and healthy children, pupils of 1 class of a comprehensive school with different type of psychological adaptation are generalized. At use system-integrativity psychophysiology the approach features are established: a) organization emotional-motivational and cognitive spheres; b) psychophysiology mechanisms of formation of adaptive reactions at tactile interaction about earlier unknown alive object--a dolphin at the surveyed contingent of healthy and ill children. PMID:21542315

  15. The Relevance of the Functional 5-HT1A Receptor Polymorphism for Attention and Working Memory Processes during Mental Rotation of Characters

    ERIC Educational Resources Information Center

    Beste, Christian; Heil, Martin; Domschke, Katharina; Konrad, Carsten

    2010-01-01

    Numerous lines of research indicate that attentional processes, working memory and saccadic processes are highly interrelated. In the current study, we examine the relation between these processes with respect to their cognitive-neurophysiological and neurobiological background by means of event-related potentials (ERPs) in a sample of N = 72…

  16. Access to Learning for Handicapped Children: A Handbook on the Instructional Adaptation Process. Field Test Version.

    ERIC Educational Resources Information Center

    Changar, Jerilynn; And Others

    The manual describes the results of a 36 month project to determine ways to modify existing curricula to meet the needs of special needs students in the mainstream. The handbook is designed in the main for administrators and facilitators as well as for teacher-adaptors. Each of eight steps in the adaptation process is broken down according to…

  17. Chinese Students and Scholars in the U.S.: An Intercultural Adaptation Process.

    ERIC Educational Resources Information Center

    Zhong, Mei

    An ethnographic study examined the culture of the Chinese students and scholars in America with a specific focus on their experiences in the cultural adaptation process. Subjects were three Chinese nationals (one female and two males) living in the area of a large midwestern university. Subjects were interviewed for about an hour each, with…

  18. Cognitive Process Development as Measured by an Adapted Version of Wechsler's Similarities Test

    ERIC Educational Resources Information Center

    Rozencwajg, Paulette

    2007-01-01

    This paper studies the development of taxonomic processing as measured by an adapted version of the Wechsler Similarities subtest, which distinguishes between categorization of concrete and abstract words. Two factors--age and concreteness--are also tested by a recall task. The results show an age-related increase in taxonomic categorization,…

  19. Factors associated with the process of adaptation among Pakistani adolescent females living in United States.

    PubMed

    Khuwaja, Salma A; Selwyn, Beatrice J; Mgbere, Osaro; Khuwaja, Alam; Kapadia, Asha; McCurdy, Sheryl; Hsu, Chiehwen E

    2013-04-01

    This study explored post-migration experiences of recently migrated Pakistani Muslim adolescent females residing in the United States. In-depth, semi-structured interviews were conducted with thirty Pakistani Muslim adolescent females between the ages of 15 and 18 years living with their families in Houston, Texas. Data obtained from the interviews were evaluated using discourse analysis to identify major reoccurring themes. Participants discussed factors associated with the process of adaptation to the American culture. The results revealed that the main factors associated with adaptation process included positive motivation for migration, family bonding, social support networks, inter-familial communication, aspiration of adolescents to learn other cultures, availability of English-as-second-language programs, participation in community rebuilding activities, and faith practices, English proficiency, peer pressure, and inter-generational conflicts. This study provided much needed information on factors associated with adaptation process of Pakistani Muslim adolescent females in the United States. The results have important implications for improving the adaptation process of this group and offer potential directions for intervention and counseling services. PMID:22940911

  20. A fuzzy model based adaptive PID controller design for nonlinear and uncertain processes.

    PubMed

    Savran, Aydogan; Kahraman, Gokalp

    2014-03-01

    We develop a novel adaptive tuning method for classical proportional-integral-derivative (PID) controller to control nonlinear processes to adjust PID gains, a problem which is very difficult to overcome in the classical PID controllers. By incorporating classical PID control, which is well-known in industry, to the control of nonlinear processes, we introduce a method which can readily be used by the industry. In this method, controller design does not require a first principal model of the process which is usually very difficult to obtain. Instead, it depends on a fuzzy process model which is constructed from the measured input-output data of the process. A soft limiter is used to impose industrial limits on the control input. The performance of the system is successfully tested on the bioreactor, a highly nonlinear process involving instabilities. Several tests showed the method's success in tracking, robustness to noise, and adaptation properties. We as well compared our system's performance to those of a plant with altered parameters with measurement noise, and obtained less ringing and better tracking. To conclude, we present a novel adaptive control method that is built upon the well-known PID architecture that successfully controls highly nonlinear industrial processes, even under conditions such as strong parameter variations, noise, and instabilities. PMID:24140160

  1. An Adaptive Altitude Information Fusion Method for Autonomous Landing Processes of Small Unmanned Aerial Rotorcraft

    PubMed Central

    Lei, Xusheng; Li, Jingjing

    2012-01-01

    This paper presents an adaptive information fusion method to improve the accuracy and reliability of the altitude measurement information for small unmanned aerial rotorcraft during the landing process. Focusing on the low measurement performance of sensors mounted on small unmanned aerial rotorcraft, a wavelet filter is applied as a pre-filter to attenuate the high frequency noises in the sensor output. Furthermore, to improve altitude information, an adaptive extended Kalman filter based on a maximum a posteriori criterion is proposed to estimate measurement noise covariance matrix in real time. Finally, the effectiveness of the proposed method is proved by static tests, hovering flight and autonomous landing flight tests. PMID:23201993

  2. Aging, exercise, and attention.

    PubMed

    Hawkins, H L; Kramer, A F; Capaldi, D

    1992-12-01

    The authors investigated the relationship among aging, attentional processes, and exercise in 2 experiments. First they examined age differences on 2 attentional tasks, a time-sharing task and an attentional flexibility task. Young adults alternated attention between 2 sequenced tasks more rapidly and time-shared the processing of 2 tasks more efficiently than older adults. They then investigated the effects of aerobic exercise on the same 2 attentional tasks in older adults. Following the 10-week exercise program, older exercisers showed substantially more improvement in alternation speed and time-sharing efficiency than older controls. Interestingly, this exercise effect was specific to dual-task processing. Both groups of subjects showed equivalent effects on single-task performance. These results indicate that aerobic exercise can exert a beneficial influence on the efficiency of at least 2 different attentional processes in older adults. PMID:1466833

  3. Influence of microbial adaption and supplementation of nutrients on the biodegradation of ionic liquids in sewage sludge treatment processes.

    PubMed

    Markiewicz, Marta; Stolte, Stefan; Lustig, Zofia; Łuczak, Justyna; Skup, Michał; Hupka, Jan; Jungnickel, Christian

    2011-11-15

    As ionic liquids are winning more attention from industry as a replacement of more hazardous chemicals, some of their structures have the potential to become persistent pollutants due to high stability towards abiotic and biotic degradation processes. Therefore it is important to determine the hazard associated with the presence of ILs in the environment, for example biodegradation under real conditions. Standard biodegradation testing procedures generally permit pre-conditioning of inoculum but do not allow for pre-exposition to the test substance. These are usually conducted in a mineral medium which does not provide additional organic nutrients. Though very valuable, as a point of reference, these tests do not fully represent real conditions. In in situ conditions, for example in wastewater treatment plants or natural soils and water bodies, the presence of readily available sources of energy and nutrients as well as the process of adaptation may often alter the fate and metabolic pathways of xenobiotics. Our results have shown that these are the opposing processes influencing the biodegradation rate of ILs in sewage sludge. The results have significant practical implications with respect to the assessment of biodegradability and environmental fate of ILs and other xenobiotics in environmental conditions and their potential remediation options. PMID:21907490

  4. The Interplay between Attentional Strategies and Language Processing in High-Functioning Adults with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Koolen, Sophieke; Vissers, Constance Th. W. M.; Hendriks, Angelique W. C. J.; Egger, Jos I. M.; Verhoeven, Ludo

    2012-01-01

    This study examined the hypothesis of an atypical interaction between attention and language in ASD. A dual-task experiment with three conditions was designed, in which sentences were presented that contained errors requiring attentional focus either at (a) low level, or (b) high level, or (c) both levels of language. Speed and accuracy for error…

  5. The Neural Substrates Associated with Attentional Resources and Difficulty of Concurrent Processing of the Two Verbal Tasks

    ERIC Educational Resources Information Center

    Mizuno, Kei; Tanaka, Masaaki; Tanabe, Hiroki C.; Sadato, Norihiro; Watanabe, Yasuyoshi

    2012-01-01

    The kana pick-out test has been widely used in Japan to evaluate the ability to divide attention in both adult and pediatric patients. However, the neural substrates underlying the ability to divide attention using the kana pick-out test, which requires participants to pick out individual letters (vowels) in a story while also reading for…

  6. Signal subspace analysis for decoherent processes during interferometric fiber-optic gyroscopes using synchronous adaptive filters.

    PubMed

    Li, Yongxiao; Wang, Zinan; Peng, Chao; Li, Zhengbin

    2014-10-10

    Conventional signal processing methods for improving the random walk coefficient and the bias stability of interferometric fiber-optic gyroscopes are usually implemented in one-dimension sequence. In this paper, as a comparison, we allocated synchronous adaptive filters with the calculations of correlations of multidimensional signals in the perspective of the signal subspace. First, two synchronous independent channels are obtained through quadrature demodulation. Next, synchronous adaptive filters were carried out in order to project the original channels to the high related error channels and the approximation channels. The error channel signals were then processed by principal component analysis for suppressing coherent noises. Finally, an optimal state estimation of these error channels and approximation channels based on the Kalman gain coefficient was operated. Experimental results show that this signal processing method improved the raw measurements' variance from 0.0630 [(°/h)2] to 0.0103 [(°/h)2]. PMID:25322393

  7. Adaptive passive fathometer processing using ambient noise received by vertical nested array

    NASA Astrophysics Data System (ADS)

    Kim, Junghun; Cho, Sungho; Choi, Jee Woong

    2015-07-01

    A passive fathometer technique utilizes surface-generated ambient noise received by a vertical line array as a sound source to estimate the depths of water-sediment interface and sub-bottom layers. Ambient noise was measured using a 24-channel, vertical nested line array consisting of four sub-arrays, in shallow water off the eastern coast of Korea. In this paper, nested array processing is applied to passive fathometer technique to improve the performance. Passive fathometer processing is performed for each sub-array, and the results are then combined to form a passive fathometer output for broadband ambient noise. Three types of beamforming technique, including conventional and two adaptive methods, are used in passive fathometer processing. The results are compared to the depths of water-sediment interface measured by an echo sounder. As a result, it is found that the adaptive methods have better performance than the conventional method.

  8. A new hypothesis: some metastases are the result of inflammatory processes by adapted cells, especially adapted immune cells at sites of inflammation

    PubMed Central

    Shahriyari, Leili

    2016-01-01

    There is an old hypothesis that metastasis is the result of migration of tumor cells from the tumor to a distant site. In this article, we propose another mechanism for metastasis, for cancers that are initiated at the site of chronic inflammation. We suggest that cells at the site of chronic inflammation might become adapted to the inflammatory process, and these adaptations may lead to the initiation of an inflammatory tumor. For example, in an inflammatory tumor immune cells might be adapted to send signals of proliferation or angiogenesis, and epithelial cells might be adapted to proliferation (like inactivation of tumor suppressor genes). Therefore, we hypothesize that metastasis could be the result of an inflammatory process by adapted cells, especially adapted immune cells at the site of inflammation, as well as the migration of tumor cells with the help of activated platelets, which travel between sites of inflammation.  If this hypothesis is correct, then any treatment causing necrotic cell death may not be a good solution. Because necrotic cells in the tumor micro-environment or anywhere in the body activate the immune system to initiate the inflammatory process, and the involvement of adapted immune cells in the inflammatory processes leads to the formation and progression of tumors. Adapted activated immune cells send more signals of proliferation and/or angiogenesis than normal cells. Moreover, if there were adapted epithelial cells, they would divide at a much higher rate in response to the proliferation signals than normal cells. Thus, not only would the tumor come back after the treatment, but it would also grow more aggressively. PMID:27158448

  9. Moving to Capture Children’s Attention: Developing a Methodology for Measuring Visuomotor Attention

    PubMed Central

    Coats, Rachel O.; Mushtaq, Faisal; Williams, Justin H. G.; Aucott, Lorna S.; Mon-Williams, Mark

    2016-01-01

    Attention underpins many activities integral to a child’s development. However, methodological limitations currently make large-scale assessment of children’s attentional skill impractical, costly and lacking in ecological validity. Consequently we developed a measure of ‘Visual Motor Attention’ (VMA)—a construct defined as the ability to sustain and adapt visuomotor behaviour in response to task-relevant visual information. In a series of experiments, we evaluated the capability of our method to measure attentional processes and their contributions in guiding visuomotor behaviour. Experiment 1 established the method’s core features (ability to track stimuli moving on a tablet-computer screen with a hand-held stylus) and demonstrated its sensitivity to principled manipulations in adults’ attentional load. Experiment 2 standardised a format suitable for use with children and showed construct validity by capturing developmental changes in executive attention processes. Experiment 3 tested the hypothesis that children with and without coordination difficulties would show qualitatively different response patterns, finding an interaction between the cognitive and motor factors underpinning responses. Experiment 4 identified associations between VMA performance and existing standardised attention assessments and thereby confirmed convergent validity. These results establish a novel approach to measuring childhood attention that can produce meaningful functional assessments that capture how attention operates in an ecologically valid context (i.e. attention's specific contribution to visuomanual action). PMID:27434198

  10. A neurodevelopmental approach to understanding memory processes among intellectually gifted youth with attention-deficit hyperactivity disorder.

    PubMed

    Whitaker, Ashley M; Bell, Terece S; Houskamp, Beth M; O'Callaghan, Erin T

    2015-01-01

    Intellectual giftedness is associated with strong strategic verbal memory while attention-deficit hyperactivity disorder (ADHD) is associated with strategic verbal memory deficits; however, no previous research has explored how this contradiction manifests in gifted populations with diagnoses of ADHD. The purpose of this study was to explore strategic verbal memory processes among intellectually gifted youth with and without ADHD to provide clarification regarding this specific aspect of neuropsychological functioning within this population. One hundred twenty-five youth completed neuropsychological evaluations including the Wechsler Intelligence Scale for Children-Fourth Edition and California Verbal Learning Test-Children's Version (CVLT-C). Results revealed significant differences between groups, with intellectually gifted youth with ADHD achieving lower T scores on CVLT-C Trials 1 through 5 compared with intellectually gifted youth without ADHD, and intellectually gifted youth with ADHD achieving higher T scores than youth of average intellectual abilities with ADHD. Additionally, repeated-measures analysis of variance revealed a main effect improvement among gifted youth with ADHD in short-delay recall when provided with organizational cues. Findings revealed new evidence about the role of twice exceptionality (specifically intellectual giftedness and ADHD) in strategic verbal memory and have important implications for parents, educators, psychologists and neuropsychologists, and other mental health professionals working with this population. PMID:24191777

  11. Signal processing through a generalized module of adaptation and spatial sensing.

    PubMed

    Krishnan, J

    2009-07-01

    Signal transduction in many cellular processes is accompanied by the feature of adaptation, which allows certain key signalling components to respond to temporal and/or spatial variation of external signals, independent of the absolute value of the signal. We extend and formulate a more general module which accounts for robust temporal adaptation and spatial response. In this setting, we examine various aspects of spatial and temporal signalling, as well as the signalling consequences and restrictions imposed by virtue of adaptation. This module is able to exhibit a variety of behaviour in response to temporal, spatial and spatio-temporal inputs. We carefully examine the roles of various parameters in this module and how they affect signal processing and propagation. Overall, we demonstrate how a simple module can account for a range downstream responses to a variety of input signals, and how elucidating the downstream response of many cellular components in systems with such adaptive signalling can be consequently very non-trivial. PMID:19254728

  12. Repair or Violation Detection? Pre-Attentive Processing Strategies of Phonotactic Illegality Demonstrated on the Constraint of g-Deletion in German

    ERIC Educational Resources Information Center

    Steinberg, Johanna; Jacobsen, Thomas Konstantin; Jacobsen, Thomas

    2016-01-01

    Purpose: Effects of categorical phonotactic knowledge on pre-attentive speech processing were investigated by presenting illegal speech input that violated a phonotactic constraint in German called "g-deletion." The present study aimed to extend previous findings of automatic processing of phonotactic violations and to investigate the…

  13. Visual Attentional Engagement Deficits in Children with Specific Language Impairment and Their Role in Real-Time Language Processing

    PubMed Central

    Dispaldro, Marco; Leonard, Laurence B.; Corradi, Nicola; Ruffino, Milena; Bronte, Tiziana; Facoetti, Andrea

    2015-01-01

    In order to become a proficient user of language, infants must detect temporal cues embedded within the noisy acoustic spectra of ongoing speech by efficient attentional engagement. According to the neuro-constructivist approach, a multi-sensory dysfunction of attentional engagement – hampering the temporal sampling of stimuli – might be responsible for language deficits typically shown in children with Specific Language Impairment (SLI). In the present study, the efficiency of visual attentional engagement was investigated in 22 children with SLI and 22 typically developing (TD) children by measuring attentional masking (AM). AM refers to impaired identification of the first of two sequentially presented masked objects (O1 and O2) in which the O1-O2 interval was manipulated. Lexical and grammatical comprehension abilities were also tested in both groups. Children with SLI showed a sluggish engagement of temporal attention, and individual differences in AM accounted for a significant percentage of unique variance in grammatical performance. Our results suggest that an attentional engagement deficit – probably linked to a dysfunction of the right fronto-parietal attentional network – might be a contributing factor in these children’s language impairments. PMID:23154040

  14. Three-dimensional region-based adaptive image processing techniques for volume visualization applications

    NASA Astrophysics Data System (ADS)

    de Deus Lopes, Roseli; Zuffo, Marcelo K.; Rangayyan, Rangaraj M.

    1996-04-01

    Recent advances in three-dimensional (3D) imaging techniques have expanded the scope of applications of volume visualization to many areas such as medical imaging, scientific visualization, robotic vision, and virtual reality. Advanced image filtering, enhancement, and analysis techniques are being developed in parallel in the field of digital image processing. Although the fields cited have many aspects in common, it appears that many of the latest developments in image processing are not being applied to the fullest extent possible in visualization. It is common to encounter the use of rather simple and elementary image pre- processing operations being used in visualization and 3D imaging applications. The purpose of this paper is to present an overview of selected topics from recent developments in adaptive image processing and demonstrate or suggest their applications in volume visualization. The techniques include adaptive noise removal; improvement of contrast and visibility of objects; space-variant deblurring and restoration; segmentation-based lossless coding for data compression; and perception-based measures for analysis, enhancement, and rendering. The techniques share the common base of identification of adaptive regions by region growing, which lends them a perceptual basis related to the human visual system. Preliminary results obtained with some of the techniques implemented so far are used to illustrate the concepts involved, and to indicate potential performance capabilities of the methods.

  15. The association of physical activity to neural adaptability during visuo-spatial processing in healthy elderly adults: A multiscale entropy analysis.

    PubMed

    Wang, Chun-Hao; Tsai, Chia-Liang; Tseng, Philip; Yang, Albert C; Lo, Men-Tzung; Peng, Chung-Kang; Wang, Hsin-Yi; Muggleton, Neil G; Juan, Chi-Hung; Liang, Wei-Kuang

    2014-10-29

    Physical activity has been shown to benefit brain and cognition in late adulthood. However, this effect is still unexplored in terms of brain signal complexity, which reflects the level of neural adaptability and efficiency during cognitive processing that cannot be acquired via averaged neuroelectric signals. Here we employed multiscale entropy analysis (MSE) of electroencephalography (EEG), a new approach that conveys important information related to the temporal dynamics of brain signal complexity across multiple time scales, to reveal the association of physical activity with neural adaptability and efficiency in elderly adults. A between-subjects design that included 24 participants (aged 66.63±1.31years; female=12) with high physical activity and 24 age- and gender-matched low physical activity participants (aged 67.29±1.20years) was conducted to examine differences related to physical activity in performance and MSE of EEG signals during a visuo-spatial cognition task. We observed that physically active elderly adults had better accuracy on both visuo-spatial attention and working memory conditions relative to their sedentary counterparts. Additionally, these physically active elderly adults displayed greater MSE values at larger time scales at the Fz electrode in both attention and memory conditions. The results suggest that physical activity may be beneficial for adaptability of brain systems in tasks involving visuo-spatial information. MSE thus might be a promising approach to test the effects of the benefits of exercise on cognition. PMID:25463141

  16. Adapting School-Based Substance Use Prevention Curriculum Through Cultural Grounding: A Review and Exemplar of Adaptation Processes for Rural Schools

    PubMed Central

    Colby, Margaret; Hecht, Michael L.; Miller-Day, Michelle; Krieger, Janice L.; Syvertsen, Amy K.; Graham, John W.; Pettigrew, Jonathan

    2014-01-01

    A central challenge facing twenty-first century community-based researchers and prevention scientists is curriculum adaptation processes. While early prevention efforts sought to develop effective programs, taking programs to scale implies that they will be adapted, especially as programs are implemented with populations other than those with whom they were developed or tested. The principle of cultural grounding, which argues that health message adaptation should be informed by knowledge of the target population and by cultural insiders, provides a theoretical rational for cultural regrounding and presents an illustrative case of methods used to reground the keepin’ it REAL substance use prevention curriculum for a rural adolescent population. We argue that adaptation processes like those presented should be incorporated into the design and dissemination of prevention interventions. PMID:22961604

  17. ADAPT: A knowledge-based synthesis tool for digital signal processing system design

    SciTech Connect

    Cooley, E.S.

    1988-01-01

    A computer aided synthesis tool for expansion, compression, and filtration of digital images is described. ADAPT, the Autonomous Digital Array Programming Tool, uses an extensive design knowledge base to synthesize a digital signal processing (DSP) system. Input to ADAPT can be either a behavioral description in English, or a block level specification via Petri Nets. The output from ADAPT comprises code to implement the DSP system on an array of processors. ADAPT is constructed using C, Prolog, and X Windows on a SUN 3/280 workstation. ADAPT knowledge encompasses DSP component information and the design algorithms and heuristics of a competent DSP designer. The knowledge is used to form queries for design capture, to generate design constraints from the user's responses, and to examine the design constraints. These constraints direct the search for possible DSP components and target architectures. Constraints are also used for partitioning the target systems into less complex subsystems. The subsystems correspond to architectural building blocks of the DSP design. These subsystems inherit design constraints and DSP characteristics from their parent blocks. Thus, a DSP subsystem or parent block, as designed by ADAPT, must meet the user's design constraints. Design solutions are sought by searching the Components section of the design knowledge base. Component behavior which matches or is similar to that required by the DSP subsystems is sought. Each match, which corresponds to a design alternative, is evaluated in terms of its behavior. When a design is sufficiently close to the behavior required by the user, detailed mathematical simulations may be performed to accurately determine exact behavior.

  18. A Low Processing Cost Adaptive Algorithm Identifying Nonlinear Unknown System with Piecewise Linear Curve

    NASA Astrophysics Data System (ADS)

    Fujii, Kensaku; Aoki, Ryo; Muneyasu, Mitsuji

    This paper proposes an adaptive algorithm for identifying unknown systems containing nonlinear amplitude characteristics. Usually, the nonlinearity is so small as to be negligible. However, in low cost systems, such as acoustic echo canceller using a small loudspeaker, the nonlinearity deteriorates the performance of the identification. Several methods preventing the deterioration, polynomial or Volterra series approximations, have been hence proposed and studied. However, the conventional methods require high processing cost. In this paper, we propose a method approximating the nonlinear characteristics with a piecewise linear curve and show using computer simulations that the performance can be extremely improved. The proposed method can also reduce the processing cost to only about twice that of the linear adaptive filter system.

  19. Adapting existing natural language processing resources for cardiovascular risk factors identification in clinical notes.

    PubMed

    Khalifa, Abdulrahman; Meystre, Stéphane

    2015-12-01

    The 2014 i2b2 natural language processing shared task focused on identifying cardiovascular risk factors such as high blood pressure, high cholesterol levels, obesity and smoking status among other factors found in health records of diabetic patients. In addition, the task involved detecting medications, and time information associated with the extracted data. This paper presents the development and evaluation of a natural language processing (NLP) application conceived for this i2b2 shared task. For increased efficiency, the application main components were adapted from two existing NLP tools implemented in the Apache UIMA framework: Textractor (for dictionary-based lookup) and cTAKES (for preprocessing and smoking status detection). The application achieved a final (micro-averaged) F1-measure of 87.5% on the final evaluation test set. Our attempt was mostly based on existing tools adapted with minimal changes and allowed for satisfying performance with limited development efforts. PMID:26318122

  20. Attention's Accelerator.

    PubMed

    Reinhart, Robert M G; McClenahan, Laura J; Woodman, Geoffrey F

    2016-06-01

    How do people get attention to operate at peak efficiency in high-pressure situations? We tested the hypothesis that the general mechanism that allows this is the maintenance of multiple target representations in working and long-term memory. We recorded subjects' event-related potentials (ERPs) indexing the working memory and long-term memory representations used to control attention while performing visual search. We found that subjects used both types of memories to control attention when they performed the visual search task with a large reward at stake, or when they were cued to respond as fast as possible. However, under normal circumstances, one type of target memory was sufficient for slower task performance. The use of multiple types of memory representations appears to provide converging top-down control of attention, allowing people to step on the attentional accelerator in a variety of high-pressure situations. PMID:27056975

  1. A process for developing community consensus regarding the diagnosis and management of attention-deficit/hyperactivity disorder.

    PubMed

    Foy, Jane Meschan; Earls, Marian F

    2005-01-01

    There remain large discrepancies between pediatricians' practice patterns and the American Academy of Pediatrics (AAP) guidelines for the assessment and treatment of children with attention-deficit/hyperactivity disorder (ADHD). Several studies raise additional concerns about access to ADHD treatment for girls, blacks, and poorer individuals. Barriers may occur at multiple levels, including identification and referral by school personnel, parents' help-seeking behavior, diagnosis by the medical provider, treatment decisions, and acceptance of treatment. Such findings confirm the importance of establishing appropriate mechanisms to ensure that children of both genders and all socioeconomic, racial, and ethnic groups receive appropriate assessment and treatment. Publication of the AAP ADHD toolkit provides resources to assist with implementing the ADHD guidelines in clinical practice. These resources address a number of the barriers to office implementation, including unfamiliarity with Diagnostic and Statistical Manual of Mental Disorders criteria, difficulty identifying comorbidities, and inadequate knowledge of effective coding practices. Also crucial to the success of improved processes within clinical practice is community collaboration in care, particularly collaboration with the educational system. Such collaboration addresses other barriers to good care, such as pressures from parents and schools to prescribe stimulants, cultural biases that may prevent schools from assessing children for ADHD or may prevent families from seeking health care, and inconsistencies in recognition and referral among schools in the same system. Collaboration may also create efficiencies in collection of data and school-physician communications, thereby decreasing physicians' non-face-to-face (and thus nonreimbursable) elements of care. This article describes a process used in Guilford County, North Carolina, to develop a consensus among health care providers, educators, and child

  2. Attention Alters Perceived Attractiveness.

    PubMed

    Störmer, Viola S; Alvarez, George A

    2016-04-01

    Can attention alter the impression of a face? Previous studies showed that attention modulates the appearance of lower-level visual features. For instance, attention can make a simple stimulus appear to have higher contrast than it actually does. We tested whether attention can also alter the perception of a higher-order property-namely, facial attractiveness. We asked participants to judge the relative attractiveness of two faces after summoning their attention to one of the faces using a briefly presented visual cue. Across trials, participants judged the attended face to be more attractive than the same face when it was unattended. This effect was not due to decision or response biases, but rather was due to changes in perceptual processing of the faces. These results show that attention alters perceived facial attractiveness, and broadly demonstrate that attention can influence higher-level perception and may affect people's initial impressions of one another. PMID:26966228

  3. Early processing variations in selective attention to the color and direction of moving stimuli during 30 days head-down bed rest

    NASA Astrophysics Data System (ADS)

    Wang, Lin-Jie; He, Si-Yang; Niu, Dong-Bin; Guo, Jian-Ping; Xu, Yun-Long; Wang, De-Sheng; Cao, Yi; Zhao, Qi; Tan, Cheng; Li, Zhi-Li; Tang, Guo-Hua; Li, Yin-Hui; Bai, Yan-Qiang

    2013-11-01

    Dynamic variations in early selective attention to the color and direction of moving stimuli were explored during a 30 days period of head-down bed rest. Event-related potentials (ERPs) were recorded at F5, F6, P5, P6 scalp locations in seven male subjects who attended to pairs of bicolored light emitting diodes that flashed sequentially to produce a perception of movement. Subjects were required to attend selectively to a critical feature of the moving target, e.g., color or direction. The tasks included: a no response task, a color selective response task, a moving direction selective response task, and a combined color-direction selective response task. Subjects were asked to perform these four tasks on: the 3rd day before bed rest; the 3rd, 15th and 30th day during the bed rest; and the 5th day after bed rest. Subjects responded quickly to the color than moving direction and combined color-direction response. And they had a longer reaction time during bed rest on the 15th and 30th day during bed rest after a relatively quicker response on the 3rd day. Using brain event-related potentials technique, we found that in the color selective response task, the mean amplitudes of P1 and N1 for target ERPs decreased in the 3rd day during bed rest and 5th day after bed rest in comparison with pre-bed rest, 15th day and 30th day during bed rest. In the combined color-direction selective response task, the P1 latencies for target ERPs on the 3rd and 30th day during bed rest were longer than on the 15th day during bed rest. As 3rd day during bed rest was in the acute adaptation period and 30th day during bed rest was in the relatively adaptation stage of head-down bed rest, the results help to clarify the effects of bed rest on different task loads and patterns of attention. It was suggested that subjects expended more time to give correct decision in the head-down tilt bed rest state. A difficulty in the recruitment of brain resources was found in feature selection task

  4. Spectroscopic analyses of chemical adaptation processes within microalgal biomass in response to changing environments.

    PubMed

    Vogt, Frank; White, Lauren

    2015-03-31

    Via photosynthesis, marine phytoplankton transforms large quantities of inorganic compounds into biomass. This has considerable environmental impacts as microalgae contribute for instance to counter-balancing anthropogenic releases of the greenhouse gas CO2. On the other hand, high concentrations of nitrogen compounds in an ecosystem can lead to harmful algae blooms. In previous investigations it was found that the chemical composition of microalgal biomass is strongly dependent on the nutrient availability. Therefore, it is expected that algae's sequestration capabilities and productivity are also determined by the cells' chemical environments. For investigating this hypothesis, novel analytical methodologies are required which are capable of monitoring live cells exposed to chemically shifting environments followed by chemometric modeling of their chemical adaptation dynamics. FTIR-ATR experiments have been developed for acquiring spectroscopic time series of live Dunaliella parva cultures adapting to different nutrient situations. Comparing experimental data from acclimated cultures to those exposed to a chemically shifted nutrient situation reveals insights in which analyte groups participate in modifications of microalgal biomass and on what time scales. For a chemometric description of these processes, a data model has been deduced which explains the chemical adaptation dynamics explicitly rather than empirically. First results show that this approach is feasible and derives information about the chemical biomass adaptations. Future investigations will utilize these instrumental and chemometric methodologies for quantitative investigations of the relation between chemical environments and microalgal sequestration capabilities. PMID:25813024

  5. Ultrasound nondestructive evaluation (NDE) imaging with transducer arrays and adaptive processing.

    PubMed

    Li, Minghui; Hayward, Gordon

    2012-01-01

    This paper addresses the challenging problem of ultrasonic non-destructive evaluation (NDE) imaging with adaptive transducer arrays. In NDE applications, most materials like concrete, stainless steel and carbon-reinforced composites used extensively in industries and civil engineering exhibit heterogeneous internal structure. When inspected using ultrasound, the signals from defects are significantly corrupted by the echoes form randomly distributed scatterers, even defects that are much larger than these random reflectors are difficult to detect with the conventional delay-and-sum operation. We propose to apply adaptive beamforming to the received data samples to reduce the interference and clutter noise. Beamforming is to manipulate the array beam pattern by appropriately weighting the per-element delayed data samples prior to summing them. The adaptive weights are computed from the statistical analysis of the data samples. This delay-weight-and-sum process can be explained as applying a lateral spatial filter to the signals across the probe aperture. Simulations show that the clutter noise is reduced by more than 30 dB and the lateral resolution is enhanced simultaneously when adaptive beamforming is applied. In experiments inspecting a steel block with side-drilled holes, good quantitative agreement with simulation results is demonstrated. PMID:22368457

  6. The Contextualized Technology Adaptation Process (CTAP): Optimizing Health Information Technology to Improve Mental Health Systems.

    PubMed

    Lyon, Aaron R; Wasse, Jessica Knaster; Ludwig, Kristy; Zachry, Mark; Bruns, Eric J; Unützer, Jürgen; McCauley, Elizabeth

    2016-05-01

    Health information technologies have become a central fixture in the mental healthcare landscape, but few frameworks exist to guide their adaptation to novel settings. This paper introduces the contextualized technology adaptation process (CTAP) and presents data collected during Phase 1 of its application to measurement feedback system development in school mental health. The CTAP is built on models of human-centered design and implementation science and incorporates repeated mixed methods assessments to guide the design of technologies to ensure high compatibility with a destination setting. CTAP phases include: (1) Contextual evaluation, (2) Evaluation of the unadapted technology, (3) Trialing and evaluation of the adapted technology, (4) Refinement and larger-scale implementation, and (5) Sustainment through ongoing evaluation and system revision. Qualitative findings from school-based practitioner focus groups are presented, which provided information for CTAP Phase 1, contextual evaluation, surrounding education sector clinicians' workflows, types of technologies currently available, and influences on technology use. Discussion focuses on how findings will inform subsequent CTAP phases, as well as their implications for future technology adaptation across content domains and service sectors. PMID:25677251

  7. Low Temperature Adaptation Is Not the Opposite Process of High Temperature Adaptation in Terms of Changes in Amino Acid Composition

    PubMed Central

    Yang, Ling-Ling; Tang, Shu-Kun; Huang, Ying; Zhi, Xiao-Yang

    2015-01-01

    Previous studies focused on psychrophilic adaptation generally have demonstrated that multiple mechanisms work together to increase protein flexibility and activity, as well as to decrease the thermostability of proteins. However, the relationship between high and low temperature adaptations remains unclear. To investigate this issue, we collected the available predicted whole proteome sequences of species with different optimal growth temperatures, and analyzed amino acid variations and substitutional asymmetry in pairs of homologous proteins from related species. We found that changes in amino acid composition associated with low temperature adaptation did not exhibit a coherent opposite trend when compared with changes in amino acid composition associated with high temperature adaptation. This result indicates that during their evolutionary histories the proteome-scale evolutionary patterns associated with prokaryotes exposed to low temperature environments were distinct from the proteome-scale evolutionary patterns associated with prokaryotes exposed to high temperature environments in terms of changes in amino acid composition of the proteins. PMID:26614525

  8. A review of culturally adapted versions of the Oswestry Disability Index: the adaptation process, construct validity, test-retest reliability and internal consistency.

    PubMed

    Sheahan, Peter J; Nelson-Wong, Erika J; Fischer, Steven L

    2015-12-01

    The Oswestry Disability Index (ODI) is a self-report-based outcome measure used to quantify the extent of disability related to low back pain (LBP), a substantial contributor to workplace absenteeism. The ODI tool has been adapted for use by patients in several non-English speaking nations. It is unclear, however, if these adapted versions of the ODI are as credible as the original ODI developed for English-speaking nations. The objective of this study was to conduct a review of the literature to identify culturally adapted versions of the ODI and to report on the adaptation process, construct validity, test-retest reliability and internal consistency of these ODIs. Following a pragmatic review process, data were extracted from each study with regard to these four outcomes. While most studies applied adaptation processes in accordance with best-practice guidelines, there were some deviations. However, all studies reported high-quality psychometric properties: group mean construct validity was 0.734 ± 0.094 (indicated via a correlation coefficient), test-retest reliability was 0.937 ± 0.032 (indicated via an intraclass correlation coefficient) and internal consistency was 0.876 ± 0.047 (indicated via Cronbach's alpha). Researchers can be confident when using any of these culturally adapted ODIs, or when comparing and contrasting results between cultures where these versions were employed. Implications for Rehabilitation Low back pain is the second leading cause of disability in the world, behind only cancer. The Oswestry Disability Index (ODI) has been developed as a self-report outcome measure of low back pain for administration to patients. An understanding of the various cross-cultural adaptations of the ODI is important for more concerted multi-national research efforts. This review examines 16 cross-cultural adaptations of the ODI and should inform the work of health care and rehabilitation professionals. PMID:25738913

  9. Visual attention to dynamic faces and objects is linked to face processing skills: a combined study of children with autism and controls.

    PubMed

    Parish-Morris, Julia; Chevallier, Coralie; Tonge, Natasha; Letzen, Janelle; Pandey, Juhi; Schultz, Robert T

    2013-01-01

    Although the extant literature on face recognition skills in Autism Spectrum Disorder (ASD) shows clear impairments compared to typically developing controls (TDC) at the group level, the distribution of scores within ASD is broad. In the present research, we take a dimensional approach and explore how differences in social attention during an eye tracking experiment correlate with face recognition skills across ASD and TDC. Emotional discrimination and person identity perception face processing skills were assessed using the Let's Face It! Skills Battery in 110 children with and without ASD. Social attention was assessed using infrared eye gaze tracking during passive viewing of movies of facial expressions and objects displayed together on a computer screen. Face processing skills were significantly correlated with measures of attention to faces and with social skills as measured by the Social Communication Questionnaire (SCQ). Consistent with prior research, children with ASD scored significantly lower on face processing skills tests but, unexpectedly, group differences in amount of attention to faces (vs. objects) were not found. We discuss possible methodological contributions to this null finding. We also highlight the importance of a dimensional approach for understanding the developmental origins of reduced face perception skills, and emphasize the need for longitudinal research to truly understand how social motivation and social attention influence the development of social perceptual skills. PMID:23596436

  10. Capturing Attention When Attention "Blinks"

    ERIC Educational Resources Information Center

    Wee, Serena; Chua, Fook K.

    2004-01-01

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

  11. Attention enhances feature integration.

    PubMed

    Paul, Liza; Schyns, Philippe G

    2003-08-01

    Perceptual processing delays between attribute dimensions (e.g. color, form and motion) [Proceedings of the Royal Society of London Series B 264 (1997) 1407] have been attributed to temporal processing asynchronies resulting from functional segregation of visual information [Science 240 (1988) 740]. In addition, several lines of evidence converge to suggest that attention plays an important role in the integration of functionally processed information. However, exactly how attention modulates the temporal integration of information remains unclear. Here, we examined how attention modulates the integration of color and form into a unitary perception. Results suggest that attending to the location of an object enhances the integration of its defining attributes by speeding up the perceptual processing of each attribute dimension. Moreover, the perceptual asynchrony between attributes remains constant across attended and unattended conditions because attention seems to offer each processing dimension an equal processing advantage. PMID:12826102

  12. Adaptive constructive processes and memory accuracy: Consequences of counterfactual simulations in young and older adults

    PubMed Central

    Gerlach, Kathy D.; Dornblaser, David W.; Schacter, Daniel L.

    2013-01-01

    People frequently engage in counterfactual thinking: mental simulations of alternative outcomes to past events. Like simulations of future events, counterfactual simulations serve adaptive functions. However, future simulation can also result in various kinds of distortions and has thus been characterized as an adaptive constructive process. Here we approach counterfactual thinking as such and examine whether it can distort memory for actual events. In Experiments 1a/b, young and older adults imagined themselves experiencing different scenarios. Participants then imagined the same scenario again, engaged in no further simulation of a scenario, or imagined a counterfactual outcome. On a subsequent recognition test, participants were more likely to make false alarms to counterfactual lures than novel scenarios. Older adults were more prone to these memory errors than younger adults. In Experiment 2, younger and older participants selected and performed different actions, then recalled performing some of those actions, imagined performing alternative actions to some of the selected actions, and did not imagine others. Participants, especially older adults, were more likely to falsely remember counterfactual actions than novel actions as previously performed. The findings suggest that counterfactual thinking can cause source confusion based on internally generated misinformation, consistent with its characterization as an adaptive constructive process. PMID:23560477

  13. Adaptive optimal control of highly dissipative nonlinear spatially distributed processes with neuro-dynamic programming.

    PubMed

    Luo, Biao; Wu, Huai-Ning; Li, Han-Xiong

    2015-04-01

    Highly dissipative nonlinear partial differential equations (PDEs) are widely employed to describe the system dynamics of industrial spatially distributed processes (SDPs). In this paper, we consider the optimal control problem of the general highly dissipative SDPs, and propose an adaptive optimal control approach based on neuro-dynamic programming (NDP). Initially, Karhunen-Loève decomposition is employed to compute empirical eigenfunctions (EEFs) of the SDP based on the method of snapshots. These EEFs together with singular perturbation technique are then used to obtain a finite-dimensional slow subsystem of ordinary differential equations that accurately describes the dominant dynamics of the PDE system. Subsequently, the optimal control problem is reformulated on the basis of the slow subsystem, which is further converted to solve a Hamilton-Jacobi-Bellman (HJB) equation. HJB equation is a nonlinear PDE that has proven to be impossible to solve analytically. Thus, an adaptive optimal control method is developed via NDP that solves the HJB equation online using neural network (NN) for approximating the value function; and an online NN weight tuning law is proposed without requiring an initial stabilizing control policy. Moreover, by involving the NN estimation error, we prove that the original closed-loop PDE system with the adaptive optimal control policy is semiglobally uniformly ultimately bounded. Finally, the developed method is tested on a nonlinear diffusion-convection-reaction process and applied to a temperature cooling fin of high-speed aerospace vehicle, and the achieved results show its effectiveness. PMID:25794375

  14. Coevolution of information processing and topology in hierarchical adaptive random Boolean networks

    NASA Astrophysics Data System (ADS)

    Górski, Piotr J.; Czaplicka, Agnieszka; Hołyst, Janusz A.

    2016-02-01

    Random Boolean Networks (RBNs) are frequently used for modeling complex systems driven by information processing, e.g. for gene regulatory networks (GRNs). Here we propose a hierarchical adaptive random Boolean Network (HARBN) as a system consisting of distinct adaptive RBNs (ARBNs) - subnetworks - connected by a set of permanent interlinks. We investigate mean node information, mean edge information as well as mean node degree. Information measures and internal subnetworks topology of HARBN coevolve and reach steady-states that are specific for a given network structure. The main natural feature of ARBNs, i.e. their adaptability, is preserved in HARBNs and they evolve towards critical configurations which is documented by power law distributions of network attractor lengths. The mean information processed by a single node or a single link increases with the number of interlinks added to the system. The mean length of network attractors and the mean steady-state connectivity possess minima for certain specific values of the quotient between the density of interlinks and the density of all links in networks. It means that the modular network displays extremal values of its observables when subnetworks are connected with a density a few times lower than a mean density of all links.

  15. Shared Attention.

    PubMed

    Shteynberg, Garriy

    2015-09-01

    Shared attention is extremely common. In stadiums, public squares, and private living rooms, people attend to the world with others. Humans do so across all sensory modalities-sharing the sights, sounds, tastes, smells, and textures of everyday life with one another. The potential for attending with others has grown considerably with the emergence of mass media technologies, which allow for the sharing of attention in the absence of physical co-presence. In the last several years, studies have begun to outline the conditions under which attending together is consequential for human memory, motivation, judgment, emotion, and behavior. Here, I advance a psychological theory of shared attention, defining its properties as a mental state and outlining its cognitive, affective, and behavioral consequences. I review empirical findings that are uniquely predicted by shared-attention theory and discuss the possibility of integrating shared-attention, social-facilitation, and social-loafing perspectives. Finally, I reflect on what shared-attention theory implies for living in the digital world. PMID:26385997

  16. ADAPT: building conceptual models of the physical and biological processes across permafrost landscapes

    NASA Astrophysics Data System (ADS)

    Allard, M.; Vincent, W. F.; Lemay, M.

    2012-12-01

    Fundamental and applied permafrost research is called upon in Canada in support of environmental protection, economic development and for contributing to the international efforts in understanding climatic and ecological feedbacks of permafrost thawing under a warming climate. The five year "Arctic Development and Adaptation to Permafrost in Transition" program (ADAPT) funded by NSERC brings together 14 scientists from 10 Canadian universities and involves numerous collaborators from academia, territorial and provincial governments, Inuit communities and industry. The geographical coverage of the program encompasses all of the permafrost regions of Canada. Field research at a series of sites across the country is being coordinated. A common protocol for measuring ground thermal and moisture regime, characterizing terrain conditions (vegetation, topography, surface water regime and soil organic matter contents) is being applied in order to provide inputs for designing a general model to provide an understanding of transfers of energy and matter in permafrost terrain, and the implications for biological and human systems. The ADAPT mission is to produce an 'Integrated Permafrost Systems Science' framework that will be used to help generate sustainable development and adaptation strategies for the North in the context of rapid socio-economic and climate change. ADAPT has three major objectives: to examine how changing precipitation and warming temperatures affect permafrost geosystems and ecosystems, specifically by testing hypotheses concerning the influence of the snowpack, the effects of water as a conveyor of heat, sediments, and carbon in warming permafrost terrain and the processes of permafrost decay; to interact directly with Inuit communities, the public sector and the private sector for development and adaptation to changes in permafrost environments; and to train the new generation of experts and scientists in this critical domain of research in Canada

  17. Performance-Based Adaptive Fuzzy Tracking Control for Networked Industrial Processes.

    PubMed

    Wang, Tong; Qiu, Jianbin; Yin, Shen; Gao, Huijun; Fan, Jialu; Chai, Tianyou

    2016-08-01

    In this paper, the performance-based control design problem for double-layer networked industrial processes is investigated. At the device layer, the prescribed performance functions are first given to describe the output tracking performance, and then by using backstepping technique, new adaptive fuzzy controllers are designed to guarantee the tracking performance under the effects of input dead-zone and the constraint of prescribed tracking performance functions. At operation layer, by considering the stochastic disturbance, actual index value, target index value, and index prediction simultaneously, an adaptive inverse optimal controller in discrete-time form is designed to optimize the overall performance and stabilize the overall nonlinear system. Finally, a simulation example of continuous stirred tank reactor system is presented to show the effectiveness of the proposed control method. PMID:27168605

  18. Two Adaptation Processes in Auditory Hair Cells Together Can Provide an Active Amplifier

    PubMed Central

    Vilfan, Andrej; Duke, Thomas

    2003-01-01

    The hair cells of the vertebrate inner ear convert mechanical stimuli to electrical signals. Two adaptation mechanisms are known to modify the ionic current flowing through the transduction channels of the hair bundles: a rapid process involves Ca2+ ions binding to the channels; and a slower adaptation is associated with the movement of myosin motors. We present a mathematical model of the hair cell which demonstrates that the combination of these two mechanisms can produce “self-tuned critical oscillations”, i.e., maintain the hair bundle at the threshold of an oscillatory instability. The characteristic frequency depends on the geometry of the bundle and on the Ca2+ dynamics, but is independent of channel kinetics. Poised on the verge of vibrating, the hair bundle acts as an active amplifier. However, if the hair cell is sufficiently perturbed, other dynamical regimes can occur. These include slow relaxation oscillations which resemble the hair bundle motion observed in some experimental preparations. PMID:12829475

  19. Improved electromagnetic induction processing with novel adaptive matched filter and matched subspace detection

    NASA Astrophysics Data System (ADS)

    Hayes, Charles E.; McClellan, James H.; Scott, Waymond R.; Kerr, Andrew J.

    2016-05-01

    This work introduces two advances in wide-band electromagnetic induction (EMI) processing: a novel adaptive matched filter (AMF) and matched subspace detection methods. Both advances make use of recent work with a subspace SVD approach to separating the signal, soil, and noise subspaces of the frequency measurements The proposed AMF provides a direct approach to removing the EMI self-response while improving the signal to noise ratio of the data. Unlike previous EMI adaptive downtrack filters, this new filter will not erroneously optimize the EMI soil response instead of the EMI target response because these two responses are projected into separate frequency subspaces. The EMI detection methods in this work elaborate on how the signal and noise subspaces in the frequency measurements are ideal for creating the matched subspace detection (MSD) and constant false alarm rate matched subspace detection (CFAR) metrics developed by Scharf The CFAR detection metric has been shown to be the uniformly most powerful invariant detector.

  20. Multiresolution stroke sketch adaptive representation and neural network processing system for gray-level image recognition

    NASA Astrophysics Data System (ADS)

    Meystel, Alexander M.; Rybak, Ilya A.; Bhasin, Sanjay

    1992-11-01

    This paper describes a method for multiresolutional representation of gray-level images as hierarchial sets of strokes characterizing forms of objects with different degrees of generalization depending on the context of the image. This method transforms the original image into a hierarchical graph which allows for efficient coding in order to store, retrieve, and recognize the image. The method which is described is based upon finding the resolution levels for each image which minimizes the computations required. This becomes possible because of the use of a special image representation technique called Multiresolutional Attentional Representation for Recognition, based upon a feature which the authors call a stroke. This feature turns out to be efficient in the process of finding the appropriate system of resolutions and construction of the relational graph. Multiresolutional Attentional Representation for Recognition (MARR) is formed by a multi-layer neural network with recurrent inhibitory connections between neurons, the receptive fields of which are selectively tuned to detect the orientation of local contrasts in parts of the image with appropriate degree of generalization. This method simulates the 'coarse-to-fine' algorithm which an artist usually uses, making at attentional sketch of real images. The method, algorithms, and neural network architecture in this system can be used in many machine-vision systems with AI properties; in particular, robotic vision. We expect that systems with MARR can become a component of intelligent control systems for autonomous robots. Their architectures are mostly multiresolutional and match well with the multiple resolutions of the MARR structure.

  1. ERP and Adaptive Autoregressive identification with spectral power decomposition to study rapid auditory processing in infants.

    PubMed

    Piazza, C; Cantiani, C; Tacchino, G; Molteni, M; Reni, G; Bianchi, A M

    2014-01-01

    The ability to process rapidly-occurring auditory stimuli plays an important role in the mechanisms of language acquisition. For this reason, the research community has begun to investigate infant auditory processing, particularly using the Event Related Potentials (ERP) technique. In this paper we approach this issue by means of time domain and time-frequency domain analysis. For the latter, we propose the use of Adaptive Autoregressive (AAR) identification with spectral power decomposition. Results show EEG delta-theta oscillation enhancement related to the processing of acoustic frequency and duration changes, suggesting that, as expected, power modulation encodes rapid auditory processing (RAP) in infants and that the time-frequency analysis method proposed is able to identify this modulation. PMID:25571014

  2. Maternal migration and child health: An analysis of disruption and adaptation processes in Benin

    PubMed Central

    Smith-Greenaway, Emily; Madhavan, Sangeetha

    2016-01-01

    Children of migrant mothers have lower vaccination rates compared to their peers with non-migrant mothers in low-income countries. Explanations for this finding are typically grounded in the disruption and adaptation perspectives of migration. Researchers argue that migration is a disruptive process that interferes with women’s economic well-being and social networks, and ultimately their health-seeking behaviors. With time, however, migrant women adapt to their new settings, and their health behaviors improve. Despite prominence in the literature, no research tests the salience of these perspectives to the relationship between maternal migration and child vaccination. We innovatively leverage Demographic and Health Survey data to test the extent to which disruption and adaptation processes underlie the relationship between maternal migration and child vaccination in the context of Benin—a West African country where migration is common and child vaccination rates have declined in recent years. By disaggregating children of migrants according to whether they were born before or after their mother’s migration, we confirm that migration does not lower children’s vaccination rates in Benin. In fact, children born after migration enjoy a higher likelihood of vaccination, whereas their peers born in the community from which their mother eventually migrates are less likely to be vaccinated. Although we find no support for the disruption perspective of migration, we do find evidence of adaptation: children born after migration have an increased likelihood of vaccination the longer their mother resides in the destination community prior to their birth. PMID:26463540

  3. Evolutionary adaptations for the temporal processing of natural sounds by the anuran peripheral auditory system.

    PubMed

    Schrode, Katrina M; Bee, Mark A

    2015-03-01

    Sensory systems function most efficiently when processing natural stimuli, such as vocalizations, and it is thought that this reflects evolutionary adaptation. Among the best-described examples of evolutionary adaptation in the auditory system are the frequent matches between spectral tuning in both the peripheral and central auditory systems of anurans (frogs and toads) and the frequency spectra of conspecific calls. Tuning to the temporal properties of conspecific calls is less well established, and in anurans has so far been documented only in the central auditory system. Using auditory-evoked potentials, we asked whether there are species-specific or sex-specific adaptations of the auditory systems of gray treefrogs (Hyla chrysoscelis) and green treefrogs (H. cinerea) to the temporal modulations present in conspecific calls. Modulation rate transfer functions (MRTFs) constructed from auditory steady-state responses revealed that each species was more sensitive than the other to the modulation rates typical of conspecific advertisement calls. In addition, auditory brainstem responses (ABRs) to paired clicks indicated relatively better temporal resolution in green treefrogs, which could represent an adaptation to the faster modulation rates present in the calls of this species. MRTFs and recovery of ABRs to paired clicks were generally similar between the sexes, and we found no evidence that males were more sensitive than females to the temporal modulation patterns characteristic of the aggressive calls used in male-male competition. Together, our results suggest that efficient processing of the temporal properties of behaviorally relevant sounds begins at potentially very early stages of the anuran auditory system that include the periphery. PMID:25617467

  4. Evolutionary adaptations for the temporal processing of natural sounds by the anuran peripheral auditory system

    PubMed Central

    Schrode, Katrina M.; Bee, Mark A.

    2015-01-01

    ABSTRACT Sensory systems function most efficiently when processing natural stimuli, such as vocalizations, and it is thought that this reflects evolutionary adaptation. Among the best-described examples of evolutionary adaptation in the auditory system are the frequent matches between spectral tuning in both the peripheral and central auditory systems of anurans (frogs and toads) and the frequency spectra of conspecific calls. Tuning to the temporal properties of conspecific calls is less well established, and in anurans has so far been documented only in the central auditory system. Using auditory-evoked potentials, we asked whether there are species-specific or sex-specific adaptations of the auditory systems of gray treefrogs (Hyla chrysoscelis) and green treefrogs (H. cinerea) to the temporal modulations present in conspecific calls. Modulation rate transfer functions (MRTFs) constructed from auditory steady-state responses revealed that each species was more sensitive than the other to the modulation rates typical of conspecific advertisement calls. In addition, auditory brainstem responses (ABRs) to paired clicks indicated relatively better temporal resolution in green treefrogs, which could represent an adaptation to the faster modulation rates present in the calls of this species. MRTFs and recovery of ABRs to paired clicks were generally similar between the sexes, and we found no evidence that males were more sensitive than females to the temporal modulation patterns characteristic of the aggressive calls used in male–male competition. Together, our results suggest that efficient processing of the temporal properties of behaviorally relevant sounds begins at potentially very early stages of the anuran auditory system that include the periphery. PMID:25617467

  5. Flexible Description and Adaptive Processing of Earth Observation Data through the BigEarth Platform

    NASA Astrophysics Data System (ADS)

    Gorgan, Dorian; Bacu, Victor; Stefanut, Teodor; Nandra, Cosmin; Mihon, Danut

    2016-04-01

    The Earth Observation data repositories extending periodically by several terabytes become a critical issue for organizations. The management of the storage capacity of such big datasets, accessing policy, data protection, searching, and complex processing require high costs that impose efficient solutions to balance the cost and value of data. Data can create value only when it is used, and the data protection has to be oriented toward allowing innovation that sometimes depends on creative people, which achieve unexpected valuable results through a flexible and adaptive manner. The users need to describe and experiment themselves different complex algorithms through analytics in order to valorize data. The analytics uses descriptive and predictive models to gain valuable knowledge and information from data analysis. Possible solutions for advanced processing of big Earth Observation data are given by the HPC platforms such as cloud. With platforms becoming more complex and heterogeneous, the developing of applications is even harder and the efficient mapping of these applications to a suitable and optimum platform, working on huge distributed data repositories, is challenging and complex as well, even by using specialized software services. From the user point of view, an optimum environment gives acceptable execution times, offers a high level of usability by hiding the complexity of computing infrastructure, and supports an open accessibility and control to application entities and functionality. The BigEarth platform [1] supports the entire flow of flexible description of processing by basic operators and adaptive execution over cloud infrastructure [2]. The basic modules of the pipeline such as the KEOPS [3] set of basic operators, the WorDeL language [4], the Planner for sequential and parallel processing, and the Executor through virtual machines, are detailed as the main components of the BigEarth platform [5]. The presentation exemplifies the development

  6. Investigating bottom-up auditory attention

    PubMed Central

    Kaya, Emine Merve; Elhilali, Mounya

    2014-01-01

    Bottom-up attention is a sensory-driven selection mechanism that directs perception toward a subset of the stimulus that is considered salient, or attention-grabbing. Most studies of bottom-up auditory attention have adapted frameworks similar to visual attention models whereby local or global “contrast” is a central concept in defining salient elements in a scene. In the current study, we take a more fundamental approach to modeling auditory attention; providing the first examination of the space of auditory saliency spanning pitch, intensity and timbre; and shedding light on complex interactions among these features. Informed by psychoacoustic results, we develop a computational model of auditory saliency implementing a novel attentional framework, guided by processes hypothesized to take place in the auditory pathway. In particular, the model tests the hypothesis that perception tracks the evolution of sound events in a multidimensional feature space, and flags any deviation from background statistics as salient. Predictions from the model corroborate the relationship between bottom-up auditory attention and statistical inference, and argues for a potential role of predictive coding as mechanism for saliency detection in acoustic scenes. PMID:24904367

  7. Can survival processing enhance story memory? Testing the generalizability of the adaptive memory framework.

    PubMed

    Seamon, John G; Bohn, Justin M; Coddington, Inslee E; Ebling, Maritza C; Grund, Ethan M; Haring, Catherine T; Jang, Sue-Jung; Kim, Daniel; Liong, Christopher; Paley, Frances M; Pang, Luke K; Siddique, Ashik H

    2012-07-01

    Research from the adaptive memory framework shows that thinking about words in terms of their survival value in an incidental learning task enhances their free recall relative to other semantic encoding strategies and intentional learning (Nairne, Pandeirada, & Thompson, 2008). We found similar results. When participants used incidental survival encoding for a list of words (e.g., "Will this object enhance my survival if I were stranded in the grasslands of a foreign land?"), they produced better free recall on a surprise test than did participants who intentionally tried to remember those words (Experiment 1). We also found this survival processing advantage when the words were presented within the context of a survival or neutral story (Experiment 2). However, this advantage did not extent to memory for a story's factual content, regardless of whether the participants were tested by cued recall (Experiment 3) or free recall (Experiments 4-5). Listening to a story for understanding under intentional or incidental learning conditions was just as good as survival processing for remembering story content. The functionalist approach to thinking about memory as an evolutionary adaptation designed to solve reproductive fitness problems provides a different theoretical framework for research, but it is not yet clear if survival processing has general applicability or is effective only for processing discrete stimuli in terms of fitness-relevant scenarios from our past. PMID:22288816

  8. Auditory Temporal Processing in Children with Specific Reading Disability with and without Attention Deficit/Hyperactivity Disorder.

    ERIC Educational Resources Information Center

    Breier, Joshua I.; Fletcher, Jack M.; Foorman, Barbara R.; Klaas, Patricia; Gray, Lincoln C.

    2003-01-01

    Tasks assessing perception of auditory temporal and nontemporal cues were administered to children with reading disorders (RD) with or without attention deficit hyperactivity disorder or with ADHD alone. The presence of RD was associated only with a deficit in detection of a tone onset time synchrony. The presence of ADHD was associated with a…

  9. Slow Perceptual Processing at the Core of Developmental Dyslexia: A Parameter-Based Assessment of Visual Attention

    ERIC Educational Resources Information Center

    Stenneken, Prisca; Egetemeir, Johanna; Schulte-Korne, Gerd; Muller, Hermann J.; Schneider, Werner X.; Finke, Kathrin

    2011-01-01

    The cognitive causes as well as the neurological and genetic basis of developmental dyslexia, a complex disorder of written language acquisition, are intensely discussed with regard to multiple-deficit models. Accumulating evidence has revealed dyslexics' impairments in a variety of tasks requiring visual attention. The heterogeneity of these…

  10. Allocation of Attention to Second Language Form and Meaning: Issues of Think-Alouds and Depth of Processing

    ERIC Educational Resources Information Center

    Morgan-Short, Kara; Heil, Jeanne; Botero-Moriarty, Andrea; Ebert, Shane

    2012-01-01

    The aims of the present study were twofold. The study addressed the issues of simultaneous attention to form and meaning in second language (L2) written input and reactivity of think-alouds. Specifically, the study examined the comprehension of L2 learners of Spanish who either attended to lexical or grammatical forms while reading for meaning or…

  11. Effects of Age and Attention on Auditory Global-Local Processing in Children with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Foster, Nicholas E. V.; Ouimet, Tia; Tryfon, Ana; Doyle-Thomas, Krissy; Anagnostou, Evdokia; Hyde, Krista L.

    2016-01-01

    In vision, typically-developing (TD) individuals perceive "global" (whole) before "local" (detailed) features, whereas individuals with autism spectrum disorder (ASD) exhibit a local bias. However, auditory global-local distinctions are less clear in ASD, particularly in terms of age and attention effects. To these aims, here…

  12. Response Switching Process in Children with Attention-Deficit-Hyperactivity Disorder on the Novel Continuous Performance Test

    ERIC Educational Resources Information Center

    Inoue, Yuki; Inagaki, Masumi; Gunji, Atsuko; Furushima, Wakana; Kaga, Makiko

    2008-01-01

    We examined the effects of previous trials on subsequent trials on performance in the continuous performance test (CPT) in children with attention-deficit-hyperactivity disorder (ADHD). Thirty-five non-medicated children with ADHD (31 males, four females; mean age 9y 10mo [SD 2y 4mo]) and 33 comparison children (20 males, 13 females; mean age 10y…

  13. Look who's talking: The deployment of visuo-spatial attention during multisensory speech processing under noisy environmental conditions

    PubMed Central

    Senkowski, Daniel; Saint-Amour, Dave; Gruber, Thomas; Foxe, John J.

    2008-01-01

    In a crowded scene we can effectively focus our attention on a specific speaker while largely ignoring sensory inputs from other speakers. How attended speech inputs are extracted from similar competing information has been primarily studied in the auditory domain. Here we examined the deployment of visuo-spatial attention in multiple speaker scenarios. Steady-state visual evoked potentials (SSVEP) were monitored as a real-time index of visual attention towards three competing speakers. Participants were instructed to detect a target syllable by the center speaker and ignore syllables from two flanking speakers. The study incorporated interference trials (syllables from three speakers), no-interference trials (syllable from center speaker only), and periods without speech stimulation in which static faces were presented. An enhancement of flanking speaker induced SSVEP was found 70-220 ms after sound onset over left temporal scalp during interference trials. This enhancement was negatively correlated with the behavioral performance of participants - those who showed largest enhancements had the worst speech recognition performance. Additionally, poorly performing participants exhibited enhanced flanking speaker induced SSVEP over visual scalp during periods without speech stimulation. The present study provides neurophysiologic evidence that the deployment of visuo-spatial attention to flanking speakers interferes with the recognition of multisensory speech signals under noisy environmental conditions. PMID:18678262

  14. A Follow-Up Study of Relational Processes and Consultation Outcomes for Students with Attention Deficit Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Erchul, William P.; DuPaul, George J.; Bennett, Megan S.; Grissom, Priscilla F.; Jitendra, Asha K.; Tresco, Katy E.; Volpe, Robert J.; Vile Junod, Rosemary E.; Flammer-Rivera, Lizette M.; Mannella, Mark C.

    2009-01-01

    The purpose of this study was to link consultant and teacher verbal interaction patterns to consultation outcomes. Participants were 4 consultants, 20 teachers, and 20 elementary school students with attention deficit hyperactivity disorder. Audiotaped Problem Analysis Interviews (PAIs) from Project PASS (Promoting Academic Success in Students)…

  15. Working Memory, Processing Speed, and Set-Shifting in Children with Developmental Coordination Disorder and Attention-Deficit-Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Piek, Jan P.; Dyck, Murray J.; Francis, Mona; Conwell, Alistair

    2007-01-01

    It has been suggested that the high levels of comorbidity between attention-deficit-hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) may be attributed to a common underlying neurocognitive mechanism. This study assessed whether children with DCD and ADHD share deficits on tasks measuring working memory, set-shifting, and…

  16. Forest, Trees, Dynamics: Results from a Novel Wisconsin Card Sorting Test Variant Protocol for Studying Global-Local Attention and Complex Cognitive Processes

    PubMed Central

    Cowley, Benjamin; Lukander, Kristian

    2016-01-01

    Background: Recognition of objects and their context relies heavily on the integrated functioning of global and local visual processing. In a realistic setting such as work, this processing becomes a sustained activity, implying a consequent interaction with executive functions. Motivation: There have been many studies of either global-local attention or executive functions; however it is relatively novel to combine these processes to study a more ecological form of attention. We aim to explore the phenomenon of global-local processing during a task requiring sustained attention and working memory. Methods: We develop and test a novel protocol for global-local dissociation, with task structure including phases of divided (“rule search”) and selective (“rule found”) attention, based on the Wisconsin Card Sorting Task (WCST). We test it in a laboratory study with 25 participants, and report on behavior measures (physiological data was also gathered, but not reported here). We develop novel stimuli with more naturalistic levels of information and noise, based primarily on face photographs, with consequently more ecological validity. Results: We report behavioral results indicating that sustained difficulty when participants test their hypotheses impacts matching-task performance, and diminishes the global precedence effect. Results also show a dissociation between subjectively experienced difficulty and objective dimension of performance, and establish the internal validity of the protocol. Contribution: We contribute an advance in the state of the art for testing global-local attention processes in concert with complex cognition. With three results we establish a connection between global-local dissociation and aspects of complex cognition. Our protocol also improves ecological validity and opens options for testing additional interactions in future work. PMID:26941689

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

    PubMed Central

    Di Nocera, Dario; Finzi, Alberto; Rossi, Silvia; Staffa, Mariacarla

    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 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. PMID:24744746

  18. Adapting Semantic Natural Language Processing Technology to Address Information Overload in Influenza Epidemic Management

    PubMed Central

    Keselman, Alla; Rosemblat, Graciela; Kilicoglu, Halil; Fiszman, Marcelo; Jin, Honglan; Shin, Dongwook; Rindflesch, Thomas C.

    2013-01-01

    Explosion of disaster health information results in information overload among response professionals. The objective of this project was to determine the feasibility of applying semantic natural language processing (NLP) technology to addressing this overload. The project characterizes concepts and relationships commonly used in disaster health-related documents on influenza pandemics, as the basis for adapting an existing semantic summarizer to the domain. Methods include human review and semantic NLP analysis of a set of relevant documents. This is followed by a pilot-test in which two information specialists use the adapted application for a realistic information seeking task. According to the results, the ontology of influenza epidemics management can be described via a manageable number of semantic relationships that involve concepts from a limited number of semantic types. Test users demonstrate several ways to engage with the application to obtain useful information. This suggests that existing semantic NLP algorithms can be adapted to support information summarization and visualization in influenza epidemics and other disaster health areas. However, additional research is needed in the areas of terminology development (as many relevant relationships and terms are not part of existing standardized vocabularies), NLP, and user interface design. PMID:24311971

  19. Adapting Semantic Natural Language Processing Technology to Address Information Overload in Influenza Epidemic Management.

    PubMed

    Keselman, Alla; Rosemblat, Graciela; Kilicoglu, Halil; Fiszman, Marcelo; Jin, Honglan; Shin, Dongwook; Rindflesch, Thomas C

    2010-12-01

    Explosion of disaster health information results in information overload among response professionals. The objective of this project was to determine the feasibility of applying semantic natural language processing (NLP) technology to addressing this overload. The project characterizes concepts and relationships commonly used in disaster health-related documents on influenza pandemics, as the basis for adapting an existing semantic summarizer to the domain. Methods include human review and semantic NLP analysis of a set of relevant documents. This is followed by a pilot-test in which two information specialists use the adapted application for a realistic information seeking task. According to the results, the ontology of influenza epidemics management can be described via a manageable number of semantic relationships that involve concepts from a limited number of semantic types. Test users demonstrate several ways to engage with the application to obtain useful information. This suggests that existing semantic NLP algorithms can be adapted to support information summarization and visualization in influenza epidemics and other disaster health areas. However, additional research is needed in the areas of terminology development (as many relevant relationships and terms are not part of existing standardized vocabularies), NLP, and user interface design. PMID:24311971

  20. OFDM Radar Space-Time Adaptive Processing by Exploiting Spatio-Temporal Sparsity

    SciTech Connect

    Sen, Satyabrata

    2013-01-01

    We propose a sparsity-based space-time adaptive processing (STAP) algorithm to detect a slowly-moving target using an orthogonal frequency division multiplexing (OFDM) radar. We observe that the target and interference spectra are inherently sparse in the spatio-temporal domain. Hence, we exploit that sparsity to develop an efficient STAP technique that utilizes considerably lesser number of secondary data and produces an equivalent performance as the other existing STAP techniques. In addition, the use of an OFDM signal increases the frequency diversity of our system, as different scattering centers of a target resonate at different frequencies, and thus improves the target detectability. First, we formulate a realistic sparse-measurement model for an OFDM radar considering both the clutter and jammer as the interfering sources. Then, we apply a residual sparse-recovery technique based on the LASSO estimator to estimate the target and interference covariance matrices, and subsequently compute the optimal STAP-filter weights. Our numerical results demonstrate a comparative performance analysis of the proposed sparse-STAP algorithm with four other existing STAP methods. Furthermore, we discover that the OFDM-STAP filter-weights are adaptable to the frequency-variabilities of the target and interference responses, in addition to the spatio-temporal variabilities. Hence, by better utilizing the frequency variabilities, we propose an adaptive OFDM-waveform design technique, and consequently gain a significant amount of STAP-performance improvement.

  1. Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes

    PubMed Central

    Gonzales, Gustavo F

    2013-01-01

    Populations living at high altitudes (HAs), particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis (16 g dl−121 g dl−1). Elevated haemoglobin values (EE) are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to HA. According to current data, native men from regions of HA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate (DHEAS) to testosterone. Men with erythrocytosis at HAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity. Lower 17beta-HSD activity via Δ4-steroid production in men with erythrocytosis at HA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DHEAS to testosterone in subjects with EE indicates increased 17beta-HSD activity via the Δ5-pathway. Currently, there are various situations in which people live (human biodiversity) with low or high haemoglobin levels at HA. Antiquity could be an important adaptation component for life at HA, and testosterone seems to participate in this process. PMID:23524530

  2. Adaptive Sparse Signal Processing for Discrimination of Satellite-based Radiofrequency (RF) Recordings of Lightning Events

    NASA Astrophysics Data System (ADS)

    Moody, D. I.; Smith, D. A.; Heavner, M.; Hamlin, T.

    2014-12-01

    Ongoing research at Los Alamos National Laboratory studies the Earth's radiofrequency (RF) background utilizing satellite-based RF observations of terrestrial lightning. The Fast On-orbit Recording of Transient Events (FORTE) satellite, launched in 1997, provided a rich RF lightning database. Application of modern pattern recognition techniques to this dataset may further lightning research in the scientific community, and potentially improve on-orbit processing and event discrimination capabilities for future satellite payloads. We extend sparse signal processing techniques to radiofrequency (RF) transient signals, and specifically focus on improved signature extraction using sparse representations in data-adaptive dictionaries. We present various processing options and classification results for on-board discharges, and discuss robustness and potential for capability development.

  3. Adaptation of the IBM ECR (electric cantilever robot) robot to plutonium processing applications

    SciTech Connect

    Armantrout, G.A.; Pedrotti, L.R. ); Halter, E.A.; Crossfield, M. )

    1990-12-01

    The changing regulatory climate in the US is adding increasing incentive to reduce operator dose and TRU waste for DOE plutonium processing operations. To help achieve that goal the authors have begun adapting a small commercial overhead gantry robot, the IBM electric cantilever robot (ECR), to plutonium processing applications. Steps are being taken to harden this robot to withstand the dry, often abrasive, environment within a plutonium glove box and to protect the electronic components against alpha radiation. A mock-up processing system for the reduction of the oxide to a metal was prepared and successfully demonstrated. Design of a working prototype is now underway using the results of this mock-up study. 7 figs., 4 tabs.

  4. High-quality laser cutting of ceramics through adapted process techniques

    NASA Astrophysics Data System (ADS)

    Toenshoff, Hans K.; Gonschior, Martin

    1994-02-01

    Laser cutting of ceramics is a promising alternative to conventional machining methods. In this paper, processing results using several lasers and beam guidance optics to cut different oxide and non-oxide ceramics are presented. Adapted process parameters in pulsed mode operation provide high quality cut surfaces at acceptable feed rates. Especially Nd:YAG lasers can be used for cutting extremely brittle ceramics. The use of fiber optics for beam guidance, however, is limited to certain ceramics with high fracture toughness, due to a loss in beam quality. In laser cutting of ceramics, thermally-induced crack damage is one of the main problems preventing a wider use of this method in industry. Several methods were investigated in order to reduce crack formation. Adapted pulse parameters, calculated by a theoretical model, and also a newly-developed process control system lead to a remarkable reduction of crack damage. Crack-free cutting can be obtained by preheating the workpiece above a temperature of 1.100 degree(s)C. Based on these investigations, requirements on laser systems for ceramics cutting are worked out.

  5. Mechanisms for Rapid Adaptive Control of Motion Processing in Macaque Visual Cortex

    PubMed Central

    Baker, Pamela M.; Ahmed, Bashir; Kohn, Adam; Bair, Wyeth

    2015-01-01

    A key feature of neural networks is their ability to rapidly adjust their function, including signal gain and temporal dynamics, in response to changes in sensory inputs. These adjustments are thought to be important for optimizing the sensitivity of the system, yet their mechanisms remain poorly understood. We studied adaptive changes in temporal integration in direction-selective cells in macaque primary visual cortex, where specific hypotheses have been proposed to account for rapid adaptation. By independently stimulating direction-specific channels, we found that the control of temporal integration of motion at one direction was independent of motion signals driven at the orthogonal direction. We also found that individual neurons can simultaneously support two different profiles of temporal integration for motion in orthogonal directions. These findings rule out a broad range of adaptive mechanisms as being key to the control of temporal integration, including untuned normalization and nonlinearities of spike generation and somatic adaptation in the recorded direction-selective cells. Such mechanisms are too broadly tuned, or occur too far downstream, to explain the channel-specific and multiplexed temporal integration that we observe in single neurons. Instead, we are compelled to conclude that parallel processing pathways are involved, and we demonstrate one such circuit using a computer model. This solution allows processing in different direction/orientation channels to be separately optimized and is sensible given that, under typical motion conditions (e.g., translation or looming), speed on the retina is a function of the orientation of image components. SIGNIFICANCE STATEMENT Many neurons in visual cortex are understood in terms of their spatial and temporal receptive fields. It is now known that the spatiotemporal integration underlying visual responses is not fixed but depends on the visual input. For example, neurons that respond selectively to

  6. Adapting high-level language programs for parallel processing using data flow

    NASA Technical Reports Server (NTRS)

    Standley, Hilda M.

    1988-01-01

    EASY-FLOW, a very high-level data flow language, is introduced for the purpose of adapting programs written in a conventional high-level language to a parallel environment. The level of parallelism provided is of the large-grained variety in which parallel activities take place between subprograms or processes. A program written in EASY-FLOW is a set of subprogram calls as units, structured by iteration, branching, and distribution constructs. A data flow graph may be deduced from an EASY-FLOW program.

  7. Motion adaptive signal integration-high dynamic range (MASI-HDR) video processing for dynamic platforms

    NASA Astrophysics Data System (ADS)

    Piacentino, Michael R.; Berends, David C.; Zhang, David C.; Gudis, Eduardo

    2013-05-01

    Two of the biggest challenges in designing U×V vision systems are properly representing high dynamic range scene content using low dynamic range components and reducing camera motion blur. SRI's MASI-HDR (Motion Adaptive Signal Integration-High Dynamic Range) is a novel technique for generating blur-reduced video using multiple captures for each displayed frame while increasing the effective camera dynamic range by four bits or more. MASI-HDR processing thus provides high performance video from rapidly moving platforms in real-world conditions in low latency real time, enabling even the most demanding applications on air, ground and water.

  8. Effects of Age and Attention on Auditory Global-Local Processing in Children with Autism Spectrum Disorder.

    PubMed

    Foster, Nicholas E V; Ouimet, Tia; Tryfon, Ana; Doyle-Thomas, Krissy; Anagnostou, Evdokia; Hyde, Krista L

    2016-04-01

    In vision, typically-developing (TD) individuals perceive "global" (whole) before "local" (detailed) features, whereas individuals with autism spectrum disorder (ASD) exhibit a local bias. However, auditory global-local distinctions are less clear in ASD, particularly in terms of age and attention effects. To these aims, here ASD and TD children judged local and global pitch structure in nine-tone melodies. Both groups showed a similar global precedence effect, but ASD children were less sensitive to global interference than TD children at younger ages. There was no effect of attention task. These findings provide novel evidence of developmental differences in auditory perception and may help to refine sensory phenotypes in ASD. PMID:26724923

  9. Can emotion modulate attention? Evidence for reciprocal links in the attentional network test.

    PubMed

    Cohen, Noga; Henik, Avishai; Mor, Nilly

    2011-01-01

    Evolution theory suggests that adaptive behavior depends on our ability to give preferential attention to emotional information when it is necessary for our survival, and to down-regulate irrelevant emotional influence. However, empirical work has shown that the interaction between emotion and attention varies, based on the attentional network in question. The aim of the current research was to examine the influence of stimulus emotionality on attention in three attentional networks: alerting, orienting, and executive functions. In two studies, using negative and neutral cues in a modified version of the Attention Network Test, it was found that negative cues impaired task performance in the absence of executive conflict, but not when executive processes were activated. Moreover, it was found that the influence of negative cues on task performance in a given trial was attenuated following activation of executive processes in the previous trial. These results suggest that when executive resources are required, inhibitory mechanisms are recruited to decrease the disruptive effect of emotional stimuli. More importantly, these findings indicate that the effect of emotional stimuli on attention is down-regulated both during cognitive conflict and after the conflict has already ended. PMID:20705545

  10. Workload-Matched Adaptive Automation Support of Air Traffic Controller Information Processing Stages

    NASA Technical Reports Server (NTRS)

    Kaber, David B.; Prinzel, Lawrence J., III; Wright, Melanie C.; Clamann, Michael P.

    2002-01-01

    Adaptive automation (AA) has been explored as a solution to the problems associated with human-automation interaction in supervisory control environments. However, research has focused on the performance effects of dynamic control allocations of early stage sensory and information acquisition functions. The present research compares the effects of AA to the entire range of information processing stages of human operators, such as air traffic controllers. The results provide evidence that the effectiveness of AA is dependent on the stage of task performance (human-machine system information processing) that is flexibly automated. The results suggest that humans are better able to adapt to AA when applied to lower-level sensory and psychomotor functions, such as information acquisition and action implementation, as compared to AA applied to cognitive (analysis and decision-making) tasks. The results also provide support for the use of AA, as compared to completely manual control. These results are discussed in terms of implications for AA design for aviation.

  11. Effect of Margin Design and Processing Steps on Marginal Adaptation of Captek Restorations

    PubMed Central

    Shih, Amy; Flinton, Robert; Vaidyanathan, Jayalakshmi; Vaidyanathan, Tritala

    2011-01-01

    This study examined the effect of four margin designs on marginal adaptation of Captek crowns during selected processing steps. Twenty-four Captek crowns were fabricated, six each of four margin designs: shoulder (Group A), chamfer (Group B), chamfer with bevel (Group C), and shoulder with bevel (Group D). Marginal discrepancies between crowns and matching dies were measured at selected points for each sample at the coping stage (Stage 1), following porcelain application (Stage 2) and cementation (Stage 3). Digital imaging methods were used to measure marginal gap. The results indicate decreasing trend of margin gap as a function of margin design in the order A>B>C>D. Between processing steps, the trend was in the order Stage 3 < Stage 1 < Stage 2. Porcelain firing had no significant effect on marginal adaptation, but cementation decreased the marginal gap. Generally, the margin gap in Captek restorations were in all cases less than the reported acceptable range of margin gaps for ceramometal restorations. These results are clinically favorable outcomes and may be associated with the ductility and burnishability of matrix phase in Captek metal coping margins. PMID:21991488

  12. [Super sweet corn hybrid sh2 adaptability for industrial canning process].

    PubMed

    Ortiz de Bertorelli, Ligia; De Venanzi, Frank; Alfonzo, Braunnier; Camacho, Candelario

    2002-12-01

    The super sweet corns Krispy king, Victor and 324 (sh2 hybrids) were evaluated to determine their adaptabilities to the industrial canning process as whole kernels. All these hybrids and Bonanza (control) were sown in San Joaquín (Carabobo, Venezuela), harvested and canned. After 110 days storage at room temperature they were analyzed to be compared physically, chemically and sensorially with Bonanza hybrid. Results did not show significant differences among most of the physical characteristics, except for percentage of broken kernels which was higher in 324 hybrid. Chemical parameters showed significant differences (P < 0.05) comparing each super sweet hybrid with Bonanza. The super sweet hybrids presented a higher sugar content and soluble solid of the brine than Bonanza, also a lower pH. The super sweet whole kernel presented a lower soluble solids content than Bonanza but they were not significant (Krispy king and 324). Appearance, odor and overall quality were the same for super sweet hybrids and Bonanza (su). Color, flavor and sweetness were better for 324 than all the other hybrids. Super sweet hybrids presented a very good adaptation to the canning process, having as an advantage that doesn't require sugar addition in the brine and a very good texture (firm and crispy). PMID:12868279

  13. A self-adaptive parameter optimization algorithm in a real-time parallel image processing system.

    PubMed

    Li, Ge; Zhang, Xuehe; Zhao, Jie; Zhang, Hongli; Ye, Jianwei; Zhang, Weizhe

    2013-01-01

    Aiming at the stalemate that precision, speed, robustness, and other parameters constrain each other in the parallel processed vision servo system, this paper proposed an adaptive load capacity balance strategy on the servo parameters optimization algorithm (ALBPO) to improve the computing precision and to achieve high detection ratio while not reducing the servo circle. We use load capacity functions (LC) to estimate the load for each processor and then make continuous self-adaptation towards a balanced status based on the fluctuated LC results; meanwhile, we pick up a proper set of target detection and location parameters according to the results of LC. Compared with current load balance algorithm, the algorithm proposed in this paper is proceeded under an unknown informed status about the maximum load and the current load of the processors, which means it has great extensibility. Simulation results showed that the ALBPO algorithm has great merits on load balance performance, realizing the optimization of QoS for each processor, fulfilling the balance requirements of servo circle, precision, and robustness of the parallel processed vision servo system. PMID:24174920

  14. Automatic ultrasonic imaging system with adaptive-learning-network signal-processing techniques

    SciTech Connect

    O'Brien, L.J.; Aravanis, N.A.; Gouge, J.R. Jr.; Mucciardi, A.N.; Lemon, D.K.; Skorpik, J.R.

    1982-04-01

    A conventional pulse-echo imaging system has been modified to operate with a linear ultrasonic array and associated digital electronics to collect data from a series of defects fabricated in aircraft quality steel blocks. A thorough analysis of the defect responses recorded with this modified system has shown that considerable improvements over conventional imaging approaches can be obtained in the crucial areas of defect detection and characterization. A combination of advanced signal processing concepts with the Adaptive Learning Network (ALN) methodology forms the basis for these improvements. Use of established signal processing algorithms such as temporal and spatial beam-forming in concert with a sophisticated detector has provided a reliable defect detection scheme which can be implemented in a microprocessor-based system to operate in an automatic mode.

  15. Adaptive sparse signal processing for discrimination of satellite-based radiofrequency (RF) recordings of lightning events

    NASA Astrophysics Data System (ADS)

    Moody, Daniela I.; Smith, David A.

    2015-05-01

    For over two decades, Los Alamos National Laboratory programs have included an active research effort utilizing satellite observations of terrestrial lightning to learn more about the Earth's RF background. The FORTE satellite provided a rich satellite lightning database, which has been previously used for some event classification, and remains relevant for advancing lightning research. Lightning impulses are dispersed as they travel through the ionosphere, appearing as nonlinear chirps at the receiver on orbit. The data processing challenge arises from the combined complexity of the lightning source model, the propagation medium nonlinearities, and the sensor artifacts. We continue to develop modern event classification capability on the FORTE database using adaptive signal processing combined with compressive sensing techniques. The focus of our work is improved feature extraction using sparse representations in overcomplete analytical dictionaries. We explore two possible techniques for detecting lightning events, and showcase the algorithms on few representative data examples. We present preliminary results of our work and discuss future development.

  16. Combining molecular evolution and environmental genomics to unravel adaptive processes of MHC class IIB diversity in European minnows (Phoxinus phoxinus)

    PubMed Central

    Collin, Helene; Burri, Reto; Comtesse, Fabien; Fumagalli, Luca

    2013-01-01

    Abstract Host–pathogen interactions are a major evolutionary force promoting local adaptation. Genes of the major histocompatibility complex (MHC) represent unique candidates to investigate evolutionary processes driving local adaptation to parasite communities. The present study aimed at identifying the relative roles of neutral and adaptive processes driving the evolution of MHC class IIB (MHCIIB) genes in natural populations of European minnows (Phoxinus phoxinus). To this end, we isolated and genotyped exon 2 of two MHCIIB gene duplicates (DAB1 and DAB3) and 1′665 amplified fragment length polymorphism (AFLP) markers in nine populations, and characterized local bacterial communities by 16S rDNA barcoding using 454 amplicon sequencing. Both MHCIIB loci exhibited signs of historical balancing selection. Whereas genetic differentiation exceeded that of neutral markers at both loci, the populations' genetic diversities were positively correlated with local pathogen diversities only at DAB3. Overall, our results suggest pathogen-mediated local adaptation in European minnows at both MHCIIB loci. While at DAB1 selection appears to favor different alleles among populations, this is only partially the case in DAB3, which appears to be locally adapted to pathogen communities in terms of genetic diversity. These results provide new insights into the importance of host–pathogen interactions in driving local adaptation in the European minnow, and highlight that the importance of adaptive processes driving MHCIIB gene evolution may differ among duplicates within species, presumably as a consequence of alternative selective regimes or different genomic context. Using next-generation sequencing, the present manuscript identifies the relative roles of neutral and adaptive processes driving the evolution of MHC class IIB (MHCIIB) genes in natural populations of a cyprinid fish: the European minnow (Phoxinus phoxinus). We highlight that the relative importance of neutral

  17. Urbanization decreases attentional engagement.

    PubMed

    Linnell, Karina J; Caparos, Serge; de Fockert, Jan W; Davidoff, Jules

    2013-10-01

    Exposure to the urban environment has been shown dramatically to increase the tendency to process contextual information. To further our understanding of this effect of urbanization, we compared performance on a local-selection task of a remote people, the Himba, living traditionally or relocated to town. We showed that (a) spatial attention was defocused in urbanized Himba but focused in traditional Himba (Experiment 1), despite urbanized Himba performing better on a working memory task (Experiment 3); (b) imposing a cognitive load made attention as defocused in traditional as in urbanized Himba (Experiment 2); and (c) using engaging stimuli/tasks made attention as focused in urbanized Himba, and British, as in traditional Himba (Experiments 4 and 5). We propose that urban environments prioritize exploration at the expense of attentional engagement and cognitive control of attentional selection. PMID:23339348

  18. The Process of Adaptation of a Community-Level, Evidence-Based Intervention for HIV-Positive African American Men Who Have Sex with Men in Two Cities

    ERIC Educational Resources Information Center

    Robinson, Beatrice E.; Galbraith, Jennifer S.; Lund, Sharon M.; Hamilton, Autumn R.; Shankle, Michael D.

    2012-01-01

    We describe the process of adapting a community-level, evidence-based behavioral intervention (EBI), Community PROMISE, for HIV-positive African American men who have sex with men (AAMSM). The Centers for Disease Control and Prevention (CDC) Map of the Adaptation Process (MAP) guided the adaptation process for this new target population by two…

  19. Human Topological Task Adapted for Rats: Spatial Information Processes of the Parietal Cortex

    PubMed Central

    Goodrich-Hunsaker, Naomi J.; Howard, Brian P.; Hunsaker, Michael R.; Kesner, Raymond P.

    2008-01-01

    Human research has shown that lesions of the parietal cortex disrupt spatial information processing, specifically topological information. Similar findings have been found in nonhumans. It has been difficult to determine homologies between human and non-human mnemonic mechanisms for spatial information processing because methodologies and neuropathology differ. The first objective of the present study was to adapt a previously established human task for rats. The second objective was to better characterize the role of parietal cortex (PC) and dorsal hippocampus (dHPC) for topological spatial information processing. Rats had to distinguish whether a ball inside a ring or a ball outside a ring was the correct, rewarded object. After rats reached criterion on the task (>95%) they were randomly assigned to a lesion group (control, PC, dHPC). Animals were then re-tested. Post-surgery data show that controls were 94% correct on average, dHPC rats were 89% correct on average, and PC rats were 56% correct on average. The results from the present study suggest that the parietal cortex, but not the dHPC processes topological spatial information. The present data are the first to support comparable topological spatial information processes of the parietal cortex in humans and rats. PMID:18571941

  20. Spectral Doppler estimation utilizing 2-D spatial information and adaptive signal processing.

    PubMed

    Ekroll, Ingvild K; Torp, Hans; Løvstakken, Lasse

    2012-06-01

    The trade-off between temporal and spectral resolution in conventional pulsed wave (PW) Doppler may limit duplex/triplex quality and the depiction of rapid flow events. It is therefore desirable to reduce the required observation window (OW) of the Doppler signal while preserving the frequency resolution. This work investigates how the required observation time can be reduced by adaptive spectral estimation utilizing 2-D spatial information obtained by parallel receive beamforming. Four adaptive estimation techniques were investigated, the power spectral Capon (PSC) method, the amplitude and phase estimation (APES) technique, multiple signal classification (MUSIC), and a projection-based version of the Capon technique. By averaging radially and laterally, the required covariance matrix could successfully be estimated without temporal averaging. Useful PW spectra of high resolution and contrast could be generated from ensembles corresponding to those used in color flow imaging (CFI; OW = 10). For a given OW, the frequency resolution could be increased compared with the Welch approach, in cases in which the transit time was higher or comparable to the observation time. In such cases, using short or long pulses with unfocused or focused transmit, an increase in temporal resolution of up to 4 to 6 times could be obtained in in vivo examples. It was further shown that by using adaptive signal processing, velocity spectra may be generated without high-pass filtering the Doppler signal. With the proposed approach, spectra retrospectively calculated from CFI may become useful for unfocused as well as focused imaging. This application may provide new clinical information by inspection of velocity spectra simultaneously from several spatial locations. PMID:22711413