A recurrent issue of the imaging industry is to be able to con- trol the visual quality of their products. The only way to cope with this problem is to have an accurate quality met- ric. It must be an automatic metric which provides computed quality scores well correlated with the ones given by human observers. Image quality assessment has been extensively studied these past few decades. The most efficient metrics are based on the HVS    . One of the most impor- tant components is called the visual attention. It is divided into the top-down and the bottom-up processes. The bottom- up process is guided by the low-level features of the viewed stimuli, and the top-down process is guided by high level cognitive factors .
and left cerebellum were not explained by the severity of the disease, reinforcing the role of these regions inde- pendently of the progression of the disease.
By comparing our group of DLB patients to healthy controls, we were able to confirm the existence of atten- tional deficits, even at the early stage of the disease, which is consistent with the literature [ 4 , 6 , 45 ]. Indeed, the majority of the patients included in the present study were at the prodromal or mild stages of the disease (only 6 out of the 93 patients were at the moderate stage at the time of the evaluations). The 2 tasks we used have in common that they measure the speed of processing as they require a series of operations to be performed under time pressure, and they both involve visual analysis, fo- cused attention, response selection, and motor execution, yet each task has its own specificity. The DSST is a widely used, standardized psychometric test that also targets the maintenance of stimulus-response associations, and has high re-test reliability [ 42 , 46 ]. Hence, this measure in- volves more operations than the TMTA, which might ex- plain, based on the variability of patterns of atrophy in DLB patients, why correlations between DSST scores and the degree of atrophy are less specific of one particular brain region. Conversely, the TMTA requires more basic processes involving the correct sequencing of simple ele- ments. The present results are in accordance with the lit- erature suggesting that this measure constitutes a key discriminator between DLB and AD [ 11 ].
attentional resources on stimuli with a valence, compared to neutral ones. In “healthy”
people, the use of this strategy is adapted since individuals will direct their attention over a
longer period of time and more frequently towards positive cues from their environment (i.e.
positive bias; e.g. Armstrong & Olatunji, 2012). This bias has been highlighted in a fairly
Our everyday work is becoming increasingly complex and cognitively demanding. What we pay attentionto during our day influences how effectively our brain prepares itself for action, and how much effort we apply to a task. To address this issue we present AttentivU - a system that uses wearable electroencephalography (EEG) to measure theattention of a person in real- time. When the user’s attention level is low, the system provides real-time, subtle, haptic or audio feedback to nudge the person to become attentive again. We tested a first version of the system, which uses an EEG headband on 48 adults over several sessions in both a lab and classroom setting. The results show that the biofeedback redirects theattention of the participants tothetask at hand and improves their performance on comprehension tests. We next tested the same approach in the form of glasses on 6 adults in a lab setting, as the glasses form factor may be more acceptable in the long run. We conclude with a discussion of an improved third version of AttentivU, currently under development, which combines a custom-made solution of the glasses form-factor with built-in electrooculography (EOG) and EEG electrodes as well as auditory feedback.
Christina Schmidt, 1 Philippe Peigneux, 1,2 * Pierre Maquet, 1 Christophe Phillips 1,3 Astafiev et al. question whether the blood oxygen level–dependent (BOLD) response that we reported in the brainstem was located in the locus coeruleus (LC). Using high-resolution T1-turbo spin echo images (T1-TSE) acquired in an independent group of subjects, we show that the reported task-related BOLD response in the brainstem is actually compatible with the anatomical location of the LC.
For Peer Review Only
Over the last few decades, a number of studies showed how performance measures are affected by sleep drive (homeostatic influence) and circadian phase. The demonstration of an interaction of circadian phase and time awake in the regulation of performance came from laboratory studies under controlled conditions and/or manipulation of the sleep/wake cycle (for a review, Akerstedt, 2007). Several theoretical models conceptualized this interaction by proposing an optimal position and duration for sleep, with any deviation impairing performance and alertness (Folkard & Akerstedt, 1992; Achermann & Borbély, 1994; Van Dongen, Maislin, Mullington, & Dinges, 2003). Systematic performance measures in relation to different simulated shift systems further confirmed a sharp performance drop in the early morning hours (Colquhoun, 1969). This was observed in most tasks that require sustained attention, such as reaction time performance or throughput in cognitive tasks (Fröberg, 1975; Colquhoun, 1968; Johnson, 1992). At the same time, physiological, and subjective arousal were reported to strongly decrease (Akerstedt & Gillberg, 1990). A simulation study revealed that at high fatigue levels errors involving a failure to act (errors of omission) were increased, whereas incorrect responses (errors of commission) were decreased in a simulated train driving task (Dorrian, Roach, Fletcher, & Dawson, 2007). The differential effect of fatigue on error type was explained by a cognitive disengagement with the virtual train, which increased accident risk. In real shift-work settings, the findings of higher occurrences of risk and accidents on night- compared to day-duty, further stressed the potential consequences of
But how exactly do top-down signals from frontal cortex influence visual cortex? First, it may act via a cascade down the visual cortical hierarchy instead of being “broadcast” simultaneously to multiple visual cortical areas. Just as volitional shifts of attention appear with a shorter latency in frontal cortex than in LIP , they are seen in LIP before visual cortical area MT . Similar effects are seen in the ventral visual stream: attentionto a visual stimulus first enhances the response of V4 neurons, then V2 neurons, and, finally, V1 neurons . This cascade presumably allows the top-down signals to selectively enhance the level of stimulus representation (cortical hierarchy level) appropriate for thetask at hand. Second, top-down signals seem to be excitatory in nature. Inputs from the FEF make excitatory synapses on pyramidal neurons in prefrontal, parietal and visual cortex, suggesting that top-down signals boost the activity corresponding to attended stimuli , perhaps after their amplification via local recurrent connections. Then, the suppression of unattended stimuli can occur via local lateral inhibitory interactions, perhaps via center- surround antagonism (see above; Figure 2).
2.5 Design and Hypotheses
The experiment covers different configurations of virtual attractors. In this study, we are considering the Stimuli (Baseline, Auditory, Visual and Auditory), the Position of the stimuli (inside/outside the CAVE) and the Relationship between the stimuli and the user (fixed position, or following the user). For practical reasons, we con- strained the number of levels for the Relationship factor. We only considered two fixed attractors (Goose and Crow) and two mov- ing attractors (Mosquito and Snake). Figure 2 depicts the position of the attractors with respect the user and the CAVE, note that the position is symmetrical with respect tothe path. Furthermore, as environmental factors (physical environment) or user factors (eye dominance, handedness) can influence the user behavior when per- forming thetask, we considered the Direction of the walk as an additional factor with two levels: Left to Right (L2R) and Right to Left (R2L).
Similar to ERPs, researchers can compute event-related spectral perturbation (ERSP) analyses that are time-locked to stimulus presentation. These analyses measure the average oscillatory amplitude induced by the presentation of stimuli relative to a prestimulus period (Makeig, 1993), enabling studies of spectral dynamics (i.e., how oscillatory amplitude changes over time). Spectral amplitude variations (increase/decrease) are thought to reflect changes in the activity of large assemblies of neurons in response to a stimulus or to other events of interest. Event-related synchronization (ERS) occurs when the amplitude of a given frequency increases with stimulus presentation, while event-related desynchronization (ERD) reflects a reduction of amplitude in response to a stimulus (Pfurtscheller & Lopes da Silva, 1999). According to some researchers, a large increase in alpha amplitude reflects a state of inhibition or cortical deactivation, whereas a decrease in power reflects a state of comparatively high neuronal excitability (Klimesch, 2012; Pfurtscheller, 2003). A decrease in alpha power is characteristically observed in the occipital regions when subjects process visual inputs or when they respond to internal events like mental activation or cognitive effort (Pfurtscheller & Lopes da Silva, 1999). Alpha power is also known to decrease as a function of attentional demands and generally spreads over the entire scalp, argued to reflect the gradual release of inhibition associated with the activation of attentional networks during information processing (Klimesch, Sauseng, & Hanslmayr, 2007).
Moreover, in the present study, the self-face did not elicit reliable distraction effect when it was presented outside the focus of attention. This result is consistent with Gronau et al.’s (2003) study reporting that the participant’s own name did not produce any distraction when presented outside the focus of attention and irrelevantly tothe ongoing task. Nonetheless, our data indicated that participants temporarily shifted their attention towards peripheral faces once they mastered the digit-parity task. Importantly, the observation that the capacity of the familiar faces to provoke a distraction was dependent upon their location within the focus of attention indicates that this distraction is not due to an automatic capture of attention (see also Bundesen et al., 1999). Indeed, in Experiment 1 the central location of the faces between the two target digits forced participants to attend tothe distractor faces (despite of the instruction) in order to perceive the two digits. By contrast, in Experiment 2, there was no need to attend tothe distractor faces presented at periphery in order to process the target digits. Our results indicate that in this case participants successfully followed the instruction to ignore the faces in the first part of the experiment since the presentation of the familiar faces did not affect reaction times. In the second part of the experiment however, they apparently temporarily shifted their attention towards peripheral faces. Rather, present findings suggest that familiar faces hold attention and elicit a transient difficulty to disengage attention only once they are attended 1 , as in Experiment 1 and in the second part of Experiment 2 (see Fox, Russo, Bowles, & Dutton, 2001, for similar findings with threatening words; see also Weierich, Treat, & Hollingworth, in press, for a recent review on the distinction between capture and retention of attention in anxiety). This hypothesis should be addressed more precisely and with paradigms allowing a clear distinction between these two components of capture and retention of attention in future work. Note that the digit-parity task we used is a quite demanding task. Harris and Pashler (2004)’s study showed that theattention grabbing capacity of one’s own name depended on the amount of available resources. It is possible that a less demanding task would have allowed more substantial shifts of attention towards the peripheral distractor faces. This should also be addressed in future work.
Introduction: Driving is a complex and dynamic task that requires performing simultaneously
several sub-tasks, as traffic management and vehicle control. Driving involves both automatic and controlled processing depending on situation met and drivers’ experience. Method: Three groups of drivers with different driving experience were submitted to a divided-attentiontask in order to assess the interference linked to a secondary task on driving behaviour. The main task was a car- following task and the secondary task was a number identification task which could appear on central or peripheral vision. Results and discussion: Results showed that driving performances increase with experience. Indeed, novice drivers, compared to more experienced drivers, took more time to brake and had more difficulties to maintain a stable position in the lane. This task allowed to differentiate driving behaviour depending on experience and could be used in training of novice drivers.
Response Times (ms) Correct response rate (%)
We adapted a task used by the group of Majerus et al. (2012) in young people to an elderly population. 26 Trials are presented in each memory load condition (2 and 5) with and without distractor stimulus (DS) during maintenance.
IFSC USP (3 runs)  Mainly focused on automatic shape boundary anal- ysis, these participants adapted their approach according the image content and obtained the best results for the Photograph with a semi-automatic approach. Full-automatic approaches were used for Scan and Scan-like, but also on Pho- tograph for one run. They started by an automatic leaf contour extraction with Otsu’s method on Scan and Scan-like, while they used a k-means clustering al- gorithm in the RGB colorspace for Photograph. The semi-automatic approach on Photograph needs that a user marks leaf and background on regions auto- matically detected by a Mean Shift algorithm. Then, a merging process labelled gradually all content of the picture with these 2 parts. Contour were described with complex network, volumetric fractal dimension [?] and geometric param- eters. Gabor filters, and local binary patterns were used too. They included for each run the GPS information. Classification was performed by using Linear Discriminant Analysis. The first run used all samples from the 3 images cate- gories for the training stage, which paid off comparing tothe second run where only Scan and Scan-like were used. Only Gabor and GPS features were used for the automatic run on Photograph because contour extraction were sufficiently reliable.
In Living in the Maniototo, the continuum that ranges from creative to "sterile" writing includes the tendencies of "attending" tothe world and searching for truths as opposed to "avoiding", turning away from the "original" to hide in a world of replicas. Although this pattern largely resembles that of the novels mentioned above, it acquires here a more problematic form, since the entire artistic spectrum is embraced by a ubiquitous narrator with an apparently three-facetted personality: the writer, Mavis, whose book, The Green Fuse, an insider's account of "life in a mental hospital" (217), seemingly endows her with the role of the true artist; Violet Pansy Proudlock, the ventriloquist "on the margin of creation and recreation" who "hope[s] to progress from stick to pocket head to person, real person" (13) and thus use her talent for impersonation to create replicas that might one day approach the "real thing"; and finally, Alice Thumb, the "eavesdropp[er] and gossip" (13) who, by definition, disseminates a superficial and distorted account of reality. These three personae are initially fused, as the narrator refers to them in the first person (see prologue 11-14). In the course of the novel, however, occasional shifts tothe third person demonstrate that the autonomy of these different characters is subject to fluctuation (see, for example, 22). The narrator's multifarious personalities certainly serve to reject any sense of a monolithic identity in favour of a fluid, forever shifting alternative. The latter's variable nature is also rendered by the lack of differentiation between the intertwined facets, as suggested in one of the epigraphs, attributed to "Alice Thumb or Violet Pansy Proudlock or Mavis Halleton":
map a route that is pre-printed on the Instruction Giver’s version.
Participants may say anything necessary to accomplish their commu- nicative goals.
Remote condition: Participants cannot see each other. Face-to-face condition: Participants can see each other.
Fig. 1. Switched reluctance motor structure and field distribution. A common method used to simulate the SRM, here named indirect approach, is to predict the flux linkages with a phase as a function of angle and current, neglecting coupling between phases. Circuit equations, which incoIDOrate a model of the converter, are then used to calculate the phase current as a function of time, assuming constant speed. Torque can be derived from the rate of change of co-energy , . Another indirect approach is based on the use of nonlinear magnetic field solutions and statc space models, including the speed equation .
Attention- Concentration- Free Throw- Player Midlle Class- Diferent Type of Attention-Basket Ball
attention a vital dimensions affecting performance in the sports field where theattention of the individual at a given moment is not usually found only in a particular topic, but theattention does not stop and I was traveling on an ongoing basis and speed peek through fractions of a second, and understands theattention as a "ready Perceptual year directs the individual feeling about a certain whole attitude or part" .uallah theattention Mental process plays an important role in human life for his contribution to recognize and adapt tothe environment and its connection with the permanence( PERRAUT-PIERRE,E,2000.la gestionmentale du stress pour la performance sportive).ED,Amphora,France.
Abstract— In this paper, we apply the synchronous approach
to real time active visual 3D reconstruction using a camera mounted on a robot end-effector. It illustrates the adequate- ness of Signal, a synchronous data flow programming language and environment, for the specification of a system dealing with various domains in control theory and computer vision. More precisely, our application consists in the 3D structure estima- tion of a set of geometrical primitives using an active vision paradigm. At the level of camera motion control, the visual servoing approach is specified and implemented in Signal as a function from sensor inputs to control outputs. Furthermore, the 3D structure estimation method is based on the “structure from controlled motion” approach (constraining camera motion for optimal estimation). Its specification is made in parallel to visual servoing, and involves the delay mechanism of Signal for the specification of filters. This reconstruction involves to be fo- cused on each object; we thus present a perception strategy for sequencing several estimations, using task preemption and time intervals in Signal. It allows to consider in an unified frame- work the various aspects of the application: from data-flow task specification to multi-tasking and hierarchical task preemption. The integration of these techniques is validated experimentally by their implementation on a robotic cell. Merits and draw- backs of the proposed framework with respect to more usual asynchronous approaches are finally discussed.