Attentional Enhancement Opposite a Peripheral Flash Revealed Using Change Blindness

2003 ◽  
Vol 14 (2) ◽  
pp. 91-99 ◽  
Author(s):  
P.U. Tse ◽  
D.L. Sheinberg ◽  
N.K. Logothetis

We describe a new method for mapping spatial attention that reveals a pooling of attention in the hemifield opposite a peripheral flash. Our method exploits the fact that a brief full-field blank can interfere with the detection of changes in a scene that occur during the blank. Attending to the location of a change, however, can overcome this change blindness, so that changes are detected. The likelihood of detecting a new element in a scene therefore provides a measure of the occurrence of attention at that element's location. Using this measure, we mapped how attention changes in response to a task-irrelevant peripheral cue. Under conditions of visual fixation, change detection was above chance across the entire visual area tested. In addition, a “hot spot” of attention (corresponding to near-perfect change detection) elongated along the cue-fixation axis, such that performance improved not only at the cued location but also in the opposite hemifield.

Author(s):  
Dany Gatsinzi ◽  
Francisco J Saez Nieto ◽  
Irfan Madani

This paper discusses a possibility to evolve the current Air Traffic Flow and Capacity Management towards a more proactive approach. This new method focuses on reducing the expected probability of air traffic control intervention based on “hot spot” identification and mitigation at strategic level by applying subliminal changes on the times of arrival at the crossing or merging points (junctions). The concept is fully aligned with the trajectory-based operation principles. The approach assumes that the changes on the times of arrival only demand small speed changes from the involved aircraft. In this study, the hot spots are defined as clusters of aircraft expected to arrive to the junctions. Two aircraft are said to be in the same cluster if their proximity and closure rate are below a given threshold. Some exercises are proposed and solved by applying this method. The obtained results show its ability to remove the potential conflicts by applying simple linear programming. This approach seeks to change the current capacity limiting factor, established by the number of aircraft occupying simultaneously each sector, to another parameter where the level of traffic complexity, flowing towards junctions, is identified and mitigated at strategic level. The speed changes, used as the control variable and computed before or during the flight, are designed to provide an adjustment on aircraft’s required time of arrival at the junctions in order to have a de-randomised and well-behaved (conflict free) traffic. This will enable improvements in airspace capacity/ safety binomial. It is recognised that this measure alone is unable to produce a conflict free airspace, and then other collaborative and coordinated actions, such as adjusting and swapping departing times at the departing airports (before the aircraft are taking off), offsetting some flights from nominal route, and allowing multi-agent separation management (while they are in flight) should be applied together with this method.


2021 ◽  
Vol 11 ◽  
Author(s):  
Wang Xiang

To investigate whether implicit detection occurs uniformly during change blindness with single or combination feature stimuli, and whether implicit detection is affected by exposure duration and delay, two one-shot change detection experiments are designed. The implicit detection effect is measured by comparing the reaction times (RTs) of baseline trials, in which stimulus exhibits no change and participants report “same,” and change blindness trials, in which the stimulus exhibits a change but participants report “same.” If the RTs of blindness trials are longer than those of baseline trials, implicit detection has occurred. The strength of the implicit detection effect was measured by the difference in RTs between the baseline and change blindness trials, where the larger the difference, the stronger the implicit detection effect. In both Experiments 1 and 2, the results showed that the RTs of change blindness trials were significantly longer than those of baseline trials. Whether under set size 4, 6, or 8, the RTs of the change blindness trials were significantly longer than those in the baseline trials. In Experiment 1, the difference between the baseline trials’ RTs and change blindness trials’ RTs of the single features was significantly larger than that of the combination features. However, in Experiment 2, the difference between the baseline trials’ RTs and the change blindness trials’ RTs of single features was significantly smaller than that of the combination features. In Experiment 1a, when the exposure duration was shorter, the difference between the baseline and change blindness trials’ RTs was smaller. In Experiment 2, when the delay was longer, the difference between the two trials’ RTs was larger. These results suggest that regardless of whether the change occurs in a single or a combination of features and whether there is a long exposure duration or delay, implicit detection occurs uniformly during the change blindness period. Moreover, longer exposure durations and delays strengthen the implicit detection effect. Set sizes had no significant impact on implicit detection.


2012 ◽  
Vol 25 (0) ◽  
pp. 90
Author(s):  
Serena Mastroberardino ◽  
Valerio Santangelo ◽  
Emiliano Macaluso

The presentation of an auditory stimulus semantically-congruent with a visual element of a multi-objects display can enhance processing of that element. Here we used multisensory objects (MO) as non-informative cues in a spatial cueing paradigm, aiming to directly assess the interplay between MO integration and spatial attention. We presented two pictures (e.g., left — dog, right — cat) plus a central sound (e.g., a dog’s bark) that defined the location of the MO (left, in this example). This was followed by a target (a Gabor patch) either at the MO location or in the opposite hemifield. Subjects discriminated the orientation of the Gabor, while ignoring all task-irrelevant pictures and sounds. Further, we manipulated the task requirements including ‘easy’ or ‘difficult’ discrimination (Gabor tilt = ±5° or ±10°), and by presenting either a single unilateral Gabor (Exp. 1, ‘low’ competition) or two Gabors bilaterally (red and blue, with the target now defined by colour; Exp. 2, ‘high’ competition). Functional imaging data revealed activation of frontal regions when the target was presented on the opposite side of the MO (invalid trials). The frontal eye-fields activated irrespective of task requirements, while the inferior frontal gyrus activated only when the MO-cue was invalid and competition was low (Exp. 1 only). These findings show that MOs automatically affect the distribution of spatial attention, and that re-orienting operations on invalid trials activate dorsal and ventral frontal areas depending on top-down task constraints. Overall, the results are consistent with the hypothesis linking the integration of multisensory objects with biases of spatial attention.


2009 ◽  
Vol 21 (12) ◽  
pp. 2384-2397 ◽  
Author(s):  
Valerio Santangelo ◽  
Marta Olivetti Belardinelli ◽  
Charles Spence ◽  
Emiliano Macaluso

In everyday life, the allocation of spatial attention typically entails the interplay between voluntary (endogenous) and stimulus-driven (exogenous) attention. Furthermore, stimuli in different sensory modalities can jointly influence the direction of spatial attention, due to the existence of cross-sensory links in attentional control. Using fMRI, we examined the physiological basis of these interactions. We induced exogenous shifts of auditory spatial attention while participants engaged in an endogenous visuospatial cueing task. Participants discriminated visual targets in the left or right hemifield. A central visual cue preceded the visual targets, predicting the target location on 75% of the trials (endogenous visual attention). In the interval between the endogenous cue and the visual target, task-irrelevant nonpredictive auditory stimuli were briefly presented either in the left or right hemifield (exogenous auditory attention). Consistent with previous unisensory visual studies, activation of the ventral fronto-parietal attentional network was observed when the visual targets were presented at the uncued side (endogenous invalid trials, requiring visuospatial reorienting), as compared with validly cued targets. Critically, we found that the side of the task-irrelevant auditory stimulus modulated these activations, reducing spatial reorienting effects when the auditory stimulus was presented on the same side as the upcoming (invalid) visual target. These results demonstrate that multisensory mechanisms of attentional control can integrate endogenous and exogenous spatial information, jointly determining attentional orienting toward the most relevant spatial location.


2006 ◽  
Vol 16 (20) ◽  
pp. 2066-2072 ◽  
Author(s):  
Leila Reddy ◽  
Rodrigo Quian Quiroga ◽  
Patrick Wilken ◽  
Christof Koch ◽  
Itzhak Fried

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