scholarly journals Spatially guided distractor suppression during visual search

2020 ◽  
Author(s):  
Tobias Feldmann-Wüstefeld ◽  
Marina Weinberger ◽  
Edward Awh
Keyword(s):  
Multivariate Analyses ◽  
Target Selection ◽  
Basic Question ◽  
Spatial Gradient ◽  
Selection Effects ◽  
Theta Band ◽  
Neural Signals ◽  
Past Work ◽  
Visual Encoding ◽  
Selection Of

AbstractPast work has demonstrated that active suppression of salient distractors is a critical part of visual selection. Evidence for goal-driven suppression includes below-baseline visual encoding at the position of salient distractors (Gaspelin and Luck, 2015) and neural signals such as the Pd that track the position and number of distractors in the visual field (Feldmann-Wustefeld and Vogel, 2019). One basic question regarding distractor suppression is whether it is inherently spatial or nonspatial in character. Indeed, past work has shown that distractors evoke both spatial (Theeuwes, 1992) and nonspatial forms of interference (Folk and Remington, 1998), motivating a direct examination of whether space is integral to goal-driven distractor suppression. Here, we provide clear evidence for a spatial gradient of suppression surrounding salient singleton distractors. Replicating past work, both reaction time and neural indices of target selection improved monotonically as the distance between target and distractor increased. Importantly, these target selection effects were paralleled by a monotonic decline in the amplitude of the Pd, an electrophysiological index of distractor suppression. Moreover, multivariate analyses revealed spatially selective activity in the theta band that tracked the position of the target and – critically – revealed suppressed activity at spatial channels centered on distractor positions. Thus, goal-driven selection of relevant over irrelevant information benefits from a spatial gradient of suppression surrounding salient distractors.

A Target Selection Algorithm of Seeker Based on the Prior Information and SVM

2013 ◽  
Vol 734-737 ◽  
pp. 3071-3074
Author(s):  
Guo Dong Zhang ◽  
Zhong Liu
Keyword(s):  
Prior Information ◽  
Simulation Experiment ◽  
Target Selection ◽  
Support Vector ◽  
Selection Algorithm ◽  
Distribution Law ◽  
Surface Ship ◽  
False Target ◽  
Target Characteristics ◽  
Selection Of

Aiming at the phenomenon that the chaff and corner reflector released by surface ship can influence the selection of missile seeker, this paper proposed a multi-target selection method based on the prior information of false targets distribution and Support Vector Machine (SVM). By analyzing the false targets distribution law we obtain two classification principles, which are used to train the SVM studies the true and false target characteristics. The trained SVM is applied to the seeker in the target selection. This method has advantages of simple programming and high classification accuracy, and the simulation experiment in this paper confirms the correctness and effectiveness of this method.

Electrophysiological Correlates of Similarity-based Interference during Detection of Visual Forms

2006 ◽  
Vol 18 (6) ◽  
pp. 880-888 ◽  
Author(s):  
Markus Conci ◽  
Klaus Gramann ◽  
Hermann J. Müller ◽  
Mark A. Elliott
Keyword(s):  
Target Selection ◽  
Event Related Potentials ◽  
Form Perception ◽  
Psychological Review ◽  
Physiological Basis ◽  
Related Potentials ◽  
Kanizsa Figure ◽  
Global And Local ◽  
Selection Of ◽  
Form Information

Illusory figure completion demonstrates the ability of the visual system to integrate information across gaps. Mechanisms that underlie figural emergence support the interpolation of contours and the filling-in of form information [Grossberg, S., & Mingolla, E. Neural dynamics of form perception: Boundary completion, illusory figures and neon colour spreading. Psychological Review, 92, 173–211, 1985]. Although both processes contribute to figure formation, visual search for an illusory target configuration has been shown to be susceptible to interfering form, but not contour, information [Conci, M., Müller, H. J., & Elliott, M. A. The contrasting impact of global and local object attributes on Kanizsa figure detection. Submitted]. Here, the physiological basis of form interference was investigated by recording event-related potentials elicited from contour- and surface-based distracter interactions with detection of a target Kanizsa figure. The results replicated the finding of form interference and revealed selection of the target and successful suppression of the irrelevant distracter to be reflected by amplitude differences in the N2pc component (240–340 msec). In conclusion, the observed component variations reflect processes of target selection on the basis of integrated form information resulting from figural completion processes.

LINGUOCULTURAL POTENTIAL OF EUPHEMISMS-AMULETS

2021 ◽  
pp. 68-74
Author(s):  
SERGEY I. ROMANOV ◽  
Keyword(s):  
Target Selection ◽  
Cultural Factors ◽  
Point Of View ◽  
Negative Consequences ◽  
Cultural Community ◽  
Magical Power ◽  
Selection For ◽  
Cultural Code ◽  
Russian Linguistic ◽  
Selection Of

The article deals with a special type of euphemisms-amulets, that is, linguocultural units endowed with the function of protection. There are two types of euphemisms-amulets from the point of view of relevance: obsolete and current units. Obsolete euphemisms- amulets have targets that are not recognized as dangerous by the modern linguistic and cultural community. Current euphemisms-amulets, although not always consciously, are used by representatives of the modern Russian linguistic and cultural community to protect against something bad. The paper establishes that the use of the euphemism-amulet is based on the transla- tion of the target's representation into another cultural code. The work reveals that the euphemisms-amulets are directed not to mitigate an unwanted nomination but how to replace it. An undesirable nomination is endowed with negative magical properties, which is why the linguocultural community imposes a ban on its use. A protective cultural function is superim- posed on the euphemism. The main pragmatic explanation for the use of the euphemism- amulet is the speaker's desire not to predict an encounter with an unwanted object, which is based on belief in the magical power of the word. The factors that determine the linguocultural specificity of euphemisms-amulets are revealed. The first factor is target selection. For the Russian linguocultural community, such targets include a totemic animal, evil forces representing another world, death. The second factor is the selection of nominations for the euphemistic function, which is determined by culturally marked background knowledge, ideas, and typical practices. The communicative- pragmatic platform for the use of euphemisms-amulets is the belief in the magical power of the word, in the fact that the use of the forbidden word can lead to negative consequences (in particular, to cause the appearance of something dangerous, undesirable). The work proves that the identified cultural factors are universal, based on universal archetypes: one's own / another's, permission / prohibition, life / death. At the same time, the fact of the appearance of the euphemism-amulet, the choice of its internal form is determined by national and cultural factors.

Military Targeting in the Context of Self-Defence Actions

2015 ◽  
Vol 84 (1) ◽  
pp. 3-28 ◽  
Author(s):  
James A. Green ◽  
Christopher P.M. Waters
Keyword(s):  
Target Selection ◽  
Jus In Bello ◽  
Customary International Law ◽  
Jus Ad Bellum ◽  
Conceptual Clarity ◽  
Starting Point ◽  
Definition Of ◽  
The Relationship ◽  
Self Defence ◽  
Selection Of

For self-defence actions to be lawful, they must be directed at military targets. The absolute prohibition on non-military targeting under the jus in bello is well known, but the jus ad bellum also limits the target selection of states conducting defensive operations. Restrictions on targeting form a key aspect of the customary international law criteria of necessity and proportionality. In most situations, the jus in bello will be the starting point for the definition of a military targeting rule. Yet it has been argued that there may be circumstances when the jus ad bellum and the jus in bello do not temporally or substantively overlap in situations of self-defence. In order to address any possible gaps in civilian protection, and to bring conceptual clarity to one particular dimension of the relationship between the two regimes, this article explores the independent sources of a military targeting rule. The aim is not to displace the jus in bello as the ‘lead’ regime on how targeting decisions must be made, or to undermine the traditional separation between the two ‘war law’ regimes. Rather, conceptual light is shed on a sometimes assumed but generally neglected dimension of the jus ad bellum’s necessity and proportionality criteria that may, in limited circumstances, have significance for our understanding of human protection during war.

scholarly journals Multivariate EEG analyses support high-resolution tracking of feature-based attentional selection

2016 ◽  
Author(s):  
Johannes Jacobus Fahrenfort ◽  
Anna Grubert ◽  
Christian N. L. Olivers ◽  
Martin Eimer
Keyword(s):  
Visual Field ◽  
Multivariate Analyses ◽  
Target Selection ◽  
Target Position ◽  
Attentional Selection ◽  
Forward Model ◽  
Hemispheric Differences ◽  
Neural Basis ◽  
Eeg Data ◽  
Feature Based

AbstractThe primary electrophysiological marker of feature-based selection is the N2pc, a lateralized posterior negativity emerging around 180-200 ms. As it relies on hemispheric differences, its ability to discriminate the locus of focal attention is severely limited. Here we demonstrate that multivariate analyses of raw EEG data provide a much more fine-grained spatial profile of feature-based target selection. When training a pattern classifier to determine target position from EEG, we were able to decode target positions on the vertical midline, which cannot be achieved using standard N2pc methodology. Next, we used a forward encoding model to construct a channel tuning function that describes the continuous relationship between target position and multivariate EEG in an eight-position display. This model can spatially discriminate individual target positions in these displays and is fully invertible, enabling us to construct hypothetical topographic activation maps for target positions that were never used. When tested against the real pattern of neural activity obtained from a different group of subjects, the constructed maps from the forward model turned out statistically indistinguishable, thus providing independent validation of our model. Our findings demonstrate the power of multivariate EEG analysis to track feature-based target selection with high spatial and temporal precision.Significance StatementFeature-based attentional selection enables observers to find objects in their visual field. The spatiotemporal profile of this process is difficult to assess with standard electrophysiological methods, which rely on activity differences between cerebral hemispheres. We demonstrate that multivariate analyses of EEG data can track target selection across the visual field with high temporal and spatial resolution. Using a forward model, we were able to capture the continuous relationship between target position and EEG measurements, allowing us to reconstruct the distribution of cortical activity for target locations that were never shown during the experiment. Our findings demonstrate the existence of a temporally and spatially precise EEG signal that can be used to study the neural basis of feature-based attentional selection.

Computer Control by Gaze

2012 ◽  
pp. 78-102 ◽  
Author(s):  
Henrik Skovsgaard ◽  
Kari-Jouko Räihä ◽  
Martin Tall
Keyword(s):  
Eye Gaze ◽  
Computer Control ◽  
Target Selection ◽  
Specific Area ◽  
Head Movements ◽  
Interaction Techniques ◽  
Information Spaces ◽  
Speed Up ◽  
Small Targets ◽  
Selection Of

This chapter provides an overview of gaze-based interaction techniques. We will first explore specific techniques intended to make target selection easier and to avoid the Midas touch problem. We will then take a look at techniques that do not require the use of special widgets in the interface but instead manipulate the rendering on the basis of eye gaze to facilitate the selection of small targets. Dwell-based interaction makes use of fixations; recent research has looked into the other option, using saccades as the basis for eye gestures. We will also discuss examples of how eye gaze has been used with other input modalities (blinks and winks, keyboard and mouse, facial gestures, head movements, and speech) to speed up interaction. Finally, we will discuss examples of interaction techniques in the context of a specific area of application: navigating information spaces.

Coordination of Smooth Pursuit and Saccade Target Selection in Monkeys

2007 ◽  
Vol 98 (4) ◽  
pp. 2206-2214 ◽  
Author(s):  
Gilbert R. Case ◽  
Vincent P. Ferrera
Keyword(s):  
Smooth Pursuit ◽  
Target Selection ◽  
Saccade Target ◽  
Target Color ◽  
Smooth Pursuit Eye Movements ◽  
Moving Targets ◽  
Neural Signals ◽  
Pursuit Eye Movements ◽  
Selection For ◽  
Selection Signal

The coordination of saccadic and smooth pursuit eye movements in macaque monkeys was investigated using a target selection paradigm with two moving targets crossing at a center fixation point. A task in which monkeys selected a target based on its color was used to test the hypothesis that common neural signals underlie target selection for pursuit and saccades, as well as testing whether target selection signals are available to the saccade and pursuit systems simultaneously or sequentially. Several combinations of target color, speed, and direction were used. In all cases, smooth pursuit was highly selective for the rewarded target before any saccade occurred. On >80% of the trials, the saccade was directed toward the same target as both pre- and postsaccadic pursuit. The results favor a model in which a shared target selection signal is simultaneously available to both the saccade and pursuit systems, rather than a sequential model.

A Method for Prediction of Accessible Sites on an mRNA Sequence for Target Selection of Hammerhead Ribozymes

2002 ◽  
Vol 9 (4) ◽  
pp. 641-653 ◽  
Author(s):  
Alberto Mercatanti ◽  
Giuseppe Rainaldi ◽  
Laura Mariani ◽  
Roberto Marangoni ◽  
Lorenzo Citti
Keyword(s):  
Target Selection ◽  
Mrna Sequence ◽  
Hammerhead Ribozymes ◽  
Selection Of

scholarly journals Mutanome Engineered RNA Immunotherapy: Towards Patient-Centered Tumor Vaccination

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Mathias Vormehr ◽  
Barbara Schrörs ◽  
Sebastian Boegel ◽  
Martin Löwer ◽  
Özlem Türeci ◽  
...  
Keyword(s):  
Target Selection ◽  
Efficient Production ◽  
Patient Centered ◽  
Sequencing Technologies ◽  
Cost Efficient ◽  
Potent Drug ◽  
Personalized Cancer ◽  
The Cost ◽  
Synthetic Mrna ◽  
Selection Of

Advances in nucleic acid sequencing technologies have revolutionized the field of genomics, allowing the efficient targeting of mutated neoantigens for personalized cancer vaccination. Due to their absence during negative selection of T cells and their lack of expression in healthy tissue, tumor mutations are considered as optimal targets for cancer immunotherapy. Preclinical and early clinical data suggest that synthetic mRNA can serve as potent drug format allowing the cost efficient production of highly efficient vaccines in a timely manner. In this review, we describe a process, which integrates next generation sequencing based cancer mutanome mapping,in silicotarget selection and prioritization approaches, and mRNA vaccine manufacturing and delivery into a process we refer to as MERIT (mutanome engineered RNA immunotherapy).

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