Impaired selection of a previously ignored singleton: Evidence for salience map plastic changes

2021 ◽  
pp. 174702182110478
Author(s):  
Massimo Turatto ◽  
Matteo Valsecchi
Keyword(s):  
Target Selection ◽  
Test Phase ◽  
Distractor Location ◽  
Subsequent Test ◽  
Singleton Distractor ◽  
Signal Suppression ◽  
Priority Map ◽  
Plastic Changes ◽  
Salience Map ◽  
Selection Of

Spatial suppression of a salient colour distractor is achievable via statistical learning. Distractor suppression attenuates unwanted capture, but at the same time target selection at the most likely distractor location is impaired. This result corroborates the idea that the distractor salience is attenuated via inhibitory signals applied to the corresponding location in the priority map. What is less clear, however, is whether lingering impairment in target selection when the distractor is removed are due to the proactive strategic maintenance of the suppressive signal at the previous most likely distractor location or result from the fact that suppression has induced plastic changes in the priority map, probably changing input weights. Here, we provide evidence that supports the latter possibility, as we found that impairment in target selection persisted even when the singleton distractor in the training phase became the target of search in a subsequent test phase. This manipulation rules out the possibility that the observed impairments at the previous most likely distractor location were caused by a signal suppression maintained at this location. Rather, the results reveal that the inhibitory signals cause long-lasting changes in the priority map, which affect future computation of the target salience at the same location, and therefore the efficiency of attentional selection.

scholarly journals Influence of Mismatch of Parameters of Quadrature Channels on the Work of the Adaptive Selection System for Moving Targets

2020 ◽  
Vol 23 (3) ◽  
pp. 25-31
Author(s):  
S. I. Ziatdinov
Keyword(s):  
Noise Suppression ◽  
Target Selection ◽  
Average Frequency ◽  
Complex Conjugate ◽  
Selection System ◽  
Moving Targets ◽  
Adaptive Selection ◽  
Signal Suppression ◽  
Passive Noise ◽  
Selection Of

Introduction. The paper considers the operation of an adaptive selection system for moving targets, represented by a one-time multi-period subtractor. The system of selection of moving targets is made in the form of two quadrature channels, in which high-frequency input radio signals are converted to video frequency. Goal. Investigation of the system of selection of moving targets in the conditions of amplitude and phase misalignment of quadrature channels. Aim. The study of the operation of the moving targets selection system in the conditions of amplitude and phase mismatches of quadrature channels. Materials and methods. The method of complex variable is used, in which the input and output signals of the adaptive selection system for moving targets are represented as a pair of complex-conjugate components. Results. An expression is obtained for the frequency transfer function of an adaptive passive noise suppression system with a variable cut-off zone relative to the average frequency of the spectrum of interference signals. The influence of almost unavoidable amplitude and phase mismatches in the characteristics of quadrature channels is studied. Expressions are obtained for the dispersion of output noise signals of the considered system of moving targets with amplitude and phase misalignment of quadrature channels. Analytical relations for the coefficients of passive interference suppression are presented. The dependences of the jamming signal suppression coefficients were calculated and constructed depending on the deviation of the transmission coefficients of quadrature channels and the phase misalignment of the reference voltages for different values of the average frequency of the passive noise spectrum. Conclusion. The essential dependence of the jamming signal suppression coefficient on their average frequency, as well as amplitude and phase misalignments of quadrature channels is shown. The proposed research method allows us to evaluate the effect of misalignment of quadrature channels on the operation of a moving target selection system using high-order cutting filters.

scholarly journals Probability cueing of singleton-distractor locations in visual search: priority-map‐ or dimension-based inhibition?

2018 ◽  
Author(s):  
Bei Zhang ◽  
Fredrik Allenmark ◽  
Heinrich R. Liesefeld ◽  
Zhuanghua Shi ◽  
Hermann J. Müller
Keyword(s):  
Visual Search ◽  
Target Location ◽  
Negative Bias ◽  
Distractor Location ◽  
Strong Suppression ◽  
Singleton Distractor ◽  
Priority Map ◽  
The Cost ◽  
Search Guidance ◽  
Different Levels

ABSTRACTObservers can learn the likely locations of salient distractors in visual search, reducing their potential to capture attention (Ferrante et al., 2018; Sauter et al., 2018a; Wang & Theeuwes, 2018a). While there is agreement that this involves positional suppression of the likely distractor location(s), it is contentious at which stage of search guidance the suppression operates: the supra-dimensional priority map or feature-contrast signals within the distractor dimension. On the latter account, advocated by Sauter et al., target processing should be unaffected by distractor suppression when the target is defined in a different (non-suppressed) dimension to the target. At odds with this, Wang and Theeuwes found strong suppression not only of the (color) distractor, but also of the (shape) target when it appeared at the likely distractor location. Adopting their paradigm, the present study ruled out that increased cross-trial inhibition of the single frequent (frequently inhibited) as compared to any of the rare (rarely inhibited) distractor locations is responsible for this target-location effect. However, a reduced likelihood of the target appearing at the frequent vs. a rare distractor location contributes to this effect: removing this negative bias abolished the cost to target processing with increasing practice, indicative of a transition from priority-map‐ to dimension-based – and thus a flexible locus of – distractor suppression.Public Significance StatementDistraction by a salient visual stimulus outside the ‘focus’ of the task at hand occurs frequently. The present study examined whether and how ‘knowledge’ of the likely location(s) where the distractors occur helps the observer to mitigate distraction. The results confirmed that observers can learn to suppress distracting stimuli at likely locations. Further, they showed that, the suppression may occur at different levels in the hierarchically organized visual system where the priorities of which objects to be attended in the environment are determined.

Acquisition and Use of Mental Operators: Effects of Type of Practice

2002 ◽  
Vol 49 (2) ◽  
pp. 141-152 ◽  
Author(s):  
Burkhard Müller ◽  
Jürgen Gehrke
Keyword(s):  
Mental Models ◽  
Test Performance ◽  
Physical World ◽  
Test Phase ◽  
Acquisition Phase ◽  
Practice Test ◽  
Subsequent Test ◽  
Use Of Knowledge

Abstract. Planning interactions with the physical world requires knowledge about operations; in short, mental operators. Abstractness of content and directionality of access are two important properties to characterize the representational units of this kind of knowledge. Combining these properties allows four classes of knowledge units to be distinguished that can be found in the literature: (a) rules, (b) mental models or schemata, (c) instances, and (d) episodes or chunks. The influence of practicing alphabet-arithmetic operators in a prognostic, diagnostic, or retrognostic way (A + 2 = ?, A? = C, or ? + 2 = C, respectively) on the use of that knowledge in a subsequent test was used to assess the importance of these dimensions. At the beginning, the retrognostic use of knowledge was worse than the prognostic use, although identical operations were involved (A + 2 = ? vs. ? - 2 = A). This disadvantage was reduced with increased practice. Test performance was best if the task and the letter pairs were the same as in the acquisition phase. Overall, the findings support theories proposing multiple representational units of mental operators. The disadvantage for the retrognosis task was recovered in the test phase, and may be evidence for the importance of the order of events independent of the order of experience.

Spatial suppression due to statistical regularities is driven by distractor suppression not by target activation

2018 ◽  
Author(s):  
Michel Failing ◽  
Benchi Wang ◽  
Jan Theeuwes
Keyword(s):  
High Probability ◽  
Target Location ◽  
Target Selection ◽  
Visual Space ◽  
Alternative Interpretation ◽  
Distractor Location ◽  
Target Presentation ◽  
Statistical Regularities ◽  
Low Probability ◽  
Presentation Experiment

Where and what we attend to is not only determined by what we are currently looking for but also by what we have encountered in the past. Recent studies suggest that biasing the probability by which distractors appear at locations in visual space may lead to attentional suppression of high probability distractor locations which effectively reduces capture by a distractor but also impairs target selection at this location. However, in many of these studies introducing a high probability distractor location was tantamount to increasing the probability of the target appearing in any of the other locations (i.e. the low probability distractor locations). Here, we investigate an alternative interpretation of previous findings according to which attentional selection at high probability distractor locations is not suppressed. Instead, selection at low probability distractor locations is facilitated. In two visual search tasks, we found no evidence for this hypothesis: neither when there was only a bias in target presentation but no bias in distractor presentation (Experiment 1), nor when there was only a bias in distractor presentation but no bias in target presentation (Experiment 2). We conclude that recurrent presentation of a distractor in a specific location leads to attentional suppression of that location through a mechanism that is unaffected by any regularities regarding the target location.

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.

scholarly journals Sonic Artefacts of Teotihuacan, Mexico (Horns, Trumpets and Pipes)

Acoustics ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 507-544
Author(s):  
Arnd Adje Both
Keyword(s):  
World Heritage ◽  
Experimental Models ◽  
Wind Instruments ◽  
Unesco World Heritage ◽  
Urban Settings ◽  
Subsequent Test ◽  
Acoustic Study ◽  
Teotihuacan Mexico ◽  
Selection Of

This paper presents the acoustic study of a sample of sonic artefacts, in particular a selection of wind instruments (horns, trumpets and pipes), from the UNESCO World Heritage Centre of Teotihuacan, Mexico, based on a thorough examination of the accessible and playable archaeological finds and the construction and subsequent test of a series of experimental models. Combined with the archaeological and iconographical information, the study helps to deduce information with regard to the urban settings in which these instruments might have been used. It also reveals some basic acoustic components of the music once performed in Teotihuacan.

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.

Diversion of Attention Leads to Conflict between Concurrently Attended Stimuli, Not Delayed Orienting to the Object of Interest

2021 ◽  
pp. 1-17
Author(s):  
Jennifer-Ashley Hoffmeister ◽  
Andrea N. Smit ◽  
Ashley C. Livingstone ◽  
John J. McDonald
Keyword(s):  
Visual Search ◽  
Focus Of Attention ◽  
Search Array ◽  
Distractor Location ◽  
Control Processes ◽  
Subsequent Target ◽  
Selection Of

Abstract The control processes that guide attention to a visual-search target can result in the selection of an irrelevant object with similar features (a distractor). Once attention is captured by such a distractor, search for a subsequent target is momentarily impaired if the two stimuli appear at different locations. The textbook explanation for this impairment is based on the notion of an indivisible focus of attention that moves to the distractor, illuminates a nontarget that subsequently appears at that location, and then moves to the target once the nontarget is rejected. Here, we show that such delayed orienting to the target does not underlie the behavioral cost of distraction. Observers identified a color-defined target appearing within the second of two stimulus arrays. The first array contained irrelevant items, including one that shared the target's color. ERPs were examined to test two predictions stemming from the textbook serial-orienting hypothesis. Namely, when the target and distractor appear at different locations, (1) the target should elicit delayed selection activity relative to same-location trials, and (2) the nontarget search item appearing at the distractor location should elicit selection activity that precedes selection activity tied to the target. Here, the posterior contralateral N2 component was used to track selection of each of these search-array items and the previous distractor. The results supported neither prediction above, thereby disconfirming the serial-orienting hypothesis. Overall, the results show that the behavioral costs of distraction are caused by perceptual and postperceptual competition between concurrently attended target and nontarget stimuli.

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