scholarly journals Statistical learning of frequent distractor locations in visual search: A role for post-selective distractor rejection processes?

2020 ◽  
Author(s):  
Marian Sauter ◽  
Nina Maria Hanning ◽  
Heinrich René Liesefeld ◽  
Hermann J. Müller
Keyword(s):  
Statistical Learning ◽  
Target Location ◽  
Learning Effects ◽  
Distractor Location ◽  
Oculomotor Capture ◽  
Methodological Choices ◽  
Visual Dimension ◽  
Reduced Rate ◽  
Distractor Rejection

People can learn to ignore salient distractors that occur frequently at particular locations. This distractor-location probability-cueing effect has been attributed to learnt suppression of the likely distractor locations at a pre-selective stage of attentional-priority computations. An alternative, post-selective account would be that distractors are as likely to capture attention at frequent as at rare locations, but attention can be disengaged faster from distractors at frequent locations. Eye-movement studies confirm that learnt suppression, evidenced by a reduced rate of oculomotor capture by distractors at frequent locations, is a major factor, whereas the evidence is mixed with regard to a role of rapid disengagement (pro: Wang et al., 2019; contra: Di Caro et al., 2019). However, methodological choices in these studies limited conclusions as to the contribution of a post-capture effect. Using an adjusted design, here we positively establish the rapid-disengagement effect and demonstrate further processes contributing to probability cueing beyond the oculomotor capture and disengagement dynamics. Moreover, we examine statistical-learning effects not only for distractors defined in a different visual dimension to the search target (comparable with previous work), but also for distractors defined within the same dimension, which are known to cause particularly strong attentional capture. Of theoretical importance, we corroborate our previous finding of responses being slowed (on distractor-absent trials) to targets at frequent distractor locations only in the same-, but not the different-, dimension condition. Consistent with a pre-selective origin, this target-location effect already impacted the latency of the very first saccade.

The Impact of Quantitative Easing on Emerging Markets – Literature Review

e-Finanse ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 67-76
Author(s):  
Piotr Bartkiewicz
Keyword(s):  
Emerging Markets ◽  
Large Scale ◽  
Empirical Literature ◽  
Quantitative Easing ◽  
Methodological Choices ◽  
The Subject ◽  
Methodological Approaches ◽  
The Impact ◽  
Sufficient Precision

AbstractThe article presents the results of the review of the empirical literature regarding the impact of quantitative easing (QE) on emerging markets (EMs). The subject is of interest to policymakers and researchers due to the increasingly larger role of EMs in the world economy and the large-scale capital flows occurring after 2009. The review is conducted in a systematic manner and takes into consideration different methodological choices, samples and measurement issues. The paper puts the summarized results in the context of transmission channels identified in the literature. There are few distinct methodological approaches present in the literature. While there is a consensus regarding the direction of the impact of QE on EMs, its size and durability have not yet been assessed with sufficient precision. In addition, there are clear gaps in the empirical findings, not least related to relative underrepresentation of the CEE region (in particular, Poland).

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.

Presence, Environment, and Sound and the Role of Imagination

2019 ◽  
pp. 667-681
Author(s):  
Mark Grimshaw-Aagaard
Keyword(s):  
Computer Games ◽  
Virtual World ◽  
Actual World ◽  
Sensory Input ◽  
The World ◽  
Visual Dimension ◽  
The Creation ◽  
First Person Shooter ◽  
Selection Of

Mark Grimshaw-Aagaard addresses the role of sound in the creation of presence in virtual and actual worlds. He argues that imagination is a central part of the generation and selection of perceptual hypotheses—models of the world in which we can act—that emerge from what Grimshaw-Aagaard calls the “exo-environment” (the sensory input) and the “endo-environment” (the cognitive input). Grimshaw-Aagaard further divides the exo-environment into a primarily auditory and a primarily visual dimension and he deals with the actual world of his own apartment and the virtual world of first-person-shooter computer games in order to exemplify how we perceptually construct an environment that allows for the creation of presence.

scholarly journals A meta-analysis of the literature on climate change and migration

2021 ◽  
pp. 1-52
Author(s):  
Michel Beine ◽  
Lionel Jeusette
Keyword(s):  
Climate Change ◽  
Climatic Factors ◽  
Human Mobility ◽  
Meta Analysis ◽  
Empirical Studies ◽  
Displacement Effect ◽  
Methodological Choices ◽  
Econometric Methods ◽  
And Migration

Abstract Recent surveys of the literature on climate change and migration emphasize the important diversity of outcomes and approaches of the empirical studies. In this paper, we conduct a meta-analysis in order to investigate the role of the methodological choices of these empirical studies in finding some particular results concerning the role of climatic factors as drivers of human mobility. We code 51 papers representative of the literature in terms of methodological approaches. This results in the coding of more than 85 variables capturing the methodology of the main dimensions of the analysis at the regression level. These dimensions include authors' reputation, type of mobility, measures of mobility, type of data, context of the study, econometric methods, and last but not least measures of the climatic factors. We look at the influence of these characteristics on the probability of finding any effect of climate change, a displacement effect, an increase in immobility, and evidence in favor of a direct vs. an indirect effect. Our results highlight the role of some important methodological choices, such as the frequency of the data on mobility, the level of development, the measures of human mobility and of the climatic factors as well as the econometric methodology.

scholarly journals Centromere Protein B Null Mice are Mitotically and Meiotically Normal but Have Lower Body and Testis Weights

1998 ◽  
Vol 141 (2) ◽  
pp. 309-319 ◽  
Author(s):  
Damien F. Hudson ◽  
Kerry J. Fowler ◽  
Elizabeth Earle ◽  
Richard Saffery ◽  
Paul Kalitsis ◽  
...  
Keyword(s):  
Cell Cycle Progression ◽  
Mammalian Species ◽  
Experimental Studies ◽  
Conflicting Evidence ◽  
Body Weights ◽  
Reduced Rate ◽  
And Function ◽  
Centromere Assembly ◽  
Mitosis And Meiosis

CENP-B is a constitutive centromere DNA-binding protein that is conserved in a number of mammalian species and in yeast. Despite this conservation, earlier cytological and indirect experimental studies have provided conflicting evidence concerning the role of this protein in mitosis. The requirement of this protein in meiosis has also not previously been described. To resolve these uncertainties, we used targeted disruption of the Cenpb gene in mouse to study the functional significance of this protein in mitosis and meiosis. Male and female Cenpb null mice have normal body weights at birth and at weaning, but these subsequently lag behind those of the heterozygous and wild-type animals. The weight and sperm content of the testes of Cenpb null mice are also significantly decreased. Otherwise, the animals appear developmentally and reproductively normal. Cytogenetic fluorescence-activated cell sorting and histological analyses of somatic and germline tissues revealed no abnormality. These results indicate that Cenpb is not essential for mitosis or meiosis, although the observed weight reduction raises the possibility that Cenpb deficiency may subtly affect some aspects of centromere assembly and function, and result in reduced rate of cell cycle progression, efficiency of microtubule capture, and/or chromosome movement. A model for a functional redundancy of this protein is presented.

The role of stimulus comparison in animal perceptual learning: Effects of a distractor placement

2018 ◽  
Vol 71 (12) ◽  
pp. 2488-2496 ◽  
Author(s):  
Sergio A Recio ◽  
Adela F Iliescu ◽  
Isabel de Brugada
Keyword(s):  
Perceptual Learning ◽  
Learning Process ◽  
Time Lapse ◽  
Animal Research ◽  
Learning Effects ◽  
Stimulus Comparison ◽  
Human Research ◽  
Short Time ◽  
Effect Experiment

Research on perceptual learning shows that the way stimuli are presented leads to different outcomes. The intermixed/blocked (I/B) effect is one of these outcomes, and different mechanisms have been proposed to explain it. In human research, it seems that comparison between stimuli is important, and the placement of a distractor between the pre-exposed stimuli interferes with the effect. Results from animal research are usually interpreted in different terms because the type of procedure normally used in animal perceptual learning does not favour comparison. In our experiments, we explore the possibility that a distractor placed between the to-be-discriminated stimuli may interfere with the perceptual learning process in rats. In Experiment 1, two flavoured solutions are presented in an I/B fashion, with a short time lapse between them to favour comparison, showing the typical I/B effect. In Experiment 2, we introduced a distractor in between the solutions, abolishing this effect. Experiment 3 further replicates this by comparing two intermixed groups with or without distractor. The results replicate the findings from human research, suggesting that comparison also plays an important role in animal perceptual learning.

scholarly journals Complementary learning systems within the hippocampus: A neural network modeling approach to reconciling episodic memory with statistical learning

2016 ◽  
Author(s):  
Anna C. Schapiro ◽  
Nicholas B. Turk-Browne ◽  
Matthew M. Botvinick ◽  
Kenneth A. Norman
Keyword(s):  
Neural Network ◽  
Statistical Learning ◽  
Entorhinal Cortex ◽  
Network Modeling ◽  
Learning Systems ◽  
Neural Network Modeling ◽  
Trade Off ◽  
Rapid Learning ◽  
Rapid Extraction

AbstractA growing literature suggests that the hippocampus is critical for the rapid extraction of regularities from the environment. Although this fits with the known role of the hippocampus in rapid learning, it seems at odds with the idea that the hippocampus specializes in memorizing individual episodes. In particular, the Complementary Learning Systems theory argues that there is a computational trade-off between learning the specifics of individual experiences and regularities that hold across those experiences. We asked whether it is possible for the hippocampus to handle both statistical learning and memorization of individual episodes. We exposed a neural network model that instantiates known properties of hippocampal projections and subfields to sequences of items with temporal regularities. We found that the monosynaptic pathway — the pathway connecting entorhinal cortex directly to region CA1 — was able to support statistical learning, while the trisynaptic pathway — connecting entorhinal cortex to CA1 through dentate gyrus and CA3 — learned only individual episodes, with apparent representations of regularities resulting from associative reactivation through recurrence. Thus, in paradigms involving rapid learning, the computational trade-off between learning episodes and regularities may be handled by separate anatomical pathways within the hippocampus itself.

scholarly journals Learning what is irrelevant or relevant: Expectations facilitate distractor inhibition and target facilitation through distinct neural mechanisms

2019 ◽  
Author(s):  
Dirk van Moorselaar ◽  
Heleen A. Slagter
Keyword(s):  
Target Location ◽  
Response Times ◽  
Relevant Information ◽  
Distractor Location ◽  
Distractor Inhibition ◽  
Distractor Processing ◽  
Behavioral Studies ◽  
Outstanding Question ◽  
Target Locations ◽  
The Brain

AbstractIt is well known that attention can facilitate performance by top-down biasing processing of task-relevant information in advance. Recent findings from behavioral studies suggest that distractor inhibition is not under similar direct control, but strongly dependent on expectations derived from previous experience. Yet, how expectations about distracting information influence distractor inhibition at the neural level remains unclear. The current study addressed this outstanding question in three experiments in which search displays with repeating distractor or target locations across trials allowed observers to learn which location to selectively suppress or boost. Behavioral findings demonstrated that both distractor and target location learning resulted in more efficient search, as indexed by faster response times. Crucially, benefits of distractor learning were observed without target location foreknowledge, unaffected by the number of possible target locations, and could not be explained by priming alone. To determine how distractor location expectations facilitated performance, we applied a spatial encoding model to EEG data to reconstruct activity in neural populations tuned to the distractor or target location. Target location learning increased neural tuning to the target location in advance, indicative of preparatory biasing. This sensitivity increased after target presentation. By contrast, distractor expectations did not change preparatory spatial tuning. Instead, distractor expectations reduced distractor-specific processing, as reflected in the disappearance of the Pd ERP component, a neural marker of distractor inhibition, and decreased decoding accuracy. These findings suggest that the brain may no longer process expected distractors as distractors, once it has learned they can safely be ignored.Significance statementWe constantly try hard to ignore conspicuous events that distract us from our current goals. Surprisingly, and in contrast to dominant attention theories, ignoring distracting, but irrelevant events does not seem to be as flexible as is focusing our attention on those same aspects. Instead, distractor suppression appears to strongly rely on learned, context-dependent expectations. Here, we investigated how learning about upcoming distractors changes distractor processing and directly contrasted the underlying neural dynamics to target learning. We show that while target learning enhanced anticipatory sensory tuning, distractor learning only modulated reactive suppressive processing. These results suggest that expected distractors may no longer be considered distractors by the brain once it has learned that they can safely be ignored.

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