scholarly journals I haven’t a clue! - Expectations based on repetitions and hints facilitate perceptual experience of ambiguous images

2020 ◽  
Author(s):  
Uri Hertz ◽  
Colin Blakemore ◽  
Chris D. Frith

In recent years the role of top-down expectations on perception has been extensively researched within the framework of predictive coding. However, less attention has been given to the different sources of expectations, how they differ and how they interact. Here we examined the effects of informative hints on perceptual experience, and how these interact with repetition-based expectations to create a long-lasting effect. Over seven experiments, we used verbal hints and multiple presentations of ambiguous two-tone images. We found that vividness ratings increased from one presentation to the next, even after the object in the image had been identified. In addition, vividness ratings significantly increased when images were introduced with a hint, and this boost was greater for more detailed hints. However, the initial increase in vividness did not always carry over to the next presentation. When recognition of the image in the presentation was hard, due to memory load, inconsistent presentation, or noise level of the image, the initial advantage in vividness was attenuated. This was most apparent when participants were primed with greyscale version of the two-tone image. A computational model based on evidence accumulation was able to recover these patterns of perceptual experience, suggesting that the effect of hints is short lived if it cannot be encoded in memory for future presentations. This notion highlights the different contributions of attention, memory and their interactions on forming expectations for perception.

2019 ◽  
Author(s):  
Fabio Trecca ◽  
Kristian Tylén ◽  
Riccardo Fusaroli ◽  
Christer Johansson ◽  
Morten H. Christiansen

Language processing depends on the integration of bottom-up information with top-down cues from several different sources—primarily our knowledge of the real world, of discourse contexts, and of how language works. Previous studies have shown that factors pertaining to both the sender and the receiver of the message affect the relative weighting of such information. Here, we suggest another factor that may change our processing strategies: perceptual noise in the environment. We hypothesize that listeners weight different sources of top-down information more in situations of perceptual noise than in noise-free situations. Using a sentence-picture matching experiment with four forced-choice alternatives, we show that degrading the speech input with noise compels the listeners to rely more on top-down information in processing. We discuss our results in light of previous findings in the literature, highlighting the need for a unified model of spoken language comprehension in different ecologically valid situations, including under noisy conditions.


Author(s):  
Mariana von Mohr ◽  
Aikaterini Fotopoulou

Pain and pleasant touch have been recently classified as interoceptive modalities. This reclassification lies at the heart of long-standing debates questioning whether these modalities should be defined as sensations on their basis of neurophysiological specificity at the periphery or as homeostatic emotions on the basis of top-down convergence and modulation at the spinal and brain levels. Here, we outline the literature on the peripheral and central neurophysiology of pain and pleasant touch. We next recast this literature within a recent Bayesian predictive coding framework, namely active inference. This recasting puts forward a unifying model of bottom-up and top-down determinants of pain and pleasant touch and the role of social factors in modulating the salience of peripheral signals reaching the brain.


2004 ◽  
Vol 63 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Fred W. Mast ◽  
Charles M. Oman

The role of top-down processing on the horizontal-vertical line length illusion was examined by means of an ambiguous room with dual visual verticals. In one of the test conditions, the subjects were cued to one of the two verticals and were instructed to cognitively reassign the apparent vertical to the cued orientation. When they have mentally adjusted their perception, two lines in a plus sign configuration appeared and the subjects had to evaluate which line was longer. The results showed that the line length appeared longer when it was aligned with the direction of the vertical currently perceived by the subject. This study provides a demonstration that top-down processing influences lower level visual processing mechanisms. In another test condition, the subjects had all perceptual cues available and the influence was even stronger.


2005 ◽  
Vol 35 (140) ◽  
pp. 407-422
Author(s):  
Julia Bernstein

Based on an ethnographical study the article presents the problems of Soviet migrants with capitalistic every day life. The reaction of the migrants and the role of their imagination of capitalism, which was formed by different sources in the former Soviet Union, is investigated.


2016 ◽  
Vol 3 (2) ◽  
pp. 56-62
Author(s):  
R. Iskra ◽  
V. Vlizlo ◽  
R. Fedoruk

The results of our studies and the data of modern literature regarding the biological role of Cr(III) compounds in conditions of their application in the nutrition for pigs and cattle are discussed. The metabolic impact of Cr(III), coming from different sources – mineral and organic compounds, obtained by chemical synthesis or a nanotechnological method (chromium citrate), as well as in the form of biocomplexes from the cultural medium of Saccharomyces cerevisiae yeasts was analyzed. The metabolic connection between the impact of Cr(III) and the biosynthesis of some hormones – insulin, cortisol – as well as the sensitivity of some tissues and organs to the effect of chromium compounds was studied. A considerable part of the review material was dedicated to the metabolic effect of Cr(III) compounds on the reproductive function of pigs and cattle and their impact on the viability of the offspring and gametes of animals. The data about the stimulating effect of Cr(III) on the growth and development of the organism of piglets and calves, meat and milk performance of these species of animals are discussed. The relevance of dosing Cr(III) in the nutrition of pigs and cattle is highlighted.


2019 ◽  
Author(s):  
Chris Robert Harrison Brown

Attention has long been characterised within prominent models as reflecting a competition between goal-driven and stimulus-driven processes. It remains unclear, however, how involuntary attentional capture by affective stimuli, such as threat-laden content, fits into such models. While such effects were traditionally held to reflect stimulus-driven processes, recent research has increasingly implicated a critical role of goal-driven processes. Here we test an alternative goal-driven account of involuntary attentional capture by threat, using an experimental manipulation of goal-driven attention. To this end we combined the classic ‘contingent capture’ and ‘emotion-induced blink’ (EIB) paradigms in an RSVP task with both positive or threatening target search goals. Across six experiments, positive and threat distractors were presented in peripheral, parafoveal, and central locations. Across all distractor locations, we found that involuntary attentional capture by irrelevant threatening distractors could be induced via the adoption of a search goal for a threatening category; adopting a goal for a positive category conversely led to capture only by positive stimuli. Our findings provide direct experimental evidence for a causal role of voluntary goals in involuntary capture by irrelevant threat stimuli, and hence demonstrate the plausibility of a top-down account of this phenomenon. We discuss the implications of these findings in relation to current cognitive models of attention and clinical disorders.


2010 ◽  
Vol 27 (1-2) ◽  
pp. 81-90
Author(s):  
Krishna Poudel

Mountains have distinct geography and are dynamic in nature compared to the plains. 'Verticality' and 'variation' are two fundamental specificities of the mountain geography. They possess distinct temporal and spatial characteristics in a unique socio-cultural setting. There is an ever increasing need for spatial and temporal data for planning and management activities; and Geo Information (GI) Science (including Geographic Information and Earth Observation Systems). This is being recognized more and more as a common platform for integrating spatial data with social, economic and environmental data and information from different sources. This paper investigates the applicability and challenges of GISscience in the context of mountain geography with ample evidences and observations from the mountain specific publications, empirical research findings and reports. The contextual explanation of mountain geography, mountain specific problems, scientific concerns about the mountain geography, advances in GIScience, the role of GIScience for sustainable development, challenges on application of GIScience in the contexts of mountains are the points of discussion. Finally, conclusion has been made with some specific action oriented recommendations.


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