Local-Level and Global-Level Form Characteristics in Apparent-Motion Correspondence

Perception ◽  
1995 ◽  
Vol 24 (11) ◽  
pp. 1233-1245 ◽  
Author(s):  
Terry Palmer ◽  
Ovid J L Tzeng ◽  
Sheng He
Keyword(s):  
Apparent Motion ◽  
Motion Detection ◽  
Local Level ◽  
The Other ◽  
Correspondence Problem ◽  
Global Level ◽  
Global Precedence ◽  
Detection Mechanism ◽  
Motion Display ◽  
Motion Correspondence

This study addressed the ‘correspondence’ problem of apparent-motion (AM) perception in which parts of a scene must be matched with counterparts separated in time and space. Given evidence that AM correspondence can be mediated by two distinct processes—one based on a low-level motion-detection mechanism (the Reichardt process), the other involving the tracking of objects by visual attention (the attention-based process)—the present study explored how these processes interact in the perception of apparent motion between hierarchically structured figures. In three experiments, hierarchical figures were presented in a competition motion display so that, across frames, figures were identical at either the local or the global level. In experiment 1 it was shown that AM occurred between locally identical figures. Furthermore, with the Reichardt AM component eliminated in experiments 3 and 4, no preference was obtained for either level. While evidence from previous studies suggests that form extraction for hierarchically structured figures proceeds from the global to the local level, the present results indicate the irrelevance of such a global precedence in AM correspondence. In addition, it is suggested that Reichardt AM correspondence between local elements constrains attention-based AM correspondence between global figures so that both components move in the same direction. It is argued that this constraining process represents an elegant means of achieving AM correspondence between objects undergoing complex transformations.

The Ternus Effect

2017 ◽  
Author(s):  
Elisabeth Hein
Keyword(s):  
Twentieth Century ◽  
Eye Movements ◽  
Visual System ◽  
Apparent Motion ◽  
Perceptual Grouping ◽  
The Other ◽  
The World ◽  
Motion Display ◽  
In The Beginning ◽  
Insight Into

The Ternus effect refers to an ambiguous apparent motion display in which two or three elements presented in succession and shifted horizontally by one position can be perceived as either a group of elements moving together or as one element jumping across the other(s). This chapter introduces the phenomenon and describes observations made by Pikler and Ternus in the beginning of the twentieth century. Next, reasons for continued interest in the Ternus effect are discussed and an overview of factors that influence it offered, including low-level image-based factors, for example luminance, as well as higher-level scene-based factors, for example perceptual grouping. The chapter ends with a discussion of theories regarding the mechanisms underlying the Ternus effect, providing insight into how the visual system is able to perceive coherent objects in the world despite discontinuities in the input (e.g., as a consequence of eye movements or object occlusion).

The Effect of Two-Dimensional and Three-Dimensional Distance on Apparent Motion

Perception ◽  
1983 ◽  
Vol 12 (3) ◽  
pp. 305-312 ◽  
Author(s):  
Kathleen Mutch ◽  
Isabel M Smith ◽  
Albert Yonas
Keyword(s):  
Motion Perception ◽  
Apparent Motion ◽  
Three Dimensional ◽  
Spatial Separation ◽  
Three Dimensions ◽  
Correspondence Problem ◽  
Two Dimensional ◽  
Motion Display ◽  
Specific Concern ◽  
Actual Depth

The problem of how the visual system matches corresponding inputs from one instant to the next to produce the perception of motion has been experimentally examined. The specific concern was whether this correspondence problem is solved prior to the interpretation of three-dimensional distance. Observers judged the degree of apparent motion between pairs of lights in a conflicting motion display. Spatial separation of the lights was varied in two and three dimensions in order to assess whether retinal distance, actual depth, or some combination of these provided critical information for correspondence. The results support Ullman's contention that only two-dimensional (retinal) distances are used in establishing correspondence in motion perception.

Beyond the Forest and the Trees: Local and Global Interference in Hierarchical Visual Stimuli Containing Three Levels

Perception ◽  
10.1068/p5619 ◽  
2007 ◽  
Vol 36 (8) ◽  
pp. 1115-1122 ◽  
Author(s):  
Mark Rijpkema ◽  
Sandra van Aalderen ◽  
Jens Schwarzbach ◽  
Frans A J Verstraten
Keyword(s):  
Local Level ◽  
Middle Level ◽  
Visual Scene ◽  
Precedence Effect ◽  
Local Processing ◽  
Global Level ◽  
Global Precedence ◽  
Large Letter ◽  
Attentional Window ◽  
Hierarchical Manner

Our visual world can be thought of as organised in a hierarchical manner. Studies on hierarchical letter stimuli (a large letter composed of smaller letters) suggest that processing of a visual scene is global to local, a phenomenon known as the global-precedence effect. Elaborating on this global-to-local hypothesis we tested whether global interference will increase with increasing level of globality. For this, we used three-level hierarchical letter stimuli with a global, middle, and local level. When attending to the local level of the stimulus, only the middle level showed an interference effect, whereas the global level did not interfere at all. We argue that, considering the perceptual and attentional contributions to this effect, the hypothesis of global-to-local processing of a visual scene may only hold within a limited spatial attentional window.

On the Different Processing of Wholes and Parts: A Psychophysiological Analysis

1997 ◽  
Vol 9 (5) ◽  
pp. 687-698 ◽  
Author(s):  
Shihui Han ◽  
Silu Fan ◽  
Lin Chen ◽  
Yan Zhuo
Keyword(s):  
Interference Effect ◽  
Local Level ◽  
Precedence Effect ◽  
Global Level ◽  
Global Precedence ◽  
Attention Task ◽  
Brain Potentials ◽  
Compound Stimuli ◽  
Global And Local ◽  
Local Levels

The global precedence hypothesis (Navon, 1977) assumes that the processing of the global level of a hierarchical pattern precedes that of the local level. To explore further the nature of global and local processing of compound stimuli, we recorded the event-related brain potentials (ERPs) associated with ident@ing the global and local levels of nonlinguistic compound stimuli in a selective attention task. Wile subjects' behavioral responses were similar to those observed by Navon (1977), the analyses of ERP data showed that identification of the local level elicited longer N2 and P3 peak latencies with enhanced N2 and decreased P3 amplitudes relative to the identification of the global level. The inconsistency between the global and local levels made N2 and P3 amplitudes more negative with longer peak latencies. This interference effect on N2 and P3 amplitude and P3 latency was stronger on the local level than on the global level. The modulation of N2 by the consistency of the global and local levels observed in this and the previous (Heinze, Muente, et al., 1994) study suggests that the interference effect may be mediated by the early perceptual processing. Moreover, we found that the amplitude of an early posterior P1 component was modulated by attention to the global and local levels, being larger to the local target than to the global one. This PI effect gives no support to the notion that the variation of attentional spotlight determines the global precedence effect.

scholarly journals Illusory size determines the perception of ambiguous apparent motion

2020 ◽  
Vol 27 (6) ◽  
pp. 1230-1238
Author(s):  
Madeleine Y. Stepper ◽  
Cathleen M. Moore ◽  
Bettina Rolke ◽  
Elisabeth Hein
Keyword(s):  
Motion Perception ◽  
Apparent Motion ◽  
Apparent Depth ◽  
Correspondence Problem ◽  
Ambiguous Information ◽  
Depth Cues ◽  
Pictorial Depth ◽  
Retinal Input ◽  
Motion Display ◽  
Level Of Processing

AbstractThe visual system constructs perceptions based on ambiguous information. For motion perception, the correspondence problem arises, i.e., the question of which object went where. We asked at which level of processing correspondence is solved – lower levels based on information that is directly available in the retinal input or higher levels based on information that has been abstracted beyond the input directly available at the retina? We used a Ponzo-like illusion to manipulate the perceived size and separations of elements in an ambiguous apparent motion display. Specifically, we presented Ternus displays – for which the type of motion that is perceived depends on how correspondence is resolved – at apparently different distances from the viewer using pictorial depth cues. We found that the perception of motion depended on the apparent depth of the displays, indicating that correspondence processes utilize information that is produced at higher-level processes.

Do You Want to See the Tree? Ignore the Forest

2014 ◽  
Vol 61 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Nicolas Poirel ◽  
Claire Sara Krakowski ◽  
Sabrina Sayah ◽  
Arlette Pineau ◽  
Olivier Houdé ◽  
...  
Keyword(s):  
Visual Recognition ◽  
Local Level ◽  
Local Information ◽  
Visual Environment ◽  
Global Information ◽  
Focus Attention ◽  
Global Level ◽  
Hierarchical Stimuli ◽  
Priming Paradigm ◽  
The One

The visual environment consists of global structures (e.g., a forest) made up of local parts (e.g., trees). When compound stimuli are presented (e.g., large global letters composed of arrangements of small local letters), the global unattended information slows responses to local targets. Using a negative priming paradigm, we investigated whether inhibition is required to process hierarchical stimuli when information at the local level is in conflict with the one at the global level. The results show that when local and global information is in conflict, global information must be inhibited to process local information, but that the reverse is not true. This finding has potential direct implications for brain models of visual recognition, by suggesting that when local information is conflicting with global information, inhibitory control reduces feedback activity from global information (e.g., inhibits the forest) which allows the visual system to process local information (e.g., to focus attention on a particular tree).

Documentary credit between international rules and norms and Iraqi trade law

2021 ◽  
Author(s):  
Hardi Tofiq
Keyword(s):  
International Trade ◽  
The Other ◽  
Global Level ◽  
Financial Systems ◽  
Trade Law ◽  
The Difference ◽  
Credit Contracts

The difference in the countries to which both the seller and the buyer belong in the commercial exchanges has increased the discrepancy in the laws and rules that govern the conduct of the most important banking count approved for the settlement of such exchanges, which is the documentary credit process, as a result of the different economic, banking and financial systems from the other, so there was a need to unify These customs and customs are in a unified form, which is called today the unified rules and customs of documentary credit, which are applied to the conduct of documentary credit contracts at the global level. Therefore, we consider it necessary to make an amendment in the Iraqi law regarding the organization of the documentary credit process, because the articles related to the provisions of documentary credits are not sufficient in themselves to indicate all the problems that may result from it due to developments in international trade.

Diagnosis of embankment dam distresses using Bayesian networks. Part I. Global-level characteristics based on a dam distress database

2011 ◽  
Vol 48 (11) ◽  
pp. 1630-1644 ◽  
Author(s):  
L.M. Zhang ◽  
Y. Xu ◽  
J.S. Jia ◽  
C. Zhao
Keyword(s):  
Bayesian Networks ◽  
Local Level ◽  
Companion Paper ◽  
General Information ◽  
Dam Safety ◽  
Global Level ◽  
Embankment Dam ◽  
The Public ◽  
Embankment Dams ◽  
Level Performance

Dam safety has drawn increasing attention from the public. To ensure dam safety, it is essential to diagnose any dam distresses and their causes properly. The main objective of this paper is to develop a robust probability-based tool using Bayesian networks for the diagnosis of embankment dam distresses at the global level based on past dam distress data. A database of 993 distressed in-service embankment dams in China has been compiled, including general information on the dams, distresses, and causes. Based on the database, general characteristics of embankment dam distresses are studied using Bayesian networks, which can tackle not only the multiplicity of dam distresses and causes, but also the complex interrelations among them. Common patterns and causes of distresses are identified. The interrelations among the dam distresses and their causes are quantified using conditional probabilities determined based on the historical frequencies from the dam distress database. A sensitivity analysis is also conducted to identify and rank the most important factors that cause the distresses. With the prior information of common characteristics extracted from the database, Bayesian networks are further used to diagnose a specific distressed dam at the local level by combining global-level performance records and project-specific evidence in a systematic structure, which is presented in a companion paper.

scholarly journals Combat as an Interpersonal Synergy: An Ecological Dynamics Approach to Combat Sports

2019 ◽  
Vol 49 (12) ◽  
pp. 1825-1836 ◽  
Author(s):  
Kai Krabben ◽  
Dominic Orth ◽  
John van der Kamp
Keyword(s):  
Dynamic Systems ◽  
Local Level ◽  
Control Parameters ◽  
Combat Sports ◽  
Global Level ◽  
Interactive Approach ◽  
Ecological Dynamics ◽  
Skilled Performance ◽  
Initial Support ◽  
And Control

Abstract In combat sports, athletes continuously co-adapt their behavior to that of the opponent. We consider this interactive aspect of combat to be at the heart of skilled performance, yet combat sports research often neglects or limits interaction between combatants. To promote a more interactive approach, the aim of this paper is to understand combat sports from the combined perspective of ecological psychology and dynamic systems. Accordingly, combat athletes are driven by perception of affordances to attack and defend. Two combatants in a fight self-organize into one interpersonal synergy, where the perceptions and actions of both athletes are coupled. To be successful in combat, performers need to manipulate and take advantage of the (in)stability of the system. Skilled performance in combat sports therefore requires brinkmanship: combatants need to be aware of their action boundaries and purposefully act in meta-stable regions on the limits of their capabilities. We review the experimental literature to provide initial support for a synergetic approach to combat sports. Expert combatants seem able to accurately perceive action boundaries for themselves and their opponent. Local-level behavior of individual combatants has been found to lead to spatiotemporal synchronization at the global level of a fight. Yet, a formal understanding of combat as a dynamic system starting with the identification of order and control parameters is still lacking. We conclude that the ecological dynamics perspective offers a promising approach to further our understanding of skilled performance in combat sports, as well as to assist coaches and athletes to promote optimal training and learning.

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