The Differential Effects of Brief Exposures and Surrounding Contours on Direct and Indirect Tilt Illusions

Perception ◽  
1988 ◽  
Vol 17 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Peter Wenderoth ◽  
Syren Johnstone
Keyword(s):  
Direct Effect ◽  
Visual Processing ◽  
Indirect Effects ◽  
Global Analysis ◽  
Stimulus Presentation ◽  
Direct Effects ◽  
Flash Duration ◽  
Tilt Illusion ◽  
A Value ◽  
Colour Form

Four experiments in which logarithmic intervals between 25 and 1600 ms were used for stimulus duration in tests for the tilt illusion are reported. It is demonstrated that the direct and the indirect tilt illusions both increase in magnitude inversely with length of stimulus presentation. The data suggest that whereas the direct effect peaks with a value of about +7° at the shortest flash duration used (25 ms), peak indirect effects (of about +2°) do not occur at this duration. In addition, whereas direct effects level out after 100 ms stimulus exposure times, to the usual magnitude obtained with long presentations (about + 2°), indirect effects reach their standard magnitude (−0.5° to −1.0°) later, at exposures of about 400 ms. Even at very short flash durations, a luminance square frame surrounding the illusion display reduces the indirect effect by two thirds of its magnitude but has no effect at all on the direct effect. It is suggested that direct effects arise early in visual processing, in area V1, where there are transient mechanisms and where corruption of orientation analysis by the inducing grating would occur prior to later, extrastriate, global analysis of the surrounding peripheral frame. Indirect effects, on the other hand, may arise later, along the sustained parvocellular colour—form pathway, where more global processing occurs and susceptibility to surrounding fields might be expected.

Exposure-Time and Spatial-Frequency Effects in the Tilt Illusion

Perception ◽  
1979 ◽  
Vol 8 (5) ◽  
pp. 557-564 ◽  
Author(s):  
Brian I O'Toole
Keyword(s):  
Spatial Frequency ◽  
Indirect Effects ◽  
Time Course ◽  
Test Line ◽  
Acute Angle ◽  
Direct Effects ◽  
Time Constants ◽  
Frequency Effects ◽  
Tilt Illusion ◽  
Vertical Test

The exposure durations of a vertical test line and a tilted inducing grating were varied and the tilt illusion thus generated was found to change as a function of this variation. Significant direct effects (acute-angle expansion) and indirect effects (acute-angle contraction) were found to occur at times consistent with Andrews's estimate of the time course of inhibition in the visual system when the inducing grating had a spatial frequency of 10 cycles deg−1. However, a 2 · 71 cycles deg−1 grating gave significant effects at exposure durations of 10 as well as 1000 ms, while in a further experiment a 10 · 91 cycles deg−1 grating gave significant effects at 1000 ms only. These results seem to suggest that orientation interactions thought to be due to inhibition (direct effect) and disinhibition (indirect effect) may occur within both sustained and transient channels with concomitant differences in time constants.

scholarly journals Aerosol radiative effects with MACv2

2019 ◽  
Vol 19 (16) ◽  
pp. 10919-10959 ◽  
Author(s):  
Stefan Kinne
Keyword(s):  
Direct Effect ◽  
Indirect Effects ◽  
Anthropogenic Sources ◽  
Current Evidence ◽  
Direct Effects ◽  
Radiative Effects ◽  
Anthropogenic Aerosol ◽  
Aerosol Radiative Effects ◽  
Sky Conditions ◽  
Aerosol Radiative

Abstract. Monthly global maps for aerosol properties of the Max Planck Aerosol Climatology version 2 (MACv2) are applied in an offline radiative transfer model to determine aerosol radiative effects. This model setup cannot address rapid adjustments by clouds, but current evidence suggests their contribution to be small when compared to the instantaneous radiative forcing. Global maps are presented to detail the regional and seasonal variability associated with (annual) global averages. Radiative effects caused by the aerosol presence (direct effects) and by aerosol modified clouds (indirect effects) are examined. Direct effects are determined for total aerosol, anthropogenic aerosol and extracted individual aerosol components. Indirect effects cover the impact of reduced cloud drop sizes by anthropogenic aerosol. Present-day global annual radiative effects for anthropogenic aerosol yield (1) a climate cooling of −1.0 W m−2 at the top of the atmosphere (TOA); (2) a surface net-flux reduction of −2.1 W m−2; and, by difference; (3) an atmospheric effect of +1.1 W m−2. This atmospheric solar heating is almost entirely a direct effect. On a global basis, indirect effects (−0.65 W m−2) dominate direct effects (−0.35 W m−2) for the present-day climate response at the TOA, whereas the present-day surface radiative budget is more strongly reduced by direct effects (−1.45 W m−2) than by indirect effects (−0.65 W m−2). Natural aerosols are on average less absorbing and larger in size. However, their stronger solar TOA cooling efficiency is offset by a non-negligible infrared (IR) greenhouse warming efficiency. In the sum the global average annual direct forcing efficiencies (per unit AOD) for natural and anthropogenic aerosol are similar: −12 W m−2 per unit AOD for all-sky conditions and −24 W m−2 per unit AOD for clear-sky conditions. The present-day direct TOA impact by all soot (BC) is +0.55 W m−2, when globally and annually averaged. Between +0.25 and +0.45 W m−2 of that can be attributed to anthropogenic sources, depending on assumptions for the preindustrial BC reference state. Similarly, the preindustrial fine-mode reference uncertainty has a strong influence not just on the direct effect but even more on the indirect effect. Present-day aerosol TOA forcing is estimated to stay within the −0.7 to −1.6 W m−2 range (with the best estimate at −1.0 W m−2). Calculations with scaled temporal changes to anthropogenic AOD from global modeling indicate that the global annual aerosol forcing has not changed much over the last decades, despite strong shifts in regional maxima for anthropogenic AOD. These regional shifts explain most solar insolation (brightening or dimming) trends that have been observed by ground-based radiation data.

The Effect of Agrochemicals on the Growth of Cladonia Furcata

1994 ◽  
Vol 26 (1) ◽  
pp. 73-82 ◽  
Author(s):  
I. Vagts ◽  
M. Kinder ◽  
J. Müller
Keyword(s):  
Direct Effect ◽  
Indirect Effects ◽  
Field Experiments ◽  
Mineral Fertilizer ◽  
Lethal Effect ◽  
Organic Manure ◽  
Direct Effects ◽  
Calcium Cyanamide ◽  
Lichen Growth

AbstractField experiments were conducted to test the effect of some agrochemicals on the growth of Cladonia furcata. Mineral fertilizer had no direct effect on lichen growth. In contrast, organic manure promoted the length of podetia. A lethal effect was recorded in the case of calcium cyanamide. In addition to direct effects of agrochemicals, indirect effects were also recorded.

scholarly journals Creating Democratic Citizens: Political Effects of the Internet in China

2018 ◽  
Vol 71 (4) ◽  
pp. 757-771 ◽  
Author(s):  
Narisong Huhe ◽  
Min Tang ◽  
Jie Chen
Keyword(s):  
Indirect Effects ◽  
The Political ◽  
The Internet ◽  
Direct Effects ◽  
A Value ◽  
Political Effects ◽  
Political Outcomes ◽  
Political Impact ◽  
Causal Mediation Analysis

This study explores the perplexing role of the Internet in authoritarian settings. We disentangle the political impact of the Internet along two distinct dimensions, indirect effects and direct effects. While the direct effects of the exposure to the Internet shape political attitudes in a manifest and immediate way, the indirect effects shape various political outcomes via instilling fundamental democratic orientations among citizens. In authoritarian societies such as China, we argue the indirect effects of the Internet as a value changer tend to be potent, transformative, and persistent. But the direct effects of the Internet as a mere alternative messenger are likely to be markedly contingent. Relying on the newly developed method of causal mediation analysis and applying the method to data from a recent survey conducted in Beijing, we find strong empirical evidence to support our argument about the two-dimensional impacts of the Internet in authoritarian countries.

Trophic Cascades in Grasslands

2018 ◽  
Author(s):  
Brian J. Wilsey
Keyword(s):  
Indirect Effects ◽  
Prey Species ◽  
Trophic Levels ◽  
Herbaceous Plant ◽  
Direct Effects ◽  
Temperate Grasslands ◽  
Cascading Effect ◽  
Top Predators ◽  
Invertebrate Predators ◽  
Ecology Of Fear

Top predators have effects that can ‘cascade down’ on lower trophic levels. Because of this cascading effect, it matters how many trophic levels are present. Predators are either ‘sit and wait’ or ‘active’. Wolves are top predators in temperate grasslands and can alter species composition of smaller-sized predators, prey, and woody and herbaceous plant species, either through direct effects or indirect effects (‘Ecology of Fear’). In human derived grasslands, invertebrate predators fill a similar ecological role as wolves. Migrating populations of herbivores tend to be more limited by food than non-migratory populations. The phenology and synchrony of births vary among prey species in a way that is consistent with an adaptation to predation. Precocious species have highly synchronous birth dates to satiate predators. Non-precocious species (‘hiders’) have asynchronous births. Results from studies that manipulate both predators and food support the hypothesis that bottom-up and top-down effects interact.

Moral Disengagement About Cyberbullying and Parental Monitoring: Effects on Traditional Bullying and Victimization via Cyberbullying Involvement

2016 ◽  
Vol 38 (3) ◽  
pp. 303-326 ◽  
Author(s):  
Diana J. Meter ◽  
Sheri Bauman
Keyword(s):  
Direct Effect ◽  
Indirect Effect ◽  
Indirect Effects ◽  
Parental Monitoring ◽  
Moral Disengagement ◽  
Traditional Bullying ◽  
Traditional Victimization ◽  
And Gender

The indirect effects of moral disengagement about cyberbullying and parental monitoring on traditional victimization and bullying via cyberbullying involvement were examined in a diverse sample of 800 youth in Grades 3 to 8. After controlling for grade and gender, moral disengagement about cyberbullying and parental monitoring had an indirect effect on traditional victimization and bullying through cyberbullying involvement. Moral disengagement about cyberbullying and parental monitoring had a direct effect on traditional bullying. Results suggest that moral disengagement about cyberbullying and parental monitoring affect cyberbullying involvement and additionally impact experiences beyond the cyber context.

scholarly journals Possible Traffic Safety Effects of the Implementation of Section Control in Hungary

2020 ◽  
Vol 13 (4) ◽  
pp. 309-323
Author(s):  
Zsolt Sándor
Keyword(s):  
Traffic Safety ◽  
Indirect Effects ◽  
Social Cost ◽  
Cost Savings ◽  
International Studies ◽  
Direct Effects ◽  
Implementation Cost ◽  
Short Term ◽  
Environmental Loads

This article presents the anticipated safety effects of the implantation of section control in Hungary. The proposed results were originated from international studies and the local circumstances. Effects are depending on the control coverage and the magnitude of the sanctions. Direct (short term benefits) and indirect effects (long term benefits) can be identified. Direct effects are the decreasing of accident numbers, while indirect effects are the decrease of other externalities of transport like environmental loads. Based on the results the implementation cost of the enforcement system is measureable with the proposed social cost savings come from the decreasing number of accidents.

The Interaction of Reactions and Transport Part II: Combined Reactors and Exchangers

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Stuart W. Churchill
Keyword(s):  
Indirect Effects ◽  
Molecular Level ◽  
Chemical Reactor ◽  
Complex Behavior ◽  
Geometrical Configuration ◽  
Direct Effects ◽  
Optimal Conditions ◽  
Chemical Reactors ◽  
And Performance ◽  
Transport Part

The interactions between chemical reactions and transport may be divided into direct effects, for example on the molecular level, and indirect effects, for example those arising from the geometrical configuration of the integrated reactor/exchanger. Attention herein is focused on the latter, although in many instances the direct effects must be accounted for as well. Particular attention is given to the identification of behavior that does not arise in chemical reactors not connected to an exchanger or in exchangers not connected to a chemical reactor, as well as to optimal conditions and configurations of combined reactors and exchangers. Generalizations are difficult to formulate for such complex behavior and equipment, necessitating a primary reliance on illustrative examples. However, some general conclusions are drawn concerning the occurrence, identification, and performance of interactive designs.

A generalist nematode destabilizes plant competition: no evidence for direct effects, but strong evidence for indirect effects on rhizobia abundance

2021 ◽  
Author(s):  
Samantha A. Catella ◽  
Castilleja Fallon Olmsted ◽  
Shaniya H. Markalanda ◽  
Connor J. McFadden ◽  
Corlett W. Wood ◽  
...  
Keyword(s):  
Strong Evidence ◽  
Indirect Effects ◽  
Plant Competition ◽  
Direct Effects
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