The Double-Nail Illusion: Experiments on Binocular Vision with Nails, Needles, and Pins

Perception ◽  
1980 ◽  
Vol 9 (6) ◽  
pp. 651-669 ◽  
Author(s):  
Jodi D Krol ◽  
Wim A van de Grind
Keyword(s):  
Quantitative Study ◽  
Neuronal Network ◽  
Binocular Vision ◽  
The Other ◽  
Necessary Condition ◽  
Neuronal Interactions ◽  
Length Width ◽  
Reading Distance ◽  
Straight Ahead ◽  
Network Type

When two nails or similar slender objects are held straight ahead at reading distance, one a few centimetres behind the other and aligned at the same eye level, they are seen side by side rather than one behind the other. A quantitative study of this ‘double-nail’ illusion shows that the objects are judged to be at the positions of the so-called apparent or ghost images known from fusional theories of stereopsis. Most recent fusional theories assume that apparent images are suppressed by neuronal interactions, and the usual absence of percepts corresponding with apparent images is often quoted as an argument against ‘projection’ theories of stereopsis. The double-nail illusion shows, however, that percepts which correspond with apparent images do occur. The results are interpreted in terms of a neuronal-network type of fusional theory, in which the interpretation that corresponds with the minimum overall disparity is assumed to dominate. The following parameters were varied in the experiments: length, width, colour, and contrast for each of the nails; and fixation point position; and the orientation of the nail carrier. The results show that identity of the stimuli is not a necessary condition for the illusion. A stable vergence can be enforced by the double-nail illusion, and with additional nails multistable states of vergence can be obtained.

Occlusion Constraints and Stereoscopic Slant

Perception ◽  
1997 ◽  
Vol 26 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Jukka Häkkinen ◽  
Göte Nyman
Keyword(s):  
Binocular Vision ◽  
Retinal Image ◽  
Three Dimensional ◽  
Vertical Axis ◽  
The Other ◽  
Necessary Condition ◽  
Slant Perception ◽  
Frontoparallel Plane ◽  
Reduction Effect

In binocular vision horizontal magnification of one retinal image leads to a percept of three-dimensional slant around a vertical axis. It is demonstrated that the perception of slant is diminished when an occlusion interpretation is possible. A frontoparallel plane located in the immediate vicinity of a slanted surface in a location which allows a perception of occlusion reduces the magnitude of perceived slant significantly. When the same plane is placed on the other side, the slant perception is normal because there is no alternative occlusion interpretation. The results indicate that a common border between the occluder and a slanted surface is not a necessary condition for the reduction effect. If the edges are displaced and the edge of the slanted surface is placed in a location in which it could be occluded, the effect still appears.

scholarly journals Comportamento tático coletivo em Pequenos Jogos no Futebol: influência de jogadores adicionais

2016 ◽  
Vol 18 (1) ◽  
pp. 62 ◽  
Author(s):  
Gibson Moreira Praça ◽  
Hugo Folgado ◽  
André Gustavo Pereira de Andrade ◽  
Pablo Juan Greco
Keyword(s):  
The Other ◽  
Soccer Players ◽  
Width Ratio ◽  
Collective Variables ◽  
Other Hand ◽  
Centroid Distance ◽  
Friedman's Test ◽  
Polar Coordinate ◽  
Length Width ◽  
Positional Data

DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n1p62 The aim of this study was to compare the collective tactical behavior between numerically balanced and unbalanced small-sided soccer games. Eighteen male soccer players (mean age 16.4 years) participated in the study. Polar coordinate analysis was performed using positional data obtained with a 15-Hz GPS device. Collective variables including length, width, centroid distance (average point between teammates), and length per width ratio (LPWratio) were collected. Data were analyzed using Friedman’s test. The results showed greater length and width values in 4vs.3 games, while a higher LPWratiowas observed in 3vs.3+2 games compared to the other configurations. In games with an additional player (4vs.3), ball circulation and the increase in effective game space were alternatives to overcome the more concentrated defensive systems near the goal. On the other hand, 3vs.3+2 games allowed more actions in the length axis and a fast reach of the opponent’s goal.

Effects of Time Delay on Burst Synchronization Transition of Neuronal Networks

2018 ◽  
Vol 28 (12) ◽  
pp. 1850143 ◽  
Author(s):  
Xiaojuan Sun ◽  
Tianshu Xue
Keyword(s):  
Time Delay ◽  
Neuronal Network ◽  
Coupling Strength ◽  
Neuronal Networks ◽  
The Other ◽  
Electrical Synapses ◽  
Synchronization Transition ◽  
Burst Synchronization ◽  
Chemical Synapses ◽  
Bursting Activity

In this paper, we focus on investigating the effects of time delay on burst synchronization transitions of a neuronal network which is locally modeled by Hindmarsh–Rose neurons. Here, neurons inside the neuronal network are connected through electrical synapses or chemical synapses. With the numerical results, it is revealed that burst synchronization transitions of both electrically and chemically coupled neuronal networks could be induced by time delay just when the coupling strength is large enough. Meanwhile, it is found that, in electrically and excitatory chemically coupled neuronal networks, burst synchronization transitions are observed through change of spiking number per burst when coupling strength is large enough; while in inhibitory chemically coupled neuronal network, burst synchronization transitions are observed for large enough coupling strength through changing fold-Hopf bursting activity to fold-homoclinic bursting activity and vice versa. Namely, two types of burst synchronization transitions are observed. One type of burst synchronization transitions occurs through change of spiking numbers per burst and the other type of burst synchronization transition occurs through change of bursting types.

Influencing travel behaviour

2019 ◽  
pp. 107-130
Author(s):  
Stewart Barr ◽  
John Preston
Keyword(s):  
Qualitative Study ◽  
Case Studies ◽  
Behaviour Change ◽  
Social Marketing ◽  
Quantitative Study ◽  
Behavioural Change ◽  
Travel Behaviour ◽  
Air Travel ◽  
The Other ◽  
Car Travel

As travel planning’s theoretical underpinnings have broadened from engineering and economics to embrace psychology and sociology, an emphasis has been placed on social marketing and nudge theory. It is argued that this is consistent with a neo-liberal trend towards governing from a distance. Using two case studies, one a qualitative study of reducing short-haul air travel, the other a quantitative study of attempts to reduce local car travel, it is found that actual behaviour change is limited. This seems to arise because behavioural change has been too narrowly defined and overly identified with personal choice.

Flight muscle and flight activity of melon fly, Bactrocera cucurbitae (Diptera: Tephritidae)

2021 ◽  
Vol 30 (2) ◽  
pp. 179-185
Author(s):  
Farhana Ferdousi ◽  
Shanjida Sultana ◽  
Tangin Akter ◽  
Pinakshi Roy ◽  
Shefali Begum
Keyword(s):  
Longitudinal Muscle ◽  
Flight Muscle ◽  
Flight Activity ◽  
The Other ◽  
Bactrocera Cucurbitae ◽  
Male And Female ◽  
Melon Fly ◽  
Length Width ◽  
Flight Muscles ◽  
The Mean

The flight activity and flight muscle of the melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) were observed. The Tethered technique was used to observe the flight activity in this study. The flight activity, and wing and flight muscles were compared between male and female melon flies. The results indicate that the female was relatively better and strong flier than the male. The mean duration of the flight activity of the females was 13.90 min/hour and of the males was 7.12 min./hour. The mean length, width, volume of wings of the males were 6.07 mm, 2.67 mm and 10.99 mm³, respectively. On the other hand, the mean length, width and volume of the wings of females were 7.07 mm, 2.87 mm and 15.60 mm³, respectively. In case of wing muscles, the mean volume of dorsal longitudinal muscle (DLM) in male and female was found 5.20 mm³ and 5.67 mm³, respectively. The mean length of flight wing muscle of male and female was 2.22 and 2.23 mm, respectively and the mean breadth of male and female was 1.65 and 1.77 mm, respectively. Dhaka Univ. J. Biol. Sci. 30(2): 179-185, 2021 (July)

Monetary and Financial Stability

2013 ◽  
Author(s):  
Brigitte Granville
Keyword(s):  
Financial Stability ◽  
The Other ◽  
Necessary Condition ◽  
Financial Instability ◽  
Information Flows ◽  
Asset Bubbles ◽  
Root Cause ◽  
Monetary Stability ◽  
Long Run ◽  
The Mean

This chapter examines the relation between monetary and financial stability, looking at possible chains of cause and effect running in both directions between them—from the possibility that an unexpected tightening of monetary policy increases the mean probability of financial system distress, to the general risk of monetary stability being undermined by financial instability. The idea that monetary stability encourages financial instability is controversial. Inflation is often the root cause of financial instability by distorting information flows between lenders and borrowers, leading to asset bubbles and over investment. Most empirical evidence tends to support the view that monetary stability should promote financial stability in the long run and not the other way around. But while monetary stability is a necessary condition for financial stability, it is not a sufficient one. In other words, financial instability can still occur even with the inflation rate under control.

An Empirical Formula to Estimate the Resistance of a Convoy in a Restricted Waterway

1996 ◽  
Vol 40 (02) ◽  
pp. 107-111
Author(s):  
J.L.J. Marchal ◽  
Y.-D. Shen ◽  
D. Kicheva
Keyword(s):  
Cross Section ◽  
Empirical Formula ◽  
The Other ◽  
Total Resistance ◽  
Empirical Methods ◽  
Joint Research ◽  
Ship Hydrodynamics ◽  
Joint Research Project ◽  
Length Width ◽  
The Subject

An examination of the literature produced very few references related to the subject of estimating the resistance of a convoy navigating in a waterway of limited cross section. This paper reports the findings of one such study—a joint research project undertaken by Belgium's University of Liege and the Bulgarian Ship Hydrodynamics Centre. A polynomial is presented here for evaluating the total resistance of a convoy moving in a restricted waterway. The resistance was found to depend on Froude number and on the relative dimensions (length, width and depth) between the convoy and the channel. The results obtained by the suggested polynomial are compared with those obtained by the other three existing empirical methods.

scholarly journals The theory of hegemony: Laclau’s path not taken

2019 ◽  
Vol 46 (10) ◽  
pp. 1225-1243
Author(s):  
Andro Kitus
Keyword(s):  
The Other ◽  
Necessary Condition ◽  
Theoretical Underpinning ◽  
Ernesto Laclau ◽  
Chantal Mouffe ◽  
Normative Dimension ◽  
The Relationship

The article revisits the theory of hegemony of Ernesto Laclau and Chantal Mouffe and shows how a normative injunction, which according to Laclau is not compatible with the hegemonic logic, is not only possible but a necessary condition for hegemony to function. The article claims that the path to demonstrate this involves rethinking the relationship between the theory of hegemony and Derridean deconstruction. Following criticisms that the theory of hegemony overlooks the aporetic nature of Derridean undecidability that it nevertheless relies upon, the hegemonic logic is submitted to a deconstructive reading, which reveals an internal aporia in it. It is further argued that the unaccounted aporia in the logic of hegemony explains the theory’s inability to satisfactorily account for its essential theoretical underpinning, the radical exclusion. However, the article also demonstrates that the aporia does not destroy hegemonic logic but, instead, supplements it by a normative dimension, by a demand of opening to the other as other.

scholarly journals THE COMPOSITION AND STRUCTURE OF ISOLATED CHROMOSOMES

1951 ◽  
Vol 34 (5) ◽  
pp. 475-492 ◽  
Author(s):  
A. E. Mirsky ◽  
H. Ris
Keyword(s):  
Phosphoric Acid ◽  
Microscopic Study ◽  
Quantitative Study ◽  
Crystal Violet ◽  
The Other ◽  
Microscopic Appearance ◽  
Basic Dye ◽  
Residual Protein ◽  
Composition And Structure ◽  
Different Tissues

1. The preparation of isolated chromosomes from liver, kidney, and pancreas has been described. 2. It has been shown that there is no gross cytoplasmic contamination in these preparations. 3. In a microscopic study of isolated chromosomes the same chromosomes have been found in different tissues of the same organism. Since individuality is one of the main characteristics of chromosomes, there can be little doubt that the preparations do, in fact, contain isolated chromosomes. 4. A quantitative study of staining with crystal violet shows that this basic dye competes with histone for the phosphoric acid groups of the DNA in chromosomes. The displacement of histone by protamine has been demonstrated. 5. Preparation of histone-free chromosomes has been described. Removal of histone does not affect the microscopic appearance of chromosomes. 6. The non-histone or residual protein has been prepared from histone-free chromosomes. The quantity of residual protein in a preparation of chromosomes is correlated with the amount of cytoplasm in the cells from which the chromosomes were prepared. 7. The microscopic appearance of chromosomes depends upon the association of DNA with residual protein. 8. Evidence has been given that in a chromosome there are two DNA-containing nucleoproteins; in one DNA is combined with histone, and in the other it is combined with residual protein.

Blind-Spots in Aristotle’s Doctrine of the Perceptual Mean

Apeiron ◽  
2020 ◽  
Vol 53 (3) ◽  
pp. 257-284
Author(s):  
Roberto Grasso
Keyword(s):  
Blind Spot ◽  
The Other ◽  
Final Part ◽  
Necessary Condition ◽  
Physiological Reaction ◽  
Sensory Apparatus ◽  
The Mean ◽  
Sense Of Touch ◽  
Blind Spots

AbstractThis paper aims to identify several interpretive problems posed by the final part of DA II.11 (423b27–424 a10), where Aristotle intertwines the thesis that a sense is like a ‘mean’ and an explanation for the existence of a ‘blind spot’ related to the sense of touch, adding the further contention that we are capable of discriminating because the mean ‘becomes the other opposite’ in relation to the perceptible property being perceived. To solve those problems, the paper explores a novel interpretation of Aristotle’s claims, arguing that they describe a homeostatic physiological reaction by which the sensory apparatus responds to perceptible stimuli. According to the proposed interpretation, such homeostatic reaction constitutes a necessary condition for perceiving what Aristotle refers to as ‘proper’ perceptible features, which include properties like ‘hot’ and ‘cold’ as well as colors and sounds.

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