
	Where results make sense

Topic: Grid illusion

Related Topics

Hermann grid illusion

Optical illusion

Poggendorf Illusion

Cafe wall illusion

Fraser spiral illusion

Moon illusion

Stereogram

Autostereogram

Afterimage

Necker cube

Optical phenomenon

Magic Eye

Penrose triangle

Visual system

Oregon Vortex

In the News (Fri 27 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Grid illusion - Encyclopedia, History, Geography and Biography
		The Scintillating grid illusion is an optical illusion when dots seem to appear and disappear at the intersections of two lines crossing each other vertically and diagonally.
		Like the Scintillating grid illusion, when looking at a grid of fl squares on a white (or light-colored) background, one will have the impression that there are "ghostlike" grey blobs at the intersections of the white lines.
		The difference between the Hermann grid illusion and the Scintillating illusion is that Scintillating illusions have dots already in place at the intersection, whereas there are no dots already in place at the intersections of Hermann grid illusions.
	www.arikah.net /encyclopedia/Grid_illusion (495 words)

	Optical illusion - Wikipedia, the free encyclopedia
		There are physiological illusions, that occur naturally, and cognitive illusions, that can be demonstrated by specific visual tricks that show particular assumptions in the human perceptual system [2].
		The variation in the apparent size of the Moon (smaller when overhead, larger when near the horizon) is another natural illusion; it is not an optical phenomenon, but rather a cognitive or perceptual illusion.
		Fiction illusions are the perception of objects that are genuinely not there to all but a single observer, such as those induced by schizophrenia or hallucinogenic drugs.
	en.wikipedia.org /wiki/Optical_illusion (725 words)

	Optical illusion - the free encyclopedia (Site not responding. Last check: 2007-10-14)
		An optical illusion is any illusion that deceives the human visual system into perceivingsomething that is not present or incorrectly perceiving what is present.
		Paradox illusions offer objects that are paradoxical or impossible, such as the Penrose triangle or impossible staircasesseen, for example, in the work of M.
		Fiction illusions are the perception of objects that are genuinely not there to all but a single observer, such as thoseinduced by schizophrenia or hallucinogenic drugs.
	www.free-web-encyclopedia.com /?t=Oi (526 words)

	Perception: ECVP 2000 abstracts (Site not responding. Last check: 2007-10-14)
		The scintillating-grid illusion is a brightness-contrast phenomenon in which small white disks are added to the intersections of a gray-on-fl Hermann grid.
		In the second experiment, illusion strength was rated for an entire scintillating grid exposed for various durations as well as for one consisting of a Hermann grid onto which the white disks were briefly projected.
		Illusion strength was found to increase less rapidly with exposure duration when only the disks, rather than the whole scintillating grid, were briefly exposed.
	www.pion.co.uk /perception/ecvp00/0245.html (238 words)

	Optical illusion - LearnThis.Info Enclyclopedia (Site not responding. Last check: 2007-10-14)
		An optical illusion is any illusion that deceives the human visual system into perceiving something that is not present or incorrectly perceiving what is present.
		A mirage is an example of a natural illusion that is an optical phenomenon.
		Physiological illusions, such as the afterimages following bright lights or adapting stimuli of prolonged alternating patterns (contingent perceptual aftereffect, CAE), are the effects on the eyes or brain of prolonged stimulation of a specific type - brightness, tilt, colour, movement, and so on.
	encyclopedia.learnthis.info /o/op/optical_illusion.html (544 words)

	Hermann Grid Illusion and Lateral Inhibition
		The original grid was distorted by using an increased size of 110% and decreased sizes of 75% and 50%.
		The subjects were asked to rate the strength of the clouds within the Hermann Grid on a scale of 1-5; 1 being the clouds are not visible and 5 being the clouds are clearly visible.
		With the longer grid exposure time (.25 seconds), subjects were able to see the clouds clearly; but with the shortest grid exposure time (.05 seconds), the subjects were barely able to see the clouds.
	www.alma.edu /departments/psychology/sp2003/grid/webpagejm.htm (603 words)

	Schufreider (Background) - MONDRIAN'S OPENING: The Space of Painting
		Moreover, its grid is designed to open up the space between the inside and the outside of the painting, as it raises the question of the relationship between the work and the wall.
		Instead, figure and ground are in mutual equivalence and revealed in their own dynamic relationality, as the field of color planes that forms the emergent grid serves as the ground for the appearance of the non-color areas as surely as those areas serve in return as the equally unstable ground for whatever structure is visible.
		If the grid has been a sign of this space, then a trace of it may be thought to remain in the spacing between color planes, but precisely in the network of what I have called informal edges: at the outside that is formed within the work as belonging to it.
	www.focusing.org /apm_papers/schuf.html (8485 words)

	Perception: ECVP 2004 abstracts (Site not responding. Last check: 2007-10-14)
		Almost the only explanation of the Hermann grid illusion is the Baumgartner model: the effect is generated by the response of cells having concentric ON - OFF or OFF - ON receptive fields (ie a Mexican-hat weighting function).
		This model predicts that the illusion is independent from the relative directions of the right-angled intersections.
		We conclude that the Baumgartner model is not an adequate explanation of the Hermann grid illusion, because its prediction is contrary to the observations.
	www.perceptionweb.com /ecvp04/0585.html (234 words)

	Perception: ECVP 2002 abstracts (Site not responding. Last check: 2007-10-14)
		As equiluminous coloured grids produced no illusory spots [Schrauf et al, 1998 Tübinger Wahrnehmungskonferenz Eds H H Bülthoff et al (Kirchentellingfurth, Germany: Knirsch)], luminance differences were kept maximal between the grid elements (dark background, lines of medium luminance, bright disks).
		Three configurations were tested: (a) grids with coloured background and gray lines, (b) grids with fl background and coloured lines, (c) grids with complementary colour of lines and background.
		Illusion colours were found to be always desaturated and either of the same hue as the background [(a) and (c)] or of the complementary hue to the lines [(b)].
	www.perceptionweb.com /ecvp02/0285.html (236 words)

	Journal of Vision - The chromatic Hermann grid illusion for stimuli equated in chroma, by Comerford, Thorn, & Bodkin
		Using a restricted range of contrasts near isoluminance, we have found that the chromatic illusion may be weaker than the equivalent achromatic illusion for grids darker than the background.
		Subjects rated the magnitude of the illusion with the highest rating referenced to a standard achromatic grid presented adjacent to the comparison stimulus.
		The discrepancy between the strength of the Hermann Grid illusion for red and blue grids and for luminance equated achromatic grids is even larger at high contrast levels than we found in our previous work for low contrast levels; the discrepancy was not significant for green and yellow grids.
	journalofvision.org /5/8/53 (406 words)

	Journal of Vision - The chromatic Hermann grid illusion for stimuli equated in chroma, by Comerford, Thorn, & Bodkin
		The chromatic Hermann grid illusion for stimuli equated in chroma
		The Hermann Grid Illusion increased with contrast for all hues (P < 0.0001).
		Comerford, J. P., Thorn, F., and Bodkin, B. The chromatic Hermann grid illusion for stimuli equated in chroma [Abstract].
	www.journalofvision.org /5/8/53 (406 words)

	Hermann Grid Illusion
		The Hermann Grid illusion depends on high contrast fl and white areas to fool the eyes into perceiving intermediate grey areas.
		Imagine the Hermann Grid as a map of city streets; most intersections appear to be grey, but when you look closely at any individual intersection, you will see that it is white.
		In the Hermann Grid, the intersection that you are looking directly at (orange circle) falls onto the fovea, and so there is very little lateral inhibition in that area.
	www.brainconnection.com /teasers?main=illusion/hermann (667 words)

	Perception: ECVP '99 abstracts (Site not responding. Last check: 2007-10-14)
		The scintillating grid illusion results when small bright discs are superimposed upon the intersections of a Hermann grid (Schrauf et al, 1997 Vision Research 37 1033 - 1038).
		In the present study, the retinal eccentricity at which the illusion disappeared for grids varying in size was measured.
		This suggests that the perceptual fields for scintillating grids involve the integrated activity of large, overlapping receptive fields at higher levels.
	www.pion.co.uk /perception/ecvp99/0214.html (156 words)

	Slide Show: A15-1 (Site not responding. Last check: 2007-10-14)
		, the Hermann grid illusion and the clustered bistable quartets illusion.
		The illusions are best viewed when your browser window is set to the maximum possible size and with a screen resolution of 1024x768 or higher.
		The clustered bistable quartets illusion by Ramachandran and Anstis
	web.mit.edu /bcs/schillerlab/research/A-Vision/A15-1.html (54 words)

	Mach's Band and Hermann's Grid: Things 'aint always what they seem (Site not responding. Last check: 2007-10-14)
		One of the most powerful illusions that can be explained by the receptive field properties of retinal ganglion cells are Mach bands, named after a 19th century Austrian physicist.
		If you look closely at the top left grid you will see dark spots appearing at each intersection in the grid but not at the intersection that you are looking at.
		This helps to reduce the lightness contrast illusion that is so striking when the light/dark border is obscured and the ring does not appear to be continuous.
	www.brad.ac.uk /acad/lifesci/optometry/resources/modules/stage1/pvp1/Spatial.html (3007 words)

	[No title] (Site not responding. Last check: 2007-10-14)
		$grid{$name}{endsize} = $endsize; # <-- store the size of this grid for later use.
		is set to "; # set this point in the grid to zero.
		system "clear"; $randsize = $grid{hashgrid}{size}; # change one random spot on the grid to a random number between 0 and 9..
	www.illusion.org /code/grid (354 words)

	Optical Illusions Etc: free, scary, word & picture optical illusions
		These Optical Illusions are presented on this blog in the spirit of providing an entertaining venue to educate those interested in optical illusions and expanding the traditional assumptions of what constitutes an optical illusion.
		Optical illusions can naturally happen by specific optical tricks that show particular assumptions in the human perceptual system.
		Square A is exactly the same shade of grey as square B. mirage is a natural illusion that is an optical phenomenon.
	illusionsetc.blogspot.com /2004/05/what-are-optical-illusions.html (901 words)

	Scintillating Grid Simulation
		A standard experimental technique used by psychophysical researchers is to have the experimental subjects estimate the "magnitude of the illusion", i.e., the intensity of the illusory spot.
		Focus your vision on one intersection near the center of the grid and note the appearance of the grid in the periphery of your visual field.
		Note that the white circles at the edges of the grid are adjacent to two, rather than four, grid squares.
	www.unm.edu /~toolson/435scinte.html (1160 words)

	Journal of Vision - The vanishing disk; a revealing quirk of the scintillating grid illusion, by McAnany & Levine
		Take a Hermann grid of gray alleys on a fl background and place white disks at the intersections; observers report a striking illusion of transient fl spots on the disks (scintillation).
		To assess the importance of a repeating pattern, we tested a Hermann grid with a single white disk at one intersection.
		Disks of various luminances were presented with delays of various duration between the onsets of the grid and the disk.
	journalofvision.org /2/7/204 (366 words)

	Encyclopedia: Grid illusion (Site not responding. Last check: 2007-10-14)
		GRID can refer to : GRID computing short for gay-related immune deficiency, a former name for AIDS.
		The Scintillating grid illusion is an optical illusion An optical illusion is any illusion that deceives the human visual system into perceiving something that is not present or incorrectly perceiving what is present.
		The Hermann grid illusion is an optical illusion An optical illusion is any illusion that deceives the human visual system into perceiving something that is not present or incorrectly perceiving what is present.
	www.nationmaster.com /encyclopedia/Grid-illusion (368 words)

	The Scintillating Grid
		Scan across the grid on the right and watch the dots at the intersections fill in and then change back to white as your eyes move across the grid.
		The scintillating grid allows you to become consciously aware of one aspect of your out-of-consciousness processing system at work.
		It is incorrect to assume, unfortunately, that consumers will somehow be able to differentiate and then process marketing and advertising signals in ways that are contrary to the on-going operations and significant biases of their out-of-conscious processing systems, even when those signals are the result of reasoned, convincing, and creative thought.
	americanresearchgroup.com /grid (463 words)

	Herman Grid Illusion (Site not responding. Last check: 2007-10-14)
		This figure is called the Hermann grid after L. Herman (1870).
		Just in case you think you are being fooled, try taking two pieces of paper and cover all but two vertical or horizontal rows of fl squares.
		If you haven't yet looked at the receptive field story you should look at it or else the explanation for the Hermann grid won't make a lot of sense to you.
	www.yorku.ca /eye/hermann.htm (150 words)

	Journal of Vision - A direct estimate of the size of the illusory spots in the Hermann Grid Illusion, by Macuda, ...
		The Hermann Grid Illusion has been used to investigate the properties of human perceptive fields, the psychophysical analogue of physiological receptive fields.
		Spillman (1994) suggested that the bar width at which the illusion is strongest corresponds to the perceptive field centre size at a given retinal location.
		Observers viewed a 6x6 grid in the centre of which was presented a circular field set at the same luminance as the grid bars.
	www.journalofvision.com /3/9/754 (373 words)

	Perception: ECVP '97 abstracts (Site not responding. Last check: 2007-10-14)
		The scintillating grid is an example of a brightness contrast illusion in which bright disks are superimposed on a Hermann grid.
		The task of 5 trained subjects was to scan scintillation grids of five different spacings (0.5 - 2.0 deg separation of grid elements, observation time 60 s) in a manner yielding a maximum scintillating effect.
		Unlike the Hermann grid illusion, where illusory dark spots can be perceived at very brief exposure durations, the scintillating grid illusion takes much more time to develop.
	www.pion.co.uk /perception/ecvp97/64mon.html (305 words)

	The Hermann-Hering grid illusion demonstrates disruption of lateral inhibition processing in diabetes mellitus -- ...
		The Hermann-Hering grid illusion demonstrates disruption of lateral inhibition processing in diabetes mellitus -- Davies and Morland 86 (2): 203 -- British Journal of Ophthalmology
		The Hermann-Hering grid illusion demonstrates disruption of lateral inhibition processing in diabetes mellitus
		illusion was used to investigate the hypothesis that lateral
	www.bjophthalmol.com /cgi/content/abstract/86/2/203 (271 words)

	Scintillating Grid (Site not responding. Last check: 2007-10-14)
		This is a brand new illusion called the Scintillating Grid illusion.
		This Scintillating Grid illusion is distinct from the Hermann Grid illusion in that eye movements are important.
		Although there was a pretty comprehensive article on this illusion in Vision Research, the underlying mechanism behind it is not yet fully understood.
	www.psy.dmu.ac.uk /mirrors/illusionworks/html/scintillating_grid.html (88 words)

	The Grid illusion of Spot 06
		It has been proven that this brightness illusion is not created in the retina but only after the interaction of both optic nerves in the higher regions of the visuosensory cortex (similar, for example, to the darkening and lightening at the intersection points in the classic Hering Illusion) [1].
		Both the phantom edge phenomenon (Ehrenstein illusion) shown in the picture and the Kanisza figure [3] are triggered by the T-effect [2,5]: there are groups of neural cells which react to line ends (so-called terminators) and without further input create the intersections to the horizontal bar of the letter T as a precautionary measure.
		The gaps in the classic Ehrenstein illusion are very frequently complemented with coloured strokes in connection with research into the neon effect.
	www.blelb.com /english/blelbspots/spot06/exspot06_en.htm (451 words)

	JAC
		The movement from grid to network is traced in somewhat utopian and anarchist terms: the grid reflects the (old) Cold War system--"it simplifi[es] complex relations.
		Although the campus follows a strict grid logic from the exterior (and from the air, where all is flattened to two-dimensions), contemporary architectural historians would want to know more than how the campus buildings are sited.
		In contrast to the linear, two dimensional grid he uses to describe le Corbusier’s and Mies’ work, when Taylor discusses Robert Venturi, it is in terms of describing his work as surface, supplanting the grid, but not yet achieving the complexity of a network architecture.
	www.ndsu.nodak.edu /ndsu/birmingh/fall2003/454/JAC.html (7210 words)

	Journal of Vision - Chromatic and achromatic processing in the Hermann Grid illusion, by Comerford, Bodkin, & Thorn (Site not responding. Last check: 2007-10-14)
		When observing a Chromatic Hermann Grid, illusory dots with a color similar to the background are often perceived at the intersection of horizontal and vertical bars seen against a colored background.
		All subjects perceived the Chromatic Hermann Grid illusion except when the bars and background approached isoluminance, at which point no illusion was seen.
		The achromatic illusion has been explained by center-surround interaction within concentric receptive fields, while the chromatic illusion has been associated with the function of double opponent cells.
	www.journalofvision.com /4/8/328 (287 words)

Try your search on: Qwika (all wikis)