The Hermann Grid is a visual Illusion developed by Ludimar Hermann in 1870. The original layout of the illusion consists of black squares superimposed on a white background. The illusory effect reported by most people are the appearance of faint gray dots at the intersections of the white bars that separate the black squares. Many psychologists attribute the explanation of the illusory effect created by the Hermann Grid to a Psychologist by the name of Baumgartner in 1960. Baumgartner claimed that the perception of the faint gray dot was the result of lateral inhibition in the receptive fields in the ganglion cells (Blatchley and Moses, 2012). A visual receptive field is the portion of the visual field that enables a given neuron to fire once stimulated. These receptive fields are composed of an inner circular and an outer circular ring. The response of the inner ring is the opposite of the outer ring, so that an on-center/off-surround receptive field sends an excitatory response with the stimulation of the inner ring and an inhibitory response with the stimulation of the outer ring (Blatchley and Moses, 2012). Lateral inhibition is an interaction between the center (inner ring) and the surround (outer ring) part of the receptive field (Blatchley and Moses, 2012). Within the Hermann Grid, at the intersections of the white bars, the inhibitory surround of an on-center/off-surround in the receptive fields receives more inhibition than the does the excitatory center of the receptive field, thus creating the perception of the faint grey spots (Blatchley and Moses, 2012). This theory proposed by Baumgartner has also been referred to as the “retinal ganglion cell theory” (Schiller and Carvey, 2005). While the retinal ganglion theory has...
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... Baumgartner as the explanation of the illusory effect created by the Hermann grid has been deemed the most plausible explanation. Schiller and Carvey (2005), through a series of analytical observations provided evidence on as to why the retinal ganglion cell theory is a feeble explanation for the illusion. Their research, along with others, looked to disprove the untenability of Baumgartner’s theory by examining the theory’s lack of explanation for several key aspects that effect the perception of the Hermann grid illusion; size, orientation (De Lafuente and Ruiz, 2004), grid manipulation (Levine and McAnany, 2008), color (Blatchley and Moses, 2012), and spatial arrangement (Cox et al., 2007). Each of these aspects took aim at the validity of the retinal ganglion cell theory and suggested that there is a possibility for a new explanation to arise and be discovered.
Sullivan, G. D., Georgeson, M. A., & Oatley, K. (1972). Channels for spatial frequency selection and detection of single bars by the human visual system. Vision Research, 12, 383-94.
40. The earliest vision researchers, Hubel and Wiesel, discovered that neurons in the rear occipital cortex of cats respond only to:
The 2's and 5's were arranged in such a way that one number formed a distinct shape in the midst of the jumble of the other number. A non-synesthetic would be incapable of distinguishing any pattern due to the close resemblance of the numbers. But, in 90% of the cases where people claimed to see colors they were easily able to discern the shape because it registered stood out for them as a completely different color.
The illusion is so convincing that the person that is admiring the room would think that the figures or persons are different sizes and might be twins, but in reality it is all about how they are collocated ( one is closer than the other one ) and the way the shape of the walls are and how they’re connected. Although theres other studies that show that theres no need for the room to have a ceiling or walls. This happens because the same room can have a horizontal division but in reality is not horizontal against an appropriate background and the eye relies on the apparent relative height of an object above that horizon. However, this effect can be seen in many movies nowadays.
Kandel, E. R., J. H. Schwarz, and T. M. Jessel. Principles of Neural Science. 3rd ed. Elsevier. New York: 1991.
Weber, in his study of the senses, experimented with muscular sensations and cutaneous senses by way of the two-point threshold and the just noticeable difference. His research revealed that there could not be a direct connection between our perception of a physical stimulus and the stimulus itself.
Sajda P. & Finkle, L.H. (1995) Intermediate Visual Representations and the Construction of Surface Perception. Journal of Cognitive Neuroscience, 7, 267-291.
Muller-Lyer illusion is one of the most studied perceptual illusions experiment in cognitive psychology. The illusion experiment was created by Psychiatrist Franz Carl Muller-Lyer in 1889. The Muller-Lyer illusion reveals that when three horizontal lines with the same length are presented together. The first line has two outward wings at its end; the second doesn’t have wings; and the last line has two inward wings at its end. Muller-Lyer illusion says that the line with outward wings looks longer than the line without wings, and the other line with inward wings looks shorter than the one without wings. In our CogLab experiment, it is designed to have only a line with outward wings and another line that has no wings showing to the participants; their task was to choose which line is longer than the other in the experiment. In this experiment, the constant stimuli experimental method will keep the length of the line with outward wings constant throughout the experiment. The result will tell us participants’ judgments of physical length may be deluded by the presence of outward wings. Participants tend to perceive that the line with wings looks longer than a line without wings. (CogLab, Muller-Lyer Illusion, Cengage Learning)
In 1976, Thomas was present at a scientific symposium where she surveyed an exhibit displaying an illusion. The exhibit utilized concave mirrors to trick the onlooker into assuming that an illuminated bulb was glowing even after it had been unscrewed from the socket. She was so fascinated by what she observed that she believed this would be extensive if, ...
In Stephen Jay Gould’s essay, “Some close encounters of a mental kind,” Gould discussed about how certainty can be both blessing and dangerous. According to Gould, certainty can be blessing because it can provide warmth, comfort and secure. However, it can also be a danger because it can trick our mind with false information of what we see and remember in our mind. Gould also talked about the three levels of possible error in direct visual observation: misperception, retention and retrieval. According to Gould, our human mind is the greatest miracle of nature and the wicked of all frauds and tricksters mixed. To support his argument and statements, he used an example of an experiment that Elizabeth Loftus, a professor from University of California Irvine, did to her students and a personal experience of his childhood trip to the Devils Tower. I agree with Gould that sight and memory do not provide certainty because what we remember is not always true, our mind can be tricky and trick us into believing what we see/hear is real due to the three potential error of visual observation. Certainty is unreliable and tricky.
This fourth dimension effect was reached by stripping away the distractions. Malevich's art was made to be felt and he broke down complex characters into the simplest of geometric shapes. The colors that he chose for his subjects were not the ones that were true to life. He did this by choice to get past the human biased way of seeing an object. He was trying to transmit pure sensation. The actual subject is irrelevant; the feelings of it are the main focus.
Michael Tye comments that, “Viewers of [a] painting can apprehend not only its content... but also the colors, shapes, and spatial relations obtaining among the blobs of paint on the canvas.” In this sense, qualia explains how humans can understand and recognize images on an everyday basis. If a person that had never seen a tree before was shown a drawing of a brown rectangle with a green circle attached to the top, the image would be foreign and unrecognizable. However, if a person had seen a tree before and was given the same drawing, they would recognize the general shape and colors of the image and assume it was a tree. By giving objects and experiences distinct, subjective qualia, images become recognizable and organized in the
From its conception Baroque art, especially painting, has been designed to overwhelm and wow the viewer. Artistic devices of spatial illusion were developed during the Baroque in response to cultural anxieties occasioned by revolutionary scientific discoveries, revolutionary religious upheaval, and the new taste for virtuosic visual display. A spectacular painted phenomena, quadratura painting, make Baroque paintings seem to reach beyond their architectural limits into the viewer’s space. This trend of illusionistic painted surfaces begins early with Andrea Mantegna’s fresco Camera degli Sposi in 1465. With a di sotto in su, or “seen from below”, perspective the illusion of winged puttos, a peacock and some women lean out into what appears to be a third dimension. Viewers and painters alike grasped onto this illusionistic perspective in painting and ran with it. It was the Baroque era that really explored and perfected the techniques of illusionistic painting. From Mantegna to Pozzo and beyond, to this day illusionistic painting of the Baroque era still leaves viewers in awe.
The seaside is one of my favorite places. According to my expectation, as soon as I arrived at Santa Monica beach, I recalled the memories of happiness, pleasure, serenity, and comfort. I think that this mantal experience is based on my memory and my past experience that may be related to the beach, because I always felt these emotions whenever I came the beach. So, it can be considered as a kind of “Necker tube.” I think that my past experiences and prior knowledge related to the beach ,which is a stimulus, helped me make inferences. My perceptions of the beach come from what I saw, what I thought, and what I felt at the beach. When it comes to visual illusions, such as the Necker tube, Gregory believed that the brain may create incorrect hypotheses, leading to several errors of
Blakslee, S. (1993, August 31). The New York Times. Retrieved May 2, 2014, from www.nytimes.com: http://www.nytimes.com/1993/08/31/science/seeing-and-imagining-clues-to-the-workings-of-the-mind-s-eye.html