Limitations Of The Possibility Of Objective Perception
The limitations of perception are even more far reaching: our perception is not only limited when we do not have access to the thing in itself, it is very practically limited to the quality of processing and the general specifications of our perceptual system. For instance, our acoustic sense can only register and process a very narrow band of frequencies ranging from about 16 Hz20 kHz as a young adultthis band gets narrower and narrower with increasing age. Typically, infrasonic and ultrasonic bands are just not perceivable despite being essential for other species such as elephants and bats, respectively. The perception of the environment and, consequently, the perception and representation of the world as such, is different for these specieswhat would be the favorite music of an elephant, which preference would a bat indicate if honestly asked? What does infrasonic acoustics sound and feel like? Note: infrasonic frequencies can also be perceived by humans not acoustically in a strict sense but via vibrationsstill, the resulting experiences are very different . To make such information accessible we need transformation techniques for instance, a Geiger-Müller tube for making ionizing radiation perceivable as we have not developed any sensory system for detecting and feeling this band of extremely high frequency electromagnetic radiation.
What Is A Hallucination
Hallucinations refer to false perceptions. The key characteristic is that in hallucinations there are no external stimuli. Hence, they can be the result of internal stimulation. Hallucinations are not universal as in the case of illusions. On the contrary, they tend to be unique and personal. In psychology, it is believed that people who are suffering from mental conditions experience hallucinations.
Let us take a small example. In the Shakespearean drama Macbeth, Macbeth begins to have hallucinations as the story progresses. He begins to see the ghost of Banquo. Here there are no external stimuli whatsoever. Hence, it can be considered as a hallucination that results from the guilty conscience of Macbeth. Even in day to day life, people can experience hallucinations. Having hallucinations is considered as one of the symptoms of schizophrenia, a mental disorder.
What Do You See
In the top half of image above, which line appears the longest? For most people, the line with the fins of the arrow protruding outward appears to be the longest, while the line with the arrow fins pointing inwards appears shorter. While your eyes might tell you that line in the middle is the longest, the shafts of both lines are exactly the same length, as shown in the bottom half of the image.
Like other optical illusions, the Muller-Lyer illusion has become the subject of considerable interest in psychology over the years. Different theories have emerged to explain the phenomenon.
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The Relationship Between Reality And Object
Sensory perception is often the most striking proof of something factualwhen we perceive something, we interpret it and take it as objective, real. Most obviously, you can experience this with eyewitness testimonies: If an eyewitness has seen it with the naked eye, judges, jury members and attendees take the reports of these percepts not only as strong evidence, but usually as factdespite the active and biasing processes on basis of perception and memory. Indeed, it seems that there is no better, no more proof of something being factual knowledge than having perceived it. The assumed link between perception and physical reality is particularly strong for the visual sensein fact, we scrutinize it only when sight conditions have been unfortunate, when people have bad vision or when we know that the eyewitness was under stress or was lacking in cognitive faculties. When people need even more proof of reality than via the naked eye, they intuitively try to touch the to-be-analyzed entity in order to investigate it haptically. Feeling something by touch seems to be the ultimate perceptual experience in order for humans to speak of physical proof .
What Are Some Famous Optical Illusions
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Physiology Of Vision And The Visual System
John V. Forrester MB ChB MD FRCS FRCP FRCOphth FMedSci FRSE FARVO, … Eric Pearlman BSc PhD, in, 2016
Visual illusions such as the Schrödinger staircase and Rubins vase occur in a cyclical manner in which each of the perceptions regularly alternates. Such illusions have a periodicity and are in this sense time-dependent. In addition they can be modified spatially, as in the tilt illusion in which a vertically oriented tilted image occupying a surround regions of vertical stripes will generate the illusion that the orthogonally vertical surround stripes are tilted in the opposite direction. This illusion can be overcome by adaptation using an image after-effect induced by gazing for 30 seconds or more at stripes tilted anti-parallel to the original image and then quickly fixating on the tilted image once more. The periodicity of the fluctuations is also alterable with drugs.
M. Walker, in, 2014
Intersensory Facilitation And Rivalry
Stimulation through one sense may enhance the function of another. Seeing a boat rocked by waves may activate the sense of balance in an observer on a pier to the point at which it causes seasickness. A painting of an Arctic scene of frost and snow may evoke the sensation of cold or a shiver that produces gooseflesh. An explosion or gunshots may give a bystander the illusion of being struck. A picture of appetizing food may evoke sensations of taste and smell.
Sensory rivalry, in which one stimulus inhibits the perception of another, may result from a conflict of cues if sensory information is ambiguous or discrepant, as in the tilted-room experiment discussed above, during which the visual sense conflicts with cues from the sense of equilibrium. States of pain, panic, monotony, or fatigue may create conditions in which various senses mask or inhibit each other. A witness of a terrifying sight, for example, may become oblivious to all sounds. Distraction also can elevate the pain threshold, as in the case of wounded soldiers whose injuries become painful only after the stress of combat has subsided. Similarly, some dentists have used auditory analgesia .
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How Do Optical Illusions Work
What is an optical illusion? Optical illusions, more appropriately known as visual illusions, involves visual deception. Due to the arrangement of images, the effect of colors, the impact of light source or other variables, a wide range of misleading visual effects can be seen.
If you’ve ever struggled to see the hidden image in a single-image stereogram, you may have discovered that not everyone experiences visual illusions in the same way. For some illusions, some people simply are not able to see the effect.
While optical illusions can be fun and interesting, they also reveal a great deal about the working of the brain. Learn more about some of the most famous optical illusions and discover exactly how and why these visual illusions occur.
Reconstructing Human Psychological Reality
All these intelligent perceptual processes can most easily be demonstrated by perceptual illusions: For instance, when we look at the inner horizontal bar of Figure 4, we observe a continuous shift from light to dark gray and from left to right, although there is no physical change in the gray valuein fact only one gray value is used for creating this region. The illusion is induced by the distribution of the peripheral gray values which indeed show a continuous shift of gray levels, although in a reverse direction. The phenomenon of simultaneous contrast helps us to make the contrast clearer helping us to identify figure-ground relations more easily, more quickly and more securely.
Figure 4. Demonstration of the simultaneous contrast, an optical illusion already described as phenomenon 200 years ago by Johan Wolfgang von Goethe and provided in high quality and with an intense effect by McCourt : the inner horizontal bar is physically filled with the same gray value all over, nevertheless, the periphery with its continuous change of gray from darker to lighter values from left to right induce the perception of a reverse continuous change of gray values. The first one who showed the effect in a staircase of grades of gray was probably Ewald Hering , who also proposed the theory of opponent color processing.
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Visual Deficit In Autism Spectrum Disorder
Autism spectrum disorder is a pervasive developmental condition characterized by abnormalities in communication, social interaction, and presence of markedly restricted interests and stereotyped behaviors .
According to the neuroconstructivist approach early abnormalities in low-level perception and attention could cause the typical developmental trajectories to deviate and produce impairments in high-level cognitive domains . Attentional impairments are probably the most consistently reported neurocognitive deficit in infants and children with ASD .
The attention spotlight is not only oriented in a specific location, but also has to be adjusted in its size . This ability allows one to process visual stimuli from a narrow or a broad visual region . Lovaas and Schreibman showed that children with autism responded to a restricted range of environmental stimuli, suggesting that their attention was excessively focused. The authors explained these findings in terms of stimulus over-selectivity. More recently, this idea was corroborated by a prolonged zoom-in and sluggish zoom-out attentional mechanism . This abnormal attentional focusing is probably linked to dysfunctional topdown feedback from the fronto-parietal network to the early visual areas. The attentional zoom-out deficit could contribute to the atypical visual perception associated to individuals with ASD, which, in turn, could have consequences in their social-communicative development .
How Does The Spinning Dancer Illusion Work
After it was initially created by Nobuyuki Kayahara, the illusion was mistakenly referred to as a scientific personality test of right brain/left brain dominance by numerous websites and blogs. In reality, the spinning dancer illusion is related to a bistable perception in which an ambiguous 2-dimensional figure can be seen from two different perspectives. Because there is no third dimension, our brains try to construct space around the figure. Similar illusions include the Necker Cube and the Reversible Face/Vase Illusion.
People typically see the clockwise variation, which research suggests can be attributed to a tendency to assume a viewpoint from above the figure as well as a tendency to perceive movements of the right as opposed to the left foot.
In the Zöllner illusion, straight lines appear to move even though they are static.
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What Happens In Our Brain In Optical Illusions
We have known for a long time that our brain does not perceive reality as it is, but tends to interpret it in its own way, filling in the missing gaps and generating hypotheses and patterns that allow us to give coherence and meaning to what we see. Our brain resorts to cognitive and perceptual shortcuts to save time and resources.
Optical illusions, such as the Müller-Lyer illusion, generate doubts in our perceptual system, and not finding a known and congruent pattern, the brain decides to reinterpret what it sees through your store of previous experiences and statistics and after having extracted the available information, he comes to a conclusion: the lines with the arrows facing out are longer. An erroneous, but coherent conclusion.
On the one hand, from a physiological point of view, optical illusions can be explained as a phenomenon of refraction of light, as when we put a pencil in a glass of water and it apparently twists.
These illusions can also be explained as a perspective effect, in which the observer is forced to use a certain preset point of view, as with anamorphoses, deformed drawings that recover their image without deformation when viewed from a certain angle or cylindrical mirror. Similarly, certain contrasts between colors and shades, in combination with the movement of the eyes, can generate illusions of a false sensation of movement.
What Does It Mean If You See The Duck Before The Rabbit
The meaning of the rabbit duck illusion says that people who are able to see both animals easily are more creative in general. Most people can see the duck, but have difficulty seeing the rabbit so if you can see both, congratulations! You probably have a greater sense of creativity than most people.
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What Is The Mller
The Müller-Lyer illusion is one of the best known geometric optical illusions consisting of a set of lines that end in arrowheads. The orientation of the tips of each arrow determines how accurately we perceive the length of the lines.
As with most visual and perceptual illusions, the Müller-Lyer illusion has helped neuroscientists to study the functioning of the brain and the visual system, as well as the way we perceive and interpret images and visual stimuli.
This optical illusion Named after German psychiatrist and sociologist Franz Carl Müller-Lyer, who published up to 15 versions of this illusion in a well-known German magazine, at the end of the 19th century.
One of the best known versions is the one that consists of two parallel lines: one of them ends in arrows pointing inwards and the other ends with arrows pointing outwards. When looking at the two lines, the one with the arrows pointing inward appears significantly longer than the other.
In other alternate versions of the Müller-Lyer illusion, each arrow is placed at the end of a single line, and the observer tends to perceive the midpoint of the line, just to make sure the arrows constantly stay to one side of it.
A Final Note: Science Doesnt Always Produce Simple Results
Professor Witts study had interesting results however, they werent quite as simple as we have made them seem. The researchers actually had two different hole sizes: 2 inches and 4 inches. The Ebbinghaus circles were adjusted to be relatively larger or smaller than the putting hole.
The Ebbinghaus illusion worked for the smaller putting holes, but not for the larger putting holes. In other words, when people drew the circles as they perceived them , they drew different sized circles for the 2 inch holes , but the same size circles for the 4 inch holes .
For the larger putting holes, putting accuracy was the same for the two different conditions. This didnt bother the experimenters, becauseas we have already notedthe participants did not experience the Ebbinghaus illusion with the larger holes. If the holes were perceived as the same, then self-confidence should not have been affected and, in turn, putting should not have been better in one condition than the other.
- Ebbinghaus Application and Text on Illusions. : Patrick J Carroll. Provided by: Lumen Learning. License: CC BY: Attribution
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A If You Saw The Old Man
The Old Man
If you saw the old man first, it means that you are quite mature in your thoughts. You have seen the world, experienced its ups and downs and have grown to see the world for what it is. You have had the experiences and knowledge which have helped you grow as a person. You have, as time passed, grown as a wise soul and if this was the picture you observed first, you are calm and humble as well .
Illusion Due To Cognitive Processes
Cognitive illusions occur in the presence of the stimulus but the individual simply misinterprets the situation or the stimulus. There are countless illusions related to cognitive processes, that can be broadly divided into two categories:
- Illusion of size
- The illusion of shape or area
Illusion of Size
Illusions of size occur because we perceptually distort the length of various lines. The theory of misapplied constancy suggests that we perceive some parts are farther away than others. There are several examples of size illusions. They are,
Muller Lyer illusion: Both arrowheads and the feather-headed lines are the same lengths. But the one with the feather looks longer or bigger. The symbols create the illusion.
The vertical line falsely appears taller than the horizontal line. But both lines are actually equal. The horizontal-vertical illusions stem from our tendency to perceive objects higher in our visual field as more distant.
The two-line segments are equal on the other figure, but the straight line outside of the circle appears bigger than the straight line within the circle.
Ebbinghaus illusion or illusion of contrast. The center circles are the same size, but one to the left looks larger because of its background.
Wundt illusion based on intersecting lines. The horizontal lines are parallel. We see the parallel lines as bent.
Hering illusion. The horizontal lines are parallel.
The Illusions of Shape or Area
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The Psychology Behind Optical Illusions With Pictures
Psychreg on Cognitive Psychology
According to the National Eye Institute: An optical illusion is something that plays tricks on your vision. Optical illusions teach us how our eyes and brain work together to see.
You live in a three-dimensional world, so your brain gets clues about depth, shading, lighting, and position to help you interpret what you see. But when you look at a two-dimensional image, your brain can be fooled because it doesnt get the same clues.
More recently, new class of illusion, developed by a visual artist and a psychology researcher, underscores the highly constructive nature of visual perception.
The illusion, which the creators label Scintillating Starburst, evokes illusory rays that seem to shimmer or scintillate like a starburst. Composed of several concentric star polygons, the images prompt viewers to see bright fleeting rays emanating from the centre that are not actually there.
Heres are some optical illusions:
Dennis Relojo-Howell is the founder of Psychreg.