Probably The Best Optical Illusion I’ve Seen In A While… And The Idea Of Priming!
August 24, 2009
An illusion is a distortion of the senses, revealing how the brain normally organizes and interprets sensory stimulation. While illusions distort reality, they tend to be generally shared by most people. Illusions may occur with more of the human senses than vision, but visual illusions, a.k.a. optical illusions, are the most well known and understood. The emphasis on visual illusions occurs because vision often dominates the other senses.
Now I will present you with the illusion in question:
Right… What do we see? Well… What I see (and hoefully all of you see too) are two colored spirals, one blue one and one green one in alternate sequence, that are hatched by orange and pinky-red lines, all swirling out from the center. But as we know it’s an illusion, let’s zoom into the details somewhat and see if we can spot what’s “wrong” with this first impression.
Hopefully, you can now see that the apparently green and blue spirals are really just green spirals. If you look at the two larger parts of the “green and blue” spirals in the left and center, you’ll notice that they are really green. However, if you pull away suficiently from the picture, you’ll notice that the “green and blue” spiral in the right hand corner is still blue. So let’s zoom in some more to see without a doubt what the colors really are.
As you can see… There is no blue… Just green.
Still not sure… Let’s remove some of the surroundingly loud orange and pinky-red colors.
Pretty cool, huh? Here’s another version of it using straight lines this time:
Now we’ve seen it… Let me expand on the idea of an optical illusion.
An optical illusion is always characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. Therefore, the information gathered by the eye is processed by the brain to give, on the face of it, a percept that does not tally with a physical measurement of the stimulus source. A conventional assumption is that there are physiological illusions that occur naturally and cognitive illusions that can be demonstrated by specific visual tricks that say something more basic about how human perceptual systems work. The human brain constructs a world inside our head based on what it samples from the surrounding environment. However, sometimes it tries to organise this information in a way it thinks is best or easiest to understand, while at other times it simply fills in the gaps. This way in which our brain works is the basis of an illusion.
Just like many other words often used in a different sense in spiritual philosophy, the word “illusion” is used to denote different aspects in Hindu Philosphy. Many Monist philosophies clearly demarcate illusion from truth and falsehood. As per Hindu advaita philosophy, Illusion is something which is not true and not false. Whereas in general usage it is common to assume that illusion is false, Hindu philosophy makes a distinction between Maya (illusion) and falsehood. In terms of this philosophy maya is true in itself but it is not true in comparison with the truth. As per this philosophy, illusion is not the opposite of truth or reality. Based on these assumptions Vedas declare that the world as humans normally see is illusion (Maya). It does not mean world is not real. The world is only so much real as the image of a person in a mirror. The world is not real/true when compared to the reality. But the world is also not false. Falsehood is something which does not exist. If we apply this philosophy to the above example, the illusion is not actually an illusion but is false. This is because, in general usage, people tend to consider lllusion is the same thing as falsehood. As per Adishankar’s teachings, the world we think is true is not true. Rather it is an illusion, which is not true and not false. The truth of the world is something which can only be experienced by removing the identity (or the Ego).
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On the same note of Illusion, I’d like to bring to your attention an experiment that was conducted by the BBC in order to demonstrate just how susceptible we all are to the effects of “priming”.
So… What is Priming?
Priming in psychology refers to activating parts of particular representations or associations in memory just before carrying out an action or task. It is considered to be one of the manifestations of implicit memory i.e. a type of memory in which previous experiences aid in the performance of a task without conscious awareness of these previous experiences. A property of priming is that the remembered item is remembered best in the form in which it was originally encountered. If a priming list is given in an auditory mode, then an auditory cue produces better performance than a visual cue.
Priming is also an experimental technique by which a stimulus is used to sensitize the subject to a later presentation of the same or similar stimulus. For example, when a subject reads a list of words including the word “table,” and is later asked to complete a word that starts with “tab,” the list “primes” the subject to answer “table,” meaning that the probability that the “primed” subject answers “table” is higher than for non-”primed” subjects.
Priming can also be demonstrated in the following way. Subjects are shown an incomplete sketch and asked what it is. If they fail to identify the sketch, they are shown another sketch that is slightly more complete. This process continues until they eventually recognize the picture. When subjects are shown the same sketch at a later date, they will identify the sketch at an earlier stage than was possible for them the first time.
Priming can be conceptual or perceptual. Conceptual priming is based on stimulus meaning and is enhanced by semantic tasks. For example, when primed with the word table, the subject will show priming effects on the word chair, because table and chair belong to the same category. Perceptual priming is based on the stimulus form and is enhanced by the match between stimulus form at study and test. Perceptual priming is sensitive to the modality and exact format of the stimulus. An example of perceptual priming is seeing the same sketch in the experiment mentioned above.
An important feature of a priming task is that amnesic subjects perform as well on it as control subjects do, indicating through their performance that they, too, remember what was on the previous study list, even though they report no conscious recollection of ever having seen the list. This is taken as one kind of evidence that implicit and explicit memory are different.
Priming of amnesic subjects with words that were unknown to them prior to the injury is impaired, which has been argued to demonstrate that priming depends on the activation of existing memory, however this interpretation is undermined by normal or near normal priming using nonverbal materials in amnesic subjects.
In the near future I will post a blog that will address the extent to which We all, as human beings, have already been primed by the societies in which we live. Again I cannot stress how careful we should all be before presuming we know something i.e. what is real and what is not real…
“I know that you believe you understand what you think I said, but I’m not sure you realize that what you heard is not what I meant.”