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The Wisdom of Psychopaths
In this engrossing journey into the lives of psychopaths and their infamously crafty behaviors, the renowned psychologist Kevin Dutton reveals that there is a...
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It is a fact of neuroscience that everything we experience is actually a figment of our imagination. Although our sensations feel accurate and truthful, they do not necessarily reproduce the physical reality of the outside world. Of course, many experiences in daily life reflect the physical stimuli that enter the brain. But the same neural machinery that interprets actual sensory inputs is also responsible for our dreams, delusions and failings of memory. In other words, the real and the imagined share a physical source in the brain. So take a lesson from Socrates: “All I know is that I know nothing.”
One of the most important tools neuroscientists use to understand how the brain creates its sense of reality is the illusion. Historically, artists as well as illusionists have used illusions to develop deep insights into the inner workings of the visual system. Long before scientists were studying the properties of neurons, artists had devised a series of techniques to “trick” the brain into thinking that a flat canvas was three-dimensional or that a series of brushstrokes was actually a still life. Applied to architecture, their work continues to astound.
Visual illusions are defined by the dissociation between physical reality and subjective perception of an object or event. When we experience such an illusion, we may see something that is not there, or fail to see something that is there, or even see something different from what is there. Because of this disconnect between perception and reality, these optical tricks demonstrate the ways in which the brain can fail to re-create the physical world. By studying these failings, we can learn about the computational methods the brain uses to construct visual experience.
Your Lying Eyes
Visual artists often try to imitate reality closely. Realistic painters convey the illusion of reality, volume or distance by making good intuitive use of perspective, color, lighting and shadow. When they are successful, the creation is sometimes difficult to distinguish from the model. Pliny the Elder, in his Natural History, narrates the legendary competition between two renowned painters in ancient Greece: Zeuxis and Parrhasios. Each of the artists brought a covered painting to the contest. Zeuxis uncovered his work: he had painted grapes so realistic that birds flew from the sky to peck at them. Convinced of his victory, Zeuxis tried to uncover Parrhasios’s painting to confirm the superiority of his work. He was defeated, however, because the curtain he tried to pull back was Parrhasios’s painting itself.
Realism in paintings did not start in ancient Greece. Even prehistoric painters used tricks to make their works appear more realistic. For instance, the Altamira bison are strategically painted over bulges of the rock, which enhances the impression of the beasts’ volume (a).
Such techniques were carried to the limit in trompe l’oeil. Trompe l’oeil, sometimes called illusionism, is a French term that means “to trick the eye.” This style of photographic realism first appeared in the Renaissance and flourished in the 17th century in the Netherlands. The lifelike pictures sometimes appeared to literally jump from the frame.
The cupola of the church of St. Ignatius of Loyola in Rome is a great example of Baroque illusionism (b). The architect of the church, Orazio Grassi, had originally planned to build a cupola but died before finishing the church, and the money was used for something else. Thirty years later, in 1685, Jesuit artist Andrea Pozzo was asked to paint a fake dome on the ceiling over the altar. Pozzo was already considered a master in the art of perspective, but the results he accomplished still could hardly be believed. Even today many visitors to St. Ignatius are amazed to find out that the magnificent cupola is not real, but an illusion.
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6 Comments
Add CommentThis article was particularly interesting, informative, but ultimately pessimistic. Although our perceptions of the world around us reside solely of our neurons, you have to remember that your perceptions and subsequent microcosm of thought is not where that world ends nor begins. Life, and the world around us, is more than just an illusion created by our neurons, and we should take time to appreciate the beauty & complexity of this "illusion" we see around us.
Reply | Report Abuse | Link to thisBased on the title, I expected a more detailed explanation of the inner workings of optic/neural interactions. Maybe the title should have been - "A history of 3-D illusionists"? The slide show was fascinating, but would have been more illuminating had they added secondary gif animations, moving a single line from one to the other to convince the skeptical. (I did it myself just to prove to my brain they were!)
Reply | Report Abuse | Link to thisI also expected the talented sidewalk painter to get more than a one line credit - "Even today artist Julian Beever creates perspective illusions in his sidewalk art." Surely not the way to inspire readers to check out his work, which is pretty awesome. No honorable mention of bodypainting illusions, either, though some are not just sexy but creatively deceptive to the mind's eye.
Final rant- the layout of SciAm articles is not user-friendly. IMHO, there was no good reason to strew this over 3 pages.
Its bad enough that this nonsense is being inculcated in academia philosophy classrooms. Its an entirely different thing to suggest that reality is a figment of our imagination. Just try telling a starving child that his/her hunger is a figment of his/her imagination or a cancer patient that their condition is simply chemical in the brain not anything concrete as reality. Both the philosophical and scientific implications of his thesis are more devastating than any abuses people could suffer, because it suggests that not only should we accept on scientific grounds that nothing is real but that we couldnt possibly perceive anything real if it hit us in the face. A person is then left to whim or the loudest voice that forces an agenda. Sorry, Mr. Macknik and Ms. Martinez-Conde, you can fool all of us with this rhetoric. Try some sciences that actually help mankind, not blind and deafen him to the truth.
Reply | Report Abuse | Link to thisto rosabrand. i think you read into it too much. lol.
Reply | Report Abuse | Link to thishunger and pain are subjective reality, they are real to the person experiencing them.
Reply | Report Abuse | Link to thisThat is different from oblective reality, or how our brains interpret outside reality
It's just as provoking as always to read about how the "real world" is somehow disconnected from the experience of the human mind. They both exist in context of one another and are intricately bound together. I pose that you could might as well say that the "real world" is an illusion conjured up by an experiential founding as well as you could pose the statements made by this article. I think the way the terms 'illusion' and 'real' are used in sciences of the mind in general undermines this philosophical possibility. Besides, people feel a little miserable about being some caleidoscopic error factory floating around in the nowhere ever disconnected from what is 'real'.
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