Biology 202
2003 First Web Paper
On Serendip

"I'll believe it when I see it:" is one of many common catch phrases included in our every day vernacular. A person who declares this is asserting that they will not be fooled by another's assumptions or perceptions of the world. This understanding raises a great sense of security within us, concerning the things that we do see, and inversely, an unavoidable sense of insecurity in those beliefs that are not supported by vision. Do you believe in Ghosts? Angels? Out of body experiences? Would you believe if you could see them? Maybe not. But it is possible to offer those who are withholding there stamp of approval on things that exist but cannot be seen, a better summary of evidence, which could make the inability to see something an invalid criteria for belief. Could a summary of evidence be compiled that would support this: Our vision is incomplete, incorrect, and can even be as misleading as to create something within the brain that does not exist at all, shedding light on a brain that is more of a visionary, and less of a reporter.
Human beings rarely contemplate the significance of their own blind spot, a place where processes of neurons join together and form the optic nerve; it is here that the brain receives no input from the eye about this particular part of the world. What I discovered while entertaining myself with a simple eye exam aimed at divulging the capabilities of the brain in the face of the eyes blind spots was fundamental in my exploration of the trust we place in vision, and so I will explain it briefly. Our brain can ignore a dot that exists on the page and "fill" the spot with the color of its surroundings, no matter what the color. However, it is not that our brain cannot conceive of an image or of a shape to fill this place. Continuing with the experiment leads you to find that the brain will continue the line that is obstructed with the black dot, covering the sides of the dot in the surrounding color, and transforming the image before you into a line within your brain. A line that is absolutely not there. This reveals more than just a weakness in the eye, but an ability of the brain! (1)
John Whitfield, within A Brain in Doubt Leaves it Out, argues that it is due to the hemispheres in the brain and their disagreements with one another. In short, "The left hemisphere seems to suppress sensory information that conflicts with its idea of what the world should be like; the right sees the world how it really is." (2) This would explain why people with paralysis due to an injury affecting the right side of their brain might deny that they are disabled. More specifically, the parietal lobe can be held responsible for this congestion of what the brain wants to see. When tampered with, injured patients can witness their legs vanish before their eyes. (2) This further damages the credibility of our perceptions. It is alarming to acknowledge that the brain has the power to create, superimpose, and even remove.
Some still may not be satisfied that with manipulation of our brains, either by covering one eye to explore our blind spot or by prodding of the parietal lobe to cause a disappearing act, that we have conclusive evidence to discard sight as a valid criteria for believing or not believing in the existence of anything. This is understandable. However, there are many instances where the brain displays misconceptions and contortions due to a preconceived notion of the world. David Whitaker and Paul V. McGraw reported in Nature Neuroscience (3), that what our brain finds unfamiliar, we tend to distort, simply because of a lack of understanding or previous model. For example, when people are asked to identify the degree of tilt of italicized letters in one display, and then in those of a display of its mirror image, an interesting fact about perception was revealed. It was consistently reported that the mirror image was slanted 2 1/2 degrees greater than the letters italics in the commonly seen clockwise way. However, the same over exaggeration of tilt was not made with shapes or characters, leaving the misinterpretation to exist in a place within the brain that associates with "memory and meaning." (3) Without being provoked in any way, the brain continues to distort at a higher level of understanding.
Can a brain be stimulated to see an entire body that does not exist? Helen Pearson found that it can be. Through electrode stimulation of the right angular gyrus, patients reported experiences such as this; "I see myself lying in bed, from above." (4) We have established that the mere fact that you may be able to see a body (or a phantom limb) does not mean it exists. In much the same way, not see another body or entity, perhaps a ghost or an angel, does not shed enough light on whether or not they actually exist. To question the gift of vision's position as the warden of reality, and to come to terms with its capabilities to present us with inaccurate, distorted and often dream like perceptions of reality is vital in opening the window of possibilities to what exists past our noses.
And so, we could take from this that all individuals are, to some degree, "blind." Blindness leads the brain to create. In fact, when tested in a large group, people's brains tend to "create" even without the excuse of missing information attributed to their blind spot. And if we go further, and take the findings of John Whitfield and Helen Pearson into account, our brains are even capable of causing our surrounding to act in peculiar ways or cause completely new surroundings to appear. We must gain a new sense of self-awareness when we evaluate what exists beyond ourselves. The ability of our brain to ignore and create forces us to look at the fabric of what we consider reality. Beyond the existence of ghosts and angels, we must question our entire perceptions of the outside world as being always incomplete, leaving us more open to explore things that our eyes may not see. There may be an argument for believing something, even without "having seen it with your own eyes."

References

1)Serendip Vision Exam, A site within the courses homepage that explains and tests the boundaries of our blind spot.
2)Article, A Brain in Doubt Leaves it Out, by John Whitfield concerning the behaviors of the brain when it is unsure and the origins of those reactions.
3)Article, A Different Angle, on studies of the brain's response to degrees of change in similar but mirror image italics print.
4)Article, Electrodes Trigger Out-of-Body Experiences, just helped to add to the capabilities of the brain to create whole figures.


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