The Muller-Lyer Illusion Demonstrating How Parts of the Mind Work in Isolation to Other Parts

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The human mind contains areas, or compartments, that perform specific mental tasks. For example one compartment is used to understand language, another to perceive smell. Some of these compartments are isolated from other parts of the brain. They work on their own, not influenced to goings on elsewhere.

This working in isolation is illustrated by the below common optical illusion, called a Muller-Lyer illusion. Look at the two horizontal lines.

The lines appear to be of different lengths. However they are the same length. Measure them with a ruler to prove this to yourself. It is a part of your mind that incorrectly perceives the lines to be of different lengths.

The key here is not the erroneous perception itself. The key is that even after the viewer knows the lengths are identical, the lines still appear of different lengths. Even after the viewer measures the lines and agrees 100 percent that the lines are of identical lengths, the illusion still exists to this viewer.

This shows that the part of the mind that makes this perception of the lines works in isolation, unaffected even by your conscious knowledge that the lines are of identical lengths. If the part of the mind that creates the perception was influenced by your conscious knowledge, the misperception would dissapear once you discovered the lines were the same length.

Muller Lyer illusion is real life:The center vertival lines appear of different lengths, though they are equal. Without the illusion being pointed out, the error goes unnoticed in daily life.