What do visual illusions reveal about the human brain?

An illusion is a distortion of the senses that reveals how the mind normally organizes and interprets sensory stimulation. While illusions distort our perception of reality, they are generally shared by most people and can arise from general brain assumptions, biological sensory structures, or external physical conditions. Visual illusions specifically occur because vision often dominates the other senses, and they are typically categorized into physical, physiological, and cognitive classes.

What we know

• An illusion is a distortion of the senses that can reveal how the human brain normally organizes and interprets sensory stimulation. [1, 2]
• Unlike a hallucination, which happens in the absence of a stimulus, an illusion describes a misinterpretation of a true sensation. [2]
• Visual illusions are the best-known and understood type of illusion because vision frequently dominates the other senses. [2]
• Richard Gregory proposed a useful classification of optical illusions into three main classes: physical, physiological, and cognitive illusions. [3]

Still open

• Categorization of optical illusions remains difficult because their underlying causes are often not entirely clear.

Where to go next

• the bigger pictureHow does visual perception work?
• compared withWhat is the difference between illusions and hallucinations?
• a case in pointWhat are examples of cognitive visual illusions?
• how it workedHow do unconscious inferences cause optical illusions?
• what followedCan optical illusions help monitor psychological disorders?
• an unexpected connectionHow can visual illusions treat phantom limb syndrome?Optical and multi-sensory visual illusions can be utilized in the monitoring and rehabilitation of psychological and neurological conditions like phantom limb syndrome.

Sources

• [1]illusion (Wikidata Q182593) · CC0 1.0
• [2]Illusion · CC BY-SA 4.0
• [3]Optical illusion · CC BY-SA 4.0
• [4]List of optical illusions · CC BY-SA 4.0
• [5]Visual perception · CC BY-SA 4.0