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Transcript of Illusions
Types of Illusions
The most well-known illusion is an optical illusion, which involves sight.
However, illusions of other senses are also possible.
How Illusions Work
Optical illusions can use color, light and patterns to create images that can be deceptive or fool our brains.
The information gathered by the senses are processed by the brain, creating a perception that in reality, does not match the truth.
Illusions occur because our brain is trying to interpret what is going on and make sense of the world around us.
What is an Illusion?
An illusion is something that appears to be different than what it actually is.
An optical illusion is an image that is perceived differently than its reality.
Brain Games on National Geographic
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Illusion of Sound
Does the pitch seem to continually ascend and descend?
Does the pitch actually seem to get any higher or lower?
Information about this audio will be located in this presentation.
A perception as a visual stimuli that represents what is perceived in a way that is different than in reality.
Types of Optical Illusions
There are many types of optical illusions, which are either named after what they are or someone associated with them.
In an investigation by Massimiliano Zampini and Charles Spence, altering the sound when a chip was bitten changed its perceived crispness and staleness. If the sound level or higher frequency sounds were amplified, chips were considered more crisp.
Illusion of Touch
Also editing how stale or crisp this food is, participants were blindfolded while they felt pretzels and rated how fresh and crunchy they were. New pretzels that were bit into were considered stale and soft, when a stale pretzel was held. This also happened vice versa.
Pattern Recognition, or Kanizsa Triangle
Rotational Illusions, or Peripheral Drift
Blinking Effect Illusions, or Scintillating Grid
Induction Illusion, or Bezold Effect
This particular illusion is caused by one of Gestalt's Principles, called the Principle of Closure. Whenever we see disconnected pieces, our mind automatically fills in the spaces with what should be there, even though it is not actually drawn.
Gestalt's Principle of Closure
Named after Roger Shepard, the shepard tone seems to increase or decrease forever in pitch, but never does so.
Octaves separate the sine waves, with the beginning and end of each scale fading so that those parts are impossible to hear.
Illusions other than optical include those such as auditory illusions.
The listener hears sounds that are not actually there, or sounds that are not possible.
Tactile illusion pertains to touch, such as phantom limb, the sensation that an amputated body part is still attached.
Illusions in Real Life
Magicians and illusionists often make use of illusions in order to amaze their audiences. One of the most famous is Harry Houdini.
Hallucinations and mirages are also forms of illusions.
Hallucinations happen because the mind is between our conscious and subconscious state.
Mirages occur when a shift of air density in the atmosphere changes rapidly, and light waves bend.