Psychology & Psychiatry

How 'swapping bodies' with a friend changes our sense of self

Our sense of who we are is thought to be influenced by things like our childhood experiences, our interactions with others, and now, researchers say, our bodies. A study appearing August 26 in the journal iScience shows that, ...

Neuroscience

Optical illusions explained in a fly's eyes

Why people perceive motion in some static images has mystified not only those who view these optical illusions but neuroscientists who have tried to explain the phenomenon. Now Yale neuroscientists have found some answers ...

Neuroscience

Why visual perception is a decision process

A popular theory in neuroscience called predictive coding proposes that the brain produces all the time expectations that are compared with incoming information. Errors arising from differences between actual input and prediction ...

Neuroscience

Binaural beats synchronize brain activity, don't affect mood

An auditory illusion thought to synchronize brain waves and alter mood is no more effective than other sounds, according to research in adults recently published in eNeuro. The effect reported in other studies might be a ...

Neuroscience

Pupillary response to glare illusions of different colors

The Department of Computer Science and Engineering at Toyohashi University of Technology formed a research team with the University of Oslo to measure the size of subjects' pupils when viewing a brightness illusion (glare ...

Neuroscience

Fear center in the brain protects against illusions

If functionality of the brain's amygdala is impaired, illusory perceptions arise much faster and more pronounced. This was discovered by a team of researchers led by the University of Bonn, who studied identical twins in ...

page 1 from 12

Illusion

An illusion is a distortion of the senses, revealing how the brain normally organizes and interprets sensory stimulation. While illusions distort reality, they are generally shared by most people. Illusions may occur with more of the human senses than vision, but visual illusions, optical illusions, are the most well known and understood. The emphasis on visual illusions occurs because vision often dominates the other senses. For example, individuals watching a ventriloquist will perceive the voice is coming from the dummy since they are able to see the dummy mouth the words. Some illusions are based on general assumptions the brain makes during perception. These assumptions are made using organizational principles, like Gestalt, an individual's ability of depth perception and motion perception, and perceptual constancy. Other illusions occur because of biological sensory structures within the human body or conditions outside of the body within one’s physical environment.

The term illusion refers to a specific form of sensory distortion. Unlike a hallucination, which is a distortion in the absence of a stimulus, an illusion describes a misinterpretation of a true sensation. For example, hearing voices regardless of the environment would be a hallucination, whereas hearing voices in the sound of running water (or other auditory source) would be an illusion.

Mimes are known for a repertoire of illusions that are created by physical means. The mime artist creates an illusion of acting upon or being acted upon by an unseen object. These illusions exploit the audience's assumptions about the physical world. Well known examples include "walls", "climbing stairs", "leaning", "descending ladders", "pulling and pushing" etc.

This text uses material from Wikipedia, licensed under CC BY-SA