An illusion is a distortion of the senses, which can reveal how the mind normally organizes and interprets sensory stimulation. Although illusions distort the human perception of reality, they are generally shared by most people.[1]
Illusions may occur with any of the human senses, but visual illusions (optical illusions) are the best-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.[2]
Some illusions are based on general assumptions the brain makes during perception. These assumptions are made using organizational principles (e.g., Gestalt theory), an individual's capacity for depth perception and motion perception, and perceptual constancy. Other illusions occur because of biological sensory structures within the human body or conditions outside 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 another auditory source) would be an illusion.
Example of visual illusion: a real gecko hunts the pointer of a mouse, confused with a prey
An optical illusion. Square A is exactly the same shade of grey as Square B. (See Checker shadow illusion.)
A visual illusion or optical illusion[3] is characterized by visually perceived images that are deceptive or misleading. Therefore, the information gathered by the visual sense is processed to give, on the face of it, a percept that does not tally with information from other senses or physical measurement. A conventional assumption is that there are physiological illusions that occur naturally and cognitive illusions that can be demonstrated by specific visual tricks[dubious – discuss] that say something more basic about how human perceptual systems work. The visual system (eye and brain) constructs a world inside our head[dubious – discuss] based on what it samples from the surrounding environment. However, sometimes it tries to organize this information "it thinks best" while other times it fills in the gaps.[4][5] This way in which our brain works is the basis of an illusion.
An auditory illusion is an illusion of hearing, the auditory equivalent of a visual illusion: the listener hears either sound which are not present in the stimulus, or "impossible" sounds. In short, audio illusions highlight areas where the human ear and brain, as organic, makeshift tools, differ from perfect audio receptors (for better or for worse). One example of an auditory illusion is a Shepard tone.
Examples of tactile illusions include phantom limb, the thermal grill illusion, the cutaneous rabbit illusion and a curious illusion that occurs when the crossed index and middle fingers are run along the bridge of the nose with one finger on each side, resulting in the perception of two separate noses. The brain areas activated during illusory tactile perception are similar to those activated during actual tactile stimulation.[6] Tactile illusions can also be elicited through haptic technology.[7] These "illusory" tactile objects can be used to create "virtual objects".[8]
A temporal illusion is a distortion in the perception of time, which occurs when the time interval between two or more events is very narrow (typically less than a second). In such cases, a person may momentarily perceive time as slowing down, stopping, speeding up, or running backward.
Intersensory
Illusions can occur with the other senses including those involved in food perception. Both sound[9] and touch[10] have been shown to modulate the perceived staleness and crispness of food products. It was also discovered that even if some portion of the taste receptor on the tongue became damaged that illusory taste could be produced by tactile stimulation.[11] Evidence of olfactory (smell) illusions occurred when positive or negative verbal labels were given prior to olfactory stimulation.[12] The McGurk effect shows that what we hear is influenced by what we see as we hear the person speaking; when the auditory component of one sound is paired with the visual component of another sound, leading to the perception of a third sound.[13]
Disorders
Some illusions occur as a result of an illness or a disorder. While these types of illusions are not shared with everyone, they are typical of each condition. For example, migraine sufferers often report fortification illusions.
Neuroscience
Perception is linked to specific brain activity and so can be elicited by brain stimulation. The (illusory) percepts that can be evoked range from simple phosphenes (detections of lights in the visual field) to high-level percepts.[14] In a single-case study on a patient undergoing presurgical evaluation for epilepsy treatment, electrical stimulation at the left temporo-parietal junction evoked the percept of a nearby (illusory) person who "closely 'shadowed' changes in the patient's body position and posture".[15][16]
^Solso, R. L. (2001). Cognitive psychology (6th ed.). Boston: Allyn and Bacon. ISBN0-205-30937-2
^McGurk, Hj.; MacDonald, J. (1976). "Hearing lips and seeing voices". Nature. 264 (5588): 746–748. Bibcode:1976Natur.264..746M. doi:10.1038/264746a0. PMID 1012311. S2CID 4171157.
^ The term "optical illusion" derives, not from optics in today's sense, but from the Greek word for "seeing". So an "optical illusion" is an illusion of seeing.
^ Yoon Mo Jung and Jackie (Jianhong) Shen (2008), J. Visual Comm. Image Representation, 19(1):42-55, First-order modeling and stability analysis of illusory contours.
^Yoon Mo Jung and Jackie (Jianhong) Shen (2014), arXiv:1406.1265, Illusory shapes via phase transition.
^Gross, L. (2006). "Classic Illusion Sheds New Light on the Neural Site of Tactile Perception". PLOS Biol. 4 (3): e96. doi:10.1371/journal.pbio.0040096. PMC1382017. PMID 20076548.
^(PDF). Archived from the original (PDF) on 2006-10-03. Retrieved 2006-10-03.
^Zampini M & Spence C (2004) "The role of auditory cues in modulating the perceived crispness and staleness of potato chips". Journal of Sensory Studies 19, 347-363.
^Barnett-Cowan M (2010) "An illusion you can sink your teeth into Haptic cues modulate the perceived freshness and crispness of pretzels" 2015-06-13 at the Wayback Machine. Perception 39, 1684-1686.
^Nath, A. R.; Beauchamp, M. S. (Jan 2012). "A neural basis for inter-individual differences in the McGurk effect, a multisensory, auditory-visual illusion". NeuroImage. 59 (1): 781–787. doi:10.1016/j.neuroimage.2011.07.024. PMC3196040. PMID 21787869.
^Lotto, Beau (2017-05-01). "Reality is not what it seems: the science behind why optical illusions mess with our minds". Wired UK. ISSN 1357-0978. Retrieved 2020-02-27.
^Arzy, S; Seeck, M; Ortigue, S; Spinelli, L; Blanke, O (2006). "Induction of an illusory shadow person" (PDF). Nature. 443 (7109): 287. Bibcode:2006Natur.443..287A. doi:10.1038/443287a. PMID 16988702. S2CID 4338465.
^Hopkin, Michael (20 September 2006), "Brain Electrodes Conjure up Ghostly Visions", Nature: news060918–4, doi:10.1038/news060918-4, S2CID 191491373
External links
Wikiquote has quotations related to Illusion.
Wikimedia Commons has media related to Illusions.
Universal Veiling Techniques 2010-05-07 at the Wayback Machine
by J.R. Block.
Optical illusions and visual phenomena by Michael Bach
- touch illusions, forces and the geometry of objects, by Gabriel Robles-De-La-Torre.
Silencing awareness of visual change by motion
March 30, 2023
illusion, this, article, about, perception, figures, speech, allusion, other, uses, disambiguation, illusion, distortion, senses, which, reveal, mind, normally, organizes, interprets, sensory, stimulation, although, illusions, distort, human, perception, reali. This article is about perception For figures of speech see Allusion For other uses see Illusion disambiguation An illusion is a distortion of the senses which can reveal how the mind normally organizes and interprets sensory stimulation Although illusions distort the human perception of reality they are generally shared by most people 1 Illusions may occur with any of the human senses but visual illusions optical illusions are the best 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 2 Some illusions are based on general assumptions the brain makes during perception These assumptions are made using organizational principles e g Gestalt theory an individual s capacity for depth perception and motion perception and perceptual constancy Other illusions occur because of biological sensory structures within the human body or conditions outside 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 another auditory source would be an illusion Contents 1 Visual 2 Auditory 3 Tactile 4 Temporal 5 Intersensory 6 Disorders 7 Neuroscience 8 See also 9 References 10 External linksVisual EditMain article Optical illusion source source source source source source source source source source source source source source Example of visual illusion a real gecko hunts the pointer of a mouse confused with a prey An optical illusion Square A is exactly the same shade of grey as Square B See Checker shadow illusion A visual illusion or optical illusion 3 is characterized by visually perceived images that are deceptive or misleading Therefore the information gathered by the visual sense is processed to give on the face of it a percept that does not tally with information from other senses or physical measurement A conventional assumption is that there are physiological illusions that occur naturally and cognitive illusions that can be demonstrated by specific visual tricks dubious discuss that say something more basic about how human perceptual systems work The visual system eye and brain constructs a world inside our head dubious discuss based on what it samples from the surrounding environment However sometimes it tries to organize this information it thinks best while other times it fills in the gaps 4 5 This way in which our brain works is the basis of an illusion Auditory EditMain article Auditory illusion An auditory illusion is an illusion of hearing the auditory equivalent of a visual illusion the listener hears either sound which are not present in the stimulus or impossible sounds In short audio illusions highlight areas where the human ear and brain as organic makeshift tools differ from perfect audio receptors for better or for worse One example of an auditory illusion is a Shepard tone Tactile EditMain article Tactile illusion Examples of tactile illusions include phantom limb the thermal grill illusion the cutaneous rabbit illusion and a curious illusion that occurs when the crossed index and middle fingers are run along the bridge of the nose with one finger on each side resulting in the perception of two separate noses The brain areas activated during illusory tactile perception are similar to those activated during actual tactile stimulation 6 Tactile illusions can also be elicited through haptic technology 7 These illusory tactile objects can be used to create virtual objects 8 Temporal EditMain article Time perception Types of temporal illusions A temporal illusion is a distortion in the perception of time which occurs when the time interval between two or more events is very narrow typically less than a second In such cases a person may momentarily perceive time as slowing down stopping speeding up or running backward Intersensory EditIllusions can occur with the other senses including those involved in food perception Both sound 9 and touch 10 have been shown to modulate the perceived staleness and crispness of food products It was also discovered that even if some portion of the taste receptor on the tongue became damaged that illusory taste could be produced by tactile stimulation 11 Evidence of olfactory smell illusions occurred when positive or negative verbal labels were given prior to olfactory stimulation 12 The McGurk effect shows that what we hear is influenced by what we see as we hear the person speaking when the auditory component of one sound is paired with the visual component of another sound leading to the perception of a third sound 13 Disorders EditSome illusions occur as a result of an illness or a disorder While these types of illusions are not shared with everyone they are typical of each condition For example migraine sufferers often report fortification illusions Neuroscience EditPerception is linked to specific brain activity and so can be elicited by brain stimulation The illusory percepts that can be evoked range from simple phosphenes detections of lights in the visual field to high level percepts 14 In a single case study on a patient undergoing presurgical evaluation for epilepsy treatment electrical stimulation at the left temporo parietal junction evoked the percept of a nearby illusory person who closely shadowed changes in the patient s body position and posture 15 16 See also EditAesthetic illusion A type of mental absorption Altered state of consciousness Any condition which is significantly different from a normal waking state Aporia State of puzzlement or expression of doubt in philosophy and rhetoric Argument from illusion argument for the existence of sense dataPages displaying wikidata descriptions as a fallback Augmented reality View of the real world with computer generated supplementary features Cognitive dissonance Stress from contradictory beliefs Delusion Firm and fixed belief in that which is based on inadequate grounding Dream argument Postulation about the act of dreaming Hallucination A vivid perception in the absence of external stimulus that has qualities of real perceptions Holography Recording to reproduce a three dimensional light field List of cognitive biases Systematic patterns of deviation from norm or rationality in judgment Moon illusion Optical illusion involving the Moon Paradox Statement that apparently contradicts itself Pareidolia Perception of meaningful patterns or images in random or vague stimuli Simulated reality Hypothesis that reality could be simulated References Edit Solso R L 2001 Cognitive psychology 6th ed Boston Allyn and Bacon ISBN 0 205 30937 2 McGurk Hj MacDonald J 1976 Hearing lips and seeing voices Nature 264 5588 746 748 Bibcode 1976Natur 264 746M doi 10 1038 264746a0 PMID 1012311 S2CID 4171157 The term optical illusion derives not from optics in today s sense but from the Greek word for seeing So an optical illusion is an illusion of seeing Yoon Mo Jung and Jackie Jianhong Shen 2008 J Visual Comm Image Representation 19 1 42 55 First order modeling and stability analysis of illusory contours Yoon Mo Jung and Jackie Jianhong Shen 2014 arXiv 1406 1265 Illusory shapes via phase transition Gross L 2006 Classic Illusion Sheds New Light on the Neural Site of Tactile Perception PLOS Biol 4 3 e96 doi 10 1371 journal pbio 0040096 PMC 1382017 PMID 20076548 Robles De La Torre amp Hayward 2001 PDF Archived from the original PDF on 2006 10 03 Retrieved 2006 10 03 The Cutting Edge of Haptics MIT Technology Review article Zampini M amp Spence C 2004 The role of auditory cues in modulating the perceived crispness and staleness of potato chips Journal of Sensory Studies 19 347 363 Barnett Cowan M 2010 An illusion you can sink your teeth into Haptic cues modulate the perceived freshness and crispness of pretzels Archived 2015 06 13 at the Wayback Machine Perception 39 1684 1686 Todrank J amp Bartoshuk L M 1991 Herz R S amp Von Clef J 2001 Nath A R Beauchamp M S Jan 2012 A neural basis for inter individual differences in the McGurk effect a multisensory auditory visual illusion NeuroImage 59 1 781 787 doi 10 1016 j neuroimage 2011 07 024 PMC 3196040 PMID 21787869 Lotto Beau 2017 05 01 Reality is not what it seems the science behind why optical illusions mess with our minds Wired UK ISSN 1357 0978 Retrieved 2020 02 27 Arzy S Seeck M Ortigue S Spinelli L Blanke O 2006 Induction of an illusory shadow person PDF Nature 443 7109 287 Bibcode 2006Natur 443 287A doi 10 1038 443287a PMID 16988702 S2CID 4338465 Hopkin Michael 20 September 2006 Brain Electrodes Conjure up Ghostly Visions Nature news060918 4 doi 10 1038 news060918 4 S2CID 191491373External links Edit Wikiquote has quotations related to Illusion Wikimedia Commons has media related to Illusions Universal Veiling Techniques Archived 2010 05 07 at the Wayback Machine What is an Illusion by J R Block Optical illusions and visual phenomena by Michael Bach Auditory illusions Haptic Perception of Shape touch illusions forces and the geometry of objects by Gabriel Robles De La Torre Silencing awareness of visual change by motion Retrieved from https en wikipedia org w index php title Illusion amp oldid 1136215022, wikipedia, wiki, book, books, library,
