Illusion Delusion and Fantasy definitions

Illusion From Wikipedia, the free encyclopedia Not to be confused with allusion. For other uses, see Illusion (disambiguation). "Head on a Platter" exhibit at theRegional Science Centre, Bhopal An illusion is a distortion of the senses, revealing how the brain normally organizes and interprets sensory stimulation. Though illusions distort 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 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.[2]Some illusions are based on general assumptions the brain makes duringperception. 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 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", and "pulling and pushing". Contents [hide] • 1 Optical illusions • 2 Auditory illusions • 3 Tactile illusions • 4 Temporal illusions • 5 Other senses • 6 Disorders • 7 Neuroscience • 8 In Hindu philosophy • 9 See also • 10 References • 11 External links Optical illusions[edit] An optical illusion. Square A is exactly the same shade of grey as Square B. (SeeChecker shadow illusion.) Main article: Optical illusion An optical illusion is characterized by visually perceived images that are deceptive or misleading. Therefore, the information gathered by the eye is processed by the brain to give, on the face of it, a percept that does not tally with a physical measurement of the stimulus source. A conventional assumption is that there are physiological illusions that occur naturally and cognitive illusions that can be demonstrated by specific visual tricks that say something more basic about how human perceptual systems work. The human brain constructs a world inside our head based on what it samples from the surrounding environment. However sometimes it tries to organise this information it thinks best while other times it fills in the gaps.[3] [4] This way in which our brain works is the basis of an illusion. Auditory illusions[edit] Main article: Auditory illusion An auditory illusion is an illusion of hearing, the sound equivalent of an optical illusion: the listener hears either sounds 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 illusions[edit] Main 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. Interestingly, the brain areas activated during illusory tactile perception are similar to those activated during actual tactile stimulation.[5] Tactile illusions can also be elicited through haptic technology.[6] These "illusory" tactile objects can be used to create "virtual objects".[7] Temporal illusions[edit] Temporal illusions can occur in many ways. Other senses Illusions can occur with the other senses including those involved in food perception. Here both sound[8] and touch[9] 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.[10]Evidence of olfactory (smell) illusions occurred when positive or negative verbal labels were given prior to olfactory stimulation.[11] Disorders Some illusions occur as 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[edit] In an experiment with one patient, electrical stimulation at the left temporoparietal junction lead to an illusion of another person close to her.[12][13] In Hindu philosophy[edit] Main article: Maya (illusion) The word "illusion" is used to denote different aspects in Hindu philosophy. Many monist philosophies clearly demarcate illusion from truth and falsehood. Per advaita philosophy, illusion is something which is not true and not false. Whereas in general usage it is common to assume that illusion is false, Hindu philosophy makes a distinction between Maya (illusion) and falsehood. Delusion From Wikipedia, the free encyclopedia A delusion is a belief held with strong conviction despite superior evidence to the contrary.[1] As a pathology, it is distinct from a belief based on false or incomplete information, confabulation, dogma, illusion, or other effects ofperception. Delusions typically occur in the context of neurological or mental illness, although they are not tied to any particular disease and have been found to occur in the context of many pathological states (both physical and mental). However, they are of particular diagnostic importance in psychotic disorders including schizophrenia, paraphrenia, manic episodes of bipolar disorder, and psychotic depression. Definition[edit] Although non-specific concepts of madness have been around for several thousand years, the psychiatrist and philosopherKarl Jaspers was the first to define the three main criteria for a belief to be considered delusional in his 1913 book General Psychopathology.[2] These criteria are: • certainty (held with absolute conviction) • incorrigibility (not changeable by compelling counterargument or proof to the contrary) • impossibility or falsity of content (implausible, bizarre or patently untrue)[3] Furthermore, when a false belief involves a value judgment, it is only considered as a delusion if it is so extreme that it cannot be, or never can be proven true. For example: a man claiming that he flew into the sun and flew back home. This would be considered a delusion,[4] unless he was speaking figuratively. Types[edit] Delusions are categorized into four different groups: • Bizarre delusion: A delusion that is very strange and completely implausible; an example of a bizarre delusion would be that aliens have removed the reporting person's brain. • Non-bizarre delusion: A delusion that, though false, is at least possible, e.g., the affected person mistakenly believes that he is under constant police surveillance. • Mood-congruent delusion: Any delusion with content consistent with either a depressive or manic state, e.g., a depressed person believes that news anchors on television highly disapprove of him, or a person in a manic state might believe she is a powerful deity. • Mood-neutral delusion: A delusion that does not relate to the sufferer's emotional state; for example, a belief that an extra limb is growing out of the back of one's head is neutral to either depression or mania.[5] Themes[edit] In addition to these categories, delusions often manifest according to a consistent theme. Although delusions can have any theme, certain themes are more common. Some of the more common delusion themes are: • Delusion of control: This is a false belief that another person, group of people, or external force controls one's general thoughts, feelings, impulses, or behavior.[5] • Cotard delusion: This is a false belief that one does not exist or has died.[6] • Delusional jealousy: A person with this delusion falsely believes that a spouse or lover is having an affair, with no proof to back up their claim.[5] • Delusion of guilt or sin (or delusion of self-accusation): This is an ungrounded feeling of remorse or guilt of delusional intensity.[5] • Delusion of mind being read: The false belief that other people can know one's thoughts.[5] • Delusion of thought insertion: The belief that another thinks through the mind of the person.[5] • Delusion of reference: The person falsely believes that insignificant remarks, events, or objects in one's environment have personal meaning or significance.[5] • Erotomania A delusion in which someone falsely believes another person is in love with them.[5] • Grandiose religious delusion: The belief that the affected person is a god, or chosen to act as a god.[7][8] • Somatic delusion: A delusion whose content pertains to bodily functioning, bodily sensations, or physical appearance. Usually the false belief is that the body is somehow diseased, abnormal, or changed.[5] A specific example of this delusion is delusional parasitosis: a delusion in which one feels infested with insects, bacteria, mites, spiders, lice, fleas, worms, or other organisms. Affected individuals may also report being repeatedly bitten. In some cases, entomologists are asked to investigate cases of mysterious bites. Sometimes physical manifestations may occur including skin lesions.[9] • Delusion of poverty: The person strongly believes that he is financially incapacitated. Although this type of delusion is less common now, it was particularly widespread in the days before state support.[10] Grandiose delusions[edit] Main article: Grandiose delusions Grandiose delusions are distinct from grandiosity, in that the sufferer does not have insight into his loss of touch with reality. An individual is convinced he has special powers, talents, or abilities. Sometimes, the individual may actually believe they are a famous person or character. Grandiose delusions or delusions of grandeur are principally a subtype of delusional disorder but could possibly feature as a symptom of schizophrenia and manic episodes of bipolar disorder.[11] Grandiose delusions are characterized by fantastical beliefs that one is famous, omnipotent, or otherwise very powerful. The delusions are generally fantastic, often with asupernatural, science-fictional, or religious bent. In colloquial usage, one who overestimates one's own abilities, talents, stature or situation is sometimes said to have 'delusions of grandeur'. This is generally due to excessive pride, rather than any actual delusions. Grandiose delusions or delusions of grandeur can also be associated with megalomania.[citation needed] Persecutory delusions[edit] Main article: Persecutory delusion Persecutory delusions are the most common type of delusions and involve the theme of being followed, harassed, cheated, poisoned or drugged, conspired against, spied on, attacked, or otherwise obstructed in the pursuit of goals. Persecutory delusions are a condition in which the affected person wrongly believes that they are being persecuted. Specifically, they have been defined as containing three central elements:[12][page needed] The individual thinks that 1. harm is occurring, or is going to occur. 2. the persecutor(s) has(have) the intention to cause harm. 3. they are constantly being prejudged or profiled. According to the DSM-IV-TR, persecutory delusions are the most common form of delusions in schizophrenia, where the person believes they are "being tormented, followed, sabotaged, tricked, spied on, or ridiculed."[13] In the DSM-IV-TR, persecutory delusions are the main feature of the persecutory type of delusional disorder. When the focus is to remedy some injustice by legal action, they are sometimes called "querulous paranoia".[14] Diagnosis[edit] The modern definition and Jaspers' original criteria have been criticised, as counter-examples can be shown for every defining feature. Studies on psychiatric patients show that delusions vary in intensity and conviction over time, which suggests that certainty and incorrigibility are not necessary components of a delusional belief.[15] Delusions do not necessarily have to be false or 'incorrect inferences about external reality'.[16] Some religious or spiritual beliefs by their nature may not be falsifiable, and hence cannot be described as false or incorrect, no matter whether the person holding these beliefs was diagnosed as delusional or not.[17] In other situations the delusion may turn out to be true belief.[18] For example,delusional jealousy, where a person believes that their partner is being unfaithful (and may even follow them into the bathroom believing them to be seeing their lover even during the briefest of partings) may result in the faithful partner being driven to infidelity by the constant and unreasonable strain put on them by their delusional spouse. In this case the delusion does not cease to be a delusion because the content later turns out to be true. In other cases, the delusion may be assumed to be false by a doctor or psychiatrist assessing the belief, because it seemsto be unlikely, bizarre or held with excessive conviction. Psychiatrists rarely have the time or resources to check the validity of a person’s claims leading to some true beliefs to be erroneously classified as delusional.[19] This is known as the Martha Mitchell effect, after the wife of the attorney general who alleged that illegal activity was taking place in the White House. At the time her claims were thought to be signs of mental illness, and only after the Watergate scandal broke was she proved right (and hence sane). Similar factors have led to criticisms of Jaspers' definition of true delusions as being ultimately 'un-understandable'. Critics (such as R. D. Laing) have argued that this leads to the diagnosis of delusions being based on the subjective understanding of a particular psychiatrist, who may not have access to all the information that might make a belief otherwise interpretable. R.D. Laing's hypothesis has been applied to some forms of projective therapy to "fix" a delusional system so that it cannot be altered by the patient. Psychiatric researchers at Yale University, Ohio State University and the Community Mental Health Center of Middle Georgia have used novels and motion picture films as the focus. Texts, plots and cinematography are discussed and the delusions approached tangentially.[20] This use of fiction to decrease the malleability of a delusion was employed in a joint project by science-fiction author Philip Jose Farmer and Yale psychiatrist A. James Giannini. They wrote the novel Red Orc's Rage, which, recursively, deals with delusional adolescents who are treated with a form of projective therapy. In this novel's fictional setting other novels written by Farmer are discussed and the characters are symbolically integrated into the delusions of fictional patients. This particular novel was then applied to real-life clinical settings.[21] Another difficulty with the diagnosis of delusions is that almost all of these features can be found in "normal" beliefs. Many religious beliefs hold exactly the same features, yet are not universally considered delusional. These factors have led the psychiatrist Anthony David to note that "there is no acceptable (rather than accepted) definition of a delusion."[22] In practice, psychiatrists tend to diagnose a belief as delusional if it is either patently bizarre, causing significant distress, or excessively pre-occupying the patient, especially if the person is subsequently unswayed in belief by counter-evidence or reasonable arguments. It is important to distinguish true delusions from other symptoms such as anxiety, fear, or paranoia. To diagnose delusions a mental state examination may be used. This test includes appearance, mood, affect, behavior, rate and continuity of speech, evidence of hallucinations or abnormal beliefs, thought content, orientation to time, place and person, attention andconcentration, insight and judgment, as well as short-term memory.[23] Johnson-Laird suggests that delusions may be viewed as the natural consequence of failure to distinguish conceptual relevance. That is, the person takes irrelevant information and puts it in the form of disconnected experiences, then it is taken to be relevant in a manner that suggests false causal connections. Furthermore, the person takes the relevant information, in the form of counterexamples, and ignores it.[24] Development of specific delusions[edit] The top two factors mainly concerned in the germination of delusions are: 1. Disorder of brain functioning; and 2. background influences of temperament and personality.[25] Higher levels of dopamine qualify as a symptom of disorders of brain function. That they are needed to sustain certain delusions was examined by a preliminary study on delusional disorder (a psychotic syndrome) instigated to clarify if schizophrenia had a dopamine psychosis.[26] There were positive results - delusions of jealousy and persecution had different levels of dopamine metabolite HVA and Homovanillyl alcohol (which may have been genetic). These can be only regarded as tentative results; the study called for future research with a larger population. It is too simplistic to say that a certain measure of dopamine will bring about a specific delusion. Studies show age[27][28] and gender to be influential and it is most likely that HVA levels change during the life course of some syndromes.[29] On the influence personality, it has been said: "Jaspers considered there is a subtle change in personality due to the illness itself; and this creates the condition for the development of the delusional atmosphere in which the delusional intuition arises."[30] Cultural factors have "a decisive influence in shaping delusions".[31] For example, delusions of guilt and punishment are frequent in a Western, Christian country like Austria, but not in Pakistan - where it is more likely persecution.[32] Similarly, in a series of case studies, delusions of guilt and punishment were found in Austrian patients with Parkinson's being treated with l-dopa - a dopamine agonist.[33] Causes[edit] See also: Psychosis (causes) To define delusional thinking in a specific patient, it is important to consult a local psychiatrist who can make a thorough examination before diagnosing the problem.[34] Explaining the causes of delusions continues to be challenging and several theories have been developed. One is the genetic or biological theory, which states that close relatives of people with delusional disorder are at increased risk of delusional traits. Another theory is the dysfunctional cognitive processing, which states that delusions may arise from distorted ways people have of explaining life to themselves. A third theory is called motivated or defensive delusions. This one states that some of those persons who are predisposed might suffer the onset of delusional disorder in those moments when coping with life and maintaining high self-esteem becomes a significant challenge. In this case, the person views others as the cause of their personal difficulties in order to preserve a positive self-view.[35] This condition is more common among people who have poor hearing or sight. Also, ongoing stressors have been associated with a higher possibility of developing delusions. Examples of such stressors are immigration or low socio-economic status.[36] Researcher, Orrin Devinsky, MD, from the NYU Langone Medical Center, performed a study that revealed a consistentpattern of injury to the frontal lobe and right hemisphere of the human brain in patients with certain delusions and brain disorders. Devinsky explains that the cognitive deficits caused by those injuries to the right hemisphere, results in the over compensation by the left hemisphere of the brain for the injury, which causes delusions.[37] A study carried out at The Warwick Medical School at the University of Warwick, indicated that children who suffered bullyingare more likely to develop psychotic symptoms in early adolescence. The background facts demonstrated that hallucinations and delusions are common in childhood as well as in adulthood and that children who experience such symptoms are more prone to develop psychosis later in life. Furthermore, the study demonstrated that the risk of psychotic symptoms, including delusions, was multiplied by two for children who suffered bullying at age eight or ten. The authors remark that bullying can cause chronic stress that may have an effect on a genetic predisposition to schizophrenia and result in setting off the symptoms.[38] Fantasy Fantasy is a genre of fiction that commonly uses magic and other supernaturalphenomena as a primary plot element, theme, or setting. Many works within the genre take place in imaginary worlds where magic and magical creatures are common. Fantasy is generally distinguished from the genres of science fiction andhorror by the expectation that it steers clear of scientific and macabre themes, respectively, though there is a great deal of overlap between the three, all of which are subgenres of speculative fiction. In popular culture, the fantasy genre is predominantly of the medievalist form, especially since the worldwide success of The Lord of the Rings and related books by J. R. R. Tolkien. In its broadest sense, however, fantasy comprises works by many writers, artists, filmmakers, and musicians, from ancient myths and legends to many recent works embraced by a wide audience today. Fantasy is a vibrant area of academic study in a number of disciplines (English,cultural studies, comparative literature, history, medieval studies). Work in this area ranges widely, from the structuralist theory of Tzvetan Todorov, which emphasizes the fantastic as a liminal space, to work on the connections (political, historical, literary) between medievalism and popular culture.[1] Traits of fantasy The identifying traits of fantasy are the inclusion of fantastic elements in a self-coherent (internally consistent) setting, where inspiration from mythology andfolklore remains a consistent theme.[2] Within such a structure, any location of the fantastical element is possible: it may be hidden in, or leak into the apparently real world setting, it may draw the characters into a world with such elements, or it may occur entirely in a fantasy world setting, where such elements are part of the world.[3] Essentially, fantasy follows rules of its own making, allowing magic and other fantastic devices to be used and still be internally cohesive.[4] History For more details on this topic, see History of fantasy. See also: Sources of fantasy Beginning perhaps with the Epic of Gilgamesh and the earliest written documents known to humankind, mythic and other elements that would eventually come to define fantasy and its various subgenres have been a part of some of the grandest and most celebrated works of literature. From The Odyssey to Beowulf, from the Mahabharata to The Book of One Thousand and One Nights, from the Iliad to Fengshen Yanyi, from the Ramayana to the Journey to the West, and from theArthurian legend and medieval romance to the epic poetry of the Divine Comedy, fantastical adventures featuring braveheroes and heroines, deadly monsters, and secret arcane realms have inspired many audiences. In this sense, the history of fantasy and the history of literature are inextricably intertwined. There are many works where the boundary between fantasy and other works is not clear; the question of whether the writers believed in the possibilities of the marvels in A Midsummer Night's Dream or Sir Gawain and the Green Knight makes it difficult to distinguish when fantasy, in its modern sense, first began.[5] Although pre-dated by John Ruskin's The King of the Golden River (1841), the history of modern fantasy literature is usually said to begin with George MacDonald, the Scottish author of such novels as The Princess and the Goblin and Phantastes(1858), the latter of which is widely considered to be the first fantasy novel ever written for adults. MacDonald was a major influence on both J. R. R. Tolkien and C. S. Lewis. The other major fantasy author of this era was William Morris, a popular English poet who wrote several novels in the latter part of the century, including The Well at the World's End. Despite MacDonald's future influence with At the Back of the North Wind (1871), Morris's popularity with his contemporaries, and H.G. Wells's The Wonderful Visit (1895), it wasn't until the 20th century that fantasy fiction began to reach a large audience. Lord Dunsany established the genre's popularity in both the novel and the short story form. Many popular mainstream authors also began to write fantasy at this time, including H. Rider Haggard,Rudyard Kipling and Edgar Rice Burroughs. These authors, along with Abraham Merritt, established what was known as the "lost world" sub-genre, which was the most popular form of fantasy in the early decades of the 20th century, although several classic children's fantasies, such as Peter Pan and The Wonderful Wizard of Oz, were also published around this time. Indeed, juvenile fantasy was considered more acceptable than fantasy intended for adults, with the effect that writers who wished to write fantasy had to fit their work in a work for children.[6] Nathaniel Hawthorne wrote fantasy in A Wonder-Book for Girls and Boys, intended for children,[7] though works for adults only verged on fantasy. For many years, this and successes such as Alice's Adventures in Wonderland (1865), created the circular effect that all fantasy works, even the later The Lord of the Rings, were therefore classified as children's literature. Political and social trends can affect a society's reception towards fantasy. In the early 20th century, the New Culture Movement's enthusiasm for Westernization and science in China compelled them to condemn the fantastical shenmo genre of traditional Chinese literature. The spells and magical creatures of these novels were viewed as superstitious and backward, products of a feudal society hindering the modernization of China. Stories of the supernatural continued to be denounced once the Communists rose to power, and mainland China experienced a revival in fantasy only after the Cultural Revolution had ended.[8] Fantasy was a staple genre of pulp magazines published in the West. In 1923, the first all-fantasy fiction magazine, Weird Tales, was created. Many other similar magazines eventually followed, most noticeably The Magazine of Fantasy and Science Fiction. The pulp magazine format was at the height of its popularity at this time and was instrumental in bringing fantasy fiction to a wide audience in both the U.S. and Britain. Such magazines were also instrumental in the rise of science fiction, and it was at this time the two genres began to be associated with each other. By 1950, "sword and sorcery" fiction had begun to find a wide audience, with the success of Robert E. Howard's Conan the Barbarian and Fritz Leiber's Fafhrd and the Gray Mouser stories.[9] However, it was the advent of high fantasy, and most of all J. R. R. Tolkien's The Hobbit and The Lord of the Rings, which reached new heights of popularity in the late 1960s, that allowed fantasy to truly enter the mainstream.[10] Several other series, such as C. S. Lewis's Chronicles of Narnia and Ursula K. Le Guin's Earthsea books, helped cement the genre's popularity. The popularity of the fantasy genre has continued to increase in the 21st century, as evidenced by the best-selling status ofJ. K. Rowling's Harry Potter series; of George R. R. Martin's Song of Ice and Fire sequence; and of Rick Riordan's Percy Jackson & the Olympians pentalogy, which focuses on Greek mythology, The Kane Chronicles trilogy, which focuses on Egyptian mythology, and Heroes of Olympus trilogy, which focuses on Greek and Roman mythology. Several fantasy film adaptations have achieved blockbuster status, most notably The Lord of the Rings film trilogy directed by Peter Jackson, and the Harry Potter films, currently the highest-grossing film series in cinematic history. Media[edit] Further information: Fantasy art, Fantasy literature, Fantasy film, Fantasy television and Role-playing video game Fantasy is a popular genre, having found a home for itself in almost every medium. While fantasy art and recently fantasy films have been increasingly popular, it is fantasy literature which has always been the genre's primary medium. Fantasy role-playing games cross several different media. Dungeons & Dragons was the first tabletop role-playing game, and remains the most successful and influential.[11][12] The science fantasy role-playing game series Final Fantasy has been an icon of the role-playing video game genre (as of 2012 still among the top ten best-selling video game franchises). The first collectible card game, Magic: The Gathering, has a fantasy theme, and is similarly dominant in the industry.[13] Subgenres Modern fantasy, including early modern fantasy, has also spawned many new subgenres with no clear counterpart in mythology or folklore, although inspiration from mythology and folklore remains a consistent theme. Fantasy subgenres are numerous and diverse, frequently overlapping with other forms of speculative fiction in almost every medium in which they are produced. A couple of examples are the science fantasy and dark fantasy subgenres, which the fantasy genre shares with science fiction and horror, respectively. Subculture Professionals such as publishers, editors, authors, artists, and scholars within the fantasy genre get together yearly at theWorld Fantasy Convention. The World Fantasy Awards are presented at the convention. The first WFC was held in 1975, and it has occurred every year since. The convention is held at a different city each year. Additionally, many science fiction conventions, such as Florida's FX Show and MegaCon, cater to fantasy and horror fans.Anime conventions, such as Ohayocon or Anime Expo frequently feature showings of fantasy, science fantasy, and dark fantasy series and films, such as Majutsushi Orphen (fantasy), Sailor Moon (urban fantasy), Berserk (dark fantasy), andSpirited Away (fantasy). Many science fiction/fantasy and anime conventions also strongly feature or cater to one or more of the several subcultures within the main subcultures, including the cosplay subculture (in which people make and/or wear costumes based on existing or self-created characters, sometimes also acting out skits or plays as well), the fan fictionsubculture, and the fan video or AMV subculture, as well as the large internet subculture devoted to reading and writing prose fiction and/or doujinshi in or related to those genres.