Inducers and concurrents also include smells, tastes, temperatures, personalities and emotions, and can be multiple during a single synesthetic experience. The second most prevalent form is time unit (e.g., Monday, January)–color synesthesia (22.4%), followed by musical sound–color synesthesia (18.50%) (Figs (Figs2 2 and and3 3). The apparently most common form (with a 64.4% prevalence among synesthetes) is grapheme–color synesthesia, in which achromatic letters or digits automatically trigger an idiosyncratic color perceptual experience (e.g., the letter ‘m’ induces blue color percepts) (Fig. So far, over 60 types of synesthetic phenomena have been described. In contrast to its developmental counterpart, acquired synesthesia does not demonstrate either idiosyncrasy or automaticity or stability. Īcquired forms of synesthesia have also been reported, essentially associated with neurologic disorders or following psychotropic drug ingestion. They tend to be stable over time in a given individual, although this has recently been challenged by the finding that synesthetic ability can disappear over time. Usually, pairings of inducers and concurrents are specific (i.e., a particular stimulus consistently triggers the same synesthetic percept). The following criteria have been proposed to help establishing a diagnosis of developmental synesthesia: induced percepts should be elicited by a specific stimulus, they should be automatically generated, and typically have percept-like qualities. The condition is occasionally associated with autism spectrum disorders, like Asperger syndrome. Different forms of synesthesia can be observed in the same person or in the same family. It can run in families and demonstrate Mendelian transmission. Developmental synesthesia appears to be the most frequent type of this condition, with a 4.4% estimated prevalence rate. Synesthesia is commonly classified as developmental and acquired. For that very reason, scientific studies probably underestimate synesthesia prevalence in the general population. It is therefore understandable that synesthetes (i.e., persons affected by synesthesia) commonly avoid mentioning their percepts and even tend to close on themselves in psychological distress. While in 1885 the painter was taking piano lessons, his teacher noticed that he was continually relating the sounds of the piano keys with specific colors considering then that his pupil was insane, the teacher sent him away. In this regard, the following history reported by Vincent Van Gogh is representative. Unfortunately, the astonishing features of these percepts have too often led the entourage of affected persons, including physicians, to wrongfully consider them as confabulators, drug users, or schizophrenics. Clinical significance of synesthesia, however, is still largely underevaluated.Īlthough some synesthetic phenomena express the presence of a disease, developmental synesthesia as a rule is considered an individual cognitive variant in the normal population. Moreover, favored by the emergence of sophisticated tools for functional brain exploration, they have generated a considerable interest among neuroscientists. They prompted philosophical debates on the nature of perception, consciousness and even talent and creativity, and significantly impacted the course of art history, notably at the turn of the 20th Century. Synesthetic experiences have had over the centuries far-reaching sociocultural implications. Stimuli generating additional unusual experiences are termed ‘inducers’, whereas internally produced synesthetic percepts are termed ‘concurrents’. An illustrative presentation of the condition would be that of a given person in whom hearing the sound of a trumpet consistently elicits the vision of brightly colored triangles dancing in front of his eyes, in association with a sensation of pressure on his arms, letting him feel uncomfortable to sit still. In this condition, a particular stimulation in a given sensory modality (e.g., touch) or cognitive process (e.g., computing) automatically triggers additional experiences in one or several other unstimulated domains (e.g., vision, emotion). Synesthesia is an extraordinary perceptual phenomenon, in which the world is experienced in unusual ways.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |