Synesthesia

The experience of involuntary sensory cross activation where the presentation of a particular stimulus elicits a secondary sensory-perceptual experience. It most commonly occurs in the association of color with linguistic stimuli such as letters, numbers, words, or music, but can also occur between other senses. Although synesthesia can be acquired or transient due to trauma or drug use, there is also a strong genetic component, with a prevalence of about 1 in 2,000 individuals and a female to male ratio of 6:1.

Also Known As:

Chromesthesias; Colored Hearing Synesthesias; Grapheme Color Synesthesia; Grapheme-Color Synesthesias; Hearing Synesthesia, Colored; Hearing Synesthesias, Colored; Ideaesthesias; Ideasthesias; Lexical Gustatory Synesthesia; Lexical-Gustatory Synesthesias; Synesthesia, Colored Hearing; Synesthesia, Grapheme-Color; Synesthesia, Lexical-Gustatory; Synesthesias; Synesthesias, Colored Hearing; Synesthesias, Grapheme-Color; Synesthesias, Lexical-Gustatory; Chromesthesia; Colored Hearing Synesthesia; Grapheme-Color Synesthesia; Ideaesthesia; Ideasthesia; Lexical-Gustatory Synesthesia

Networked: 30 relevant articles (0 outcomes, 3 trials/studies)

Disease Context: Research Results

Nervous System Diseases: 14178
- Neurologic Manifestations: 7102
  - Neurobehavioral Manifestations: 1586
    - Perceptual Disorders: 126
      - Synesthesia: 30

Related Diseases

1.	Hallucinations (Hallucination)
2.	Illusions (Auditory Illusions)
3.	Hearing Loss (Hearing Impairment)
4.	Post-Traumatic Stress Disorders (Post Traumatic Stress Disorder)
5.	Seizures (Absence Seizure)

Experts

1.	Pearson, Joel: 2 articles (05/2020 - 05/2015)
2.	Neufeld, Janina: 2 articles (01/2020 - 09/2012)
3.	Seth, Anil K: 2 articles (01/2018 - 01/2014)
4.	Liechti, Matthias E: 2 articles (10/2017 - 10/2015)
5.	Nikolić, Danko: 2 articles (01/2017 - 11/2009)
6.	Chang, Shuai: 1 article (05/2020)
7.	Basirat, Anahita: 1 article (01/2020)
8.	Bhattacharyya, Pushpita: 1 article (01/2020)
9.	Bölte, Sven: 1 article (01/2020)
10.	Feige, Bernd: 1 article (01/2020)

Drugs and Biologics

Drugs and Important Biological Agents (IBA) related to Synesthesia:

1.	Hallucinogens (Psychedelics)IBA 01/01/2023 - "Psychedelic effects mainly include audiovisual synesthesia, complex imagery, disembodiment etc. that can impair control and cognition leading to adverse consequences such as suicide. " 01/01/2023 - "There is a very high level of comparability between the original NDE and psychedelic experiences in general, including shared characteristics such as entering other worlds, meeting menacing or benevolent entities, experiencing synesthesia, perinatal regression, and lucid dreamlike properties. " 01/01/2018 - "This case report offers rare insights into crossmodal responses to psychedelic drug use in a congenitally blind (CB) individual as a form of synthetic synesthesia. " 01/01/2012 - "Acquired synesthesias have been reported in association with deafferentation of the visual system, temporal lobe seizures, and the use of psychedelics. " 01/01/2014 - "[Synesthesias in the context of hallucinogen-induced persistent perception disorder following the use of lsd]."
2.	Lysergic Acid Diethylamide (LSD)IBA 10/01/2017 - "In a controlled setting, LSD acutely induced bliss, audiovisual synesthesia, altered meaning of perceptions, derealization, depersonalization, and mystical experiences. " 10/15/2015 - "The predominant effects induced by LSD included visual hallucinations, audiovisual synesthesia, and positively experienced derealization and depersonalization phenomena. " 01/01/2014 - "We report on a case-study in which an artist suffering from visual, auditory and olfactory hallucinations also experienced chromatic-phonemic synesthesias that had persisted for two years after he had stopped using lysergic acid diethylamide (lsd). " 01/01/2014 - "[Synesthesias in the context of hallucinogen-induced persistent perception disorder following the use of lsd]." 01/01/2018 - "BP's personal experience provides us with a unique report on the psychological and sensory alterations induced by hallucinogenic drugs, including an account of the absence of visual hallucinations, and a compelling look at the relationship between LSD induced synesthesia and crossmodal correspondences. "
3.	ElementsIBA 06/01/2015 - "In line with previous studies, our results suggest a heritable element of synesthesia. " 01/01/2020 - "Additionally, this case impressively illustrates how synesthesia can be a key element not only of sensory perception but also social and emotional processing and contributes to existing evidence of increased brain connectivity in association with synesthesia."
4.	Psilocybin (Psilocibin)IBA 01/01/2013 - "Studies of psychedelic drugs, such as psilocybin, LSD and mescaline, reveal that exposure to these drugs can induce synesthesia. "
5.	Mescaline (Peyote)IBA 01/01/2013 - "Studies of psychedelic drugs, such as psilocybin, LSD and mescaline, reveal that exposure to these drugs can induce synesthesia. "
6.	Dihydrotachysterol (AT 10)IBA 01/01/2013 - "Together with earlier findings, our study shows that grapheme-color synesthesia emerges with a protracted trajectory, with 34% of letters/digits fixed at age 6/7 years, 48% fixed at 7/8 years and 71% fixed at 10/11 years. "
7.	Serotonin (5 Hydroxytryptamine)IBA 01/01/2013 - "I conclude on these grounds that one commonality among at least some cases of acquired, developmental and drug-induced synesthesia may be the presence of excessive levels of serotonin, which increases the excitability and connectedness of sensory brain regions. " 01/01/2008 - "Psychopharmacology of synesthesia; the role of serotonin S2a receptor activation." 01/01/2013 - "Excessive serotonin levels may also play a role in synesthesia acquired after brain injury. "
8.	Retinaldehyde (Retinal)IBA 05/01/2020 - "The constructive nature of vision is perhaps most evident during hallucinations, mental imagery, synesthesia, perceptual filling-in, and many illusions in which conscious visual experience does not overtly correspond to retinal stimulation: phantom vision. " 05/01/2015 - "Hallucinations, mental imagery, synesthesia, perceptual filling-in, and many illusions are conscious visual experiences without a corresponding retinal stimulus: what we call 'phantom perception'. "
9.	Indicators and Reagents (Reagents)IBA 01/01/2018 - "The involvement of the superior parietal lobe even during rest is a strong indicator for its key role in AV synesthesia. " 11/01/2012 - "Research is recommended to confirm this finding and to determine if synesthesia is a risk indicator for PTSD among nonveterans."
10.	Explosive Agents (Explosives)IBA 10/22/2013 - "Although synesthesia has been described for centuries, only very recently has there been an explosive growth of systematic scientific examinations of this condition. "

Therapies and Procedures

1.	Transcranial Direct Current Stimulation 12/06/2011 - "We next used transcranial direct current stimulation to discriminate between two competing hypotheses of the role of hyperexcitability in the expression of synesthesia. "
2.	Telescopes 01/01/2011 - "That is, compared to achromatically perceived non-digits, synesthesia-inducing digits increase the predominance of binocular rivalry over binocular fusion. "
3.	Transcranial Magnetic Stimulation 09/01/2006 - "We used a noninvasive stimulation technique, transcranial magnetic stimulation (TMS), to determine whether the posterior parietal lobe is critical for the integration of color and shape in color-grapheme synesthesia, as it appears to be for normal color-shape binding. "
4.	Therapeutics 04/01/2018 - "The functional-anatomical changes after early sensory deprivation have translational implications for the therapy of developmental hearing loss, blindness, and sensory paralysis and might also underlie developmental synesthesia."
5.	Language Therapy (Language Training) 01/01/2020 - "We tested whether the acquisition of grapheme-color synesthesia during childhood is related to difficulties in written language learning by measuring whether it is more frequent in 79 children receiving speech and language therapy for such difficulties than in the general population of children (1.3%). "