1
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Lin IF, Kondo HM. Brain circuits in autonomous sensory meridian response and related phenomena. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230252. [PMID: 39005041 DOI: 10.1098/rstb.2023.0252] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 03/19/2024] [Indexed: 07/16/2024] Open
Abstract
Autonomous sensory meridian response (ASMR) is characterized by a tingling sensation with a feeling of relaxation and a state of flow. We explore the neural underpinnings and comorbidities of ASMR and related phenomena with altered sensory processing. These phenomena include sensory processing sensitivity (SPS), synaesthesia, Alice in Wonderland syndrome and misophonia. The objective of this article is to uncover the shared neural substrates and distinctive features of ASMR and its counterparts. ASMR, SPS and misophonia exhibit common activations in the brain regions associated with social cognition, emotion regulation and empathy. Nevertheless, ASMR responders display reduced connectivity in the salience network (SN), while individuals with SPS exhibit increased connectivity in the SN. Furthermore, ASMR induces relaxation and temporarily reduces symptoms of depression, in contrast to SPS and misophonia, which are linked to depression. These observations lead us to propose that ASMR is a distinct phenomenon owing to its attention dispatch mechanism and its connection with emotion regulation. We suggest that increased activations in the insula, along with reduction in connectivity within the salience and default mode networks in ASMR responders, may account for their experiences of relaxation and flow states. This article is part of the theme issue 'Sensing and feeling: an integrative approach to sensory processing and emotional experience'.
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Affiliation(s)
- I-Fan Lin
- Department of Occupational Medicine and Clinical Toxicology, Taipei Veterans General Hospital, Taipei 112, Taiwan
| | - Hirohito M Kondo
- School of Psychology, Chukyo University, Nagoya, Aichi 466-8666, Japan
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2
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Reeder RR, Sala G, van Leeuwen TM. A novel model of divergent predictive perception. Neurosci Conscious 2024; 2024:niae006. [PMID: 38348335 PMCID: PMC10860603 DOI: 10.1093/nc/niae006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 01/16/2024] [Accepted: 01/23/2024] [Indexed: 02/15/2024] Open
Abstract
Predictive processing theories state that our subjective experience of reality is shaped by a balance of expectations based on previous knowledge about the world (i.e. priors) and confidence in sensory input from the environment. Divergent experiences (e.g. hallucinations and synaesthesia) are likely to occur when there is an imbalance between one's reliance on priors and sensory input. In a novel theoretical model, inspired by both predictive processing and psychological principles, we propose that predictable divergent experiences are associated with natural or environmentally induced prior/sensory imbalances: inappropriately strong or inflexible (i.e. maladaptive) high-level priors (beliefs) combined with low sensory confidence can result in reality discrimination issues, a characteristic of psychosis; maladaptive low-level priors (sensory expectations) combined with high sensory confidence can result in atypical sensory sensitivities and persistent divergent percepts, a characteristic of synaesthesia. Crucially, we propose that whether different divergent experiences manifest with dominantly sensory (e.g. hallucinations) or nonsensory characteristics (e.g. delusions) depends on mental imagery ability, which is a spectrum from aphantasia (absent or weak imagery) to hyperphantasia (extremely vivid imagery). We theorize that imagery is critically involved in shaping the sensory richness of divergent perceptual experience. In sum, to predict a range of divergent perceptual experiences in both clinical and general populations, three factors must be accounted for: a maladaptive use of priors, individual level of confidence in sensory input, and mental imagery ability. These ideas can be expressed formally using nonparametric regression modeling. We provide evidence for our theory from previous work and deliver predictions for future research.
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Affiliation(s)
- Reshanne R Reeder
- Department of Psychology, Institute of Population Health, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Giovanni Sala
- Department of Psychology, Institute of Population Health, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Tessa M van Leeuwen
- Department of Communication and Cognition, Tilburg School of Humanities and Digital Sciences, Tilburg University, Tilburg, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
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3
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Taylor MJ, van Leeuwen TM, Kuja-Halkola R, Lundström S, Larsson H, Lichtenstein P, Bölte S, Neufeld J. Genetic and environmental architecture of synaesthesia and its association with the autism spectrum-a twin study. Proc Biol Sci 2023; 290:20231888. [PMID: 37876199 PMCID: PMC10598415 DOI: 10.1098/rspb.2023.1888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 09/26/2023] [Indexed: 10/26/2023] Open
Abstract
Synaesthesia is a sensory phenomenon where external stimuli, such as sounds or letters, trigger additional sensations (e.g. colours). Synaesthesia aggregates in families but its heritability is unknown. The phenomenon is more common in people on the autism spectrum compared with the general population and associated with higher autistic traits. Using classical twin design, we assessed the heritability of individual differences in self-reported synaesthesia and the genetic and environmental contributions to their association with autistic traits within a population twin cohort (n = 4262, age = 18 years). We estimated individual differences in synaesthesia to be heritable and influenced by environmental factors not shared between twins. The association between individual differences in synaesthesia and autistic traits was estimated to be predominantly under genetic influence and seemed to be mainly driven by non-social autistic traits (repetitive behaviours, restricted interests and attention to detail). Our study suggests that the link between synaesthesia and autism might reside in shared genetic causes, related to non-social autistic traits such as alterations in perception. Future studies building on these findings may attempt to identify specific groups of genes that influence both autism, synaesthesia and perception.
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Affiliation(s)
- Mark J. Taylor
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Tessa M. van Leeuwen
- Tilburg School of Humanities and Digital Sciences, Department of Communication and Cognition, Tilburg University, 5037 AB Tilburg, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6525 XZ Nijmegen, The Netherlands
| | - Ralf Kuja-Halkola
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Sebastian Lundström
- Gillberg Neuropsychiatry Centre, Centre for Ethics, Law and Mental Health, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Henrik Larsson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17165 Stockholm, Sweden
- School of Medical Sciences, Örebro University, 70281 Örebro, Sweden
| | - Paul Lichtenstein
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Sven Bölte
- Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research, Department of Women's and Children's Health, Karolinska Institutet, Stockholm Health Care Services, Region Stockholm, 11364 Stockholm, Sweden
- Curtin Autism Research Group, Curtin School of Allied Health, Curtin University, WA 66102 Perth, Western Australia
- Child and Adolescent Psychiatry, Stockholm Health Care Services, Region Stockholm, 11364 Stockholm, Sweden
| | - Janina Neufeld
- Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research, Department of Women's and Children's Health, Karolinska Institutet, Stockholm Health Care Services, Region Stockholm, 11364 Stockholm, Sweden
- Swedish Collegium for Advanced Study (SCAS), 75238 Uppsala, Sweden
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Navarro-Pardo E, Alonso-Esteban Y, Alcantud-Marin F, Murphy M. Do Savant Syndrome and Autism Spectrum Disorders Share Sex Differences? A Comprehensive Review. Soa Chongsonyon Chongsin Uihak 2023; 34:117-124. [PMID: 37035793 PMCID: PMC10080262 DOI: 10.5765/jkacap.230008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 03/24/2023] [Indexed: 04/08/2023] Open
Abstract
Savant syndrome was described before autism. However, they soon became closely associated, as many of their symptoms (intellectual disability, repetitive behaviors, alterations in social communication, and islets of abilities) overlap. Only a few women with autism have been diagnosed with savant syndrome. The theories or hypotheses that attempt to explain savant syndrome, which are common in autism, present differential treatment according to sex. We postulate that savant syndrome associated with autism as well as autism in general is underdiagnosed in women.
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Affiliation(s)
- Esperanza Navarro-Pardo
- Department of Developmental and Educational Psychology, University of Valencia, Valencia, Spain
| | - Yurena Alonso-Esteban
- Department of Psychology and Sociology, University of Zaragoza, Zaragoza, Spain
- Address for correspondence: Yurena Alonso-Esteban, Department of Psychology and Sociology, Faculty of Social Sciences and Humanities, University of Zaragoza, C/Atarazana, 4, Teruel 44003, Spain Tel: +34 978618101, E-mail:
| | | | - Mike Murphy
- School of Applied Psychology, University College Cork, Cork, Ireland
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Abstract
INTRODUCTION This study determines whether there is a familial aggregation between synaesthesia and two neuropsychiatric conditions (autism and schizophrenia). METHOD We examined the prevalence of autism and schizophrenia among synaesthetes and non-synaesthetic controls, and among their first-degree relatives. RESULTS As predicted, autism occurred at elevated levels among synaesthetes and-we document for the first time-amongst their relatives. This was not found for schizophrenia, where a link may be expected, or in a control condition (type 1 diabetes) where we had no a priori reason to assume a link. Synaesthetes, compared to controls, were also more likely to have other synaesthetes in their family. People with three or more types of synaesthesia were more likely (compared to synaesthetes with fewer types) to have synaesthetic relatives and to report autism in themselves. People with two or more types of synaesthesia (compared to synaesthetes with only one type) were more likely to report familial autism. CONCLUSIONS The results suggest a shared genetic predisposition between synaesthesia and autism, and more extreme synaesthetes may tend to hail from more neurodiverse families.
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Affiliation(s)
- Max Nugent
- School of Psychology University of Sussex, Brighton, UK
| | - Jamie Ward
- School of Psychology University of Sussex, Brighton, UK
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6
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Bottini R, Nava E, De Cuntis I, Benetti S, Collignon O. Synesthesia in a congenitally blind individual. Neuropsychologia 2022; 170:108226. [DOI: 10.1016/j.neuropsychologia.2022.108226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 02/25/2022] [Accepted: 03/23/2022] [Indexed: 11/25/2022]
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van Leeuwen TM, Wilsson L, Norrman HN, Dingemanse M, Bölte S, Neufeld J. Perceptual processing links autism and synesthesia: A co-twin control study. Cortex 2021; 145:236-249. [PMID: 34763130 DOI: 10.1016/j.cortex.2021.09.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 05/21/2021] [Accepted: 09/02/2021] [Indexed: 11/19/2022]
Abstract
Synesthesia occurs more commonly in individuals fulfilling criteria for an autism spectrum diagnosis than in the general population. It is associated with autistic traits and autism-related perceptual processing characteristics, including a more detail-focused attentional style and altered sensory sensitivity. In addition, these characteristics correlate with the degree of grapheme-color synesthesia (consistency of grapheme-color associations) in non-synesthetes. We investigated a predominantly non-synesthetic twin sample, including individuals fulfilling criteria for an autism spectrum diagnosis or other neurodevelopmental disorders (n = 65, 14-34 years, 60% female). We modelled linear relationships between the degree of grapheme-color synesthesia and autistic traits, sensory sensitivity, and visual perception, both within-twin pairs (22 pairs) where all factors shared by twins are implicitly controlled (including 50-100% genetics), and across the entire cohort. We found that the degree of grapheme-color synesthesia was associated with autistic traits within the domain of Attention to Details and with sensory hyper-, but not hypo-sensitivity. These associations were stronger within-twin pairs than across the sample. Further, twins with a higher degree of grapheme-color synesthesia were better than their co-twins at identifying fragmented images (Fragmented Pictures Test). This is the first twin study on the association between synesthesia and autism-related perceptual features and traits. The results suggest that investigating these associations within-twin pairs, implicitly adjusting for potential confounding factors shared by twins, is more sensitive than doing so in non-related individuals. Consistent with previous findings, the results suggest an association between the degree of grapheme-color synesthesia and autism-related perceptual features, while utilizing a different measure for sensory sensitivity. The novel finding of enhanced fragmented picture integration in twins with a higher degree of grapheme-color synesthesia challenges the view of a generally more detail-focused attentional style in synesthesia and might be related to enhanced memory or mental imagery in more synesthetic individuals.
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Affiliation(s)
- Tessa M van Leeuwen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands; Department of Communication and Cognition, Tilburg School of Humanities and Digital Sciences, Tilburg University, Tilburg, the Netherlands
| | - Lowe Wilsson
- Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research, Department of Women's and Children's Health, Karolinska Institutet & Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Hjalmar Nobel Norrman
- Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research, Department of Women's and Children's Health, Karolinska Institutet & Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Mark Dingemanse
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands; Centre for Language Studies, Radboud University, Nijmegen, the Netherlands
| | - Sven Bölte
- Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research, Department of Women's and Children's Health, Karolinska Institutet & Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden; Child and Adolescent Psychiatry, Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden; Curtin Autism Research Group, Curtin School of Allied Health, Curtin University, Perth, WA, Australia
| | - Janina Neufeld
- Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research, Department of Women's and Children's Health, Karolinska Institutet & Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden.
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8
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Abstract
Synaesthesia and absolute pitch (AP) are two rare conditions that occur more frequently within populations of artistic professionals. Current thinking surrounding synaesthesia and AP and their relationship to music perception form the focus of this article. Given that synaesthesia has rarely been discussed in the music literature, the article surveys and consolidates general neurobiological, psychological, and behavioural evidence to summarise what is currently known on this topic, in order to link this back to the conditions that most relate to music. In contrast, research on AP is now well established in the music literature, but the important gap of linking AP to other conditions such as synaesthesia has yet to be fully explored. This article investigates the potential relationship between synaesthesia and AP for musicians who possess both conditions by systematically comparing the definitions, classifications, prevalence, diagnoses, and impacts on music perception of synaesthesia and AP and provides insights into the varying states of the literature and knowledge of both conditions. In so doing, this article aims to facilitate a greater understanding of music and auditory forms of synaesthesia and their interaction with AP and encourage increased research effort on this important topic.
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In Prototypical Autism, the Genetic Ability to Learn Language Is Triggered by Structured Information, Not Only by Exposure to Oral Language. Genes (Basel) 2021; 12:genes12081112. [PMID: 34440286 PMCID: PMC8391732 DOI: 10.3390/genes12081112] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/24/2021] [Accepted: 07/19/2021] [Indexed: 12/24/2022] Open
Abstract
What does the way that autistic individuals bypass, learn, and eventually master language tell us about humans’ genetically encoded linguistic ability? In this theoretical review, we argue that autistic non-social acquisition of language and autistic savant abilities provide a strong argument for an innate, human-specific orientation towards (and mastery of) complex embedded structures. Autistic non-social language learning may represent a widening of the material processed during development beyond oral language. The structure detection and manipulation and generative production of non-linguistic embedded and chained material (savant abilities in calendar calculation, musical composition, musical interpretation, and three-dimensional drawing) may thus represent an application of such innate mechanisms to non-standard materials. Typical language learning through exposure to the child’s mother tongue may represent but one of many possible achievements of the same capacity. The deviation from typical language development in autism may ultimately allow access to oral language, sometimes in its most elaborate forms, and also explain the possibility of the absence of its development when applied exclusively to non-linguistic structured material. Such an extension of human capacities beyond or in parallel to their usual limits call into question what we consider to be specific or expected in humans and therefore does not necessarily represent a genetic “error”. Regardless of the adaptive success or failure of non-social language learning, it is the duty of science and ethical principles to strive to maintain autism as a human potentiality to further foster our vision of a plural society.
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10
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Ward J. Synaesthesia as a model system for understanding variation in the human mind and brain. Cogn Neuropsychol 2021; 38:259-278. [PMID: 34266374 DOI: 10.1080/02643294.2021.1950133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The aim of this article is to reposition synaesthesia as model system for understanding variation in the construction of the human mind and brain. People with synaesthesia inhabit a remarkable mental world in which numbers can be coloured, words can have tastes, and music is a visual spectacle. Key questions remain unanswered about why it exists, and how the study of synaesthesia might inform theories of the human mind. This article argues we need to rethink synaesthesia as not just representing exceptional experiences, but as a product of an unusual neurodevelopmental cascade from genes to brain to cognition of which synaesthesia is only one outcome. Specifically, differences in the brains of synaesthetes support a distinctive way of thinking (enhanced memory, imagery etc.) and may also predispose towards particular clinical vulnerabilities. In effect, synaesthesia can act as a paradigmatic example of a neuropsychological approach to individual differences.
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Affiliation(s)
- Jamie Ward
- School of Psychology, University of Sussex, Brighton, UK
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11
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Benítez-Burraco A, Progovac L. Language evolution: examining the link between cross-modality and aggression through the lens of disorders. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200188. [PMID: 33745319 PMCID: PMC8059641 DOI: 10.1098/rstb.2020.0188] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2020] [Indexed: 12/12/2022] Open
Abstract
We demonstrate how two linguistic phenomena, figurative language (implicating cross-modality) and derogatory language (implicating aggression), both demand a precise degree of (dis)inhibition in the same cortico-subcortical brain circuits, in particular cortico-striatal networks, whose connectivity has been significantly enhanced in recent evolution. We examine four cognitive disorders/conditions that exhibit abnormal patterns of (dis)inhibition in these networks: schizophrenia (SZ), autism spectrum disorder (ASD), synaesthesia and Tourette's syndrome (TS), with the goal of understanding why the two phenomena altered reactive aggression and altered cross-modality cluster together in these disorders. Our proposal is that enhanced cross-modality (necessary to support language, in particular metaphoricity) was a result, partly a side-effect, of self-domestication (SD). SD targeted the taming of reactive aggression, but reactive impulses are controlled by the same cortico-subcortical networks that are implicated in cross-modality. We further add that this biological process of SD did not act alone, but was engaged in an intense feedback loop with the cultural emergence of early forms of language/grammar, whose high degree of raw metaphoricity and verbal aggression also contributed to increased brain connectivity and cortical control. Consequently, in conjunction with linguistic expressions serving as approximations/'fossils' of the earliest stages of language, these cognitive disorders/conditions serve as confident proxies of brain changes in language evolution, helping us reconstruct certain crucial aspects of early prehistoric languages and cognition, as well as shed new light on the nature of the disorders. This article is part of the theme issue 'Reconstructing prehistoric languages'.
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Affiliation(s)
- Antonio Benítez-Burraco
- Department of Spanish, Linguistics and Theory of Literature (Linguistics), Faculty of Philology, University of Seville, Seville, Spain
| | - Ljiljana Progovac
- Linguistics Program, Department of English, Wayne State University, Detroit, MI, USA
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12
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A distinct electrophysiological signature for synaesthesia that is independent of individual differences in sensory sensitivity. Cortex 2021; 139:249-266. [PMID: 33894542 DOI: 10.1016/j.cortex.2021.02.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 01/07/2021] [Accepted: 02/25/2021] [Indexed: 11/20/2022]
Abstract
People with synaesthesia have been reported to show atypical electrophysiological responses to certain simple sensory stimuli, even if these stimuli are not inducers of synaesthesia. However, it is unclear whether this constitutes a neural marker that is relatively specific to synaesthesia or whether it reflects some other trait that co-occurs with synaesthesia, but is not specific to it. One candidate is atypical sensory sensitivity (e.g., strong aversion to certain lights and sounds, 'sensory overload') which is a feature of both synaesthesia and autism and that varies greatly in the neurotypical population. Using visual evoked-potentials (to stimuli varying in spatial frequency) and auditory-evoked potentials (to stimuli varying in auditory frequency), we found that synaesthetes had a modulated visual evoked-potential around P1/N1 (emanating from fusiform cortex), a greater auditory N1, as well as differences in the time-frequency domain (increased alpha and beta induced power for visual stimuli). This was distinct from that found in non-synaesthetes. By contrast, no significant electrophysiological differences were found that were linked to neurotypical variation in sensory sensitivity.
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Dance C, Jaquiery M, Eagleman D, Porteous D, Zeman A, Simner J. What is the relationship between Aphantasia, Synaesthesia and Autism? Conscious Cogn 2021; 89:103087. [DOI: 10.1016/j.concog.2021.103087] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/01/2021] [Accepted: 01/17/2021] [Indexed: 12/31/2022]
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Rogenmoser L, Li HC, Jäncke L, Schlaug G. Auditory aversion in absolute pitch possessors. Cortex 2020; 135:285-297. [PMID: 33421728 DOI: 10.1016/j.cortex.2020.11.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/07/2020] [Accepted: 11/09/2020] [Indexed: 11/17/2022]
Abstract
Absolute pitch (AP) refers to the ability of identifying the pitch of a given tone without reliance on any reference pitch. The downside of possessing AP may be the experience of disturbance when exposed to out-of-tune tones. Here, we investigated this so-far unexplored phenomenon in AP, which we refer to as auditory aversion. Electroencephalography (EEG) was recorded in a sample of AP possessors and matched control musicians without AP while letting them perform a task underlying a so-called affective priming paradigm: Participants judged valenced pictures preceded by musical primes as quickly and accurately as possible. The primes were bimodal, presented as tones in combination with visual notations that either matched or mismatched the actually presented tone. Both samples performed better in judging unpleasant pictures over pleasant ones. In comparison with the control musicians, the AP possessors revealed a more profound discrepancy between the two valence conditions, and their EEG revealed later peaks at around 200 ms (P200) after prime onset. Their performance dropped when responding to pleasant pictures preceded by incongruent primes, especially when mistuned by one semitone. This interference was also reflected in an EEG deflection at around 400 ms (N400) after picture onset, preceding the behavior responses. These findings suggest that AP possessors process mistuned musical stimuli and pleasant pictures as affectively unrelated with each other, supporting an aversion towards out-of-tune tones in AP possessors. The longer prime-related P200 latencies exhibited by AP possessors suggest a delay in integrating musical stimuli, underlying an altered affinity towards pitch-label associations.
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Affiliation(s)
- Lars Rogenmoser
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA; Department of Medicine, University of Fribourg, Fribourg, Switzerland.
| | - H Charles Li
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Lutz Jäncke
- Department of Psychology, University of Zurich, Zurich, Switzerland; University Research Priority Program (URPP), Dynamics of Healthy Aging, University of Zurich, Zurich, Switzerland
| | - Gottfried Schlaug
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
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van Leeuwen TM, Sauer A, Jurjut AM, Wibral M, Uhlhaas PJ, Singer W, Melloni L. Perceptual Gains and Losses in Synesthesia and Schizophrenia. Schizophr Bull 2020; 47:722-730. [PMID: 33150444 PMCID: PMC8084450 DOI: 10.1093/schbul/sbaa162] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Individual differences in perception are widespread. Considering inter-individual variability, synesthetes experience stable additional sensations; schizophrenia patients suffer perceptual deficits in, eg, perceptual organization (alongside hallucinations and delusions). Is there a unifying principle explaining inter-individual variability in perception? There is good reason to believe perceptual experience results from inferential processes whereby sensory evidence is weighted by prior knowledge about the world. Perceptual variability may result from different precision weighting of sensory evidence and prior knowledge. We tested this hypothesis by comparing visibility thresholds in a perceptual hysteresis task across medicated schizophrenia patients (N = 20), synesthetes (N = 20), and controls (N = 26). Participants rated the subjective visibility of stimuli embedded in noise while we parametrically manipulated the availability of sensory evidence. Additionally, precise long-term priors in synesthetes were leveraged by presenting either synesthesia-inducing or neutral stimuli. Schizophrenia patients showed increased visibility thresholds, consistent with overreliance on sensory evidence. In contrast, synesthetes exhibited lowered thresholds exclusively for synesthesia-inducing stimuli suggesting high-precision long-term priors. Additionally, in both synesthetes and schizophrenia patients explicit, short-term priors-introduced during the hysteresis experiment-lowered thresholds but did not normalize perception. Our results imply that perceptual variability might result from differences in the precision afforded to prior beliefs and sensory evidence, respectively.
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Affiliation(s)
- Tessa M van Leeuwen
- Department of Neurophysiology, Max Planck Institute for Brain Research, Frankfurt am Main, Germany,Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt am Main, Germany,Radboud University, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | - Andreas Sauer
- Department of Neurophysiology, Max Planck Institute for Brain Research, Frankfurt am Main, Germany,Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt am Main, Germany
| | - Anna-Maria Jurjut
- Department of Neurophysiology, Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Michael Wibral
- Magnetoencephalography Unit, Brain Imaging Center, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Peter J Uhlhaas
- Department of Neurophysiology, Max Planck Institute for Brain Research, Frankfurt am Main, Germany,Institute of Neuroscience and Psychology, University of Glasgow, Scotland,Department of Child and Adolescent Psychiatry, Charité Universitätsmedizin, Berlin, Germany
| | - Wolf Singer
- Department of Neurophysiology, Max Planck Institute for Brain Research, Frankfurt am Main, Germany,Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt am Main, Germany,Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Lucia Melloni
- Department of Neurophysiology, Max Planck Institute for Brain Research, Frankfurt am Main, Germany,Department of Neurology, New York University School of Medicine, New York, NY,Department of Neuroscience, Max Planck Institute for Empirical Aesthetics, Frankfurt am Main, Germany,To whom correspondence should be addressed; Max-Planck-Institute for Empirical Aesthetics, Department of Neuroscience, Grüneburgweg 14, 60322 Frankfurt am Main, Germany. tel: +49 (0)69-8300479-330, fax: +49 69 8300 479 399, e-mail:
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16
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Pennisi P, Giallongo L, Milintenda G, Cannarozzo M. Autism, autistic traits and creativity: a systematic review and meta-analysis. Cogn Process 2020; 22:1-36. [PMID: 33057954 DOI: 10.1007/s10339-020-00992-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 09/05/2020] [Indexed: 10/23/2022]
Abstract
Psychometric, historiometric and psychiatric studies are controversial on a hypothetical link between psychopathology and creativity. In this study, we will try to contribute to this debate by analysing the case of autism. Is there a relationship between autism and creativity? If so, can we find the same relationship in a watered-down form in subjects with autistic traits? In order to answer these questions, we carried out a systematic literature review of the studies on this topic published in the last 10 years. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We also conducted a meta-analysis of data. We found that in the clinical population there are fewer creative performances than in control groups; nonetheless, it is possible to delineate a medium creative profile of subjects with autism. The average creative profile of people with autism shows that they are inhibited in fluency and flexibility, but that they display a high level of detail and a particularly high level of originality in works either generated during tests or created in private time. In particular, the level of detail reached in the latter condition seems to be higher in the autistic population than in the control groups. Better linguistic skills appear to be linked to better creative performances. Linguistic tests, if compared with visual and performative tests, seem to favour the expression of originality in subjects with autism. Although our data on autistic traits are compatible with the hypothesis that a high level of autistic traits is a watered-down replica of the cognitive profile of subjects with autism, we have no sufficient data to support this hypothesis.
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Affiliation(s)
- Paola Pennisi
- Department of Adult and Childhood, Human Pathology "Gaetano Barresi"; Hospital G. Martino, University of Messina, Via Consolare Valeria snc, 98125, Messina, Italy.
| | - Laura Giallongo
- Department of Cognitive Science, Education and Cultural Studies, University of Messina, Via Concezione 6/8, IT, 98121, Messina, Italy
| | - Giusy Milintenda
- Department of Cognitive Science, Education and Cultural Studies, University of Messina, Via Concezione 6/8, IT, 98121, Messina, Italy
| | - Michela Cannarozzo
- Department of Adult and Childhood, Human Pathology "Gaetano Barresi"; Hospital G. Martino, University of Messina, Via Consolare Valeria snc, 98125, Messina, Italy
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17
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van Leeuwen TM, Neufeld J, Hughes J, Ward J. Synaesthesia and autism: Different developmental outcomes from overlapping mechanisms? Cogn Neuropsychol 2020; 37:433-449. [PMID: 32845799 DOI: 10.1080/02643294.2020.1808455] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Synaesthesia, a mixing of the senses, is more common in individuals with autism. Here, we review the evidence for the association between synaesthesia and autism with regard to their genetic background, brain connectivity, perception, cognitive mechanisms and their contribution to exceptional talents. Currently, the overlap between synaesthesia and autism is established most convincingly at the level of alterations in sensory sensitivity and perception, with synaesthetes showing autism-like profiles of sensory sensitivity and a bias towards details in perception. Shared features may include a predominance of local over global connectivity in the brain. When autism and synaesthesia co-occur in the same individual, the chance of developing heightened cognitive and memory abilities is increased. We discuss how the same theoretical models could potentially explain both conditions. Given the evidence, we believe the phenotypical overlap between autism and synaesthesia has been established clearly enough to invite future research to confirm overlapping mechanisms.
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Affiliation(s)
- Tessa M van Leeuwen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Janina Neufeld
- Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research, Department of Women's and Children's Health, Karolinska Institutet & Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - James Hughes
- School of Psychology, University of Sussex, Brighton, UK
| | - Jamie Ward
- School of Psychology, University of Sussex, Brighton, UK
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18
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Riedel A, Maier S, Wenzler K, Feige B, Tebartz van Elst L, Bölte S, Neufeld J. A case of co-occuring synesthesia, autism, prodigious talent and strong structural brain connectivity. BMC Psychiatry 2020; 20:342. [PMID: 32605557 PMCID: PMC7329514 DOI: 10.1186/s12888-020-02722-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 06/09/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Synesthesia is a sensory phenomenon where certain domain-specific stimuli trigger additional sensations of e.g. color or texture. The condition occurs in about 4% of the general population, but is overrepresented in individuals with Autism Spectrum Disorder (ASD), where it might also be associated with the presence of prodigious talents. CASE PRESENTATION Here we describe the case of a young transsexual man with Asperger Syndrome, synesthesia and a prodigious talent for foreign language acquisition. In our case, not only letters, numbers, spoken words, music, noises, weekdays and months lead to highly consistent, vivid color sensations but also his own and others' emotions, geometric shapes, any mathematical symbol, and letters from an unfamiliar alphabet (Hebrew). These color associations seem to aid categorization, differentiation and storage of information and might thereby contribute to the young man's language acquisition ability. We investigated the young man's structural brain connectivity in comparison to adults with or without ASD, applying global fiber tracking to diffusion-weighted Magnetic Resonance Imaging (MRI) data. The case presented with increased connectivity, especially between regions involved in visual and emotion processing, memory, and higher order associative binding regions. An electroencephalography experiment investigating synesthetic color and shape sensations while listening to music showed a negligible occipital alpha suppression, indicating that these internally generated synesthetic sensations derive from a different brain mechanism than when processing external visual information. CONCLUSIONS Taken together, this case study endorses the notion of a link between synesthesia, prodigious talent and autism, adding to the currently still sparse literature in this field. It provides new insights into the possible manifestations of synesthesia in individuals with ASD and its potential contribution to prodigious talents in people with an otherwise unexceptional cognitive profile. 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.
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Affiliation(s)
- Andreas Riedel
- grid.7708.80000 0000 9428 7911Section for Experimental Neuropsychiatry, Department for Psychiatry & Psychotherapy, Medical Center – University of Freiburg, Faculty of Medicine - University of Freiburg, Freiburg, Germany
| | - Simon Maier
- grid.7708.80000 0000 9428 7911Section for Experimental Neuropsychiatry, Department for Psychiatry & Psychotherapy, Medical Center – University of Freiburg, Faculty of Medicine - University of Freiburg, Freiburg, Germany
| | - Kerstin Wenzler
- grid.7708.80000 0000 9428 7911Section for Experimental Neuropsychiatry, Department for Psychiatry & Psychotherapy, Medical Center – University of Freiburg, Faculty of Medicine - University of Freiburg, Freiburg, Germany
| | - Bernd Feige
- grid.7708.80000 0000 9428 7911Section for Experimental Neuropsychiatry, Department for Psychiatry & Psychotherapy, Medical Center – University of Freiburg, Faculty of Medicine - University of Freiburg, Freiburg, Germany
| | - Ludger Tebartz van Elst
- grid.7708.80000 0000 9428 7911Section for Experimental Neuropsychiatry, Department for Psychiatry & Psychotherapy, Medical Center – University of Freiburg, Faculty of Medicine - University of Freiburg, Freiburg, Germany
| | - Sven Bölte
- grid.4714.60000 0004 1937 0626Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research; Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden ,grid.1032.00000 0004 0375 4078Curtin Autism Research Group, Essential Partner Autism CRC, School of Occupational Therapy, Social Work and Speech Pathology, Curtin University, Perth, Western Australia ,grid.467087.a0000 0004 0442 1056Child and Adolescent Psychiatry, Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Janina Neufeld
- Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research; Department of Women's and Children's Health, Karolinska Institutet, Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden.
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19
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Abstract
Synaesthesia is highly prevalent in autism spectrum disorder. We assessed the relation between the degree of autistic traits (Autism Spectrum Quotient, AQ) and the degree of synaesthesia in a neurotypical population, and hypothesized both are related to a local bias in visual perception. A positive correlation between total AQ scores and the degree of synaesthesia was found, extending previous studies in clinical populations. Consistent with our hypothesis, AQ-attention to detail scores were related to increased performance on an Embedded Figures Task and reduced susceptibility to visual illusions. We found no relation between autistic traits and performance on a motion coherence task, and no relation between synaesthesia and local visual perception. Possibly, this relation is reserved for supra-threshold synaesthetes.
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20
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Rabeyron T, Massicotte C. Entropy, Free Energy, and Symbolization: Free Association at the Intersection of Psychoanalysis and Neuroscience. Front Psychol 2020; 11:366. [PMID: 32256426 PMCID: PMC7093713 DOI: 10.3389/fpsyg.2020.00366] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 02/17/2020] [Indexed: 11/19/2022] Open
Abstract
Both a method of therapy and an exploration of psychic reality, free association is a fundamental element of psychoanalytical practices that refers to the way a patient is asked to describe what comes spontaneously to mind in the therapeutic setting. This paper examines the role of free association from the point of view of psychoanalysis and neuroscience in order to improve our understanding of therapeutic effects induced by psychoanalytic therapies and psychoanalysis. In this regard, we first propose a global overview of the historical origins of the concept of free association in psychoanalysis and examine how Freud established its principles. Then, from Freud's distinction between primary and secondary processes, we proceed to compare the psychoanalytic model with research originating from cognitive psychology and neuroscience. The notions of entropy and free energy appear particularly relevant at the intersection of these different domains. Finally, we propose the notion of symbolizing transmodality to describe certain specificities of symbolization processes within free association and we summarize the main functions of free association in psychoanalytic practices.
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Affiliation(s)
- Thomas Rabeyron
- Interpsy, Université de Lorraine, Nancy, France
- University of Edinburgh, Edinburgh, United Kingdom
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21
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Simner J, Hughes JEA, Sagiv N. Objectum sexuality: A sexual orientation linked with autism and synaesthesia. Sci Rep 2019; 9:19874. [PMID: 31882730 PMCID: PMC6934473 DOI: 10.1038/s41598-019-56449-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 12/06/2019] [Indexed: 01/06/2023] Open
Abstract
Objectum-sexuality (OS) is a sexual orientation which has received little attention in the academic literature. Individuals who identify as OS experience emotional, romantic and/or sexual feelings towards inanimate objects (e.g. a bridge, a statue). We tested 34 OS individuals and 88 controls, and provide the first empirical evidence that OS is linked to two separate neurodevelopmental traits - autism and synaesthesia. We show that OS individuals possess significantly higher rates of diagnosed autism and significantly stronger autistic traits compared to controls, as well as a significantly higher prevalence of synaesthesia, and significant synaesthetic traits inherent in the nature of their attractions. Our results suggest that OS may encapsulate autism and synaesthesia within its phenomenology. Our data speak to debates concerning the biological underpinnings of sexuality, to models of autism and synaesthesia, and to psychological and philosophical models of romantic love.
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Affiliation(s)
- Julia Simner
- School of Psychology, Pevensey Building, University of Sussex, Brighton, BN1 9QJ, UK.
| | - James E A Hughes
- School of Psychology, Pevensey Building, University of Sussex, Brighton, BN1 9QJ, UK
| | - Noam Sagiv
- Centre for Cognitive Neuroscience, College of Health and Life Sciences, Brunel University, London, Uxbridge, UB8 3PN, UK
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22
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van Leeuwen TM, van Petersen E, Burghoorn F, Dingemanse M, van Lier R. Autistic traits in synaesthesia: atypical sensory sensitivity and enhanced perception of details. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190024. [PMID: 31630653 PMCID: PMC6834020 DOI: 10.1098/rstb.2019.0024] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2019] [Indexed: 01/16/2023] Open
Abstract
In synaesthetes, specific sensory stimuli (e.g. black letters) elicit additional experiences (e.g. colour). Synaesthesia is highly prevalent among individuals with autism spectrum disorder (ASD), but the mechanisms of this co-occurrence are not clear. We hypothesized autism and synaesthesia share atypical sensory sensitivity and perception. We assessed autistic traits, sensory sensitivity and visual perception in two synaesthete populations. In Study 1, synaesthetes (N = 79, of different types) scored higher than non-synaesthetes (N = 76) on the Attention-to-detail and Social skills subscales of the autism spectrum quotient indexing autistic traits, and on the Glasgow Sensory Questionnaire indexing sensory hypersensitivity and hyposensitivity which frequently occur in autism. Synaesthetes performed two local/global visual tasks because individuals with autism typically show a bias towards detail processing. In synaesthetes, elevated motion coherence thresholds (MCTs) suggested reduced global motion perception, and higher accuracy on an embedded figures task suggested enhanced local perception. In Study 2, sequence-space synaesthetes (N = 18) completed the same tasks. Questionnaire and embedded figures results qualitatively resembled Study 1 results, but no significant group differences with non-synaesthetes (N = 20) were obtained. Unexpectedly, sequence-space synaesthetes had reduced MCTs. Altogether, our studies suggest atypical sensory sensitivity and a bias towards detail processing are shared features of synaesthesia and ASD. This article is part of the discussion meeting issue 'Bridging senses: novel insights from synaesthesia'.
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Affiliation(s)
- Tessa M. van Leeuwen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Eline van Petersen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Floor Burghoorn
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Mark Dingemanse
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
- Centre for Language Studies, Radboud University, Nijmegen, The Netherlands
- Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
| | - Rob van Lier
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
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23
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Tilot AK, Vino A, Kucera KS, Carmichael DA, van den Heuvel L, den Hoed J, Sidoroff-Dorso AV, Campbell A, Porteous DJ, St Pourcain B, van Leeuwen TM, Ward J, Rouw R, Simner J, Fisher SE. Investigating genetic links between grapheme-colour synaesthesia and neuropsychiatric traits. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190026. [PMID: 31630655 PMCID: PMC6834005 DOI: 10.1098/rstb.2019.0026] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2019] [Indexed: 12/22/2022] Open
Abstract
Synaesthesia is a neurological phenomenon affecting perception, where triggering stimuli (e.g. letters and numbers) elicit unusual secondary sensory experiences (e.g. colours). Family-based studies point to a role for genetic factors in the development of this trait. However, the contributions of common genomic variation to synaesthesia have not yet been investigated. Here, we present the SynGenes cohort, the largest genotyped collection of unrelated people with grapheme-colour synaesthesia (n = 723). Synaesthesia has been associated with a range of other neuropsychological traits, including enhanced memory and mental imagery, as well as greater sensory sensitivity. Motivated by the prior literature on putative trait overlaps, we investigated polygenic scores derived from published genome-wide scans of schizophrenia and autism spectrum disorder (ASD), comparing our SynGenes cohort to 2181 non-synaesthetic controls. We found a very slight association between schizophrenia polygenic scores and synaesthesia (Nagelkerke's R2 = 0.0047, empirical p = 0.0027) and no significant association for scores related to ASD (Nagelkerke's R2 = 0.00092, empirical p = 0.54) or body mass index (R2 = 0.00058, empirical p = 0.60), included as a negative control. As sample sizes for studying common genomic variation continue to increase, genetic investigations of the kind reported here may yield novel insights into the shared biology between synaesthesia and other traits, to complement findings from neuropsychology and brain imaging. This article is part of a discussion meeting issue 'Bridging senses: novel insights from synaesthesia'.
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Affiliation(s)
- Amanda K. Tilot
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, The Netherlands
- Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90033, USA
| | - Arianna Vino
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, The Netherlands
| | - Katerina S. Kucera
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, The Netherlands
| | - Duncan A. Carmichael
- School of Applied Sciences, Edinburgh Napier University, Sighthill Court, Edinburgh EH11 4BN, UK
| | - Loes van den Heuvel
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, The Netherlands
| | - Joery den Hoed
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, The Netherlands
| | | | - Archie Campbell
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
- Usher Institute for Population Health Sciences and Informatics, University of Edinburgh, Edinburgh EH16 4UX, UK
| | - David J. Porteous
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh EH8 9JZ, UK
| | - Beate St Pourcain
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, The Netherlands
| | - Tessa M. van Leeuwen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6500 HE Nijmegen, The Netherlands
| | - Jamie Ward
- School of Psychology, University of Sussex, Brighton BN1 9RH, UK
| | - Romke Rouw
- Department of Psychology, University of Amsterdam, 1018 WT Amsterdam, The Netherlands
| | - Julia Simner
- School of Psychology, University of Sussex, Brighton BN1 9RH, UK
| | - Simon E. Fisher
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, 6525 XD Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6500 HE Nijmegen, The Netherlands
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24
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Negri O, White RC, Remington A. A Friendly Article: The Qualitative Investigation of Anthropomorphism in Autistic and Nonautistic Adults. AUTISM IN ADULTHOOD 2019; 1:286-296. [PMID: 36601321 PMCID: PMC8992829 DOI: 10.1089/aut.2019.0027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Background Anthropomorphism is the attribution of human characteristics to nonhuman agents. This common tendency is thought to be driven by a heightened motivation for social connection and may therefore be expected to be reduced in autistic individuals given that this group has been claimed to demonstrate reduced social motivation in some settings. However, the subject of anthropomorphism in autism has not been studied extensively, and online forums, autobiographical accounts, and recent research on the topic suggest that, contrary to this expectation, anthropomorphism is commonly experienced by autistic individuals. Methods We conducted semi-structured interviews with eight autistic and eight nonautistic adults, all who reported a tendency to anthropomorphize. We recorded, transcribed, and analyzed the interviews according to the thematic analysis framework with the objective of identifying similarities and differences in the lived experiences of anthropomorphism in autistic and nonautistic individuals. Results Individuals in both groups described anthropomorphism as comforting, promoting a sense of safety and friendship with, and feelings of empathy and sympathy toward, nonhuman agents. Autistic individuals stressed the important role anthropomorphized agents played in their life, particularly when growing up: easing loneliness and helping develop an understanding of emotions and relationships. Participants also expressed negative aspects of the phenomenon, with both autistic and nonautistic individuals worrying about anthropomorphized agents' feelings and well-being. For some individuals, such thoughts and feelings caused distress and were experienced as intrusive due to their involuntary nature. Conclusions Autistic and nonautistic adults showed very similar anthropomorphic patterns. Although preliminary in nature, our findings highlight characteristics of anthropomorphic experiences for autistic and nonautistic individuals, furthering our understanding of individual differences in social cognition. By illustrating the important role nonhuman agents may play in the lives of autistic individuals, our findings may also guide future research and practice. Lay summary Why was this study done?: 'Anthropomorphism' is when you feel that non-human items have human characteristics, for example if you experience plants, animals, or household objects as having thoughts or feelings. Anthropomorphism is experienced by many people in many different ways. Researchers think it might happen when people have a strong desire for social connection. This has led some to suggest that autistic people will be less likely to anthropomorphise due to difficulties in social understanding and motivation. However, researchers have not examined this directly, and our prior research, together with comments in online forums and autobiographical accounts, indicated that autistic individuals may experience a special relationship with non-human items.What was the purpose of this study?: The purpose of the study was to speak directly to people who anthropomorphise and hear about their experiences. We could then compare patterns of anthropomorphism between autistic and non-autistic adults.What did the researchers do?: We interviewed 16 adults (8 autistic and 8 non-autistic) who told us they anthropomorphised, and asked about their personal experiences of anthropomorphism.What were the results of the study?: Autistic and non-autistic adults described very similar experiences of anthropomorphism. People in both groups described anthropomorphism as comforting, and said that it gave them a sense of safety and friendship. They also cared for, and experienced feelings of empathy toward, anthropomorphised items. Individuals in both groups worried about anthropomorphised items' feelings and well-being and this caused some people considerable distress. Autistic individuals stressed the important role anthropomorphised items played in their life, particularly when growing up: reducing loneliness and helping them develop an understanding of emotions and relationships.What do these findings add to what was already known?: Our findings show that there are many similarities in the experiences of anthropomorphism in autistic and non-autistic adults. The findings also show how, for some autistic adults, anthropomorphism was helpful in developing relationships with other people.What are potential weaknesses in the study?: The small number of participants means that we do not know whether the findings would apply to all people who experience anthropomorphism.How will these findings help autistic adults now or in the future?: By showing the various ways in which autistic individuals attach social meanings (such as feelings of caring or friendship) to anthropomorphised items, our findings add to a growing number of studies which challenge the commonly-held assumption that autistic individuals are less motivated to make social connections. Our work shows that autistic individuals may be highly motivated to connect socially, and that meaningful social connections and expressions of empathy need not be limited to human beings.
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Affiliation(s)
- Orli Negri
- Centre for Research in Autism and Education (CRAE), UCL Institute of Education, London, United Kingdom
- Address correspondence to: Orli Negri, MSc, Centre for Research in Autism and Education (CRAE), UCL Institute of Education, 55–59 Gordon Square, Bloomsbury, London WC1H 0NU, United Kingdom
| | - Rebekah C. White
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Anna Remington
- Centre for Research in Autism and Education (CRAE), UCL Institute of Education, London, United Kingdom
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25
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Lalwani P, Brang D. Stochastic resonance model of synaesthesia. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190029. [PMID: 31630652 DOI: 10.1098/rstb.2019.0029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In synaesthesia, stimulation of one sensory modality evokes additional experiences in another modality (e.g. sounds evoking colours). Along with these cross-sensory experiences, there are several cognitive and perceptual differences between synaesthetes and non-synaesthetes. For example, synaesthetes demonstrate enhanced imagery, increased cortical excitability and greater perceptual sensitivity in the concurrent modality. Previous models suggest that synaesthesia results from increased connectivity between corresponding sensory regions or disinhibited feedback from higher cortical areas. While these models explain how one sense can evoke qualitative experiences in another, they fail to predict the broader phenotype of differences observed in synaesthetes. Here, we propose a novel model of synaesthesia based on the principles of stochastic resonance. Specifically, we hypothesize that synaesthetes have greater neural noise in sensory regions, which allows pre-existing multisensory pathways to elicit supra-threshold activation (i.e. synaesthetic experiences). The strengths of this model are (a) it predicts the broader cognitive and perceptual differences in synaesthetes, (b) it provides a unified framework linking developmental and induced synaesthesias, and (c) it explains why synaesthetic associations are inconsistent at onset but stabilize over time. We review research consistent with this model and propose future studies to test its limits. This article is part of a discussion meeting issue 'Bridging senses: novel insights from synaesthesia'.
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Affiliation(s)
- Poortata Lalwani
- Department of Psychology, University of Michigan, 530 Church Street, Ann Arbor, MI 48109, USA
| | - David Brang
- Department of Psychology, University of Michigan, 530 Church Street, Ann Arbor, MI 48109, USA
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26
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Ioumpa K, Graham SA, Clausner T, Fisher SE, van Lier R, van Leeuwen TM. Enhanced self-reported affect and prosocial behaviour without differential physiological responses in mirror-sensory synaesthesia. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190395. [PMID: 31630658 DOI: 10.1098/rstb.2019.0395] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Mirror-sensory synaesthetes mirror the pain or touch that they observe in other people on their own bodies. This type of synaesthesia has been associated with enhanced empathy. We investigated whether the enhanced empathy of people with mirror-sensory synesthesia influences the experience of situations involving touch or pain and whether it affects their prosocial decision making. Mirror-sensory synaesthetes (N = 18, all female), verified with a touch-interference paradigm, were compared with a similar number of age-matched control individuals (all female). Participants viewed arousing images depicting pain or touch; we recorded subjective valence and arousal ratings, and physiological responses, hypothesizing more extreme reactions in synaesthetes. The subjective impact of positive and negative images was stronger in synaesthetes than in control participants; the stronger the reported synaesthesia, the more extreme the picture ratings. However, there was no evidence for differential physiological or hormonal responses to arousing pictures. Prosocial decision making was assessed with an economic game assessing altruism, in which participants had to divide money between themselves and a second player. Mirror-sensory synaesthetes donated more money than non-synaesthetes, showing enhanced prosocial behaviour, and also scored higher on the Interpersonal Reactivity Index as a measure of empathy. Our study demonstrates the subjective impact of mirror-sensory synaesthesia and its stimulating influence on prosocial behaviour. This article is part of the discussion meeting issue 'Bridging senses: novel insights from synaesthesia'.
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Affiliation(s)
- Kalliopi Ioumpa
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands.,Netherlands Institute for Neuroscience, Royal Netherlands Academy for Arts and Sciences, Amsterdam, The Netherlands
| | - Sarah A Graham
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
| | - Tommy Clausner
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Simon E Fisher
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands.,Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
| | - Rob van Lier
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Tessa M van Leeuwen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
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Ward J. Synaesthesia: a distinct entity that is an emergent feature of adaptive neurocognitive differences. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180351. [PMID: 31630648 DOI: 10.1098/rstb.2018.0351] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In this article, I argue that synaesthesia is not on a continuum with neurotypical cognition. Synaesthesia is special: its phenomenology is different; it has distinct causal mechanisms; and is likely to be associated with a distinct neurocognitive profile. However, not all synaesthetes are the same, and there are quantifiable differences between them. In particular, the number of types of synaesthesia that a person possesses is a hitherto underappreciated variable that predicts cognitive differences along a number of dimensions (mental imagery, sensory sensitivity, attention to detail). Together with enhanced memory, this may constitute a common core of abilities that may go some way to explaining why synaesthesia might have evolved. I argue that the direct benefits of synaesthesia are generally limited (i.e. the synaesthetic associations do not convey novel information about the world) but, nevertheless, synaesthesia may develop due to other adaptive functions (e.g. perceptual ability, memory) that necessitate changes to design features of the brain. The article concludes by suggesting that synaesthesia forces us to reconsider what we mean by a 'normal' mind/brain. There may be multiple 'normal' neurodevelopmental trajectories that can sculpt very different ways of experiencing the world, of which synaesthesia is but one. This article is part of a discussion meeting issue 'Bridging senses: novel insights from synaesthesia'.
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Affiliation(s)
- Jamie Ward
- School of Psychology, University of Sussex, Falmer, Brighton BN1 9QH, UK
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Andrade A, Brennecke A, Mallat S, Brown J, Gomez-Rivadeneira J, Czepiel N, Londrigan L. Genetic Associations between Voltage-Gated Calcium Channels and Psychiatric Disorders. Int J Mol Sci 2019; 20:E3537. [PMID: 31331039 PMCID: PMC6679227 DOI: 10.3390/ijms20143537] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/12/2019] [Accepted: 07/13/2019] [Indexed: 12/23/2022] Open
Abstract
Psychiatric disorders are mental, behavioral or emotional disorders. These conditions are prevalent, one in four adults suffer from any type of psychiatric disorders world-wide. It has always been observed that psychiatric disorders have a genetic component, however, new methods to sequence full genomes of large cohorts have identified with high precision genetic risk loci for these conditions. Psychiatric disorders include, but are not limited to, bipolar disorder, schizophrenia, autism spectrum disorder, anxiety disorders, major depressive disorder, and attention-deficit and hyperactivity disorder. Several risk loci for psychiatric disorders fall within genes that encode for voltage-gated calcium channels (CaVs). Calcium entering through CaVs is crucial for multiple neuronal processes. In this review, we will summarize recent findings that link CaVs and their auxiliary subunits to psychiatric disorders. First, we will provide a general overview of CaVs structure, classification, function, expression and pharmacology. Next, we will summarize tools to study risk loci associated with psychiatric disorders. We will examine functional studies of risk variations in CaV genes when available. Finally, we will review pharmacological evidence of the use of CaV modulators to treat psychiatric disorders. Our review will be of interest for those studying pathophysiological aspects of CaVs.
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Affiliation(s)
- Arturo Andrade
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA.
| | - Ashton Brennecke
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Shayna Mallat
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Julian Brown
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA
| | | | - Natalie Czepiel
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Laura Londrigan
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA
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Landmann J, Richter F, Classen J, Richter A, Penninger JM, Bechmann I. Behavioral phenotyping of calcium channel (CACN) subunit α2δ3 knockout mice: Consequences of sensory cross-modal activation. Behav Brain Res 2019; 364:393-402. [DOI: 10.1016/j.bbr.2017.12.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 12/19/2017] [Accepted: 12/26/2017] [Indexed: 01/14/2023]
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Bouvet L, Amsellem F, Maruani A, Tonus-Vic Dupont A, Mathieu A, Bourgeron T, Delorme R, Mottron L. Synesthesia & autistic features in a large family: Evidence for spatial imagery as a common factor. Behav Brain Res 2019; 362:266-272. [PMID: 30639511 DOI: 10.1016/j.bbr.2019.01.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/08/2019] [Accepted: 01/08/2019] [Indexed: 12/24/2022]
Abstract
BACKGROUND Autism and synesthesia are neurodevelopmental conditions associated with variants of perceptual processing. They also share some genetic variants and include a large magnitude of intra-categorical variation: 60 types for synesthesia, as well as a spectrum for autism. In order to investigate the relationship between these two phenomena, we investigated the family of FC, an autistic individual who also possess savant abilities and synesthesia manifestations. METHOD Autistic symptoms were assessed for the entire sample of participants entering the study (39 individuals) using the SRS. Participants above threshold were evaluated with standardized diagnostic tools. Synesthesia was explored in the entire participating sample using a self-reported questionnaire. Consistency tests were used for participants who reported synesthetic manifestations. RESULTS In addition to FC, four individuals with ASD were detected. Fifteen participants self-reported synesthesia (15 sequence-space, 4 sound-shape, 4 day-color), among which nine sequence-space synesthetes satisfied the consistency criteria. Two participants possess both autism and synesthesia. CONCLUSION This family illustrates the co-segregation of autism and synesthesia. This co-segregation is in favour of a partially overlapping genetic predisposition for both conditions, but also authorizes a large variety of manifestations in both conditions. The high prevalence of sequence-space synesthesia in this family strengthens the previous assumption that this form of synesthesia may be linked to autism. We discuss the potential role of spatial imagery in the development of this form of synesthesia and savant abilities.
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Affiliation(s)
- Lucie Bouvet
- Laboratoire CERPPS (EA7411), Université Toulouse Jean Jaurés, Toulouse, France.
| | - Frédérique Amsellem
- Human Genetics and Cognitive Functions Unit, Institut Pasteur, Paris, France; Child and Adolescent Psychiatry Department, Hôpital Robert-Debré, APHP, 75019, Paris, France; Fondation FondaMental, 94000, Créteil, France
| | - Anna Maruani
- Human Genetics and Cognitive Functions Unit, Institut Pasteur, Paris, France; Child and Adolescent Psychiatry Department, Hôpital Robert-Debré, APHP, 75019, Paris, France
| | - Adelaïde Tonus-Vic Dupont
- Human Genetics and Cognitive Functions Unit, Institut Pasteur, Paris, France; Child and Adolescent Psychiatry Department, Hôpital Robert-Debré, APHP, 75019, Paris, France
| | - Alexandre Mathieu
- Human Genetics and Cognitive Functions Unit, Institut Pasteur, Paris, France; CNRS UMR 3571: Genes, Synapses and Cognition, Institut Pasteur, Paris, France
| | - Thomas Bourgeron
- Human Genetics and Cognitive Functions Unit, Institut Pasteur, Paris, France; CNRS UMR 3571: Genes, Synapses and Cognition, Institut Pasteur, Paris, France; Fondation FondaMental, 94000, Créteil, France; Université Paris Diderot, Sorbonne Paris Cité, Human Genetics and Cognitive Functions, Paris, France
| | - Richard Delorme
- Human Genetics and Cognitive Functions Unit, Institut Pasteur, Paris, France; CNRS UMR 3571: Genes, Synapses and Cognition, Institut Pasteur, Paris, France; Child and Adolescent Psychiatry Department, Hôpital Robert-Debré, APHP, 75019, Paris, France; Fondation FondaMental, 94000, Créteil, France; Université Paris Diderot, Sorbonne Paris Cité, Human Genetics and Cognitive Functions, Paris, France
| | - Laurent Mottron
- Center of Excellence for Pervasive Developmental Disorders of the University of Montreal (CETEDUM), Rivières-des-Prairies Hospital, Montreal, Quebec, Canada; Research Center of CIUSSS of the North of Montreal and Department of Psychiatry, University of Montreal, Montreal, Quebec, Canada
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31
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Hoffman SN, Urosevich TG, Kirchner HL, Boscarino JJ, Dugan RJ, Withey CA, Adams RE, Figley CR, Boscarino JA. Grapheme-Color Synesthesia is Associated with PTSD Among Deployed Veterans: Confirmation of Previous Findings and Need for Additional Research. INTERNATIONAL JOURNAL OF EMERGENCY MENTAL HEALTH 2019; 21:https://www.omicsonline.org/open-access/graphemecolor-synesthesia-is-associated-with-ptsd-among-deployed-veterans-confirmation-of-previous-findings-and-need-for-additiona-1522-4821-108513.html. [PMID: 31285710 PMCID: PMC6613655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Post-traumatic stress disorder (PTSD) is related to alteration in neuropsychological functioning, including visual and other cognitive processes. Grapheme-color synesthesia is a phenomenon in which a letter or number elicits response of a concurrent image or color perception. Since we earlier reported an association between grapheme-color synesthesia and PTSD, our objective in the current study was to validate this association among a new study group and assess risk factors. For this, we surveyed 1,730 military veterans who have been outpatients in the Geisinger Clinic, a multi-hospital system in Pennsylvania, USA. All the study veterans served in a warzone deployment. The association between PTSD and Grapheme-color synesthesia was evaluated. The average age of veterans was 59.6 years among whom 95.1% were male. Current PTSD prevalence rate was observed to be 7.6% (95% C.I. = 6.5-9.0) and in 3.4% of veterans (95% C.I. = 2.7-4.4) grapheme-color synesthesia was found to be positive. Initial bivariate analyses suggested that synesthesia was associated with current PTSD [odds ratio (OR) = 3.3, p<0.001]. Multivariable stepwise logistic regression evaluating the age, sex, education, trauma exposure, current psychological stress, psychotropic medication use, combat exposure, history of concussion, and current depression, confirmed this association (OR = 2.33, p = 0.019). The present study corroborated that Grapheme-color synesthesia was linked to PTSD among a second cohort of deployed military veterans. Further research is recommended in order to validate this observation and to determine whether synesthesia is a risk factor for PTSD.
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Affiliation(s)
| | | | - H. Lester. Kirchner
- Biomedical and Translational Informatics, Geisinger Clinic, Danville, PA, USA
| | | | - Ryan J. Dugan
- Department of Epidemiology and Health Services Research, Geisinger Clinic, Danville, PA, USA
| | - Carrie A. Withey
- Department of Epidemiology and Health Services Research, Geisinger Clinic, Danville, PA, USA
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Hughes JEA, Ward J, Gruffydd E, Baron-Cohen S, Smith P, Allison C, Simner J. Savant syndrome has a distinct psychological profile in autism. Mol Autism 2018; 9:53. [PMID: 30344992 PMCID: PMC6186137 DOI: 10.1186/s13229-018-0237-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 09/25/2018] [Indexed: 12/30/2022] Open
Abstract
Background Savant syndrome is a condition where prodigious talent can co-occur with developmental conditions such as autism spectrum conditions (autism). It is not yet clear why some autistic people develop savant skills while others do not. Methods We tested three groups of adults: autistic individuals who have savant skills, autistic individuals without savant skills, and typical controls without autism or savant syndrome. In experiment 1, we investigated the cognitive and behavioural profiles of these three groups by asking participants to complete a battery of self-report measures of sensory sensitivity, obsessional behaviours, cognitive styles, and broader autism-related traits including social communication and systemising. In experiment 2, we investigated how our three groups learned a novel savant skill-calendar calculation. Results Heightened sensory sensitivity, obsessional behaviours, technical/spatial abilities, and systemising were all key aspects in defining the savant profile distinct from autism alone, along with a different approach to task learning. Conclusions These results reveal a unique cognitive and behavioural profile in autistic adults with savant syndrome that is distinct from autistic adults without a savant skill.
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Affiliation(s)
- James E A Hughes
- School of Psychology, Pevensey Building, University of Sussex, Brighton, BN1 9QJ UK
| | - Jamie Ward
- School of Psychology, Pevensey Building, University of Sussex, Brighton, BN1 9QJ UK
| | - Elin Gruffydd
- School of Psychology, Pevensey Building, University of Sussex, Brighton, BN1 9QJ UK
| | - Simon Baron-Cohen
- Autism Research Centre, University of Cambridge, Cambridge, CB2 8AH UK
| | - Paula Smith
- Autism Research Centre, University of Cambridge, Cambridge, CB2 8AH UK
| | - Carrie Allison
- Autism Research Centre, University of Cambridge, Cambridge, CB2 8AH UK
| | - Julia Simner
- School of Psychology, Pevensey Building, University of Sussex, Brighton, BN1 9QJ UK
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Carmichael DA, Smees R, Shillcock RC, Simner J. Is there a burden attached to synaesthesia? Health screening of synaesthetes in the general population. Br J Psychol 2018; 110:530-548. [PMID: 30281144 DOI: 10.1111/bjop.12354] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 09/04/2018] [Indexed: 11/30/2022]
Abstract
Synaesthesia has long been considered a benign alternative form of perception most often associated with positive rather than negative outcomes. The condition has been associated with a variety of cognitive and perceptual advantages, including benefits in memory, processing speed, and creativity. It is not currently recognized in the DSM-IV. Recently, however, several studies have raised the question of a possible link between synaesthesia and clinical conditions. Here, we present the first large-scale screening of the general population in which we (1) objectively identified grapheme-colour synaesthetes and (2) elicited information from our participants about a range of clinical conditions. We compared the prevalence rates of these conditions in synaesthetes versus non-synaesthetes to establish whether any conditions were found at a higher rate among synaesthetes. In our initial study, screening 3,742 people (95 synaesthetes and 3,647 controls), we found initially that grapheme-colour was significantly comorbid with two conditions (anxiety disorder and obsessive compulsive disorder). In our second study, screening a new population of 120 synaesthetes and 166 non-synaesthetes, we replicated our finding that grapheme-colour synaesthesia is comorbid with anxiety disorder. At the same time, we also addressed a methodological concern that likely elevated rates of OCD in Study 1. We consider the aetiology of synaesthesia to determine whether there may be a shared genetic or neurological basis with anxiety disorder, and we question the status of synaesthesia within a mental health framework.
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Affiliation(s)
| | | | - Richard C Shillcock
- Department of Psychology, University of Edinburgh, UK.,School of Informatics, University of Edinburgh, UK
| | - Julia Simner
- School of Psychology, University of Sussex, UK.,Department of Psychology, University of Edinburgh, UK
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Landmann J, Richter F, Oros-Peusquens AM, Shah NJ, Classen J, Neely GG, Richter A, Penninger JM, Bechmann I. Neuroanatomy of pain-deficiency and cross-modal activation in calcium channel subunit (CACN) α2δ3 knockout mice. Brain Struct Funct 2017; 223:111-130. [PMID: 28733833 DOI: 10.1007/s00429-017-1473-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 07/05/2017] [Indexed: 11/29/2022]
Abstract
The phenotype of calcium channel subunit (CACN) α2δ3 knockout (KO) mice includes sensory cross-activation and deficient pain perception. Sensory cross-activation defines the activation of a sensory cortical region by input from another modality due to reorganization in the brain such as after sensory loss. To obtain mechanistic insight into both phenomena, we employed a comprehensive battery of neuroanatomical techniques. While CACNα2δ3 was ubiquitously expressed in wild-type mice, it was absent in α2δ3 KO animals. Immunostaining of α1A, α1B, and α1E revealed upregulation of N-type and R-type, but not P/Q-type Cav2 channels in cortical neurons of CACNα2δ3 KO mice. Compared to wild-type mice, axonal processes in somatosensory cortex were enhanced, and dendritic processes reduced, in CACNα2δ3 KO mice. Immunohistochemical and MRI analyses, investigating morphology, thalamocortical and intra-/intercortical trajectories, revealed a disparity between projection and commissural fibers with reduction of the number of spatial specificity of thalamocortical projections. L1cam staining revealed wide-ranging projections of thalamocortical fibers reaching both somatosensory/motor and visual cortical areas. Activation (c-fos+) of excitatory and inhibitory neurons suggested that deficient pain perception in α2δ3 KO mice is unlikely to result from cortical disinhibition. Collectively, our data demonstrate that knock out of CACN α2δ3 results in some structural abnormalities whose functional implications converge to dedifferentiation of sensory activation.
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Affiliation(s)
- Julia Landmann
- Institute of Anatomy, University of Leipzig, Oststrasse 25, 04317, Leipzig, Germany.
| | - Franziska Richter
- Department of Veterinary Medicine, Institute of Pharmacology, Pharmacy and Toxicology, University of Leipzig, An den Tierkliniken 15, 04103, Leipzig, Germany
| | - Ana-Maria Oros-Peusquens
- Institute of Neuroscience and Medicine (INM-4), Research Centre Jülich, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - N Jon Shah
- Institute of Neuroscience and Medicine (INM-4), Research Centre Jülich, Forschungszentrum Jülich, 52425, Jülich, Germany.,Department of Neurology, Faculty of Medicine, JARA, RWTH Aachen University, Aachen, Germany
| | - Joseph Classen
- Department of Neurology, University of Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany
| | - G Gregory Neely
- Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre and School of Life & Environmental Sciences, The University of Sydney, 2006, Camperdown, NSW, Australia
| | - Angelika Richter
- Department of Veterinary Medicine, Institute of Pharmacology, Pharmacy and Toxicology, University of Leipzig, An den Tierkliniken 15, 04103, Leipzig, Germany
| | - Josef M Penninger
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030, Vienna, Austria
| | - Ingo Bechmann
- Institute of Anatomy, University of Leipzig, Oststrasse 25, 04317, Leipzig, Germany
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Ward J, Hoadley C, Hughes JEA, Smith P, Allison C, Baron-Cohen S, Simner J. Atypical sensory sensitivity as a shared feature between synaesthesia and autism. Sci Rep 2017; 7:41155. [PMID: 28266503 PMCID: PMC5339734 DOI: 10.1038/srep41155] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 12/15/2016] [Indexed: 12/23/2022] Open
Abstract
Several studies have suggested that there is a link between synaesthesia and autism but the nature of that link remains poorly characterised. The present study considers whether atypical sensory sensitivity may be a common link between the conditions. Sensory hypersensitivity (aversion to certain sounds, touch, etc., or increased ability to make sensory discriminations) and/or hyposensitivity (desire to stimulate the senses , or a reduced response to sensory stimuli are a recently introduced diagnostic feature of autism spectrum conditions (ASC). Synaesthesia is defined by unusual sensory experiences and has also been linked to a typical cortical hyper-excitability. The Glasgow Sensory Questionnaire (GSQ) was administered to synaesthetes and people with ASC. Both groups reported increased sensory sensitivity relative to controls with a large effect size. Both groups also reported a similar pattern of both increased hyper- and hypo-sensitivities across multiple senses. The AQ (Autism-Spectrum Quotient) scores were elevated in the synaesthetes, and one subscale of this measure (attention to detail) placed synaesthetes within the autistic range. A standard laboratory test of visual stress (the Pattern Glare Test), administered online, corroborated the findings of increased sensitivity to aversive visual stimuli in synaesthetes. We conclude that atypical sensory sensitivity is an important shared feature between autism and synaesthesia.
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Affiliation(s)
- Jamie Ward
- School of Psychology and Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
| | - Claire Hoadley
- School of Psychology and Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
| | - James E. A. Hughes
- School of Psychology and Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
| | - Paula Smith
- Autism Research Centre, Department of Psychiatry, University of Cambridge, UK
| | - Carrie Allison
- Autism Research Centre, Department of Psychiatry, University of Cambridge, UK
| | - Simon Baron-Cohen
- Autism Research Centre, Department of Psychiatry, University of Cambridge, UK
| | - Julia Simner
- School of Psychology and Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
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Bouvet L, Barbier JE, Cason N, Bakchine S, Ehrlé N. When synesthesia and savant abilities are mistaken for hallucinations and delusions: contribution of a cognitive approach for their differential diagnosis. Clin Neuropsychol 2017; 31:1459-1473. [PMID: 28276863 DOI: 10.1080/13854046.2017.1288269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Schizophrenia is characterized by hallucinations, delusions, disorganized speech and behavior, and other symptoms that cause social or occupational dysfunction. However, some of these symptoms, such as hallucinations and delusions, can be indicative of other phenomena such as synesthesia and savant abilities. The aim of this paper is to highlight how neurological and psychiatric conditions can be confused and how formal neuropsychological evaluations can be necessary to distinguish them. METHOD We report the case of a young woman, VA, who perceived sounds as colors and claimed to have elaborated complex astrophysical reasoning, despite having experienced difficulties at school, especially in mathematics. VA also had difficulties to orient herself, to develop social relationships, and often became confused by daily life situations. These elements were considered as symptoms of schizophrenia. RESULTS Evaluations revealed that VA exhibited savant abilities in astrophysics and colored-hearing synesthesia. We also found evidence of higher-than-average cognitive functioning. CONCLUSIONS In complex cases, neuropsychological and formal evaluations are necessary to establish a differential diagnosis. Moreover, the case highlights the link between synesthesia and savant abilities.
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Affiliation(s)
- Lucie Bouvet
- a Laboratoire CERPPS (EA 7411) , Université Toulouse Jean Jaurés , Toulouse , France
| | | | - Nia Cason
- c Laboratoire PSITEC (EA 4072) , Université de Lille 3 , Lille , France
| | - Serge Bakchine
- d Service de neurologie, Hôpital Maison-Blanche , Hôpital Universitaire de Reims , Reims , France
| | - Nathalie Ehrlé
- c Laboratoire PSITEC (EA 4072) , Université de Lille 3 , Lille , France.,d Service de neurologie, Hôpital Maison-Blanche , Hôpital Universitaire de Reims , Reims , France
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Hughes J, Simner J, Baron-Cohen S, Treffert D, Ward J. Is Synaesthesia More Prevalent in Autism Spectrum Conditions? Only Where There Is Prodigious Talent. Multisens Res 2017; 30:391-408. [DOI: 10.1163/22134808-00002558] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 02/19/2017] [Indexed: 12/28/2022]
Abstract
Savant syndrome is a condition where prodigious talent co-occurs with developmental difficulties such as autism spectrum conditions (ASC). To better understand savant skills, we previously proposed a link with synaesthesia: that savant syndrome may arise in ASC individuals who also happen to have synaesthesia. A second, unrelated claim is that people with autism may have higher rates of synaesthesia. Here we ask whether synaesthesia is indeed found more often in autism per se, or only in cases where autism co-occurs with savant skills. People with autism in previous studies when tested for synaesthesia were not differentiated into those with and without savant abilities. Here we tested three groups: people with autism who also have savant skills (), people with autism without savant skills (), and controls without autism (). We used a validated test to diagnose grapheme–colour synaesthesia. Results show a significantly higher prevalence of synaesthesia in people with ASC, but only those who also have savant skills. This suggests that synaesthesia in autism is linked to those with savant abilities rather than autism per se. We discuss the role of synaesthesia in the development of prodigious talent.
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Affiliation(s)
- James E. A. Hughes
- School of Psychology, Pevensey Building, University of Sussex, BN1 9QJ, UK
| | - Julia Simner
- School of Psychology, Pevensey Building, University of Sussex, BN1 9QJ, UK
- Department of Psychology, University of Edinburgh, 7 George Square, EH8 9JZ, UK
| | - Simon Baron-Cohen
- Autism Research Centre, Department of Psychiatry, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge CB2 8AH, UK
| | - Darold A. Treffert
- Agnesian HealthCare, 430 East Division Street, Fond du Lac, WI 54935, USA
| | - Jamie Ward
- School of Psychology, Pevensey Building, University of Sussex, BN1 9QJ, UK
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Janik McErlean AB, Susilo T, Rezlescu C, Bray A, Banissy MJ. Social perception in synaesthesia for colour. Cogn Neuropsychol 2016; 33:378-387. [PMID: 27937073 DOI: 10.1080/02643294.2016.1261820] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Synaesthesia is a rare phenomenon in which stimulation in one modality (e.g., audition) evokes a secondary percept not associated with the first (e.g., colour). Prior work has suggested links between synaesthesia and other neurodevelopmental conditions that are linked to altered social perception abilities. With this in mind, here we sought to examine social perception abilities in grapheme-colour synaesthesia (where achromatic graphemes evoke colour experiences) by examining facial identity and facial emotion perception in synaesthetes and controls. Our results indicate that individuals who experience grapheme-colour synaesthesia outperformed controls on tasks involving fine visual discrimination of facial identity and emotion, but not on tasks involving holistic face processing. These findings are discussed in the context of broader perceptual and cognitive traits previously associated with synaesthesia for colour, with the suggestion that performance benefits shown by grapheme-colour synaesthetes may be related to domain-general visual discrimination biases observed in this group.
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Affiliation(s)
- Agnieszka B Janik McErlean
- a Department of Psychology , Goldsmiths University of London , London , UK.,b Department of Psychology , James Cook University , Singapore
| | - Tirta Susilo
- c School of Psychology , Victoria University of Wellington , Wellington , New Zealand
| | - Constantin Rezlescu
- d Department of Psychology , Harvard University , Cambridge , MA , USA.,e Institute of Cognitive Neuroscience , University College London , London , UK
| | - Amy Bray
- f Department of Psychological and Brain Sciences , Dartmouth College , Hanover , NH , USA
| | - Michael J Banissy
- a Department of Psychology , Goldsmiths University of London , London , UK
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The Emergence of Synaesthesia in a Neuronal Network Model via Changes in Perceptual Sensitivity and Plasticity. PLoS Comput Biol 2016; 12:e1004959. [PMID: 27392215 PMCID: PMC4938560 DOI: 10.1371/journal.pcbi.1004959] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 05/04/2016] [Indexed: 11/19/2022] Open
Abstract
Synaesthesia is an unusual perceptual experience in which an inducer stimulus triggers a percept in a different domain in addition to its own. To explore the conditions under which synaesthesia evolves, we studied a neuronal network model that represents two recurrently connected neural systems. The interactions in the network evolve according to learning rules that optimize sensory sensitivity. We demonstrate several scenarios, such as sensory deprivation or heightened plasticity, under which synaesthesia can evolve even though the inputs to the two systems are statistically independent and the initial cross-talk interactions are zero. Sensory deprivation is the known causal mechanism for acquired synaesthesia and increased plasticity is implicated in developmental synaesthesia. The model unifies different causes of synaesthesia within a single theoretical framework and repositions synaesthesia not as some quirk of aberrant connectivity, but rather as a functional brain state that can emerge as a consequence of optimising sensory information processing. Synaesthesia is a remarkable form of altered perception, where one attribute of a stimulus (e.g. sound) leads to the conscious experience of an additional attribute (often colour). Despite being known about for 200 years, there is no commonly agreed upon model for how and why synaesthesia emerges. This study presents a new model of synaesthesia based on computational principles that accounts for the emergence of different types of synaesthesia (acquired and developmental) as well as many of its key characteristics. The model describes how two independent neuronal systems can evolve to interact with one another even though their inputs are statistically uncorrelated. Specifically, synaesthesia arises as a result of instability in the learning process that shapes the network, which can be caused by heightened plasticity or due to sensory deprivation of one of the systems. The model unifies different aspects of synaesthesia and generates novel insights and predictions.
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Jao Keehn RJ, Sanchez SS, Stewart CR, Zhao W, Grenesko-Stevens EL, Keehn B, Müller RA. Impaired downregulation of visual cortex during auditory processing is associated with autism symptomatology in children and adolescents with autism spectrum disorder. Autism Res 2016; 10:130-143. [PMID: 27205875 DOI: 10.1002/aur.1636] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 02/10/2016] [Accepted: 03/24/2016] [Indexed: 01/02/2023]
Abstract
Autism spectrum disorders (ASD) are pervasive developmental disorders characterized by impairments in language development and social interaction, along with restricted and stereotyped behaviors. These behaviors often include atypical responses to sensory stimuli; some children with ASD are easily overwhelmed by sensory stimuli, while others may seem unaware of their environment. Vision and audition are two sensory modalities important for social interactions and language, and are differentially affected in ASD. In the present study, 16 children and adolescents with ASD and 16 typically developing (TD) participants matched for age, gender, nonverbal IQ, and handedness were tested using a mixed event-related/blocked functional magnetic resonance imaging paradigm to examine basic perceptual processes that may form the foundation for later-developing cognitive abilities. Auditory (high or low pitch) and visual conditions (dot located high or low in the display) were presented, and participants indicated whether the stimuli were "high" or "low." Results for the auditory condition showed downregulated activity of the visual cortex in the TD group, but upregulation in the ASD group. This atypical activity in visual cortex was associated with autism symptomatology. These findings suggest atypical crossmodal (auditory-visual) modulation linked to sociocommunicative deficits in ASD, in agreement with the general hypothesis of low-level sensorimotor impairments affecting core symptomatology. Autism Res 2017, 10: 130-143. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.
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Affiliation(s)
- R Joanne Jao Keehn
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, 6363 Alvarado CT Suite #200, San Diego, California
| | - Sandra S Sanchez
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, 6363 Alvarado CT Suite #200, San Diego, California
| | - Claire R Stewart
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, 6363 Alvarado CT Suite #200, San Diego, California
| | - Weiqi Zhao
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, 6363 Alvarado CT Suite #200, San Diego, California
| | - Emily L Grenesko-Stevens
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, 6363 Alvarado CT Suite #200, San Diego, California
| | - Brandon Keehn
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, 6363 Alvarado CT Suite #200, San Diego, California.,Department of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, Indiana
| | - Ralph-Axel Müller
- Brain Development Imaging Laboratory, Department of Psychology, San Diego State University, 6363 Alvarado CT Suite #200, San Diego, California
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Rabeyron T. Associativité, symbolisation et entropie : propositions théoriques et cliniques. ANNALES MÉDICO-PSYCHOLOGIQUES, REVUE PSYCHIATRIQUE 2015. [DOI: 10.1016/j.amp.2015.02.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Newell FN, Mitchell KJ. Multisensory integration and cross-modal learning in synaesthesia: A unifying model. Neuropsychologia 2015; 88:140-150. [PMID: 26231979 DOI: 10.1016/j.neuropsychologia.2015.07.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/28/2015] [Accepted: 07/27/2015] [Indexed: 10/23/2022]
Abstract
Recent research into synaesthesia has highlighted the role of learning, yet synaesthesia is clearly a genetic condition. Here we ask how can the idea that synaesthesia reflects innate, genetic differences be reconciled with models that suggest it is driven by learning. A number of lines of evidence suggest that synaesthesia relies on, or at least interacts with, processes of multisensory integration that are common across all people. These include multisensory activations that arise in early regions of the brain as well as feedback from longer-term cross-modal associations generated in memory. These cognitive processes may interact independently to influence the phenomenology of the synaesthetic experience, as well as the individual differences within particular types of synaesthesia. The theoretical framework presented here is consistent with both an innate difference as the fundamental driver of the condition of synaesthesia, and with experiential and semantic influences on the eventual phenotype that emerges. In particular, it proposes that the internally generated synaesthetic percepts are treated similarly to other sensory information as the brain is learning the multisensory attributes of objects and developing cross-modal associations that merge in the concept of the object.
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Affiliation(s)
- Fiona N Newell
- School of Psychology, Trinity College Dublin, Ireland; Institute of Neuroscience, Trinity College Dublin, Ireland.
| | - Kevin J Mitchell
- Institute of Neuroscience, Trinity College Dublin, Ireland; Smurfit Institute of Genetics, Trinity College Dublin, Ireland.
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Meier B, Rothen N. Developing synaesthesia: a primer. Front Hum Neurosci 2015; 9:211. [PMID: 25941484 PMCID: PMC4403345 DOI: 10.3389/fnhum.2015.00211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 03/31/2015] [Indexed: 12/05/2022] Open
Affiliation(s)
- Beat Meier
- Institute of Psychology and Center for Learning, Memory, and Cognition, University of Bern Bern, Switzerland
| | - Nicolas Rothen
- Institute of Psychology, University of Sussex Brighton, UK
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Abstract
Purpose of review Synesthesia is an extraordinary perceptual phenomenon, in which individuals experience unusual percepts elicited by the activation of an unrelated sensory modality or by a cognitive process. Emotional reactions are commonly associated. The condition prompted philosophical debates on the nature of perception and impacted the course of art history. It recently generated a considerable interest among neuroscientists, but its clinical significance apparently remains underevaluated. This review focuses on the recent studies regarding variants of color synesthesia, the commonest form of the condition. Recent findings Synesthesia is commonly classified as developmental and acquired. Developmental forms predispose to changes in primary sensory processing and cognitive functions, usually with better performances in certain aspects and worse in others, and to heightened creativity. Acquired forms of synesthesia commonly arise from drug ingestion or neurological disorders, including thalamic lesions and sensory deprivation (e.g., blindness). Cerebral exploration using structural and functional imaging has demonstrated distinct patterns in cortical activation and brain connectivity for controls and synesthetes. Artworks of affected painters are most illustrative of the nature of synesthetic experiences. Summary Results of the recent investigations on synesthesia offered a remarkable insight into the mechanisms of perception, emotion and consciousness, and deserve attention both from neuroscientists and from clinicians.
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Bouvet L, Donnadieu S, Valdois S, Caron C, Dawson M, Mottron L. Veridical mapping in savant abilities, absolute pitch, and synesthesia: an autism case study. Front Psychol 2014; 5:106. [PMID: 24600416 PMCID: PMC3927080 DOI: 10.3389/fpsyg.2014.00106] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 01/26/2014] [Indexed: 12/11/2022] Open
Abstract
An enhanced role and autonomy of perception are prominent in autism. Furthermore, savant abilities, absolute pitch, and synesthesia are all more commonly found in autistic individuals than in the typical population. The mechanism of veridical mapping has been proposed to account for how enhanced perception in autism leads to the high prevalence of these three phenomena and their structural similarity. Veridical mapping entails functional rededication of perceptual brain regions to higher order cognitive operations, allowing the enhanced detection and memorization of isomorphisms between perceptual and non-perceptual structures across multiple scales. In this paper, we present FC, an autistic individual who possesses several savant abilities in addition to both absolute pitch and synesthesia-like associations. The co-occurrence in FC of abilities, some of them rare, which share the same structure, as well as FC’s own accounts of their development, together suggest the importance of veridical mapping in the atypical range and nature of abilities displayed by autistic people.
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Affiliation(s)
- Lucie Bouvet
- Laboratoire de Psychologie et Neurocognition, CNRS UMR 5105 Grenoble, France ; Université Lille 3 - Charles de Gaulle Lille, France
| | - Sophie Donnadieu
- Laboratoire de Psychologie et Neurocognition, CNRS UMR 5105 Grenoble, France ; Université de Savoie Chambéry, France
| | - Sylviane Valdois
- Laboratoire de Psychologie et Neurocognition, CNRS UMR 5105 Grenoble, France ; Centre National de la Recherche Scientifique Paris, France
| | - Chantal Caron
- Centre d'Excellence en Troubles Envahissants du Développement de l'Université de Montréal, Hôpital Rivière-des-Prairies Montréal, Canada
| | - Michelle Dawson
- Centre d'Excellence en Troubles Envahissants du Développement de l'Université de Montréal, Hôpital Rivière-des-Prairies Montréal, Canada
| | - Laurent Mottron
- Centre d'Excellence en Troubles Envahissants du Développement de l'Université de Montréal, Hôpital Rivière-des-Prairies Montréal, Canada
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