Some clarifications on neural noise and sensory sensitivities in Autism

Simmons, David R.

doi:10.1080/17588928.2019.1598349

Cited by 8 publications

(3 citation statements)

References 16 publications

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“…What specific neural mechanisms might underpin low excitation across multiple sensory cortices in aphantasia? Our model fits broadly with neural noise theories from the autism literature which suggest that high levels of sensory sensitivity in people with autism are drivenat least in partby increased levels of neural noise (excitation) within sensory cortices (Milne, 2011;Rubenstein & Merzenich, 2003;Simmons, 2019;Simmons et al, 2009). This theory links neural noise with an increase in excitatory (e.g., glutamate) synaptic activity and a reduction of inhibitory (e.g., GABA) synaptic activity (e.g., Rubenstein & Merzenich, 2003;Wood et al, 2021).…”

Section: Discussionsupporting

confidence: 79%

What is the Link Between Mental Imagery and Sensory Sensitivity? Insights from Aphantasia

2021

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People with aphantasia have impoverished visual imagery so struggle to form mental pictures in the mind's eye. By testing people with and without aphantasia, we investigate the relationship between sensory imagery and sensory sensitivity (i.e., hyper- or hypo-reactivity to incoming signals through the sense organs). In Experiment 1 we first show that people with aphantasia report impaired imagery across multiple domains (e.g., olfactory, gustatory etc.) rather than simply vision. Importantly, we also show that imagery is related to sensory sensitivity: aphantasics reported not only lower imagery, but also lower sensory sensitivity. In Experiment 2, we showed a similar relationship between imagery and sensitivity in the general population. Finally, in Experiment 3 we found behavioural corroboration in a Pattern Glare Task, in which aphantasics experienced less visual discomfort and fewer visual distortions typically associated with sensory sensitivity. Our results suggest for the very first time that sensory imagery and sensory sensitivity are related, and that aphantasics are characterised by both lower imagery, and lower sensitivity. Our results also suggest that aphantasia (absence of visual imagery) may be more accurately defined as a subtype of a broader imagery deficit we name dysikonesia, in which weak or absent imagery occurs across multiple senses.

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Section: Discussionsupporting

confidence: 79%

What is the Link Between Mental Imagery and Sensory Sensitivity? Insights from Aphantasia

2021

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“…Previously, we showed that MSPS, a novel situation filled with new information, is a context where young autistic children explore their environment as much as typical children do, thus providing them with similar learning opportunities ( Jacques et al, 2018 ). Current deficit-based autism criteria and theories invoking insistence on sameness, inflexibility (extreme distress in response to changes, difficulties with transitions; APA, 2013 ), sensory hypersensitivity, sensory dysfunction, and/or sensory overload ( Pellicano, 2013 ; Simmons, 2019 ; Sinha et al, 2014 ; Van de Cruys et al, 2014 ), would predict negative emotions in young autistic children who find themselves in a mostly unstructured unfamiliar context including a large array of unfamiliar objects. In the alternative, strength-based accounts of autism involving enhanced perception and perceptual capacity ( Mottron, Bouvet, et al, 2013 ; Mottron et al, 2009 ; Remington et al, 2019 ) suggest that autistics are attracted to information (familiar or not) which they can process well ( Hanley et al, 2017 ), and may benefit from access to more and more complex information of this kind ( Nader et al, 2021 ).…”

Section: Discussionmentioning

confidence: 99%

Positive, negative, neutral—or unknown? The perceived valence of emotions expressed by young autistic children in a novel context suited to autism

Jacques

Courchesne

Mineau

et al. 2022

Autism

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Starting early in life, autistics are characterized as having atypical facial expressions, as well as decreased positive and increased negative affect. The literature on autistic facial expressions remains small, however, with disparate methods and results suggesting limited understanding of common autistic emotions. Furthermore, unlike non-autistics’ emotions, autistics’ emotions have been assessed without considering this population’s characteristics. In this study, the valence of young children’s facial expressions was thus rated as positive, negative, neutral, or “unknown”—a term for perceived emotions observers do not understand. Facial expressions were assessed using the Montreal Stimulating Play Situation, a context incorporating potential autistic interests. Comparing 37 autistic and 39 typical young (27–56 months) age-matched children, we found no group differences in expressed positive, negative, and neutral emotions. We did find differences in unknown emotions, which were unique to the autistic group. Preliminary data also showed that autistic children’s repetitive behaviors co-occurred with positive, neutral, and unknown emotions, but not with negative emotions. In a novel context that considers their characteristics, we did not find decreased positive or increased negative emotions in young autistic children. Instead, they uniquely expressed emotions perceived as unknown, showing the need to improve our understanding of their full emotional repertoire. Lay abstract Autistic people are believed to have emotions that are too negative and not positive enough, starting early in life. Their facial expressions are also persistently judged to be unusual, as reflected in criteria used to identify autism. But it is possible that common autistic facial expressions are poorly understood by observers, as suggested by a range of findings from research. Another issue is that autistic emotions have always been assessed in contexts suited to non-autistics. In our study, the facial expressions of young autistic and typical children were rated as positive, negative, neutral, or “unknown”—a category we created for emotions that observers notice but do not understand. These emotions were assessed using a context suited to autistic children, including objects of potential interest to them. We found that in this context, autistic and typical children did not differ in positive, negative, or neutral facial emotions. They did differ in unknown emotions, which were found only in autistic children. We also found that repetitive behaviors in autistic children co-occurred with positive, neutral, and unknown emotions, but not with negative emotions. In a context which suits their characteristics, autistic children do not show emotions that are too negative or not positive enough. They do show emotions perceived as unknown, which means we need to improve our understanding of their full emotional repertoire.

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“…It has been hypothesized that the perceptual features of autism may be due to variable levels of internal noise, thus leading to difficulties in signal-to-noise separation 39 , 54 – 59 . Internal noise in autism has been attributed to atypical neural connectivity of sensory brain networks 35 , 37 , 60 , 61 and an imbalance in excitatory and inhibitory neurotransmitters 38 , 62 – 64 . However, in this study, we found no differences between autistic and control groups in their discriminability indices in both tasks (Figs.…”

Section: Discussionmentioning

confidence: 99%

Perceptual decision-making in autism as assessed by “spot the difference” visual cognition tasks

Jassim

Owen

Smith

et al. 2022

Sci Rep

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Discriminating between similar figures proves to be a remarkably demanding task due to the limited capacity of our visual cognitive processes. Here we examine how perceptual inference and decision-making are modulated by differences arising from neurodiversity. A large sample of autistic (n = 140) and typical (n = 147) participants completed two forced choice similarity judgement tasks online. Each task consisted of “match” (identical figures) and “mismatch” (subtle differences between figures) conditions. Signal detection theory analyses indicated a response bias by the autism group during conditions of uncertainty. More specifically, autistic participants were more likely to choose the “mismatch” option, thus leading to more hits on the “mismatch” condition, but also more false alarms on the “match” condition. These results suggest differences in response strategies during perceptual decision-making in autism.

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Some clarifications on neural noise and sensory sensitivities in Autism

Cited by 8 publications

References 16 publications

What is the Link Between Mental Imagery and Sensory Sensitivity? Insights from Aphantasia

What is the Link Between Mental Imagery and Sensory Sensitivity? Insights from Aphantasia

Positive, negative, neutral—or unknown? The perceived valence of emotions expressed by young autistic children in a novel context suited to autism

Perceptual decision-making in autism as assessed by “spot the difference” visual cognition tasks

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