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Priors Bias Perceptual Decisions in Autism, But Are Less Flexibly Adjusted to the Context / L. A. SAPEY-TRIOMPHE in Autism Research, 14-6 (June 2021)
[article]
Titre : Priors Bias Perceptual Decisions in Autism, But Are Less Flexibly Adjusted to the Context Type de document : Texte imprimé et/ou numérique Auteurs : L. A. SAPEY-TRIOMPHE, Auteur ; L. TIMMERMANS, Auteur ; J. WAGEMANS, Auteur Article en page(s) : p.1134-1146 Langues : Anglais (eng) Mots-clés : Adult Autism Spectrum Disorder/complications Autistic Disorder Humans Learning Reproducibility of Results Visual Perception autism contraction bias inflexibility learning predictive coding prior time-order effect Index. décimale : PER Périodiques Résumé : According to the predictive coding framework, percepts emerge from combinations of sensory input and prior knowledge, whose relative contributions depend on their reliability. Recent predictive coding theories suggest that Autism Spectrum Disorder (ASD) could be characterized by an atypical weighting of priors. Here, we assessed whether individuals with ASD can flexibly adjust the weight (precision) of the prior to the context. Thirty-one neurotypical adults (NT) and 26 adults with ASD participated in a visual discrimination task designed to elicit a time-order effect (TOE). The TOE reflects the integration of priors with sensory estimates. We used two experimental contexts: a narrow stimulus range (Narrow condition) and a broader range (Broad condition) in order to induce a prior with a higher and lower precision, respectively. Both groups learned a prior that biased their perception, as shown with the TOE. As expected, the NT group had a larger TOE in the Narrow condition than in the Broad condition, revealing a contextual adjustment of the prior precision. In contrast, ASD participants were more inflexible: the extent of the TOE was not modulated by the context. In addition, the accuracy increased when the stimulus range decreased in both group, which may be interpreted as a contextual adjustment of the sensory precision. To conclude, adults with and without ASD implicitly learned a prior mean, but ASD participants failed to flexibly adjust the prior precision to the context. This increased inflexibility in ASD could account for many symptoms, such as their intolerance of uncertainty. LAY SUMMARY: Based on our experience, we have expectations about our environment. Theories suggest that the symptoms encountered in autism could be due to atypical expectations, leading to an impression of an unpredictable world. Using a visual discrimination task, we showed that adults with and without autism were biased by their expectations. Yet, the extent to which expectations biased perception did not depend on the context in autism. This higher inflexibility found in autism may explain symptoms such as resistance to change. En ligne : http://dx.doi.org/10.1002/aur.2452 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=449
in Autism Research > 14-6 (June 2021) . - p.1134-1146[article] Priors Bias Perceptual Decisions in Autism, But Are Less Flexibly Adjusted to the Context [Texte imprimé et/ou numérique] / L. A. SAPEY-TRIOMPHE, Auteur ; L. TIMMERMANS, Auteur ; J. WAGEMANS, Auteur . - p.1134-1146.
Langues : Anglais (eng)
in Autism Research > 14-6 (June 2021) . - p.1134-1146
Mots-clés : Adult Autism Spectrum Disorder/complications Autistic Disorder Humans Learning Reproducibility of Results Visual Perception autism contraction bias inflexibility learning predictive coding prior time-order effect Index. décimale : PER Périodiques Résumé : According to the predictive coding framework, percepts emerge from combinations of sensory input and prior knowledge, whose relative contributions depend on their reliability. Recent predictive coding theories suggest that Autism Spectrum Disorder (ASD) could be characterized by an atypical weighting of priors. Here, we assessed whether individuals with ASD can flexibly adjust the weight (precision) of the prior to the context. Thirty-one neurotypical adults (NT) and 26 adults with ASD participated in a visual discrimination task designed to elicit a time-order effect (TOE). The TOE reflects the integration of priors with sensory estimates. We used two experimental contexts: a narrow stimulus range (Narrow condition) and a broader range (Broad condition) in order to induce a prior with a higher and lower precision, respectively. Both groups learned a prior that biased their perception, as shown with the TOE. As expected, the NT group had a larger TOE in the Narrow condition than in the Broad condition, revealing a contextual adjustment of the prior precision. In contrast, ASD participants were more inflexible: the extent of the TOE was not modulated by the context. In addition, the accuracy increased when the stimulus range decreased in both group, which may be interpreted as a contextual adjustment of the sensory precision. To conclude, adults with and without ASD implicitly learned a prior mean, but ASD participants failed to flexibly adjust the prior precision to the context. This increased inflexibility in ASD could account for many symptoms, such as their intolerance of uncertainty. LAY SUMMARY: Based on our experience, we have expectations about our environment. Theories suggest that the symptoms encountered in autism could be due to atypical expectations, leading to an impression of an unpredictable world. Using a visual discrimination task, we showed that adults with and without autism were biased by their expectations. Yet, the extent to which expectations biased perception did not depend on the context in autism. This higher inflexibility found in autism may explain symptoms such as resistance to change. En ligne : http://dx.doi.org/10.1002/aur.2452 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=449 Prediction learning in adults with autism and its molecular correlates / L. A. SAPEY-TRIOMPHE in Molecular Autism, 12 (2021)
[article]
Titre : Prediction learning in adults with autism and its molecular correlates Type de document : Texte imprimé et/ou numérique Auteurs : L. A. SAPEY-TRIOMPHE, Auteur ; J. TEMMERMAN, Auteur ; N. A. J. PUTS, Auteur ; J. WAGEMANS, Auteur Article en page(s) : 64 p. Langues : Anglais (eng) Mots-clés : Asd Gaba Glutamate Glutathione Magnetic resonance spectroscopy Prediction Prior Probabilistic learning Uncertainty Volatility Index. décimale : PER Périodiques Résumé : BACKGROUND: According to Bayesian hypotheses, individuals with Autism Spectrum Disorder (ASD) have difficulties making accurate predictions about their environment. In particular, the mechanisms by which they assign precision to predictions or sensory inputs would be suboptimal in ASD. These mechanisms are thought to be mostly mediated by glutamate and GABA. Here, we aimed to shed light on prediction learning in ASD and on its neurobiological correlates. METHODS: Twenty-six neurotypical and 26 autistic adults participated in an associative learning task where they had to learn a probabilistic association between a tone and the rotation direction of two dots, in a volatile context. They also took part in magnetic resonance spectroscopy (MRS) measurements to quantify Glx (glutamate and glutamine), GABA?+?and glutathione in a low-level perceptual region (occipital cortex) and in a higher-level region involved in prediction learning (inferior frontal gyrus). RESULTS: Neurotypical and autistic adults had their percepts biased by their expectations, and this bias was smaller for individuals with a more atypical sensory sensitivity. Both groups were able to learn the association and to update their beliefs after a change in contingency. Interestingly, the percentage of correct predictions was correlated with the Glx/GABA?+?ratio in the occipital cortex (positive correlation) and in the right inferior frontal gyrus (negative correlation). In this region, MRS results also showed an increased concentration of Glx in the ASD group compared to the neurotypical group. LIMITATIONS: We used a quite restrictive approach to select the MR spectra showing a good fit, which led to the exclusion of some MRS datasets and therefore to the reduction of the sample size for certain metabolites/regions. CONCLUSIONS: Autistic adults appeared to have intact abilities to make predictions in this task, in contrast with the Bayesian hypotheses of ASD. Yet, higher ratios of Glx/GABA?+?in a frontal region were associated with decreased predictive abilities, and ASD individuals tended to have more Glx in this region. This neurobiological difference might contribute to suboptimal predictive mechanisms in ASD in certain contexts. En ligne : http://dx.doi.org/10.1186/s13229-021-00470-6 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=459
in Molecular Autism > 12 (2021) . - 64 p.[article] Prediction learning in adults with autism and its molecular correlates [Texte imprimé et/ou numérique] / L. A. SAPEY-TRIOMPHE, Auteur ; J. TEMMERMAN, Auteur ; N. A. J. PUTS, Auteur ; J. WAGEMANS, Auteur . - 64 p.
Langues : Anglais (eng)
in Molecular Autism > 12 (2021) . - 64 p.
Mots-clés : Asd Gaba Glutamate Glutathione Magnetic resonance spectroscopy Prediction Prior Probabilistic learning Uncertainty Volatility Index. décimale : PER Périodiques Résumé : BACKGROUND: According to Bayesian hypotheses, individuals with Autism Spectrum Disorder (ASD) have difficulties making accurate predictions about their environment. In particular, the mechanisms by which they assign precision to predictions or sensory inputs would be suboptimal in ASD. These mechanisms are thought to be mostly mediated by glutamate and GABA. Here, we aimed to shed light on prediction learning in ASD and on its neurobiological correlates. METHODS: Twenty-six neurotypical and 26 autistic adults participated in an associative learning task where they had to learn a probabilistic association between a tone and the rotation direction of two dots, in a volatile context. They also took part in magnetic resonance spectroscopy (MRS) measurements to quantify Glx (glutamate and glutamine), GABA?+?and glutathione in a low-level perceptual region (occipital cortex) and in a higher-level region involved in prediction learning (inferior frontal gyrus). RESULTS: Neurotypical and autistic adults had their percepts biased by their expectations, and this bias was smaller for individuals with a more atypical sensory sensitivity. Both groups were able to learn the association and to update their beliefs after a change in contingency. Interestingly, the percentage of correct predictions was correlated with the Glx/GABA?+?ratio in the occipital cortex (positive correlation) and in the right inferior frontal gyrus (negative correlation). In this region, MRS results also showed an increased concentration of Glx in the ASD group compared to the neurotypical group. LIMITATIONS: We used a quite restrictive approach to select the MR spectra showing a good fit, which led to the exclusion of some MRS datasets and therefore to the reduction of the sample size for certain metabolites/regions. CONCLUSIONS: Autistic adults appeared to have intact abilities to make predictions in this task, in contrast with the Bayesian hypotheses of ASD. Yet, higher ratios of Glx/GABA?+?in a frontal region were associated with decreased predictive abilities, and ASD individuals tended to have more Glx in this region. This neurobiological difference might contribute to suboptimal predictive mechanisms in ASD in certain contexts. En ligne : http://dx.doi.org/10.1186/s13229-021-00470-6 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=459