RESUMO
The term "self-bias" refers to the human propensity to prioritize self- over other-related stimuli and is believed to influence various stages of the processing stream. By means of event-related potentials (ERPs), it was recently shown that the self-bias in a shape-label matching task modulates early as well as later phases of information processing in neurotypicals. Recent claims suggest autism-related deficits to specifically impact later stages of self-related processing; however, it is unclear whether these claims hold based on current findings. Using the shape-label matching task while recording ERPs in individuals with autism can clarify which stage of self-related processing is specifically affected in this condition. Therefore, this study sought to investigate the temporal course of self-related processing in adults with and without autism. Thirty-two adults with autism and 27 neurotypicals completed a shape-label matching task while ERPs were concomitantly recorded. At the behavioral level, results furnished evidence for a comparable self-bias across groups, with no differences in task performance between adults with and without autism. At the ERP level, the two groups showed a similar self-bias at early stages of self-related information processing (the N1 component). Conversely, the autism group manifested a lessened differentiation between self- and other-related stimuli at later stages (the parietal P3 component). In line with recent claims of later phases of self-related processing being altered in autism, we found an equivalent self-bias between groups at an early, sensory stage of processing, yet a strongly diminished self-bias at a later, cognitive stage in adults with autism.
Assuntos
Transtorno Autístico , Eletroencefalografia , Potenciais Evocados , Humanos , Masculino , Feminino , Transtorno Autístico/fisiopatologia , Adulto , Potenciais Evocados/fisiologia , Adulto Jovem , Encéfalo/fisiopatologia , Tempo de Reação/fisiologia , Autoimagem , Estimulação Luminosa/métodos , Testes NeuropsicológicosRESUMO
Recent theories of autism propose that a core deficit in autism would be a less context-sensitive weighting of prediction errors. There is also first support for this hypothesis on an early sensory level. However, an open question is whether this decreased context sensitivity is caused by faster updating of one's model of the world (i.e., higher weighting of new information), proposed by predictive coding theories, or slower model updating. Here, we differentiated between these two hypotheses by investigating how first impressions shape the mismatch negativity (MMN), reflecting early sensory prediction error processing. An autism and matched control group of human adults (both n = 27, 8 female) were compared on the multi-timescale MMN paradigm, in which tones were presented that were either standard (frequently occurring) or deviant (rare), and these roles reversed every block. A well-replicated observation is that the initial model (i.e., the standard and deviant sound in the first block) influences MMN amplitudes in later blocks. If autism is characterized by faster model updating, and thus a smaller primacy bias, we hypothesized (and demonstrate using a simple reinforcement learning model) that their MMN amplitudes should be less influenced by the initial context. In line with this hypothesis, we found that MMN responses in the autism group did not differ between the initial deviant and initial standard sounds as they did in the control group. These findings are consistent with the idea that autism is characterized by faster model updating during early sensory processing, as proposed by predictive coding accounts of autism.SIGNIFICANCE STATEMENT Recent theories of autism propose that a core deficit in autism is that they are faster to update their models of the world based on new sensory information. Here, we tested this hypothesis by investigating how first impressions shape brain responses during early sensory processing, and hypothesized that individuals with autism would be less influenced by these first impressions. In line with earlier studies, our results show that early sensory processing was influenced by first impressions in a control group. However, this was not the case in an autism group. This suggests that individuals with autism are faster to abandon their initial model, and is consistent with the proposal that they are faster to update their models of the world.
Assuntos
Transtorno Autístico , Potenciais Evocados Auditivos , Estimulação Acústica/métodos , Adulto , Percepção Auditiva/fisiologia , Eletroencefalografia , Potenciais Evocados Auditivos/fisiologia , Feminino , HumanosRESUMO
LAY ABSTRACT: Recent theories propose that autism is characterized by an impairment in determining when to learn and when not. Here, we investigated this hypothesis by estimating learning rates (i.e. the speed with which one learns) in three different environments that differed in rule stability and uncertainty. We found that neurotypical participants with more autistic traits performed worse in a volatile environment (with unstable rules), as they chose less often for the most rewarding option. Exploratory analyses indicated that performance was specifically worse when reward rules were opposite to those initially learned for participants with more autistic traits. However, there were no differences in the adjustment of learning rates between participants with more versus less autistic traits. Together, these results suggest that performance in volatile environments is lower in participants with more autistic traits, but that this performance difference cannot be unambiguously explained by an impairment in adjusting learning rates.
Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Humanos , Aprendizagem , RecompensaRESUMO
A common idea about individuals with autism spectrum disorder (ASD) is that they have an above-average preference for predictability and sameness. However, surprisingly little research has gone toward this core symptom, and some studies suggest the preference for predictability in ASD might be less general than commonly assumed. Here, we investigated this important symptom of ASD using three different paradigms, which allowed us to measure preference for predictability under well-controlled experimental conditions. Specifically, we used a dimensional approach by investigating correlations between autistic traits (as measured with the Autism-Spectrum Quotient and Social Responsiveness Scale in a neurotypical population) and the scores on three different tasks. The "music preference" task assessed preferences for tone sequences that varied in predictability. The "perceptual fluency" task required participants to evaluate stimuli that were preceded by a similar versus dissimilar subliminally presented prime. The "gambling" task presented four decks of cards that had equal outcome probabilities but varied in predictability. We observed positive correlations between autistic traits and a preference for predictability in both the music preference and perceptual fluency task. We did not find our hypothesized correlation with gambling behavior but did observe a post hoc correlation showing that participants with more autistic traits were faster to choose the predictable deck. Together, these findings show that a relation between autistic traits and preference for predictability can be observed in a standardized lab environment, and should be considered an important first step toward a better, more mechanistic understanding of insistence on sameness in ASD. Autism Res 2020, 13: 1144-1154. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: A core symptom of autism spectrum disorder (ASD) is a strong preference for predictability, but little research has gone toward it. We show that neurotypical adults with more autistic traits have stronger preferences for predictable tunes, evaluate images that can be predicted as more beautiful, and are faster in choosing a gambling option resulting in predictable reward. These results offer the first important evidence that insistence on sameness in ASD can be studied in controlled lab settings.
Assuntos
Transtorno Autístico , Adulto , Atenção , HumanosRESUMO
Diminished responding to hearing one's own name is one of the earliest and strongest predictors of autism spectrum disorder (ASD). Here, we studied, for the first time, the neural correlates of hearing one's own name in ASD. Based on existing research, we hypothesized enhancement of late parietal positive activity specifically for the own name in neurotypicals, and for this effect to be reduced in adults with ASD. Source localization analyses were conducted to estimate group differences in brain regions underlying this effect. Twenty-one adults with ASD, and 21 age- and gender-matched neurotypicals were presented with 3 categories of names (own name, close other, unknown other) as task-irrelevant deviant stimuli in an auditory oddball paradigm while electroencephalogram was recorded. As expected, late parietal positivity was observed specifically for own names in neurotypicals, indicating enhanced attention to the own name. This preferential effect was absent in the ASD group. This group difference was associated with diminished activation in the right temporoparietal junction (rTPJ) in adults with ASD. Further, a familiarity effect was found for N1 amplitude, with larger amplitudes for familiar names (own name and close other). However, groups did not differ for this effect. These findings provide evidence of atypical neural responding to hearing one's own name in adults with ASD, suggesting a deficit in self-other distinction associated with rTPJ dysfunction. (PsycINFO Database Record
Assuntos
Percepção Auditiva , Transtorno do Espectro Autista/fisiopatologia , Transtorno do Espectro Autista/psicologia , Encéfalo/fisiopatologia , Estimulação Acústica , Adulto , Eletroencefalografia , Potenciais Evocados Auditivos , Feminino , Humanos , Masculino , Lobo Parietal/fisiopatologia , Reconhecimento Psicológico , Lobo Temporal/fisiopatologiaRESUMO
BACKGROUND: Recent predictive coding accounts of autism spectrum disorder (ASD) suggest that a key deficit in ASD concerns the inflexibility in modulating local prediction errors as a function of global top-down expectations. As a direct test of this central hypothesis, we used electroencephalography to investigate whether local prediction error processing was less modulated by global context (i.e., global stimulus frequency) in ASD. METHODS: A group of 18 adults with ASD was compared with a group of 24 typically developed adults on a well-validated hierarchical auditory oddball task in which participants listened to short sequences of either five identical sounds (local standard) or four identical sounds and a fifth deviant sound (local deviant). The latter condition is known to generate the mismatch negativity (MMN) component, believed to reflect early sensory prediction error processing. Crucially, previous studies have shown that in blocks with a higher frequency of local deviant sequences, top-down expectations seem to attenuate the MMN. We predicted that this modulation by global context would be less pronounced in the ASD group. RESULTS: Both groups showed an MMN that was modulated by global context. However, this effect was smaller in the ASD group as compared with the typically developed group. In contrast, the P3b, as an electroencephalographic marker of conscious expectation processes, did not differ across groups. CONCLUSIONS: Our results demonstrate that people with ASD are less flexible in modulating their local predictions (reflected in MMN), thereby confirming the central hypothesis of contemporary predictive coding accounts of ASD.