The singular nature of auditory and visual scene analysis in autism

Theta and alpha oscillations may underlie improved attention and working memory in musically trained children

INTRODUCTION

Attention and working memory are key cognitive functions that allow us to select and maintain information in our mind for a short time, being essential for our daily life and, in particular, for learning and academic performance. It has been shown that musical training can improve working memory performance, but it is still unclear if and how the neural mechanisms of working memory and particularly attention are implicated in this process. In this work, we aimed to identify the oscillatory signature of bimodal attention and working memory that contributes to improved working memory in musically trained children.

MATERIALS AND METHODS

We recruited children with and without musical training and asked them to complete a bimodal (auditory/visual) attention and working memory task, whereas their brain activity was measured using electroencephalography. Behavioral, time-frequency, and source reconstruction analyses were made.

RESULTS

Results showed that, overall, musically trained children performed better on the task than children without musical training. When comparing musically trained children with children without musical training, we found modulations in the alpha band pre-stimuli onset and the beginning of stimuli onset in the frontal and parietal regions. These correlated with correct responses to the attended modality. Moreover, during the end phase of stimuli presentation, we found modulations correlating with correct responses independent of attention condition in the theta and alpha bands, in the left frontal and right parietal regions.

CONCLUSIONS

These results suggest that musically trained children have improved neuronal mechanisms for both attention allocation and memory encoding. Our results can be important for developing interventions for people with attention and working memory difficulties.

The relationship between subjective difficulty in interoceptive processing and accuracy of heartbeat perception in autistic individuals

Most autistic people experience difficulties in sensory processing, including interoceptive processing. For example, they often report subjective difficulties in the interoceptive processing of interoceptive input, such as difficulty in interpreting bodily signals, including hunger, thirst, and fatigue. However, whether these subjective interoceptive difficulties are from underlying problems in interoceptive accuracy remains unclear. This study investigated the relationship between subjective interoceptive difficulty and behavioral interoceptive accuracy in autistic adults and a control group. Subjective interoceptive accuracy was measured using an interoceptive sensitivity questionnaire, and behavioral interoceptive accuracy was measured using a heartbeat counting task. The results showed no significant relationship between subjective interoceptive difficulty and behavioral interoceptive accuracy in the autistic or control groups. This suggests that subjective interoceptive difficulty and behavioral interoceptive accuracy reflect different aspects of interoceptive processing. One possible interpretation is that autistic adults can identify individual local sensory inputs, such as heartbeats, however, they have difficulty integrating multiple inputs and recognizing internal body states such as hunger and fatigue.

Acute Aromatase Inhibition Impairs Neural and Behavioral Auditory Scene Analysis in Zebra Finches

Auditory perception can be significantly disrupted by noise. To discriminate sounds from noise, auditory scene analysis (ASA) extracts the functionally relevant sounds from acoustic input. The zebra finch communicates in noisy environments. Neurons in their secondary auditory pallial cortex (caudomedial nidopallium, NCM) can encode song from background chorus, or scenes, and this capacity may aid behavioral ASA. Furthermore, song processing is modulated by the rapid synthesis of neuroestrogens when hearing conspecific song. To examine whether neuroestrogens support neural and behavioral ASA in both sexes, we retrodialyzed fadrozole (aromatase inhibitor, FAD) and recorded in vivo awake extracellular NCM responses to songs and scenes. We found that FAD affected neural encoding of songs by decreasing responsiveness and timing reliability in inhibitory (narrow-spiking), but not in excitatory (broad-spiking) neurons. Congruently, FAD decreased neural encoding of songs in scenes for both cell types, particularly in females. Behaviorally, we trained birds using operant conditioning and tested their ability to detect songs in scenes after administering FAD orally or injected bilaterally into NCM. Oral FAD increased response bias and decreased correct rejections in females, but not in males. FAD in NCM did not affect performance. Thus, FAD in the NCM impaired neuronal ASA but that did not lead to behavioral disruption suggesting the existence of resilience or compensatory responses. Moreover, impaired performance after systemic FAD suggests involvement of other aromatase-rich networks outside the auditory pathway in ASA. This work highlights how transient estrogen synthesis disruption can modulate higher-order processing in an animal model of vocal communication.

Autistic traits and event-related potentials in the general population: A scoping review and meta-analysis

BACKGROUND

Differences in short and long-latency Event-Related Potentials (ERPs) can help us infer abnormalities in brain processing, considering early and later stages of stimuli processing across tasks and conditions. In autism research, the adult population remains largely understudied compared to samples at early stages of development. In this context, this scoping review briefly summarises what has been described in community and subclinical adult samples of autism.

METHOD

The current scoping review and meta-analysis includes 50 records (N = 1652) and comprehensively explores short and long-latency ERP amplitudes and their relationship with autistic traits in adult community samples.

RESULTS

This meta-analysis identified, with small to medium effect sizes, distinctive patterns in late ERP amplitudes, indicating enhanced responses to visual stimuli and the opposite patterns to auditory tasks in the included sample. Additionally, a pattern of higher amplitudes was also found for the component P3b in autistic traits.

DISCUSSION

Differential effects in visual and auditory domains are explored in light of the predictive processing framework for Autism. It remains possible that different brain mechanisms operate to explain symptoms related with different sensory modalities. P3b is discussed as a possible component of interest in future studies as it revealed a more robust effect for differentiating severity in the expression of autistic traits in adulthood.

Severely Attenuated Visual Feedback Processing in Children on the Autism Spectrum

Individuals on the autism spectrum often exhibit atypicality in their sensory perception, but the neural underpinnings of these perceptual differences remain incompletely understood. One proposed mechanism is an imbalance in higher-order feedback re-entrant inputs to early sensory cortices during sensory perception, leading to increased propensity to focus on local object features over global context. We explored this theory by measuring visual evoked potentials during contour integration as considerable work has revealed that these processes are largely driven by feedback inputs from higher-order ventral visual stream regions. We tested the hypothesis that autistic individuals would have attenuated evoked responses to illusory contours compared with neurotypical controls. Electrophysiology was acquired while 29 autistic and 31 neurotypical children (7-17 years old, inclusive of both males and females) passively viewed a random series of Kanizsa figure stimuli, each consisting of four inducers that were aligned either at random rotational angles or such that contour integration would form an illusory square. Autistic children demonstrated attenuated automatic contour integration over lateral occipital regions relative to neurotypical controls. The data are discussed in terms of the role of predictive feedback processes on perception of global stimulus features and the notion that weakened "priors" may play a role in the visual processing anomalies seen in autism.SIGNIFICANCE STATEMENT Children on the autism spectrum differ from typically developing children in many aspects of their processing of sensory stimuli. One proposed mechanism for these differences is an imbalance in higher-order feedback to primary sensory regions, leading to an increased focus on local object features rather than global context. However, systematic investigation of these feedback mechanisms remains limited. Using EEG and a visual illusion paradigm that is highly dependent on intact feedback processing, we demonstrated significant disruptions to visual feedback processing in children with autism. This provides much needed experimental evidence that advances our understanding of the contribution of feedback processing to visual perception in autism spectrum disorder.

Validation of the Japanese version of the Interoception Sensory Questionnaire for individuals with autism spectrum disorder

The Interoception Sensory Questionnaire (ISQ) is a self-report instrument used to assess the characteristics of interoceptive processing in individuals with autism spectrum disorder (ASD). Previous studies have shown that scores of the ISQ are more appropriate than other subjective measures for evaluating difficulties in interoceptive processing in individuals with ASD. Yet, no prior research has demonstrated the validation of the ISQ in Japanese samples. This study attempted to validate the Japanese version of the ISQ (ISQ-J) by examining its psychometric properties. We confirmed the score distribution, internal consistency, and factor structure in Japanese samples. We also examined the relationships with other interoceptive questionnaires. In addition, we compared the scores of the ISQ-J between adolescents and adults with ASD participants and control participants. Results of confirmatory factor analyses showed that the reliability of the ISQ-J in adults with ASD reached an acceptable level of a one-factor structure with excellent internal consistency (α = 0.963). The result of the ISQ-J showed a significant positive correlation with the measure of awareness of interoceptive sensitivity for localized bodily states; on the other hand, a significant negative correlation was found with those integrated bodily states. In addition, the ISQ-J scores were significantly higher in the ASD group than in the control group. The current findings depend on self-report data (including a diagnosis of ASD) to measure validity constructs. Additionally, since the ISQ-J was surveyed in adults with ASD, it is unclear whether similar the results would be obtained if the ISQ-J were conducted with children. These results indicate the validity and reliability of the ISQ-J and provide a tool for assessing confusion of interoceptive information in Japanese adults with ASD.

Perceptual category learning in autism spectrum disorder: Truth and consequences

The ability to categorize is fundamental to cognitive development. Some categories emerge effortlessly and rapidly while others can take years of experience to acquire. Children with autism spectrum disorder (ASD) are often able to name and sort objects, suggesting that their categorization abilities are largely intact. However, recent experimental work shows that the categories formed by individuals with ASD may diverge substantially from those that most people learn. This review considers how atypical perceptual category learning can affect cognitive development in children with ASD and how atypical categorization may contribute to many of the socially problematic symptoms associated with this disorder. Theoretical approaches to understanding perceptual processing and category learning at both the behavioral and neural levels are assessed in relation to known alterations in perceptual category learning associated with ASD. Mismatches between the ways in which children learn to organize perceived events relative to their peers and adults can accumulate over time, leading to difficulties in communication, social interactions, academic performance, and behavioral flexibility.

Superior Identification of Component Odors in a Mixture Is Linked to Autistic Traits in Children and Adults

Most familiar odors are complex mixtures of volatile molecules, which the olfactory system automatically synthesizes into a perceptual whole. However, odors are rarely encountered in isolation; thus, the brain must also separate distinct odor objects from complex and variable backgrounds. In vision, autistic traits are associated with superior performance in tasks that require focus on the local features of a perceptual scene. The aim of the present study was to determine whether the same advantage was observed in the analysis of olfactory scenes. To do this, we compared the ability of 1) 40 young adults (aged 16-35) with high (n = 20) and low levels of autistic traits and 2) 20 children (aged 7-11), with (n = 10) and without an autism spectrum disorder diagnosis, to identify individual odor objects presented within odor mixtures. First, we used a 4-alternative forced choice task to confirm that both adults and children were able to reliably identify 8 blended fragrances, representing food-related odors, when presented individually. We then used the same forced choice format to test participants' ability to identify the odors when they were combined in either binary or ternary mixtures. Adults with high levels of autistic traits showed superior performance on binary but not ternary mixture trials, whereas children with an autism spectrum disorder diagnosis outperformed age-matched neurotypical peers, irrespective of mixture complexity. These findings indicate that the local processing advantages associated with high levels of autistic traits in visual tasks are also apparent in a task requiring analytical processing of odor mixtures.

The impact of sensory processing on executive and cognitive functions in children with autism spectrum disorder in the school context

BACKGROUND

Theoretical approaches propose a hierarchical organization of sensory and higher-order cognitive processes, in which sensory processing influence some cognitive and executive functions.

AIMS

The main objective of this study was to analyze whether sensory processing dysfunctions can predict the cognitive and executive dysfunctions evaluated in a group of children with level 2 autism spectrum disorder (ASD) in the school context.

METHODS AND PROCEDURES

Two groups of children participated: an ASD group (n = 40) and a group of children with typical development (the comparison group, n = 40). The children's sensory processing was evaluated based on their teachers' perceptions, and the children's executive and cognitive functions were evaluated using direct performance measures.

RESULTS

In the ASD group, the sensory processing difficulties predicted executive and cognitive dysfunctions in the specific domains of inhibitory control, auditory sustained attention, and short-term verbal memory, after controlling the possible effect of ASD severity. Moreover, the ASD group showed higher levels of sensory, executive, and cognitive dysfunction than the comparison group.

CONCLUSIONS AND IMPLICATIONS

Future research should investigate whether adequate sensory interventions in children with ASD in the school context can improve these specific executive and cognitive functions.

People with autism perceive drastic illusory changes for repeated verbal stimuli

A core symptom of autism spectrum disorder (ASD) is restricted and repetitive behavior, characterized partly by insistence on sameness and excessively focused interest. This behavior has often been interpreted as a manifestation of anxiety and fear triggered by resistance to change. The implicit assumption underlying this interpretation is that perception per se (such as the judgment of sameness and changes in sensory stimuli) is not different between ASD and typically developed (TD) individuals, but that only the emotional response to the same amount of perceived change is. However, few studies have examined how individuals with ASD actually perceive a repeated presentation of the same sensory stimulus. To explore this issue, we conducted a listening test to compare perception of a repeated sound pattern, namely a spoken word, between ASD and TD groups. Prolonged listening to a repeated word without a pause may induce perceptual changes, which is known as the verbal transformation effect. We discovered that individuals with ASD tend to perceive more drastic changes or differences for the same repeated auditory pattern. This suggests that such variable perception incites individuals with ASD to persist for sameness.

Thermal Perceptual Thresholds are typical in Autism Spectrum Disorder but Strongly Related to Intra-individual Response Variability

Individuals with autism spectrum disorder (ASD) are often reported to exhibit an apparent indifference to pain or temperature. Leading models suggest that this behavior is the result of elevated perceptual thresholds for thermal stimuli, but data to support these assertions are inconclusive. An alternative proposal suggests that the sensory features of ASD arise from increased intra-individual perceptual variability. In this study, we measured method-of-limits warm and cool detection thresholds in 142 individuals (83 with ASD, 59 with typical development [TD], aged 7-54 years), testing relationships with diagnostic group, demographics, and clinical measures. We also investigated the relationship between detection thresholds and a novel measure of intra-individual (trial-to-trial) threshold variability, a putative index of "perceptual noise." This investigation found no differences in thermal detection thresholds between individuals with ASD and typical controls, despite large differences between groups in sensory reactivity questionnaires and modest group differences in intra-individual variability. Lower performance IQ, male sex, and higher intra-individual variability in threshold estimates were the most significant predictors of elevated detection thresholds. Although no psychophysical measure was significantly correlated with questionnaire measures of sensory hyporeactivity, large intra-individual variability may partially explain the elevated psychophysical thresholds seen in a subset of the ASD population.

Measuring the Behavioral Response to Spatial Audio within a Multi-Modal Virtual Reality Environment in Children with Autism Spectrum Disorder

Virtual Reality (VR) has been an active area of research in the development of interactive interventions for individuals with autism spectrum disorder (ASD) for over two decades. These immersive environments create a safe platform in which therapy can address the core symptoms associated with this condition. Recent advancements in spatial audio rendering techniques for VR now allow for the creation of realistic audio environments that accurately match their visual counterparts. However, reported auditory processing impairments associated with autism may affect how an individual interacts with their virtual therapy application. This study aims to investigate if these difficulties in processing audio information would directly impact how individuals with autism interact with a presented virtual spatial audio environment. Two experiments were conducted with participants diagnosed with ASD (n = 29) that compared: (1) behavioral reaction between spatialized and non-spatialized audio; and (2) the effect of background noise on participant interaction. Participants listening to binaural-based spatial audio showed higher spatial attention towards target auditory events. In addition, the amount of competing background audio was reported to influence spatial attention and interaction. These findings suggest that despite associated sensory processing difficulties, those with ASD can correctly decode the auditory cues simulated in current spatial audio rendering techniques.

Autism and Faux Pas. Influences of Presentation Modality and Working Memory

People diagnosed with an autism spectrum disorder (ASD) often have difficulties on Theory of Mind (ToM) tasks involving social situations, such as 'faux pas'. The objective of this study was to find the modality of presentation (visual, verbal, or mixed) that yields the best understanding of a 'faux pas', and the possible influence of other variables, including intelligence (IQ), age, and working memory. Thirty autistic children and 30 neurotypical children, all aged 7 to 12 years old and comparable in age and IQ, participated in this study. They were asked to resolve nine 'faux pas' stories (three per modality). Significant between-groups differences were found in the visual (t = 2.99, p = .004) and verbal modalities (t = 2.64, p = .011), such that the neurotypical (NT) group had higher scores than the ASD group. The ASD group's comprehension was better via the mixed modality than the verbal modality (t = 2.48, p = .019). In addition, working memory had a bigger impact on Faux Pas understanding in cases of autism than in typical development (R2 explained between .19 and .28 of variance in Faux Pas test outcomes), and could therefore explain some of the difficulties previously reported in this area. Future research should include a measure of working memory and a control among the stimuli presented to test for group differences in faux pas understanding.

How is visual salience computed in the brain? Insights from behaviour, neurobiology and modelling

Inherent in visual scene analysis is a bottleneck associated with the need to sequentially sample locations with foveating eye movements. The concept of a 'saliency map' topographically encoding stimulus conspicuity over the visual scene has proven to be an efficient predictor of eye movements. Our work reviews insights into the neurobiological implementation of visual salience computation. We start by summarizing the role that different visual brain areas play in salience computation, whether at the level of feature analysis for bottom-up salience or at the level of goal-directed priority maps for output behaviour. We then delve into how a subcortical structure, the superior colliculus (SC), participates in salience computation. The SC represents a visual saliency map via a centre-surround inhibition mechanism in the superficial layers, which feeds into priority selection mechanisms in the deeper layers, thereby affecting saccadic and microsaccadic eye movements. Lateral interactions in the local SC circuit are particularly important for controlling active populations of neurons. This, in turn, might help explain long-range effects, such as those of peripheral cues on tiny microsaccades. Finally, we show how a combination of in vitro neurophysiology and large-scale computational modelling is able to clarify how salience computation is implemented in the local circuit of the SC.This article is part of the themed issue 'Auditory and visual scene analysis'.

Interindividual variability in auditory scene analysis revealed by confidence judgements

Because musicians are trained to discern sounds within complex acoustic scenes, such as an orchestra playing, it has been hypothesized that musicianship improves general auditory scene analysis abilities. Here, we compared musicians and non-musicians in a behavioural paradigm using ambiguous stimuli, combining performance, reaction times and confidence measures. We used 'Shepard tones', for which listeners may report either an upward or a downward pitch shift for the same ambiguous tone pair. Musicians and non-musicians performed similarly on the pitch-shift direction task. In particular, both groups were at chance for the ambiguous case. However, groups differed in their reaction times and judgements of confidence. Musicians responded to the ambiguous case with long reaction times and low confidence, whereas non-musicians responded with fast reaction times and maximal confidence. In a subsequent experiment, non-musicians displayed reduced confidence for the ambiguous case when pure-tone components of the Shepard complex were made easier to discern. The results suggest an effect of musical training on scene analysis: we speculate that musicians were more likely to discern components within complex auditory scenes, perhaps because of enhanced attentional resolution, and thus discovered the ambiguity. For untrained listeners, stimulus ambiguity was not available to perceptual awareness.This article is part of the themed issue 'Auditory and visual scene analysis'.

Auditory and visual scene analysis: an overview

We perceive the world as stable and composed of discrete objects even though auditory and visual inputs are often ambiguous owing to spatial and temporal occluders and changes in the conditions of observation. This raises important questions regarding where and how 'scene analysis' is performed in the brain. Recent advances from both auditory and visual research suggest that the brain does not simply process the incoming scene properties. Rather, top-down processes such as attention, expectations and prior knowledge facilitate scene perception. Thus, scene analysis is linked not only with the extraction of stimulus features and formation and selection of perceptual objects, but also with selective attention, perceptual binding and awareness. This special issue covers novel advances in scene-analysis research obtained using a combination of psychophysics, computational modelling, neuroimaging and neurophysiology, and presents new empirical and theoretical approaches. For integrative understanding of scene analysis beyond and across sensory modalities, we provide a collection of 15 articles that enable comparison and integration of recent findings in auditory and visual scene analysis.This article is part of the themed issue 'Auditory and visual scene analysis'.

Resolving the neural dynamics of visual and auditory scene processing in the human brain: a methodological approach

In natural environments, visual and auditory stimulation elicit responses across a large set of brain regions in a fraction of a second, yielding representations of the multimodal scene and its properties. The rapid and complex neural dynamics underlying visual and auditory information processing pose major challenges to human cognitive neuroscience. Brain signals measured non-invasively are inherently noisy, the format of neural representations is unknown, and transformations between representations are complex and often nonlinear. Further, no single non-invasive brain measurement technique provides a spatio-temporally integrated view. In this opinion piece, we argue that progress can be made by a concerted effort based on three pillars of recent methodological development: (i) sensitive analysis techniques such as decoding and cross-classification, (ii) complex computational modelling using models such as deep neural networks, and (iii) integration across imaging methods (magnetoencephalography/electroencephalography, functional magnetic resonance imaging) and models, e.g. using representational similarity analysis. We showcase two recent efforts that have been undertaken in this spirit and provide novel results about visual and auditory scene analysis. Finally, we discuss the limits of this perspective and sketch a concrete roadmap for future research.

This article is part of the themed issue ‘Auditory and visual scene analysis’.