Biology subjects

Crosse, M. J.

Publications and source records attributed to Crosse, M. J..

6 recordsLinked to original sources

bioRxiv2026

Reduced flexibility in predictive tuning and contextual adaptation in autism: an EEG and behavioral study.

The brain generates predictions to prepare for upcoming events. Because the environment is not perfectly predictable, the brain also estimates the certainty of these predictions and adjusts preparatory processes accordingly. Given that autistic individuals often resist even small changes to everyday routines, we hypothesized altered tuning of prediction certainty in autism. To test this, EEG was recorded from adolescents and young autistic adults (n = 20) and from age- and IQ-matched non-autistic adults (n = 19) during a probabilistic cued target identification task during which cue validity was systematically varied across four levels: 100%, 84%, 67%, and 33%. Participants were not informed of the cue-target validity nor when it changed. We focused on two neural signatures of anticipatory readiness, contingent negative variation (CNV) and alpha-band event-related desynchronization (-ERD), and one of cognitive updating: the P3 to targets and to invalid (e.g., a non-target in place of the target) stimuli. Across groups, preparatory activity increased as contextual certainty decreased, with larger CNV amplitudes and stronger -ERD preceding targets in lower-probability contexts, suggesting enhanced preparatory engagement under greater uncertainty. Furthermore, larger CNV amplitudes predicted faster reaction times, indicating functionally significant anticipatory dynamics. However, modulation of both neural preparation and response times as a function of cue-target probability was significantly reduced in the autistic group. In addition, autistic participants showed diminished probability-dependent modulation of the P3b to both targets and invalid stimuli, and coupling between anticipatory activity (CNV) and subsequent updating (P3b) was observed in non-autistic participants whereas it was absent in autism. Together, these findings suggest that while predictive mechanisms are present in autism, anticipatory processes are less flexibly tuned to contextual uncertainty and less effectively linked to subsequent cognitive updating. This reduced adaptability may reflect difficulty adjusting internal predictive models to changing environmental contingencies, potentially contributing to core features of autism such as resistance to change and insistence on sameness. HighlightsO_LIAnticipatory brain mechanisms (CNV and alpha desynchronization) are present in autism and are behaviorally relevant, predicting faster responses. C_LIO_LIAutistic individuals exhibit reduced modulation of anticipatory CNV and alpha activity as a function of cue-target validity. C_LIO_LIP3b responses to both targets and invalid stimuli show diminished sensitivity to contextual probability in autism, consistent with altered prior updating. C_LIO_LIThe link between anticipatory activity and cognitive updating (i.e., CNV to P3b) is disrupted in autism. C_LIO_LIP3a amplitude to invalid stimuli is reduced in autism, suggesting diminished engagement of violation-sensitive processes. C_LIO_LITogether, findings point to less flexible tuning of predictive mechanisms and reduced adaptation to contextual uncertainty in autism. C_LI

neuroscience↗

bioRxiv2022

All-or-None Evaluation of Prediction Certainty in Autism

The brain generates predictions to prepare for upcoming events. As life is not always 100% predictable, it also estimates a level of certainty for these predictions. Given that autistic individuals resist even small changes in everyday life, we hypothesized impaired tuning of prediction certainty in autism. To study this, EEG was recorded from adolescents and young adults with autism while they performed a probabilistic prediction task in which cue validity was parametrically manipulated. A fully predictable condition (100% cue validity) was contrasted with less predictable conditions (84, 67 and 33% cue validity). Well characterized brain potentials were examined to assess the influence of cue validity on target anticipation (contingent negative variation; CNV), the evaluation of target statistics (P3), and prediction model updating (slow wave; SW). As expected, cue validity systematically influenced the amplitudes of the CNV, P3 and SW in controls. In contrast, cue-validity effects on CNV and SW were substantially reduced in autism. This suggests that although target statistics are accurately registered in autism, as indicated by intact modulation of the P3, they are not effectively applied to generate expectations for upcoming input or model updating. Contrasting the fully predictable with the less predictable conditions, our data suggest that autistic individuals adopted an all-or-none evaluation of certainty of their environment, rather than adjusting certainty of predictions to different levels of environmental statistics. Social responsiveness scores were associated with flexibility in representing prediction certainty, suggesting that impaired representation and updating of prediction certainty may contribute to social difficulties in autism. SIGNIFICANCE STATEMENTThe ability to make predictions is integral to everyday life. Yet, as life is not always 100% predictable and it is also essential to adjust the certainty of these predictions based on the current context. This study reveals that individuals with autism are less efficient in adjusting the certainty of their predictions to the level of predictability of events. Instead, they may adopt an all-or-none evaluation of certainty. Our findings reveal novel insights into the processes underlying impaired predictive processing in autism, which may open the door to developing targeted behavioral interventions and/or non-invasive brain stimulation therapies that help autistic individuals make more accurate predictions to ease social- and rigidity-based symptoms.

neuroscience↗

bioRxiv2022

Neurophysiological Measures Of Auditory Sensory Processing Are Associated With Adaptive Behavior In Children With Autism Spectrum Disorder

BackgroundAtypical auditory cortical processing is consistently found in scalp electrophysiological and magnetoencephalographic studies of Autism Spectrum Disorder (ASD), and may provide a marker of neuropathological brain development. However, the relationship between atypical cortical processing of auditory information and adaptive behavior in ASD is not yet well understood. MethodsWe sought to test the hypothesis that early auditory processing in ASD is related to everyday adaptive behavior through the examination of auditory event-related potentials (AEPs) in response to simple tones and Vineland Adaptive Behavior Scales in a large cohort of children with ASD (N=89), aged 6-17, and in age- and IQ-matched neurotypically (NT) developing controls (N=120). ResultsStatistical analyses revealed significant group differences in early AEPs over temporal scalp regions. Whereas the expected rightward lateralization of the AEP to tonal stimuli occurred in both groups, lateralization of the AEP was only significantly associated with adaptive functioning, in the domains of communication and daily living, in the ASD group. ConclusionsThese results lend support to the hypothesis that atypical processing of sensory information is related to everyday adaptive behavior in autism.

neuroscience↗

bioRxiv2020

Neurophysiological indices of audiovisual speech integration are enhanced at the phonetic level for speech in noise

Seeing a speakers face benefits speech comprehension, especially in challenging listening conditions. This perceptual benefit is thought to stem from the neural integration of visual and auditory speech at multiple stages of processing, whereby movement of a speakers face provides temporal cues to auditory cortex, and articulatory information from the speakers mouth can aid recognizing specific linguistic units (e.g., phonemes, syllables). However it remains unclear how the integration of these cues varies as a function of listening conditions. Here we sought to provide insight on these questions by examining EEG responses to natural audiovisual, audio, and visual speech in quiet and in noise. Specifically, we represented our speech stimuli in terms of their spectrograms and their phonetic features, and then quantified the strength of the encoding of those features in the EEG using canonical correlation analysis. The encoding of both spectrotemporal and phonetic features was shown to be more robust in audiovisual speech responses then what would have been expected from the summation of the audio and visual speech responses, consistent with the literature on multisensory integration. Furthermore, the strength of this multisensory enhancement was more pronounced at the level of phonetic processing for speech in noise relative to speech in quiet, indicating that listeners rely more on articulatory details from visual speech in challenging listening conditions. These findings support the notion that the integration of audio and visual speech is a flexible, multistage process that adapts to optimize comprehension based on the current listening conditions. Significance StatementDuring conversation, visual cues impact our perception of speech. Integration of auditory and visual speech is thought to occur at multiple stages of speech processing and vary flexibly depending on the listening conditions. Here we examine audiovisual integration at two stages of speech processing using the speech spectrogram and a phonetic representation, and test how audiovisual integration adapts to degraded listening conditions. We find significant integration at both of these stages regardless of listening conditions, and when the speech is noisy, we find enhanced integration at the phonetic stage of processing. These findings provide support for the multistage integration framework and demonstrate its flexibility in terms of a greater reliance on visual articulatory information in challenging listening conditions.

neuroscience↗

bioRxiv2019

Developmental Recovery of Impaired Multisensory Processing in Autism and the Cost of Switching Sensory Modality

Children with autism spectrum disorder (ASD) are often impaired in their ability to cope with and process multisensory information, which may contribute to some of the social and communicative deficits that are prevalent in this population. Amelioration of such deficits in adolescence has been observed for ecologically-relevant stimuli such as speech. However, it is not yet known if this recovery generalizes to the processing of nonsocial stimuli such as more basic beeps and flashes, typically used in cognitive neuroscience research. We hypothesize that engagement of different neural processes and lack of environmental exposure to such artificial stimuli leads to protracted developmental trajectories in both neurotypical (NT) individuals and individuals with ASD, thus delaying the age at which we observe this "catch up". Here, we test this hypothesis using a bisensory detection task by measuring human response times to randomly presented auditory, visual and audiovisual stimuli. By measuring the behavioral gain afforded by an audiovisual signal, we show that the multisensory deficit previously reported in children with ASD recovers in adulthood by the mid-twenties. In addition, we examine the effects of switching between sensory modalities and show that teenagers with ASD incur less of a behavioral cost than their NT peers. Computational modelling reveals that multisensory information interacts according to different rules in children and adults, and that sensory evidence is weighted differently too. In ASD, weighting of sensory information and allocation of attention during multisensory processing differs to that of NT individuals. Based on our findings, we propose a theoretical framework of multisensory development in NT and ASD individuals.

neuroscience↗

bioRxiv2017

Electrophysiological correlates of semantic dissimilarity reflect the comprehension of natural, narrative speech.

Understanding natural speech requires that the human brain convert complex spectrotemporal patterns of acoustic input into meaning in a rapid manner that is reasonably tightly time-locked to the incoming speech signal. However, neural evidence for such a time-locked process has been lacking. Here, we sought such evidence by using a computational model to quantify the meaning carried by each word based on how semantically dissimilar it was to its preceding context and then regressing this quantity against electroencephalographic (EEG) data recorded from subjects as they listened to narrative speech. This produced a prominent negativity at a time-lag of 200- 600 ms on centro-parietal EEG electrodes. Subsequent EEG experiments involving time-reversed speech, cocktail party attention and audiovisual speech-in-noise demonstrated that this response was exquisitely sensitive to whether or not subjects were understanding the speech they heard. These findings demonstrate that, when successfully comprehending natural speech, the human brain encodes meaning as a function of the amount of new information carried by each word in a relatively time-locked fashion.

neuroscience↗