Inflexible Updating of the Self-Other Divide During a Social Context in Autism; Psychophysical, Electrophysiological, and Neural Network Modeling Evidence

Abstract

Autism spectrum disorder (ASD) is a heterogenous disorder predominantly characterized by social and communicative differences, but increasingly recognized to also alter (multi)sensory function. To face the heterogeneity and ubiquity of ASD, researchers have proposed models of statistical inference operating at the level of computations. Here, we attempt to bridge both across domains, from social to sensory, and levels of description, from behavioral computations to neural ensemble activity to a biologically-plausible artificial neural network, in furthering our understanding of autism. We do so by mapping visuo-tactile peri-personal space (PPS), and examining its electroencephalography (EEG) correlates, in individuals with ASD and neurotypical individuals during both a social and non-social context given that (i) the sensory coding of PPS is well understood, (ii) this space is thought to distinguish between self and other, and (iii) PPS is known to remap during social interactions. In contrast to their neurotypical counterparts, psychophysical and EEG evidence suggested that PPS does not remap in ASD during a social context. To account for this observation, we then employed a neural network model of PPS and demonstrate that PPS remapping may be driven by changes in neural gain operating at the level of multisensory neurons. Critically, under the anomalous excitation-inhibition (E/I) regime of ASD, this gain modulation does not result in PPS resizing. Overall, our findings are in line with recent statistical inference accounts suggesting diminished flexibility in ASD, and further these accounts by demonstrating within an example relevant for social cognition that such inflexibility may be due to E/I imbalances.

Interpersonal Motor Interactions Shape Multisensory Representations of the Peripersonal Space

“…Initial evidence of the lack of plastic modulations of the PPS in a social context in autistic individuals is provided by a recent work by Noel and colleagues [ 50 ], who used EEG to investigate changes in the PPS induced by the presence of another individual in two groups of ASD and TD. Participants engaged in a tactile detection task while visual stimuli were presented in the near and far space in a social (the experimenter sat in front of them, at a distance of 150 cm) or non-social situation (they performed the task being alone in the room).…”

“…This view is consistent with the idea that, during social interactions, understanding others’ internal states stems from a sensorimotor representation of their behaviour [ 47 ]. In the last section ( Section 7 ), we link our proposal to the evidence that individuals with Autism Spectrum Disorder (ASD) show differences in PPS representations compared to neurotypical individuals [ 48 , 49 , 50 ].…”