No differences in implicit hand maps among different degrees of autistic traits

Abstract

People with autism spectrum disorder (ASD) or higher levels of autistic traits have atypical characteristics in sensory processing. Atypicalities have been reported for proprioceptive judgments, which are tightly related to internal bodily representations underlying position sense. However, no research has directly investigated whether self‐bodily representations are different in individuals with ASD. Implicit hand maps, estimated based on participants' proprioceptive sensations without sight of their hand, are known to be distorted such that the shape is stretched along the medio‐lateral hand axis even for neurotypical participants. Here, with the view of ASD as falling on a continuous distribution among the general population, we explored differences in implicit body representations along with autistic traits by focusing on relationships between autistic traits and the magnitudes of the distortions in implicit hand maps (N ~ 100). We estimated the magnitudes of distortions in implicit hand maps both for fingers and hand surfaces on the dorsal and palmar sides of the hand. Autistic traits were measured by questionnaires (Autism Spectrum [AQ] and Empathy/Systemizing [EQ‐SQ] Quotients). The distortions in implicit hand maps were replicated in our experimental situations. However, there were no significant relationships between autistic traits and the magnitudes of the distortions as well as within‐individual variabilities in the maps and localization performances. Consistent results were observed from comparisons between IQ‐matched samples of people with and without a diagnosis of ASD. Our findings suggest that there exist perceptual and neural processes for implicit body representations underlying position sense consistent across levels of autistic traits.

Proprioception, Emotion and Social Responsiveness in Children with Developmental Disorders: An Exploratory Study in Autism Spectrum Disorder, Cerebral Palsy and Different Neurodevelopmental Situations

“…In the present study, population, children with CP showed significant proprioceptive and emotional knowledge deficits, while children with ASD predominantly showed impairments in social responsiveness. Proprioceptive deficits have previously been reported in different neurodevelopmental conditions such as children with developmental coordination disorder [ 61 ], dystonia [ 62 ], dyslexia [ 24 ], CP [ 21 ] or ASD [ 63 ]. Extensive research has reported proprioceptive impairments in children with CP [ 21 , 22 , 23 , 64 , 65 ], impacting activity, participation and functional performance [ 22 , 23 ].…”

“…Proprioceptive deficits in children with CP have been associated with motor function impairment and spasticity [ 25 , 64 , 66 ] and have been attributed to abnormalities of spino- and thalamo-cortical neural tracts, abnormal cortical activity and lower muscle H-reflex excitability [ 35 , 66 , 67 ]. On the other hand, previous research in children with ASD has reported diminished proprioceptive performance, in the form of poor perception of joint position and altered speed-based proprioception [ 19 , 63 , 68 ]. These clinical findings have been corroborated by studies showing alterations in neural networks processing proprioception, such as the inferior parietal lobe, in children with ASD [ 69 ].…”