Impairment of actions chains in autism and its possible role in intention understanding

TLDR

Neurophysiological studies in monkeys show that parietal and premotor neurons coding specific motor acts exhibit goal‑dependent activation and mirror properties when observing the initial act of an action sequence. The study aims to determine whether the impairment of action‑chain organization in high‑functioning autistic children limits their experiential understanding of others’ intentions. By activating a specific action chain from its outset, observers can internally simulate the entire action before execution, and electromyographic recordings were used to assess this chained organization in children. Electromyographic data reveal that typically developing children possess intact action‑chain organization, whereas children with autism show a marked impairment.

Abstract

Experiments in monkeys demonstrated that many parietal and premotor neurons coding a specific motor act (e.g., grasping) show a markedly different activation when this act is part of actions that have different goals (e.g., grasping for eating vs. grasping for placing). Many of these "action-constrained" neurons have mirror properties firing selectively to the observation of the initial motor act of the actions to which they belong motorically. By activating a specific action chain from its very outset, this mechanism allows the observers to have an internal copy of the whole action before its execution, thus enabling them to understand directly the agent's intention. Using electromyographic recordings, we show that a similar chained organization exists in typically developing children, whereas it is impaired in children with autism. We propose that, as a consequence of this functional impairment, high-functioning autistic children may understand the intentions of others cognitively but lack the mechanism for understanding them experientially.