Neural Processing of Action Perception and Social Communication in Young Children with Autism Spectrum Disorders

• In Event: 2-128 - Function and Development of the Mirror System in Infancy and Toddlerhood

Integrative Statement

Background:
It has been proposed that individuals with Autism Spectrum Disorders (ASD) have impairments in the Mirror Neuron System (MNS), a neural mechanism that links the perception of others’ actions to one’s own motor processes. Since this system has been linked to social development, impairments in the MNS could explain social deficits seen in ASD. However, previous findings are conflicting and limited to older individuals. Thus, two important questions are whether young children with ASD have impairments in the MNS and whether they are linked to social abilities, specifically understanding and production of language.

Objectives:
The current study compared toddlers and preschoolers with and without ASD on activations in the MNS using EEG. Furthermore, it was investigated if an action that is more relevant in social context (i.e. pointing) modulates the MNS activity differently than a lower-level action (i.e. grasping). Lastly, relations between functioning of the MNS and language abilities were explored.

Methods:
Participants
Data of sufficient quality were obtained and analyzed from 23 (of 28) typically-developed (TD) young children (M = 43.4 months; range 25-59) and 11 (of 24) young children with ASD (M = 35.4 months; range 20-58). ASD diagnoses were confirmed on the ADOS-2 Toddler module, Module 1 or Module 2.

Stimuli and procedure
Electroencephalography (EEG) recordings were obtained during right-handed grasping and placing actions (execute grasp condition) and observing video clips of the same grasping action (observe grasp condition) and a second pointing action (observe point condition). Power in the 7-10 Hz frequency band at the sensorimotor areas, the mu rhythm, was explored as index of MNS activity. Receptive language and expressive language abilities were measured with the Mullen Scales of Early Learning (MSEL; Mullen, 1992).

Results:
As expected, both the TD and ASD group demonstrated activation in the sensorimotor areas when grasping and placing an object and an ANOVA did not indicate significant group differences in the execute grasp condition. For the observation conditions, there was a significant three-way interaction between condition (grasp or point), hemisphere and group. This was mainly the result of increased power in the left hemisphere when grasping actions were observed in the TD group compared to the ASD group. Interestingly, in the ASD group, responses that were more similar to the TD group in this condition were positively correlated with receptive and expressive language scores.
Conclusions:
Findings show that toddlers and preschoolers with ASD have a different activation pattern in the MNS during action observation. More typical-like responses in the MNS were associated with better language abilities. Therefore, impairments in the MNS might explain some of the deficits in communication. Observing this in toddlers and preschoolers recently diagnosed with ASD could help us to better understand the relations between neural processes and the development of social skills and may have implications for early diagnosis of ASD.

Authors

• Manon A Krol, Boston University
  Presenting Author

• Jennifer Leano, Boston University
  Non-Presenting Author

• Daniela Plesa-Skwerer, Boston University
  Non-Presenting Author

• Helen Tager-Flusberg, Boston University
  Non-Presenting Author