Interpersonal Sensory-Motor Synchronization in Adults with and without ASD during a Joint Improvisational Mirror Game

Background:

Recent research on Autism Spectrum Disorders (ASD) suggests that individuals with autism may have a basic deficit in synchronizing with others, and that this difficulty may lead to more complex social and communicative deficits (Marsh et al., 2013). The current project aims to conduct an in-depth investigation of interpersonal sensory-motor synchrony in ASD, using an innovative experimental paradigm - the Mirror Game (MG, Fig 1) – that allows high-resolution temporal and spatial motion tracking in an open-ended joint improvisation game (Noy et al., 2011).

Objectives : To investigate the ability of adults with ASD, as compared with typically developing (TD) adults, to synchronize their movements with another person.

Methods:

Participants: data from 25 participants with high-functioning ASD was compared with that of 25 TD adults.

MG procedure: two players face each other holding handles which can move along parallel tracks, and are told to “imitate each other, create synchronized and interesting motions, and enjoy playing together” (Fig 1a,b). All participants played against the same expert improviser. Participants were instructed to first lead the motion (Leader), then follow the experimenter’s motions (Follower), and then engage in Joint Improvisation (JI), with no designated leader; in 3-minute trials. The motion of the two handles is sampled at 50 HZ (Fig 1c,d).

Data analysis: Players’ synchronization was measured using the mean relative difference in velocity (dV) and the timing differences between zero-velocity events (dT). Periods of synchronized, co-confident (CC) motion (Fig 1d) were defined as periods of nonzero motion longer than 2sec with minimal jitter (i.e., in which the Fourier rms power in the 2-3 Hz band of the difference between the players’ velocities is less than 10% of their mean velocity (Noy et al., 2011)).

Results:

We found that individuals with autism can attain co-confident (CC) motion when playing the Mirror Game with an expert improviser. Interestingly, we found an interaction effect of diagnostic group (ASD, TD) by Round (Leader, Follower, Joint Improvisation), such that individuals with ASD had significantly reduced levels of CC compared to TD participants when following the experimenter (t(33)=4.44, p<.01), but not when leading or jointly improvising with them.

Conclusions:

These data provide the first evidence, to our knowledge, that individuals with autism can attain highly-synchronized, co-confident motion, when playing with another player in an open-ended joint improvisation game. Further data collection and analysis are currently underway to determine whether ASD participants differ from TD participants in their patterns of interpersonal synchronization, and whether these interpersonal motion patterns are associated both with background characteristics such as autism severity, IQ, motor coordination, and imitation ability and with more complex, everyday social and communication abilities.