Timing and communicative quality of gestures in adolescents with high-functioning autism

Background:   Gesture use, as a form of non-verbal communication, is a significant area of impairment in autism spectrum disorders (ASD).  The quality of gesture and speech integration is an ADOS criterion, and the absence of deictic gestures may be an early marker of ASD.  Despite the clinical significance of gestures, they have received scant empirical attention.  Previous work suggests that decreased variety in spontaneous gestures may be linked to ASD in infancy, and that children with ASD use fewer gestures than developmentally delayed and typically developing (TD) peers.

Objectives:   Gesture is an effective communicative tool that may be an important focus of educational programs for children with ASD.  Understanding how children with ASD spontaneously gesture is an important first step for designing such interventions.

Methods:   This study examines the spontaneous production of co-speech gestures in a sample of 12 high-functioning adolescents with ASD ages 10-17 during their production of a story narration, compared with chronological age-, gender-, and IQ-matched adolescents with TD.  Narratives, drawn from an ADOS 6-picture cartoon series, were analyzed using the McNeill coding system. Precise event timing was calculated using Noldus Observer Pro.

Results:   Findings indicate that, for adolescents with ASD, the length of their narration and the frequency of their gestures was comparable to that of their TD peers.  However, the timing of their gestures and co-occurring speech was poorly synchronized, and gestures added less information about story events (character identity, location of objects in space, etc.). 

Conclusions:   Though adolescents with ASD gestured at typical rates during a story telling task, their gestures did not exhibit the exquisitely well-timed integration with speech and enhanced informational quality that characterizes typical gestures.  Decreased coordination of gesture and speech suggests both a communicative impairment and a weak internal representation of narrative structure expressed both in gesture and speech.