"Catch the Spies": Multiple-Object Tracking in Low-Functioning Children with Autism Spectrum Disorder

Background:  

The multiple object tracking (MOT) task, considered an index of dynamic information processing as it involves the ability to focus on and track target objects as they move among distracters, allows us to better understand the real-world attentional task of focusing on dynamic objects or events in complex, busy environments.  This ecologically relevant task requires individuating several items at once and assigning mental reference indexes to a small number of selected targets so that the locations of the targets can be reported even if their properties and positions change (Pylyshyn, 2001). Since cognitive resources must be simultaneously assigned to multiple, moving objects for successful task completion, MOT is considered a measure of object-based visual attention with real-world applicability (Scholl, 2009). The preference for local processing (Happe & Frith, 2006) and strengths in visual search (Plaisted et al., 1998) among persons with ASD suggest that their performance on the MOT task might be enhanced relative to developmental level.

Objectives:  

To examine dynamic attention abilities in individuals with ASD, with the administration of an MOT task to children with ASD as compared to that of TD children matched on mental age (MA).

Methods:  

Groups of low-functioning children with ASD (n = 11) and TD children (n =10) were matched at a developmental level of 7 years of age on visual-spatial abilities as measured by the Leiter-R International Performance Scale Revised (Roid & Miller, 1997). As a measure of MOT, we administered Catch the Spies Task (Trick et al., 2005; 2009), a computer game in which the participants were asked to keep track of the locations of 1-4 spies (targets) that were disguised to look like other people (happy-face figures) in a display. Both the targets and the distracters moved randomly and independently throughout each trial for 4 seconds.  To ensure that any MOT effects did not originate from differences in encoding or reporting the target positions or remembering the target positions after a delay, control tasks requiring the reporting of target positions for static items immediately after the presentation of or 4 seconds following the presentation of targets were administered.

Results:  

The children with ASD showed similar performance to their MA-matched typically developing peers in their ability to track one through four targets on the MOT task (all p-values > .50). Both the ASD and the TD group were able to track two items reliably but were unable to track four items [Means (SE) for ASD: 1 target = 76(10), 2 targets = 73(8), 3 targets = 70(7), 4 targets = 59(6); and, TD: 1 target = 84(5), 2 targets = 79(6), 3 targets = 68(5), 4 targets = 55(4)]. The groups also performed similarly on immediate and delayed report tasks.

Conclusions:  

Low functioning children with ASD performed similarly to the MA-matched TD group in that they were able to track up to 2 items but unable to track 4 items. The findings suggest typical development in ASD individuals of processes required for MOT including object individuation and dynamic tracking.