Attention and Executive Function In Children with ASD

Background:  

Difficulties with attention are often implicated in autism. However, attention has many distinct components, and deficits have not been found in all of them. Some  HFA adults have even been reported to perform better than controls in some attentional tasks.  The previous work, however, has focused primarily on HFA adults, whose attentional function may have reached plateau.

Objectives:  

The goal of the present study is to examine a wide range of attentional functions in young children with ASD and their typically developing (TD) counterparts. We studied children aged 5 to 10 years old, which allows us to test the developmental change of attention and compare these changes between ASD and TD. We used tasks that tap into a variety of basic attentional functions, including selective attention, divided attention, executive control, conflict resolution, and attention to local and global levels. Testing different attentional functions allows us to detect any differences in the development of different aspects of attention in ASD.

Methods:  

We tested 5-10 year old children with high-functioning autism (N~10) and a large number of typically developing children (N~50) to provide a “norm” in the following attention tasks. (1) Executive function was tested with a computerized version of the Dimension Card Sorting Task, in which children first sort colored shapes according to one dimension (e.g., color),  then sort them according to another dimension (e.g., shape), hence requiring them to suppress the previously learned rule, then sort by either color or shape, depending on a contextual cue,  requiring them to flexibly implement rules based on a task cue. (2) Selective & divided attention functions were tested with the multiple object tracking task, in which children were asked to track a certain number of moving objects among other visually identical moving objects, requiring selection of pre-specified targets, filtering out of distractors, and dividing attention among the multiple moving targets. (3) Attention to local and global levels, in which children viewed compound Navon stimuli (e.g., a big triangle made of little squares) and were asked them to classify the shape either at a particular level (local or global, in different blocks), a task that requires children to select a property, and to ignore and suppress information from another property of an object. Another task measured children’s natural tendency in categorizing compound stimuli.

Results:  

ASD children were comparable with TD controls in all attention and executive function, despite lower performance in a visually-guided reaching task and other tasks such as face perception. Yet our tasks were able to detect group differences, as evidenced by significant developmental improvements in all of our tasks.

Conclusions:  

Preliminary evidence indicates that attention and executive function improve with age but are unaffected by ASD diagnosis.