Using a Change Detection Paradigm to Assess the Allocation of Visual Attention in Autism At Different Developmental Periods

Background:  Change detection, the ability to detect changes in the environment, can be affected by the type of information that is prioritized. Among  adults with typical development (TD), change detection is more efficient when change occurs in foreground (i.e. the front plane) compared to background elements (i.e. the ground) of geometric visual displays. As this foreground bias has been studied among adults only, this finding raises the question of when this phenomenon appears during development. Another question concerns how this foreground bias is affected by the presence of other competing perceptual factors, such as configurality (generally not prioritized among individuals with autism) and dynamicity (used as an external attentional cue) at different periods of development.

Objectives:  The objectives of this study were to assess (1) whether the typically-manifested attention bias for foreground information is displayed by children, adolescents, and adults with autism at different periods of development, and (2) to what extent, if any, manipulating the configurality or dynamicity of foreground information differentially influences visual attention allocation among adults with autism as compared to individuals with TD across development.

Methods:  Seven school-aged children with autism (8-12 yrs), 13 adolescents with autism (12-17 yrs), and 13 adults with autism (18-35 yrs) were matched for mean age and full-scale IQ with the same number of school-aged children, adolescents and adults with TD. In an adapted version of a change blindness paradigm (Mazza et al., 2005), the background consisted of 20 columns (alternating between purple/green and blue/red) comprising ten vertically-oriented rectangles (1.81 ^o x 1.24 ^o), and the foreground consisted of 6 horizontally-oriented rectangles (3 purple/green and 3 blue/red) arranged in either a circular (configural) or random (non-configural) manner. On a given trial, either a foreground change (horizontal rectangles changed color), a background change (vertical rectangles changed color), or no change occurred between two successively presented displays (500 ms in duration). In the static condition, no motion occurred within the rectangles. In the dynamic condition, either the foreground or background rectangles contained dynamic noise. The participants indicated whether or not they perceived a change between the two successively presented displays.

Results:  Across age groups, both the participants with autism and typical-development were more efficient at detecting foreground relative to background change in the static condition and better at detecting non-configural foreground information relative to configural foreground information. Moreover, all participants were better able to use dynamic information as a cue to detect changes in the foreground, across periods of development.

Conclusions:  Similar patterns of prioritization of visual attention were found between participants with autism and participants with TD across childhood, adolescence, and adulthood on a change detection paradigm in which perceptual attributes such as the configurality of the foreground elements were manipulated.