Intact animacy perception during chase detection in ASD

Abstract

We explored the strength of implicit social inferences in adolescents with and without Autism Spectrum Disorder (ASD) using a chasing paradigm in which participants judged the absence/presence of a chase within a display of four seemingly randomly moving dots. While two of these dots always moved randomly, the two others could fulfill the role of being either the chasing (wolf) or chased (sheep) dot. In the chase-present (but not the chase-absent) trials the wolf displayed chasing behavior defined by the degree to which the dot reliably moved towards the sheep (chasing subtlety). Previous research indicated that chasing subtlety strongly influenced chase detection in typically developing (TD) adults. We intended to replicate and extend this finding to adolescents with and without ASD, while also adding either a social or a non-social cue to the displays. Our results confirmed the importance of chasing subtlety and indicated that adding social, but not non-social, information further improved chase detection performance. Interestingly, the performance of adolescents with ASD was less dependent on chasing subtlety than that of their TD counterparts. Nonetheless, adolescents with and without ASD did not differ in their use of the added social (or non-social) cue.

Figure 1

(A) Graphical overview of the trial design. (B) Static screen shots of the different task conditions. In the baseline condition, only the chasing subtlety was manipulated. In the social condition, eyes were added to all shapes and those of the wolf were always focused on the sheep in chase-present trials. In the non-social condition, the contrast of the shapes was manipulated periodically. A movie of the task is available on http://www.gestaltrevision.be/en/resources/supplementary-material. (C) Illustration of the chasing subtlety manipulation, implemented by manipulating the maximal angular deviation of the heading of the wolf compared to perfect “heat-seeking” behavior. When the chasing subtlety was 15° (or 45° or 75°), the wolf was always heading in the general direction of the sheep, but was not perfectly heat-seeking. The dot could move in any direction within a 30° (or 90° or 150^°) window, with the window always centered on the (moving) sheep.

Figure 2

Overview of the mean accuracy performance. The data are represented as the mean performance across participants, with error bars depicting the standard error of the mean (SEM). The data of (A) the baseline condition, (B) the social condition, (C) the non-social condition and (D) all conditions combined, each time presented for all three subtlety values (15°, 45°, 75°). TD adolescents are depicted in blue and adolescents with ASD in green.

Figure 3

Visualization of the data, with the linear (per group) regression line indicating the strength of the correlation between the mean accuracy (%) on the ordinate axis and age (in years) on the abscissa. TD adolescents are depicted in blue and adolescents with ASD in green.