A Meta-Analysis on Local and Global Face Perception in Individuals with ASD

Background: Atypical global and local visual processing is often reported in individuals with ASD. However, findings on global and local face processing are inconsistent: Some studies have, for instance, revealed reduced face inversion effects in ASD, whereas others did not, leaving the field inconclusive. Factors such as stimulus, paradigm and participant characteristics could contribute to the large inconsistencies both within and across tasks.

Objectives: Instead of yet another empirical study evaluating a specific aspect of holistic face processing in individuals with ASD, the field is in need of a systematical and quantitative overview of the available evidence. We therefore wanted to systematically examine and combine all empirical data on this topic by means of a meta-analysis, in which the effect size across different studies was calculated, evaluating the overall evidence for differences in local and global face processing in individuals with and without ASD.

Methods: We have performed a formal meta-analysis, which incorporated the empirical data of 27 articles and several moderator variables in our analysis.

Results: Overall, results provided evidence for a general deficit in face processing in individuals with ASD ( (Hedges’ g effect size = -0.70). The ASD group performed significantly worse on both global (g = -.67) and local face processing tasks (g= -.76). However, no moderating effects of task or stimulus characteristics were found.

Conclusions: This meta-analysis showed an overall face perception problem in individuals with ASD. However, current analyses did not provide evidence for atypical local or global face processing. In addition, the impact of several moderating variables is discussed.