Lack of global precedence and global-to-local interference without local processing deficit: A robust finding in children with attention-deficit/hyperactivity disorder under different visual angles of the Navon task.

The Navon effect (Navon, 1977) is an automatic tendency to process the global picture prior to local details when processing compound patterns. However, several recent studies have reported that this effect is lacking in attention-deficit/hyperactivity disorder (ADHD). Although previous research has shown that the Navon effect is strongly affected by visual angles, whether this phenomenon will also be observed in ADHD is yet to be understood. We examine the lack of the Navon effect in ADHD under various visual angles to ensure that this phenomenon is not an artifact of saliency.By employing three different visual angles for the local stimuli, global and local processing of Navon-type hierarchical letters was examined in participants with ADHD (n = 15) and a comparison group (n = 17).ADHD participants presented with a lack of the Navon effect without local processing deficit regardless of visual angle, in comparison to non-ADHD participants.A lack of global precedence and global-to-local interference without local processing deficit can be generalized in ADHD. This suggests that people with ADHD experience difficulties in processing the "whole picture," and it also challenges the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; American Psychiatric Association, 2013) criteria of ADHD in which the failure to pay close attention to details was emphasized. Moreover, the current results have important implications for understanding ADHD and could also have significant clinical value.