Exploring the neural mechanisms of ADHD in children: a multifeature cross-task fNIRS analysis.

Children with attention-deficit hyperactivity disorder exhibit multidimensional abnormalities of brain function, and the identification of key brain regions is often inconsistent across studies due to the influence of specific cognitive demands and feature selection. We conducted multifeature cross-task analysis and correlation analysis of functional near-infrared spectroscopy-based functional activity and connectivity under both resting state and verbal fluency task. Results reveal that more pronounced brain activation differences were observed in the right hemisphere of attention-deficit hyperactivity disorder group compared with healthy controls, particularly in channels 7 and 13, with cross-task consistent activation patterns. The strongest connectivity appeared between the right dorsolateral prefrontal cortex and the right frontopolar cortex in both resting state and verbal fluency task. Meanwhile, the task-related significant differences were mainly found in the left hemisphere, with fewer connectivity differences between tasks than between groups. Furthermore, a complex nonlinear relationship was identified between brain activation intensity and functional connectivity in attention-deficit hyperactivity disorder, a negative correlation in resting state, and a positive correlation in half of the brain regions (including bilateral dorsolateral prefrontal cortex) during verbal fluency task. These findings support the existing attention-deficit hyperactivity disorder mechanisms and supplement the complexity of cross-task brain functional reorganization and fixed functional abnormalities, thereby advancing research on the neurobiological basis of attention-deficit hyperactivity disorder.