The hippocampus–IPL connectivity links to ADHD traits through sensory processing sensitivity

Accumulating evidence suggests that individuals with high sensory processing sensitivity often experience sensory overload and have difficulty sustaining attention, which can particularly resemble attention deficit symptoms of attention-deficit/hyperactivity disorder. However, due to the lack of understanding about the potential neural pathways involved in those processes, a comprehensive view of how sensory processing sensitivity and attention deficit are related is generally limited. Here, we quantified the sensory processing sensitivity and attention deficit using the Highly Sensitive Person Scale and the Adult Attention-deficit/Hyperactivity Disorder Self-Report Scale, respectively, to investigate the association between sensory processing sensitivity and attention deficit and further identify the corresponding neural substrates via the use of resting-state functional Magnetic Resonance Imaging (fMRI) analyses. On the behavioral level, the results indicated a significantly positive correlation between sensory processing sensitivity and attention deficit traits, while on the neural level, the sensory processing sensitivity score was positively correlated with functional connectivity between the rostral hippocampus and inferior parietal lobule, which is the core regions of the attention network. Mediation analysis revealed that hippocampus-Inferior Parietal Lobule (IPL) connectivity can further influence attention deficit through a mediating role of sensory processing sensitivity. Overall, these findings suggest that enhanced functional coupling between the hippocampus and attention network regions may heighten sensitivity to environmental stimuli, leading to increased distractibility and potentially contributing to attention deficit.