ADHD traits are not related to multisensory integration in a university population

In daily life, we are constantly bombarded with sensory information from multiple sources. Our ability to combine these cues into a single perceptual experience is known as multisensory integration. Research is starting to show that multisensory integration may be altered in individuals with attention-deficit/hyperactivity disorder (ADHD). However, most studies have focused on clinical populations, leaving little known about how multisensory integration related to ADHD traits along a dimensional spectrum, consistent with the Research Domain Criteria (RDoC) approach. The present study examined associations between ADHD traits and multisensory integration in university students using three different behavioural tasks (i.e., Sound-Induced Flash Illusion [SIFI], McGurk, and speech-in-noise). ADHD traits were assessed dimensionally, including overall ADHD traits, as well as inattentive and hyperactive-impulsive trait dimensions. Participants were also divided into High ADHD and Low ADHD trait groups for categorical comparisons. Results indicated no significant associations between overall, inattentive, or hyperactive-impulsive ADHD traits and performance on any of the multisensory tasks. Similarly, no group differences were observed between High and Low ADHD trait groups. These findings suggest that multisensory integration differences reported in previous research may emerge only when ADHD traits reach clinical severity, rather than existing across the broader continuum of traits. This study highlights the importance of considering both dimensional and categorical approaches when examining cognitive mechanisms in ADHD. Future work should explore developmental and contextual factors that may shape multisensory integration in clinically significant ADHD.