Response Inhibition in Autistic Adults: A Functional Near-Infrared Spectroscopy Study in Virtual Reality

Introduction:: Response inhibition, a core component of executive functioning, has been studied extensively in autism, though results depend substantially on task choice and design. This study investigated whether autistic and non-autistic adults differ in behavioral and neurophysiological responses during a visuospatial go/no-go task (GNGT) implemented in virtual reality (VR). Methods:: Participants (22 autistic, 10 non-autistic) completed a blocked go/no-go task in a VR environment, where stimuli appeared in varied spatial locations. Prefrontal hemodynamic responses were recorded using functional near-infrared spectroscopy (fNIRS), along with reaction times (RTs) and error rates. Results:: Both groups demonstrated slower RTs and fewer errors in no-go blocks compared to go blocks, with no significant group differences in behavioral performance. fNIRS analyses revealed significant right-lateralized increases in oxygenated hemoglobin concentration in the dorsolateral prefrontal cortex (dlPFC) during no-go blocks in non-autistic adults only. Autistic adults showed no significant task-related modulation of prefrontal cortex activity. Discussion:: While behavioral performance was comparable across groups, only non-autistic participants showed task-related modulation of dlPFC activity. These findings highlight differential neural engagement during inhibition and illustrate the potential of fNIRS paradigms for examining the executive functioning of autistic individuals in VR.