Objectives: In the present study, we utilized functional magnetic resonance imaging (fMRI) to examine the neurocognitive disruption(s) that contribute to RIVD impairment in ASD.
Methods: A sample of 16 individuals with ASD (mean age = 15.5 years) and 11 neurologically intact individuals without ASD (mean age = 15.9 years) participated. A 3T Siemens Trio scanner with a standard 8-channel head coil was used for data collection. Following acquisition of structural brain scans (for registration purposes), functional brain scans were conducted while participants performed a flanker visual filtering task (Eriksen & Eriksen, 1974). In this task, participants were asked to identify a centrally-presented target stimulus (e.g., press the left button when the letter “S” or “E” appears and press the right button when the letter “H” or “U” appears). At the time of presentation, the target was flanked closely to the left and right by distracting stimuli. These stimuli could be either compatible (i.e., mapped to the same response; e.g., “ESE") or incompatible (i.e., mapped to a competing response; e.g., “HSH”) with the target. Participants had to ignore the distracters and instead respond to the centrally-located target. RIVD ability was assessed by comparing performance between trials with incompatible flankers and trials with compatible flankers.
Results: Group-differences in RIVD-related activity were observed in several brain regions, most notably the left dorsolateral prefrontal cortex (DLPFC), t(25) = 2.22, p < .05 FDR-corrected.
Conclusions: Although speculative, these results are consistent with the hypothesis that disruptions in DLPFC-mediated processes associated with the top-down monitoring and regulation of interference control may contribute to RIVD impairment in ASD.
See more of: Brain Imaging: fMRI-Social Cognition and Emotion Perception
See more of: Brain Structure & Function