fMRI activation during response inhibition and error processing: The role of the DAT1 gene in typically developing adolescents and those diagnosed with ADHD

Association of COMT and SLC6A3 polymorphisms with impulsivity, response inhibition and brain function

“…These findings are consistent with previous evidence (Braet et al, 2011). For example, a qualitatively similar pattern was found during reward anticipation and memory in the striatum and hippocampus, respectively (Wittmann, Tan, Lisman, Dolan, & Dü zel, 2013).…”

“…In a recent study, 9R homozygotes performed worse on the incongruent condition of a Stroop task compared to 10R homozygotes and 9/10 heterozygotes (Schneider, Schote, Meyer, & Frings, 2014). A genetic imaging study of adolescents showed that during response inhibition, the homozygosity for the 10R allele may be associated with increased activation in frontal, medial, and parietal regions compared to non-10R carriers (Braet et al, 2011), although the opposite pattern was observed in adult ADHD patients (Dresler et al, 2010).…”

“…However, several imaging studies confirm the existence of modulatory effects of SLC6A3 genotype in non-striatal areas (Arnold et al, 2015;Bertolino et al, 2009;Braet et al, 2011;Dreher et al, 2009;Kasparbauer et al, 2015). It has been suggested that these neuroimaging findings result from downstream effects of phasic dopamine firing in subcortical areas (Arnold et al, 2015).…”

Biomarkers in the Diagnosis of ADHD – Promising Directions

“…Genotype 10/10 individuals were found to generate more activations corresponding to inhibition tasks, showing also its interaction with diagnostic status (ADHD vs. controls) [15]. Moreover on non-ADHD siblings of ADHD probands and controls, an influence was observed between the variant and the activation in striatum and cerebellum vermis, with its interaction with familial risk for ADHD [18].…”

Inferior frontal cortex activity is modulated by reward sensitivity and performance variability

“…However, the behavioral pattern of ADHD patients in response inhibition tasks is not only characterized by long stopping latencies, but also by poorer performance in the main (go) task, manifested as longer reaction times (RTs), more errors and increased RT variability (Bellgrove et al, 2005;Braet et al, 2011;Carmona et al, 2012;Karalunas et al, 2012;Sebastian et al, 2012;van Rooij et al, 2015;Vaurio et al, 2009). Wide RT variability is one of the most robust findings for the performance of ADHD patients during response inhibition tasks (Alderson et al, 2007), and has been proposed as an endophenotype for this disorder (Castellanos et al, 2005;van Rooij et al, 2015).…”