Response inhibition, the ability to stop prepotent responses or inappropriate actions is an important cognitive function, central to understanding substance use and conditions such as Attention-Deficit/Hyperactivity Disorder (ADHD). However, ‘response inhibition’, is not a unitary construct, and behavioral measures often correlate poorly with neuroimaging data. A fuller appreciation of the mechanistic processes underlying response inhibition, including processes that were unmodelled previously, should lead to improved associations with neuroimaging data and to better correlations with real-world outcomes. Here, a Racing Diffusion Ex-Gaussian (RDEX) model was applied to a large sample (n>1,000) at two time points (at ages 19 and 23 years-old). Parameters from the RDEX model resulted in improved predictions of stop-signal reaction time using brain connectomic data, relative to a non-parametric model. Brain networks associated with RDEX parameters were also better predictors of cigarette and cannabis use.


Prof. Robert Whelan,

Professor in Psychology at Trinity College Dublin

Robert Whelan is a Professor in Psychology in the Global Brain Health Institute and the School of Psychology, Trinity College Dublin and is a principal investigator in the Trinity College Institute of Neuroscience. His research is directed at clinically relevant questions, using both structural and functional magnetic resonance imaging, high-density electroencephalography and behavioural assays. Many of his projects can be placed under the rubric of ‘Big Data’.

Robert Whelan – Application of a computational model to stop-signal task data improves neuroimaging predictions of behaviour