Morphometric Correlation of Impulsivity in Medial Prefrontal Cortex

Abstract

Impulsivity is a complex behaviour composed of different domains encompassing behavioural disinhibition, risky decision-making and delay discounting abnormalities. To investigate regional brain correlates between levels of individual impulsivity and grey matter volume, we performed voxel-based morphometric correlation analysis in 34 young, healthy subjects using impulsivity scores measured with Barratt Impulsivity Scale-11 and computerized Kirby's delay discounting task. The VBM analysis showed that impulsivity appears to be reliant on a network of cortical (medial prefrontal cortex and dorsolateral prefrontal cortex) and subcortical (ventral striatum) structures emphasizing the importance of brain networks associated with reward related decisionmaking in daily life as morphological biomarkers for impulsivity in a normal healthy population. While our results in healthy volunteers may not directly extend to pathological conditions, they provide an insight into the mechanisms of impulsive behaviour in patients with abnormalities in prefrontal/frontal-striatal connections, such as in drug abuse, pathological gambling, ADHD and Parkinson's disease.

Brain Regions Related to Impulsivity Mediate the Effects of Early Adversity on Antisocial Behavior

“…Moreover, more impulsive individuals exhibited greater activity in the ventral striatum and less activity in the frontomedial cortex, a finding that mirrors the differential volumetric findings in the present study. Only a handful of studies have used structural neuroimaging to search for brain correlates of temporal discounting (52)(53)(54). These studies found that greater impulsivity was significantly correlated with striatal and frontal cortical gray matter volume in partial agreement with the present findings.…”

Diffusion tensor imaging of the structural integrity of white matter correlates with impulsivity in adolescents with internet gaming disorder

“…Many studies have revealed significant correlations between impulsivity and structures or functions of multiple gray matter regions in healthy subjects (Boes et al, 2009;Brown, Manuck, Flory, & Hariri, 2006;Cho et al, 2013;Dambacher et al, 2015;Farr, Hu, Zhang, & Li, 2012;Gardini, Cloninger, & Venneri, 2009;Matsuo et al, 2009;Muhlert & Lawrence, 2015;Schilling et al, 2012Van den Bos, Rodriguez, Schweitzer, & McClure, 2015). In the past few years, diffusion tensor imaging (DTI) technique shows great promise to evaluate the integrity of white matter (WM) tracts in human brain , and the white matter (WM) integrity of the bilateral frontal and temporal lobes was negatively associated with impulsivity in healthy adolescents (Olson et al, 2009).…”

Discounting and VBM

“…a negative correlation between grey matter volume within right ventromedial prefrontal cortex and impulsivity derived measures using the Pediatric Behavior Scale (PBS). Few years later, [5] showed in young people (age 23.4 ± 4.3 yrs.) a positive correlation between grey matter volume within the same brain region and impulsivity scores measured with the Barratt Impulsivity Scale-11 (BIS) and a computerized delay discounting task.…”

“…For over a while, impulsivity disorders have been associated with gray matter abnormalities in prefrontal cortex and striatal aspects [3][4][5][6]. One type of functional architecture has posited that striatal regions encode the current value of tangible rewards, whereas prefrontal regions represent more abstract rewards and long-term goals; although this view is certainly changing as we gain more knowledge [7].…”

“…However, despite all this knowledge, no studies have examined relations between brain structure and impulsivity over the course of adolescence and studies with participants in early or late puberty have not replicated findings [4,5]. For instance, colleagues demonstrated in boys [4] (age 12.08 ± 2.71 yrs.)…”