Response inhibition is associated with white matter microstructure in children

Abstract

a b s t r a c tCognitive control of thoughts, actions and emotions is important for normal behaviour and the development of such control continues throughout childhood and adolescence. Several lines of evidence suggest that response inhibition is primarily mediated by a right-lateralized network involving inferior frontal gyrus (IFG), presupplementary motor cortex (preSMA), and subthalamic nucleus. Though the brain's fibre tracts are known to develop during childhood, little is known about how fibre tract development within this network relates to developing behavioural control. Here we examined the relationship between response inhibition, as measured with the stop-signal task, and indices of regional white matter microstructure in typically-developing children. We hypothesized that better response inhibition performance would be associated with higher fractional anisotropy (FA) in fibre tracts within right IFG and preSMA after controlling for age. Mean FA and diffusivity values were extracted from right and left IFG and preSMA. As hypothesized, faster response inhibition was significantly associated with higher FA and lower perpendicular diffusivity in both the right IFG and the right preSMA, possibly reflecting faster speed of neural conduction within more densely packed or better myelinated fibre tracts. Moreover, both of these effects remained significant after controlling for age and whole brain estimates of these DTI parameters. Interestingly, right IFG and preSMA FA contributed additively to the prediction of performance variability. Observed associations may be related to variation in phase of maturation, to activity-dependent alterations in the network subserving response inhibition, or to stable individual differences in underlying neural system connectivity.

Brain microstructural correlates of visuospatial choice reaction time in children

“…Effects of CST and putamen MD were bilateral, whilst MD in right caudate nucleus exhibited a stronger relationship with 5-choice RT than did MD in the left caudate nucleus. Because both RTs (Kail, 1991) and MD (Lebel et al, 2008) decrease throughout childhood and adolescence, a simple correlation between these measures could represent a non-specific association attributable to unmeasured factors that are indexed by chronological age (for further discussion see Madsen et al, 2010). Thus, we hypothesised that the association between 5-choice RT and motor system MD would remain significant after controlling for age, i.e., that even amongst children of similar age, those with lower CST and neostriatal MD would exhibit faster choice RT.…”

“…A growing number of DWI studies in children have linked regional white matter microstructure to performance levels on, e.g., reading (Niogi and McCandliss, 2006), response inhibition (Madsen et al, 2010), and working memory (Vestergaard et al, 2011) tasks. In healthy young right-handed adults, faster right-relative to lefthanded responses have been correlated with higher FA in the left corticospinal tract in an auditory simple reaction time task (Bohr et al, 2007).…”

Attention Deficit Hyperactivity Disorder

“…Visuospatial working memory capacity is linked to a fronto-intraparietal network (Olesen et al 2003), while better visuospatial construction and psychomotor performance is associated with high corpus callosum fractional anisotropy (Fryer et al 2008). Faster response inhibition in children is associated with higher fractional anisotropy and lower perpendicular diffusivity in the right inferior frontal gyrus and presupplementary motor cortex (Madsen et al 2010). …”

Automated longitudinal intra-subject analysis (ALISA) for diffusion MRI tractography

“…These four occasions were separated by two, two, and seven weeks, respectively. The data sets are part of the HUBU cohort database (see Madsen et al, 2010Madsen et al, , 2011 for more details) and have been acquired on a 3 T Siemens Magnetom Trio MR scanner (Siemens, Erlangen, Germany) with an 8-channel head coil (Invivo, FL, USA) using a twice-refocused balanced spin echo sequence that minimized eddy current distortions (Reese et al, 2003) (TR/TE = 8200/100 ms) with a b-value of 1200 s/mm 2 along 61 directions using the electrostatic repulsion method (Jansons and Alexander, 2003;Jones et al, 1999b) available in CAMINO (Cook et al, 2006), ten b = 0 s/mm 2 images, and with a GRAPPA factor of 2. The acquisition matrix of 96×96 comprised a field-of-view of 220× 220mm 2 (2.3mm in-plane resolution) and 61 axial slices were acquired with thickness 2.3mm and without gap .…”

“…In addition, we compared these results to those obtained with FT segmentations obtained in an automated way over all time points and all subjects (Lebel et al, 2008). Sixty DTI data sets, which are part of the HUBU cohort database ("Hjernens Udvikling hos Børn og Unge": Brain maturation in children and adolescents; see Madsen et al, 2010Madsen et al, , 2011 for more details), were included in this study: five acquisitions at six-month intervals for ten healthy subjects and a set of ten repeats of one control subject scanned at weekly intervals. Important to note here is that these automated methods are not intended for case-based clinical use in cases with gross pathology, but rather for the use of longitudinal group studies of healthy development and aging, and pathologies without large displacing lesions.…”