Procedural learning is associated with microstructure of basal ganglia-cerebellar circuitry in children.

In adults, individual differences in procedural learning (PL) are associated with white matter organization within the basal ganglia-cerebellar circuit. However, no research has examined whether this circuitry is related to individual differences in PL during childhood. Here, 28 children (Mage = 10.00 ± 2.31, 10 female) completed the serial reaction time (SRT) task to measure PL, and underwent structural magnetic resonance imaging (MRI). Fixel-Based Analysis was performed to extract specific measures of white matter fiber density (FD) and fiber cross-section (FC) from the superior cerebellar peduncles (SCP) and the striatal premotor tracts (STPMT), which underlie the fronto-basal ganglia-cerebellar system. These fixel metrics were correlated with the 'rebound effect' from the SRT task - a measure of PL proficiency which compares reaction times associated with generating a sequence, to random trials. While no significant associations were observed at the fixel level, a significant positive association was observed between average FD in the right SCP and the rebound effect, with a similar trend observed in the left SCP. No significant effects were detected in the STPMT. Our results indicate that, like in adults, microstructure of the basal ganglia-cerebellar circuit may explain individual differences in childhood PL.

White matter organisation of sensorimotor tracts is associated with motor imagery in childhood.

Despite the important role of motor imagery (MI) in motor development, our understanding of the contribution of white matter fibre properties to MI performance in childhood remains limited. To provide novel insight into the white matter correlates of MI performance, this study examined the association between white matter fibre properties and motor imagery performance in a sample of typically developing children. High angular diffusion weighted imaging data were collected from 22 typically developing children aged 6-14 years (12 female, MAge= 10.56). Implicit motor imagery performance was assessed using a mental hand rotation paradigm. The cerebellar peduncles and the superior longitudinal fasciculus were reconstructed using TractSeg, a semi-automated method. For each tract, white matter microstructure (fibre density, FD) and morphology (fibre bundle cross-section, FC) were estimated using Fixel-Based Analysis. Permutation-based inference testing and partial correlation analyses demonstrated that higher FC in the middle cerebellar peduncles was associated with better MI performance. Tract-based region of interest analyses showed that higher FC in the middle and superior cerebellar peduncles were associated with better MI performance. Results suggest that white matter connectivity along the cerebellar peduncles may facilitate MI performance in childhood. These findings advance our understanding of the neurobiological systems that underlie MI performance in childhood and provide early evidence for the relevance of white matter sensorimotor pathways to internal action representations.

A new voice rating tool for clinical practice.

AIMS: Perceptual rating of voice quality is a key component in the comprehensive assessment of voice, but there are practical difficulties in making reliable measurements. We have developed the Newcastle Audio Ranking (NeAR) test, a new referential system for the rating of voice parameters. In this article, we present our first results using NeAR. METHODS: We asked five experts and 11 naive raters to assess 15 male and 15 female voices using the NeAR test. We assessed: validity with respect to the GRBAS scale; interrater reliability; sensitivity to subtle voice differences; and the performance of expert versus naïve raters. RESULTS: There was a uniformly excellent agreement with GRBAS (r=0.87) and interrater agreement (intraclass correlation coefficient=0.86). Considering each GRBAS grade of voice separately, there was still good interrater agreement in NeAR, implying it has good sensitivity to subtle changes. All these results were equally true for expert and naive raters. CONCLUSION: The NeAR test is a promising new tool in the assessment of voice disorders.