Lea Forsman

Extensive piano practicing has regionally specific effects on white matter development

Using diffusion tensor imaging, we investigated effects of piano practicing in childhood, adolescence and adulthood on white matter, and found positive correlations between practicing and fiber tract organization in different regions for each age period. For childhood, practicing correlations were extensive and included the pyramidal tract, which was more structured in pianists than in non-musicians. Long-term training within critical developmental periods may thus induce regionally specific plasticity in myelinating tracts.

Intelligence and Variability in a Simple Timing Task Share Neural Substrates in the Prefrontal White Matter

General intelligence is correlated with the mean and variability of reaction time in elementary cognitive tasks, as well as with performance on temporal judgment and discrimination tasks. This suggests a link between the temporal accuracy of neural activity and intelligence. However, it has remained unclear whether this link reflects top-down mechanisms such as attentional control and cognitive strategies or basic neural properties that influence both abilities. Here, we investigated whether millisecond variability in a simple, automatic timing task, isochronous tapping, correlates with intellectual performance and, using voxel-based morphometry, whether these two tasks share neuroanatomical substrates. Stability of tapping and intelligence were correlated and related to regional volume in overlapping right prefrontal white matter regions. These results suggest a bottom-up explanation of the link between temporal stability and intellectual performance, in which more extensive prefrontal connectivity underlies individual differences in both variables.

The dorsal auditory pathway is involved in performance of both visual and auditory rhythms

We used functional magnetic resonance imaging to investigate the effect of two factors on the neural control of temporal sequence performance: the modality in which the rhythms had been trained, and the modality of the pacing stimuli preceding performance. The rhythms were trained 1-2 days before scanning. Each participant learned two rhythms: one was presented visually, the other auditorily. During fMRI, the rhythms were performed in blocks. In each block, four beats of a visual or auditory pacing metronome were followed by repetitive self-paced rhythm performance from memory. Data from the self-paced performance phase was analysed in a 2x2 factorial design, with the two factors Training Modality (auditory or visual) and Metronome Modality (auditory or visual), as well as with a conjunction analysis across all active conditions, to identify activations that were independent of both Training Modality and Metronome Modality. We found a significant main effect only for visual versus auditory Metronome Modality, in the left angular gyrus, due to a deactivation of this region after auditory pacing. The conjunction analysis revealed a set of brain areas that included dorsal auditory pathway areas (left temporo-parietal junction area and ventral premotor cortex), dorsal premotor cortex, the supplementary and presupplementary premotor areas, the cerebellum and the basal ganglia. We conclude that these regions are involved in controlling performance of well-learned rhythms, regardless of the modality in which the rhythms are trained and paced. This suggests that after extensive short-term training, all rhythms, even those that were both trained and paced in visual modality, had been transformed into auditory-motor representations. The deactivation of the angular cortex following auditory pacing may represent cross-modal auditory-visual inhibition.

Tick-borne encephalitis carries a high risk of incomplete recovery in children.

OBJECTIVE To examine long-term outcome after tick-borne encephalitis (TBE) in children. STUDY DESIGN In this population-based cohort, 55 children with TBE with central nervous system involvement infected during 2004-2008 were evaluated 2-7 years later using the Rivermead post-concussion symptoms questionnaire (n = 42) and the Behavior Rating Inventory of Executive Functioning for parents and teachers (n = 32, n = 22, respectively). General cognitive ability was investigated in a subgroup (n = 20) using the Wechsler Intelligence Scale for Children, 4th edition. RESULTS At long-term follow-up, two-thirds of the children experienced residual problems, the main complaints being cognitive problems, headache, fatigue, and irritability. More than one-third of the children were reported by parents or teachers to have problems with executive functioning on the Behavior Rating Inventory of Executive Functioning, mainly in areas involving initiating and organizing activities and working memory. Children who underwent Wechsler Intelligence Scale for Children, 4th edition testing had a significantly lower working memory index compared with reference norms. CONCLUSION A large proportion of children experience an incomplete recovery after TBE with central nervous system involvement. Cognitive problems in areas of executive function and working memory are the most prevalent. Even if mortality and severe sequelae are low in children after TBE, all children should be followed after TBE to detect cognitive deficits.

Differences in regional brain volume related to the extraversion-introversion dimension—A voxel based morphometry study

Extraverted individuals are sociable, behaviorally active, and happy. We report data from a voxel based morphometry study investigating, for the first time, if regional volume in gray and white matter brain regions is related to extraversion. For both gray and white matter, all correlations between extraversion and regional brain volume were negative, i.e. the regions were larger in introverts. Gray matter correlations were found in regions that included the right prefrontal cortex and the cortex around the right temporo-parietal junction--regions that are known to be involved in behavioral inhibition, introspection, and social-emotional processing, e.g. evaluation of social stimuli and reasoning about the mental states of others. White matter correlations extended from the brainstem to widespread cortical regions, and were largely due to global effects, i.e. a larger total white matter volume in introverts. We speculate that these white matter findings may reflect differences in ascending modulatory projections affecting cortical regions involved in behavioral regulation.

Evidence of validity in a new method for measurement of dexterity in children and adolescents

Aim  Many everyday activities involve manipulation of objects with the fingertips. Impaired performance in manipulative tasks is common in neurodevelopmental disorders. Thus accurate assessment of an individual’s ability to coordinate fingertip forces is important for planning treatment. We evaluated a recently developed assessment tool (the Strength–Dexterity Test), which is based on manipulation of unstable objects, in a paediatric population.

Compromised approximate number system acuity in extremely preterm school‐aged children

The aim of this study was to compare the approximate number system acuity in children born extremely preterm aged 6 years 6 months and typically developing, age‐matched peers.

Visual–motor integration and fine motor skills at 6½ years of age and associations with neonatal brain volumes in children born extremely preterm in Sweden: a population-based cohort study

Objectives This exploratory study aimed to investigate associations between neonatal brain volumes and visual–motor integration (VMI) and fine motor skills in children born extremely preterm (EPT) when they reached 6½ years of age. Setting Prospective population-based cohort study in Stockholm, Sweden, during 3 years. Participants All children born before gestational age, 27 weeks, during 2004–2007 in Stockholm, without major morbidities and impairments, and who underwent MRI at term-equivalent age. Main outcome measures Brain volumes were calculated using morphometric analyses in regions known to be involved in VMI and fine motor functions. VMI was assessed with The Beery-Buktenica Developmental Test of Visual–Motor Integration—sixth edition and fine motor skills were assessed with the manual dexterity subtest from the Movement Assessment Battery for Children—second edition, at 6½ years. Associations between the brain volumes and VMI and fine motor skills were evaluated using partial correlation, adjusted for total cerebral parenchyma and sex. Results Out of 107 children born at gestational age <27 weeks, 83 were assessed at 6½ years and 66/83 were without major brain lesions or cerebral palsy and included in the analyses. A representative subsample underwent morphometric analyses: automatic segmentation (n=34) and atlas-based segmentation (n=26). The precentral gyrus was associated with both VMI (r=0.54, P=0.007) and fine motor skills (r=0.54, P=0.01). Associations were also seen between fine motor skills and the volume of the cerebellum (r=0.42, P=0.02), brainstem (r=0.47, P=0.008) and grey matter (r=−0.38, P=0.04). Conclusions Neonatal brain volumes in areas known to be involved in VMI and fine motor skills were associated with scores for these two functions when children born EPT without major brain lesions or cerebral palsy were evaluated at 6½ years of age. Establishing clear associations between early brain volume alterations and later VMI and/or fine motor skills could make early interventions possible.

Deficits in Approximate Number System Acuity and Mathematical Abilities in 6.5-Year-Old Children Born Extremely Preterm

Preterm children are at increased risk for poor academic achievement, especially in math. In the present study, we examined whether preterm children differ from term-born children in their intuitive sense of number that relies on an unlearned, approximate number system (ANS) and whether there is a link between preterm children’s ANS acuity and their math abilities. To this end, 6.5-year-old extremely preterm (i.e., <27 weeks gestation, n = 82) and term-born children (n = 89) completed a non-symbolic number comparison (ANS acuity) task and a standardized math test. We found that extremely preterm children had significantly lower ANS acuity than term-born children and that these differences could not be fully explained by differences in verbal IQ, perceptual reasoning skills, working memory, or attention. Differences in ANS acuity persisted even when demands on visuo-spatial skills and attention were reduced in the ANS task. Finally, we found that ANS acuity and math ability are linked in extremely preterm children, similar to previous results from term-born children. These results suggest that deficits in the ANS may be at least partly responsible for the deficits in math abilities often observed in extremely preterm children.