Brain Functional and Structural Predictors of Language Performance

Abstract

The relation between brain function and behavior on the one hand and the relation between structural changes and behavior on the other as well as the link between the 2 aspects are core issues in cognitive neuroscience. It is an open question, however, whether brain function or brain structure is the better predictor for age-specific cognitive performance. Here, in a comprehensive set of analyses, we investigated the direct relation between hemodynamic activity in 2 pairs of frontal and temporal cortical areas, 2 long-distance white matter fiber tracts connecting each pair and sentence comprehension performance of 4 age groups, including 3 groups of children between 3 and 10 years as well as young adults. We show that the increasing accuracy of processing complex sentences throughout development is correlated with the blood-oxygen-level-dependent activation of 2 core language processing regions in Broca's area and the posterior portion of the superior temporal gyrus. Moreover, both accuracy and speed of processing are correlated with the maturational status of the arcuate fasciculus, that is, the dorsal white matter fiber bundle connecting these 2 regions. The present data provide compelling evidence for the view that brain function and white matter structure together best predict developing cognitive performance.

Language, aging, and cognition

“…Taken together, it appears as though these frontal and dorsal tracts play an important role not only in speech production itself, but also in other aspects of cognition, such as working memory, that may require the manipulation of verbal information. Age-related development of dorsal stream white matter integrity has been linked to increased behavioral performance on complex sentence processing tasks in children and young adults [25]. Our results complement these findings, illustrating that degeneration of dorsal and frontal tracts in older adulthood affects aspects of cognition that rely on language processing.…”

Evolutionary origins of non-adjacent sequence processing in primate brain potentials

“…However, the infant dorsal pathway seems mainly to project to premotor cortex, whereas in adults it more clearly projects to the posterior portion of Broca’s territory (Brodmann Area, BA44)7852. The dorsal pathway is taken to be important for processing complex syntactic structures in adults, since development of the left arcuate fasciculus is associated with the improvement in performance with syntactically complex sentences in development from children to adults37. Although, structural connectivity data from non-human primates suggests that chimpanzees have a precursor of the dorsal arcuate fasciculus53, the extent to which monkeys have such a precursor tract, interconnecting auditory temporal lobe areas with ventral frontal cortex, remains unclear5455565758.…”

“…When given an explicit task requiring them to respond to rule deviants, those who learned the non-adjacent rule showed a more delayed negativity, an N2 component36, which may reflect greater cognitive engagement or less automaticity for processing certain sequencing operations in adults than infants17. The marked differences between the neural signatures of non-adjacent dependency processing in infants and adults not only suggest different cognitive processes but also possibly the involvement of different neural processing pathways37.…”

Dissociations among linguistic, cognitive, and auditory-motor neuroanatomical domains in children who stutter

“…In the healthy pediatric population, subtle changes in white matter structure are reported to coincide with cognitive development and function (see Craik & Bialystok, 2006 for review; Dubois et al, 2015; Skeide, Brauer, & Friederici, 2015). Cognitive functions that are dependent on widely distributed neural networks, such as executive control, show stronger correlations with white matter integrity (Gunning-Dixon & Raz, 2000; Schmithorst, Wilke, Dardzinski, & Holland, 2005).…”