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Although working memory (WM) is crucial for intellectual abilities, not much is known about its brain underpinnings, especially the structural connectivity. We used diffusion tensor imaging (DTI) to look across the whole brain for the white matter integrity correlates of the individual differences in the reading span (verbal WM capacity during reading) in healthy adults. Right-handed healthy native Russian speakers (N = 67) underwent DTI on a 3T Philips Ingenia scanner. Verbal WM was assessed with the Daneman-Carpenter reading span test (Russian version). Fractional anisotropy maps from each participant were entered into the group tract-based spatial statistics analysis with the reading span as a covariate; the results were TFCE-corrected. After taking into account effects of age, sex, education and handedness, reading span positively correlated with the white matter integrity in multiple sites: the body, the genu and the splenium of corpus callosum; bilateral corona radiata (anterior, posterior, and superior); bilateral superior longitudinal fasciculus; several tracts in the right hemisphere only, including the internal and external capsule; bilateral superior parietal and frontal white matter. Although the left hemisphere is central for verbal processing, we revealed the important role of the right hemisphere white matter for the verbal WM capacity. Our finding indicates that larger verbal working memory span may originate from additional processing resources of the right hemisphere.

Although working memory (WM) is crucial for intellectual abilities, not much is known about its brain underpinnings, especially the structural connectivity. We used diffusion tensor imaging (DTI) to look across the whole brain for the white matter integrity correlates of the individual differences in the reading span (verbal WM capacity during reading) in healthy adults. Right-handed healthy native Russian speakers (N = 47) underwent DTI on a 3T Philips Ingenia scanner. Verbal WM was assessed with the Daneman-Carpenter reading span test (Russian version). Fractional anisotropy maps from each participant were entered into the group tract-based spatial statistics analysis with the reading span as a covariate; the results were TFCE-corrected. Reading span positively correlated with the white matter integrity in several sites of the right hemisphere: the body and the splenium of corpus callosum; the posterior limb of internal capsule; posterior corona radiata; and superior parietal white matter. Although the left hemisphere is central for verbal processing, we revealed the important role of the right hemisphere white matter for the verbal WM capacity. Our finding indicates that larger verbal working memory span may originate from additional processing resources of the right hemisphere.

P300 wave is associated with working memory update, allocation of attention resources, and decision making. Numerous studies have consistently revealed P300 abnormalities in schizophrenia making it a promising neurophysiological state and trait marker. The aim of the current paper was to revalidate P300 meaning in schizophrenia as well as to analyze its associations with brain structure and function as revealed by neuroimaging. The findings did not support the wave anomalies. The correlations of P300 with current psychopathology, neuroleptic medication as well as with prefrontal cortex thickness and subcortical structures morphometry and diffusion parameters were non-significant. The pilot study has revealed the relationships between P300 amplitude and functional connectivity between parietal and anterior cingulate subcomponents of fronto-parietal neuronal circuit, however, the inconsistent nature of correlations requires further research.

Speech disfluencies are a notable component of natural discourse production and comprehension that may play a role of signals that control the flow of communication. Using task-based functional MRI, we examined how brain functional connectivity changes when listeners encounter a disfluency. Participants listened to fragments of audio recordings of natural discourse from the RUPEX corpus while looking at the speaker’s photograph and being engaged in a referential task locking their attention on the narration. Using the intrinsic connectivity contrast, as a measure for a data-driven approach, we found modified connectivity in different portions of the left parietal cortex in response to isolated phoneme lengthenings or clustered disfluencies including phoneme lengthenings. Given the important role of the parietal cortex in attention and sensory integration, our results indicate promising targets for further studies of functional connectivity and neural networks in speech disfluency perception. From a broader perspective our study demonstrates how corpus linguistics and neuroimaging may join their efforts for interdisciplinary research of the brain and language.

Objective:Goldberg, the author of the “novelty-routinization” framework, suggested a new pair of cognitive styles for agent-centered decision-making (DM), context-dependency/independency (CD/CI), quantified by the Cognitive Bias Task (CBT) and supposedly reflecting functional brain hemispheric specialization. To date, there are only three lesion and activation neuroimaging studies on the CBT with the largest sample of 12 participants. The present study is the first to analyze whole-brain functional connectivity (FC) of the dorsolateral prefrontal cortex (DLPFC), involved in contextual agent-centered DM.Method:We compared whole-brain resting-state FC of the DLPFC between CD (n = 24) and CI (n = 22) healthy participants. Additionally, we investigated associations between CD/CI and different aspects of executive functions.Results:CD participants had stronger positive FC of the DLPFC with motor and visual regions; FC of the left DLPFC was more extensive. CI participants had stronger positive FC of the left DLPFC with right prefrontal and parietal-occipital areas and of the left and right DLPFC with ipsilateral cerebellar hemispheres. No sex differences were found. CD/CI had nonlinear associations with working memory.Conclusions:The findings suggest that CD and CI are associated with different patterns of DLPFC FC. While CD is associated with FC between DLPFC and areas presumably involved in storing representations of current situation, CI is more likely to be associated with FC between DLPFC and right-lateralized associative regions, probably involved in the inhibition of the CD response and switching from processing of incoming perceptual information to creation of original response strategies.

Objective The dorsolateral prefrontal cortex (DLPFC) orchestrates other brain regions and plays a vital role for “the most uniquely human” executive functions (EFs), which are divided into distinct components. Components of EFs have been localized to different brain regions and at the same time the DLPFC was found to be involved in a majority of EF components. The possible mechanism of the DLPFC's contribution to EF components might be found in DLPFC functional connectivity (FC): this FC of the DLPFC with other brain regions contributes to different EF components. Method To explore the DLPFC FC contribution to different EFs, we used an integrative approach involving analysis of fMRI and neuropsychological assessment of EFs. Fifty healthy adults (27 females and 23 males, mean age 34.5 ± 16.6 years) underwent neuropsychological assessment of EFs as well as task-based and resting-state fMRI. Task-based fMRI was applied as a functional localizer for individually defined DLPFC ROIs that were further used for the FC seed-based correlation analysis of the resting-state data. Then we looked for associations between individual scores of different EF components and the whole-brain resting-state FC of the DLPFC. Results Resting-state correlates of DLPFC FC were revealed for three out of the seven EF components derived from an extensive neuropsychological assessment: inhibition, switching, and the verbal EF component. Conclusions Our study is the first to reveal the contribution of the DLPFC FC to several distinct EF components. The obtained results give insight into the brain mechanisms of EFs.