Musicianship and Prominence of Interhemispheric Connectivity Determine Two Different Pathways to Atypical Language Dominance.

During infancy and adolescence, language develops from a predominantly interhemispheric control-through the corpus callosum (CC)-to a predominantly intrahemispheric control, mainly subserved by the left arcuate fasciculus (AF). Using multimodal neuroimaging, we demonstrate that human left-handers (both male and female) with an atypical language lateralization show a rightward participation of language areas from the auditory cortex to the inferior frontal cortex when contrasting speech to tone perception and an enhanced interhemispheric anatomical and functional connectivity. Crucially, musicianship determines two different structural pathways to this outcome.

Neuroanatomical correlates of musicianship in left-handers.

Background: Left-handedness is a condition that reverses the typical left cerebral dominance of motor control to an atypical right dominance. The impact of this distinct control - and its associated neuroanatomical peculiarities - on other cognitive functions such as music processing or playing a musical instrument remains unexplored. Previous studies in right-handed population have linked musicianship to a larger volume in the (right) auditory cortex and a larger volume in the (right) arcuate fasciculus.

Atypical lateralization of visuospatial attention can be associated with better or worse performance on line bisection.

The causal and statistical hypotheses diverge in determining whether the lateralization of language function in one cerebral hemisphere entails the lateralization of visuospatial function in the opposite hemisphere. Additionally, it remains unclear if the atypical segregation of these functions could influence cognitive performance. This study addresses these questions by examining the hemispheric lateralization of visuospatial attention during a line bisection judgement (landmark) task in three groups of healthy non-right-handed individuals with different language production segregations: left (typical), ambilateral (atypical), and right (atypical).

What happens to the inhibitory control functions of the right inferior frontal cortex when this area is dominant for language?

A low number of individuals show an atypical brain control of language functions that differs from the typical lateralization in the left cerebral hemisphere. In these cases, the neural distribution of other cognitive functions is not fully understood. Although there is a bias towards a mirrored brain organization consistent with the Causal hypothesis, some individuals are found to be exceptions to this rule.

Depression and Agitation Factors Are Related to Regional Brain Atrophy and Faster Longitudinal Cognitive Decline in Mild Cognitive Impairment.

Background: Neuropsychiatric symptoms (NPS) are a common aspect of Alzheimer's disease (AD). Multiple studies have investigated its brain correlates, but it still remains unclear how they relate with brain atrophy in mild cognitive impairment (MCI).

Objective: Our objective was to investigate brain volume in MCI patients as a function of NPS.

Structural But Not Functional Connectivity Differences within Default Mode Network Indicate Conversion to Dementia.

Background: Malfunctioning of the default mode network (DMN) has been consistently related to mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, evidence on differences in this network between MCI converters (MCI-c) and non-converters (MCI-nc), which could mark progression to AD, is still inconsistent.

Objective: To multimodally investigate the DMN in the AD continuum.

Dynamic Effects of Immersive Bilingualism on Cortical and Subcortical Grey Matter Volumes.

Bilingualism has been shown to induce neuroplasticity in the brain, but conflicting evidence regarding its specific effects in grey matter continues to emerge, probably due to methodological differences between studies, as well as approaches that may miss the variability and dynamicity of bilingual experience. In our study, we devised a continuous score of bilingual experiences and we investigated their non-linear effects on regional GM volume in a sample of young healthy participants from an immersive and naturalistic bilingual environment. We focused our analyses on cortical and subcortical regions that had been previously proposed as part of the bilingual speech pipeline and language control network.

The adhesio interthalamica as a neuroanatomical marker of structural differences in healthy adult population.

The adhesio interthalamica (AI) is a small midline brain structure that connects the left and right thalamus. According to in vivo data, between 2.3 and 22.

The manifestation of individual differences in sensitivity to punishment during resting state is modulated by eye state.

Structural and functional neuroimaging studies have shown that brain areas associated with fear and anxiety (defensive system areas) are modulated by individual differences in sensitivity to punishment (SP). However, little is known about how SP is related to brain functional connectivity and the factors that modulate this relationship. In this study, we investigated whether a simple methodological manipulation, such as performing a resting state with eyes open or eyes closed, can modulate the manifestation of individual differences in SP.

Sustained and transient gray matter volume changes after n-back training: A VBM study.

Working memory training causes functional adaptations in the brain, which include changes in activation and functional connectivity that remain stable over time. Few studies have investigated gray matter (GM) changes after working memory training, and they have produced heterogeneous results without clarifying the stable effects of training. The present study was designed to test for sustained and transient anatomic changes after only 200 min of working memory training.

A cross-sectional and longitudinal study on the protective effect of bilingualism against dementia using brain atrophy and cognitive measures.

Background: Evidence from previous studies suggests that bilingualism contributes to cognitive reserve because bilinguals manifest the first symptoms of Alzheimer's disease (AD) up to 5 years later than monolinguals. Other cross-sectional studies demonstrate that bilinguals show greater amounts of brain atrophy and hypometabolism than monolinguals, despite sharing the same diagnosis and suffering from the same symptoms. However, these studies may be biased by possible pre-existing between-group differences.

Effects of bilingualism on white matter atrophy in mild cognitive impairment: a diffusion tensor imaging study.

Background And Purpose: Previous investigations show that bilinguals exhibit the first symptoms of dementia 4-5 years later than monolinguals. Therefore, bilingualism has been proposed as a cognitive reserve mechanism. Recent studies have advanced towards an understanding of the brain mechanisms underlying bilingualism's protection against dementia, but none of them deals with white matter (WM) diffusion.

Activity in Memory Brain Networks During Encoding Differentiates Mild Cognitive Impairment Converters from Non-Converters.

Alzheimer's disease (AD) has been associated with memory impairment due to alterations in the medial temporal lobe (MTL) and the precuneus. Therefore, the goal of this study was to investigate the effects of AD on the brain networks associated with the hippocampus and precuneus during an encoding memory task. 68 mild cognitive impairment patients (MCI), 21 AD patients, and 20 healthy controls (HC) were included.