Four Functionally Distinct Regions in the Left Supramarginal Gyrus Support Word Processing
We used fMRI in 85 healthy participants to investigate whether different parts of the left supramarginal gyrus (SMG) are involved in processing phonological inputs and outputs. The experiment involved 2 tasks (speech production (SP) and one-back (OB) matching) on 8 different types of stimuli that systematically varied the demands on sensory processing (visual vs. auditory), sublexical phonological input (words and pseudowords vs. nonverbal stimuli), and semantic content (words and objects vs. pseudowords and meaningless baseline stimuli). In ventral SMG, we found an anterior subregion associated with articulatory sequ...
Source: Cerebral Cortex - October 16, 2016 Category: Neurology Authors: Oberhuber, M., Hope, T. M. H., Seghier, M. L., Parker Jones, O., Prejawa, S., Green, D. W., Price, C. J. Tags: Original Articles Source Type: research
Assessing Variations in Areal Organization for the Intrinsic Brain: From Fingerprints to Reliability
Resting state fMRI (R-fMRI) is a powerful in-vivo tool for examining the functional architecture of the human brain. Recent studies have demonstrated the ability to characterize transitions between functionally distinct cortical areas through the mapping of gradients in intrinsic functional connectivity (iFC) profiles. To date, this novel approach has primarily been applied to iFC profiles averaged across groups of individuals, or in one case, a single individual scanned multiple times. Here, we used a publically available R-fMRI dataset, in which 30 healthy participants were scanned 10 times (10 min per session), to inves...
Source: Cerebral Cortex - October 16, 2016 Category: Neurology Authors: Xu, T., Opitz, A., Craddock, R. C., Wright, M. J., Zuo, X.-N., Milham, M. P. Tags: Original Articles Source Type: research
From Nose to Brain: Un-Sensed Electrical Currents Applied in the Nose Alter Activity in Deep Brain Structures
Rules linking patterns of olfactory receptor neuron activation in the nose to activity patterns in the brain and ensuing odor perception remain poorly understood. Artificially stimulating olfactory neurons with electrical currents and measuring ensuing perception may uncover these rules. We therefore inserted an electrode into the nose of 50 human volunteers and applied various currents for about an hour in each case. This induced assorted non-olfactory sensations but never once the perception of odor. To validate contact with the olfactory path, we used functional magnetic resonance imaging to measure resting-state brain ...
Source: Cerebral Cortex - October 16, 2016 Category: Neurology Authors: Weiss, T., Shushan, S., Ravia, A., Hahamy, A., Secundo, L., Weissbrod, A., Ben-Yakov, A., Holtzman, Y., Cohen-Atsmoni, S., Roth, Y., Sobel, N. Tags: Original Articles Source Type: research
Metabotropic Glutamate Receptor Type 5 (mGluR5) Cortical Abnormalities in Focal Cortical Dysplasia Identified In Vivo With [11C]ABP688 Positron-Emission Tomography (PET) Imaging
Metabotropic glutamate receptor type 5 (mGluR5) abnormalities have been described in tissue resected from epilepsy patients with focal cortical dysplasia (FCD). To determine if these abnormalities could be identified in vivo, we investigated mGluR5 availability in 10 patients with focal epilepsy and an MRI diagnosis of FCD using positron-emission tomography (PET) and the radioligand [11C]ABP688. Partial volume corrected [11C]ABP688 binding potentials (BPND) were computed using the cerebellum as a reference region. Each patient was compared to homotopic cortical regions in 33 healthy controls using region-of-interest (ROI) ...
Source: Cerebral Cortex - October 16, 2016 Category: Neurology Authors: DuBois, J. M., Rousset, O. G., Guiot, M.-C., Hall, J. A., Reader, A. J., Soucy, J.-P., Rosa-Neto, P., Kobayashi, E. Tags: Original Articles Source Type: research
Cortical Control of Striatal Dopamine Transmission via Striatal Cholinergic Interneurons
Corticostriatal regulation of striatal dopamine (DA) transmission has long been postulated, but ionotropic glutamate receptors have not been localized directly to DA axons. Striatal cholinergic interneurons (ChIs) are emerging as major players in striatal function, and can govern DA transmission by activating nicotinic receptors (nAChRs) on DA axons. Cortical inputs to ChIs have historically been perceived as sparse, but recent evidence indicates that they strongly activate ChIs. We explored whether activation of M1/M2 corticostriatal inputs can consequently gate DA transmission, via ChIs. We reveal that optogenetic activa...
Source: Cerebral Cortex - October 16, 2016 Category: Neurology Authors: Kosillo, P., Zhang, Y.-F., Threlfell, S., Cragg, S. J. Tags: Original Articles Source Type: research
Functional Network Dynamics of the Language System
During linguistic processing, a set of brain regions on the lateral surfaces of the left frontal, temporal, and parietal cortices exhibit robust responses. These areas display highly correlated activity while a subject rests or performs a naturalistic language comprehension task, suggesting that they form an integrated functional system. Evidence suggests that this system is spatially and functionally distinct from other systems that support high-level cognition in humans. Yet, how different regions within this system might be recruited dynamically during task performance is not well understood. Here we use network methods...
Source: Cerebral Cortex - October 16, 2016 Category: Neurology Authors: Chai, L. R., Mattar, M. G., Blank, I. A., Fedorenko, E., Bassett, D. S. Tags: Original Articles Source Type: research
Stimulus-Driven Reorienting Impairs Executive Control of Attention: Evidence for a Common Bottleneck in Anterior Insula
A classical model of human attention holds that independent neural networks realize stimulus-driven reorienting and executive control of attention. Questioning full independence, the two functions do, however, engage overlapping networks with activations in cingulo-opercular regions such as anterior insula (AI) and a reverse pattern of activation (stimulus-driven reorienting), and deactivation (executive control) in temporoparietal junction (TPJ). To test for independent versus shared neural mechanisms underlying stimulus-driven and executive control of attention, we used fMRI and a task that isolates individual from concu...
Source: Cerebral Cortex - October 16, 2016 Category: Neurology Authors: Trautwein, F.-M., Singer, T., Kanske, P. Tags: Original Articles Source Type: research
The Deceptively Simple N170 Reflects Network Information Processing Mechanisms Involving Visual Feature Coding and Transfer Across Hemispheres
A key to understanding visual cognition is to determine "where", "when", and "how" brain responses reflect the processing of the specific visual features that modulate categorization behavior—the "what". The N170 is the earliest Event-Related Potential (ERP) that preferentially responds to faces. Here, we demonstrate that a paradigmatic shift is necessary to interpret the N170 as the product of an information processing network that dynamically codes and transfers face features across hemispheres, rather than as a local stimulus-driven event. Reverse-correlation methods coupled with information-theoretic analyses rev...
Source: Cerebral Cortex - October 16, 2016 Category: Neurology Authors: Ince, R. A. A., Jaworska, K., Gross, J., Panzeri, S., van Rijsbergen, N. J., Rousselet, G. A., Schyns, P. G. Tags: Original Articles Source Type: research
Adolescent Development of Cortical and White Matter Structure in the NCANDA Sample: Role of Sex, Ethnicity, Puberty, and Alcohol Drinking
Brain structural development continues throughout adolescence, when experimentation with alcohol is often initiated. To parse contributions from biological and environmental factors on neurodevelopment, this study used baseline National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA) magnetic resonance imaging (MRI) data, acquired in 674 adolescents meeting no/low alcohol or drug use criteria and 134 adolescents exceeding criteria. Spatial integrity of images across the 5 recruitment sites was assured by morphological scaling using Alzheimer's disease neuroimaging initiative phantom-derived volume scalar...
Source: Cerebral Cortex - September 18, 2016 Category: Neurology Authors: Pfefferbaum, A., Rohlfing, T., Pohl, K. M., Lane, B., Chu, W., Kwon, D., Nolan Nichols, B., Brown, S. A., Tapert, S. F., Cummins, K., Thompson, W. K., Brumback, T., Meloy, M. J., Jernigan, T. L., Dale, A., Colrain, I. M., Baker, F. C., Prouty, D., De Bell Tags: Original Articles Source Type: research
Diversity of LFPs Activated in Different Target Regions by a Common CA3 Input
Identifying the pathways contributing to local field potential (LFP) events and oscillations is essential to determine whether synchronous interregional patterns indicate functional connectivity. Here, we studied experimentally and numerically how different target structures receiving input from a common population shape their LFPs. We focused on the bilateral CA3 that sends gamma-paced excitatory packages to the bilateral CA1, the lateral septum, and itself (recurrent input). The CA3-specific contribution was isolated from multisite LFPs in target regions using spatial discrimination techniques. We found strong modulation...
Source: Cerebral Cortex - September 18, 2016 Category: Neurology Authors: Martin-Vazquez, G., Benito, N., Makarov, V. A., Herreras, O., Makarova, J. Tags: Original Articles Source Type: research
Individual Differences in Adult Reading Are Associated with Left Temporo-parietal to Dorsal Striatal Functional Connectivity
This study investigated functional connectivity of a core phonological processing region, the temporo-parietal junction (TPJ), in relation to reading skill in an adult community sample. We hypothesized that connectivity between TPJ and regions implicated in meta-analyses of reading disorder would correlate with individual differences in reading. Forty-four adults aged 30–54, ranging in reading ability, underwent resting fMRI scans. Data-driven connectivity clustering was used to identify TPJ subregions for seed-based connectivity analyses. Correlations were assessed between TPJ connectivity and timed-pseudoword readi...
Source: Cerebral Cortex - September 18, 2016 Category: Neurology Authors: Achal, S., Hoeft, F., Bray, S. Tags: Original Articles Source Type: research
Prefrontal Regulation of Neuronal Activity in the Ventral Tegmental Area
Growing evidence indicates that midbrain dopamine (DA) cells integrate reward expectancy-related information from the prefrontal cortex to properly compute errors in reward prediction. Here we investigated how 2 major prefrontal subregions, the orbitofrontal cortex (OFC) and the medial prefrontal cortex (mPFC), contributed to DAergic prediction errors while rats performed a delay discounting task on a T-maze. Most putative DA cells in the task showed phasic responses to salient cues that predicted delayed rewards, but not to the actual rewards. After temporary inactivation of the OFC, putative DA cells exhibited strikingly...
Source: Cerebral Cortex - September 18, 2016 Category: Neurology Authors: Jo, Y. S., Mizumori, S. J. Y. Tags: Original Articles Source Type: research
Patterns of Atypical Functional Connectivity and Behavioral Links in Autism Differ Between Default, Salience, and Executive Networks
In conclusion, atypical connectivity in ASD is network-specific, ranging from extensive overconnectivity (DMN, rECN) to extensive underconnectivity (SN, lECN). Links between iFC and behavior differed between groups. Core symptomatology in the ASD group was predominantly related to connectivity within the salience network. (Source: Cerebral Cortex)
Source: Cerebral Cortex - September 18, 2016 Category: Neurology Authors: Abbott, A. E., Nair, A., Keown, C. L., Datko, M., Jahedi, A., Fishman, I., Müller, R.-A. Tags: Original Articles Source Type: research
A Dynamic Core Network and Global Efficiency in the Resting Human Brain
This study presents 2 novel findings on the fundamental issue of how different brain regions or networks interact in the resting state. First, we demonstrate the existence of multiple dynamic hubs that allow for across-network coupling. Second, dynamic network coupling and related variations in hub centrality correspond to increased global efficiency. These findings suggest that the dynamic organization of across-network interactions represents a property of the brain aimed at optimizing the efficiency of communication between distinct functional domains (memory, sensory-attention, motor). They also support the hypothesis ...
Source: Cerebral Cortex - September 18, 2016 Category: Neurology Authors: de Pasquale, F., Della Penna, S., Sporns, O., Romani, G. L., Corbetta, M. Tags: Original Articles Source Type: research
Identifying Shared Brain Networks in Individuals by Decoupling Functional and Anatomical Variability
The connectivity architecture of the human brain varies across individuals. Mapping functional anatomy at the individual level is challenging, but critical for basic neuroscience research and clinical intervention. Using resting-state functional connectivity, we parcellated functional systems in an "embedding space" based on functional characteristics common across the population, while simultaneously accounting for individual variability in the cortical distribution of functional units. The functional connectivity patterns observed in resting-state data were mapped in the embedding space and the maps were aligned across i...
Source: Cerebral Cortex - September 18, 2016 Category: Neurology Authors: Langs, G., Wang, D., Golland, P., Mueller, S., Pan, R., Sabuncu, M. R., Sun, W., Li, K., Liu, H. Tags: Original Articles Source Type: research
