Behavioral and Neural Markers of Flexible Attention over Working Memory in Aging
Working memory (WM) declines as we age and, because of its fundamental role in higher order cognition, this can have highly deleterious effects in daily life. We investigated whether older individuals benefit from flexible orienting of attention within WM to mitigate cognitive decline. We measured magnetoencephalography (MEG) in older adults performing a WM precision task with cues during the maintenance period that retroactively predicted the location of the relevant items for performance (retro-cues). WM performance of older adults significantly benefitted from retro-cues. Whereas WM maintenance declined with age, retro-...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Mok, R. M., Myers, N. E., Wallis, G., Nobre, A. C. Tags: Original Articles Source Type: research
Neural Mechanisms Behind Identification of Leptokurtic Noise and Adaptive Behavioral Response
We present a novel reinforcement learning model that fits observed choices better than the Bayes-optimal model. Only anterior insula discriminated between the 2 types of outliers. In both treatments, outliers initially activated an extensive bottom-up attention and belief network, followed by sustained engagement of the fronto-parietal control network. (Source: Cerebral Cortex)
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: d'Acremont, M., Bossaerts, P. Tags: Original Articles Source Type: research
NgR1: A Tunable Sensor Regulating Memory Formation, Synaptic, and Dendritic Plasticity
Nogo receptor 1 (NgR1) is expressed in forebrain neurons and mediates nerve growth inhibition in response to Nogo and other ligands. Neuronal activity downregulates NgR1 and the inability to downregulate NgR1 impairs long-term memory. We investigated behavior in a serial behavioral paradigm in mice that overexpress or lack NgR1, finding impaired locomotor behavior and recognition memory in mice lacking NgR1 and impaired sequential spatial learning in NgR1 overexpressing mice. We also investigated a role for NgR1 in drug-mediated sensitization and found that repeated cocaine exposure caused stronger locomotor responses but ...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Karlsson, T. E., Smedfors, G., Brodin, A. T. S., Aberg, E., Mattsson, A., Högbeck, I., Wellfelt, K., Josephson, A., Brene, S., Olson, L. Tags: Original Articles Source Type: research
Effects of the BDNF Val66Met Polymorphism on Gray Matter Volume in Typically Developing Children and Adolescents
The Val66Met polymorphism of brain-derived neurotrophic factor (BDNF) is associated with psychiatric disorders and regional gray matter volume (rGMV) in adults. However, the relationship between BDNF and rGMV in children has not been clarified. In this 3-year cross-sectional/longitudinal (2 time points) study, we investigated the effects of BDNF genotypes on rGMV in 185 healthy Japanese children aged 5.7–18.4 using magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) analyses. We found that the volume of the right cuneus in Met homozygotes (Met/Met) was greater than in Val homozygotes (Val/Val) in both ...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Hashimoto, T., Fukui, K., Takeuchi, H., Yokota, S., Kikuchi, Y., Tomita, H., Taki, Y., Kawashima, R. Tags: Original Articles Source Type: research
Unaltered Network Activity and Interneuronal Firing During Spontaneous Cortical Dynamics In Vivo in a Mouse Model of Severe Myoclonic Epilepsy of Infancy
Severe myoclonic epilepsy of infancy (SMEI) is associated with loss of function of the SCN1A gene encoding the NaV1.1 sodium channel isoform. Previous studies in Scn1a–/+ mice during the pre-epileptic period reported selective reduction in interneuron excitability and proposed this as the main pathological mechanism underlying SMEI. Yet, the functional consequences of this interneuronal dysfunction at the circuit level in vivo are unknown. Here, we investigated whether Scn1a–/+ mice showed alterations in cortical network function. We found that various forms of spontaneous network activity were similar in Scn1a...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: De Stasi, A. M., Farisello, P., Marcon, I., Cavallari, S., Forli, A., Vecchia, D., Losi, G., Mantegazza, M., Panzeri, S., Carmignoto, G., Bacci, A., Fellin, T. Tags: Original Articles Source Type: research
Monaural Congenital Deafness Affects Aural Dominance and Degrades Binaural Processing
Cortical development extensively depends on sensory experience. Effects of congenital monaural and binaural deafness on cortical aural dominance and representation of binaural cues were investigated in the present study. We used an animal model that precisely mimics the clinical scenario of unilateral cochlear implantation in an individual with single-sided congenital deafness. Multiunit responses in cortical field A1 to cochlear implant stimulation were studied in normal-hearing cats, bilaterally congenitally deaf cats (CDCs), and unilaterally deaf cats (uCDCs). Binaural deafness reduced cortical responsiveness and decrea...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Tillein, J., Hubka, P., Kral, A. Tags: Original Articles Source Type: research
Different Patterns of Cortical Inputs to Subregions of the Primary Motor Cortex Hand Representation in Cebus apella
The primary motor cortex (M1) plays an essential role in the control of hand movements in primates and is part of a complex cortical sensorimotor network involving multiple premotor and parietal areas. In a previous study in squirrel monkeys, we found that the ventral premotor cortex (PMv) projected mainly to 3 regions within the M1 forearm representation [rostro-medial (RM), rostro-lateral (RL), and caudo-lateral (CL)] with very few caudo-medial (CM) projections. These results suggest that projections from premotor areas to M1 are not uniform, but rather segregated into subregions. The goal of the present work was to stud...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Dea, M., Hamadjida, A., Elgbeili, G., Quessy, S., Dancause, N. Tags: Original Articles Source Type: research
Unmasking Language Lateralization in Human Brain Intrinsic Activity
Lateralization of function is a fundamental feature of the human brain as exemplified by the left hemisphere dominance of language. Despite the prominence of lateralization in the lesion, split-brain and task-based fMRI literature, surprisingly little asymmetry has been revealed in the increasingly popular functional imaging studies of spontaneous fluctuations in the fMRI BOLD signal (so-called resting-state fMRI). Here, we show the global signal, an often discarded component of the BOLD signal in resting-state studies, reveals a leftward asymmetry that maps onto regions preferential for semantic processing in left frontal...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: McAvoy, M., Mitra, A., Coalson, R. S., d'Avossa, G., Keidel, J. L., Petersen, S. E., Raichle, M. E. Tags: Original Articles Source Type: research
The Effects of Cognitive Control and Time on Frontal Beta Oscillations
Frontal beta oscillations are associated with top-down control mechanisms but also change over time during a task. It is unclear whether change over time represents another control function or a neural instantiation of vigilance decrements over time, the time-on-task effect. We investigated how frontal beta oscillations are modulated by cognitive control and time. We used frontal chronic electrocorticography in monkeys performing a trial-and-error task, comprising search and repetition phases. Specific beta oscillations in the delay period of each trial were modulated by task phase and adaptation to feedback. Beta oscillat...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Stoll, F. M., Wilson, C. R. E., Faraut, M. C. M., Vezoli, J., Knoblauch, K., Procyk, E. Tags: Original Articles Source Type: research
The Effects of Age on the Neural Correlates of Recollection Success, Recollection-Related Cortical Reinstatement, and Post-Retrieval Monitoring
Functional magnetic resonance imaging (fMRI) was used to investigate whether age-related differences in episodic memory performance are accompanied by a reduction in the specificity of recollected information. We addressed this question by comparing recollection-related cortical reinstatement in young and older adults. At study, subjects viewed objects and concrete words, making 1 of 2 different semantic judgments depending on the study material. Test items were words that corresponded to studied words or the names of studied objects. Subjects indicated whether each test item was recollected, familiar, or novel. Reinstatem...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Wang, T. H., Johnson, J. D., de Chastelaine, M., Donley, B. E., Rugg, M. D. Tags: Original Articles Source Type: research
Electrophysiological Correlates of a Versatile Executive Control System in the Monkey Anterior Cingulate Cortex
In this study, we eliminated methodological biases and recorded single-neuron activity in monkeys performing a Stroop-like task. We found specific changes in dACC activity during incongruent trials but only in a small subpopulation of cells. Critically, these changes were not related to reaction time and were absent before any incorrect action was taken. A larger fraction of neurons exhibited sustained activity during the whole decision period, whereas another subpopulation of neurons was modulated by reaction time, with a gradual increase in their firing rate that peaked at movement onset. Most of the neurons found in the...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Michelet, T., Bioulac, B., Langbour, N., Goillandeau, M., Guehl, D., Burbaud, P. Tags: Original Articles Source Type: research
Structural Connectivity Fingerprints Predict Cortical Selectivity for Multiple Visual Categories across Cortex
A fundamental and largely unanswered question in neuroscience is whether extrinsic connectivity and function are closely related at a fine spatial grain across the human brain. Using a novel approach, we found that the anatomical connectivity of individual gray-matter voxels (determined via diffusion-weighted imaging) alone can predict functional magnetic resonance imaging (fMRI) responses to 4 visual categories (faces, objects, scenes, and bodies) in individual subjects, thus accounting for both functional differentiation across the cortex and individual variation therein. Furthermore, this approach identified the particu...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Osher, D. E., Saxe, R. R., Koldewyn, K., Gabrieli, J. D. E., Kanwisher, N., Saygin, Z. M. Tags: Original Articles Source Type: research
Enhancing Consolidation of a New Temporal Motor Skill by Cerebellar Noninvasive Stimulation
Cerebellar transcranial direct current stimulation (tDCS) has the potential to modulate cerebellar outputs and visuomotor adaptation. The cerebellum plays a pivotal role in the acquisition and control of skilled hand movements, especially its temporal aspects. We applied cerebellar anodal tDCS concurrently with training of a synchronization-continuation motor task. We hypothesized that anodal cerebellar tDCS will enhance motor skill acquisition. Cerebellar tDCS was applied to the right cerebellum in 31 healthy subjects in a double-blind, sham-controlled, parallel design. During synchronization, the subjects tapped the sequ...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Wessel, M. J., Zimerman, M., Timmermann, J. E., Heise, K. F., Gerloff, C., Hummel, F. C. Tags: Original Articles Source Type: research
Reward Motivation Enhances Task Coding in Frontoparietal Cortex
Reward motivation often enhances task performance, but the neural mechanisms underlying such cognitive enhancement remain unclear. Here, we used a multivariate pattern analysis (MVPA) approach to test the hypothesis that motivation-related enhancement of cognitive control results from improved encoding and representation of task set information. Participants underwent two fMRI sessions of cued task switching, the first under baseline conditions, and the second with randomly intermixed reward incentive and no-incentive trials. Information about the upcoming task could be successfully decoded from cue-related activation patt...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Etzel, J. A., Cole, M. W., Zacks, J. M., Kay, K. N., Braver, T. S. Tags: Original Articles Source Type: research
The Organization of Right Prefrontal Networks Reveals Common Mechanisms of Inhibitory Regulation Across Cognitive, Emotional, and Motor Processes
Inhibitory control/regulation is critical to adapt behavior in accordance with changing environmental circumstances. Dysfunctional inhibitory regulation is ubiquitous in neurological and psychiatric populations. These populations exhibit dysfunction across psychological domains, including memory/thought, emotion/affect, and motor response. Although investigation examining inhibitory regulation within a single domain has begun outlining the basic neural mechanisms supporting regulation, it is unknown how the neural mechanisms of these domains interact. To investigate the organization of inhibitory neural networks within and...
Source: Cerebral Cortex - March 10, 2016 Category: Neurology Authors: Depue, B. E., Orr, J. M., Smolker, H. R., Naaz, F., Banich, M. T. Tags: Original Articles Source Type: research
