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https://www.readbyqxmd.com/read/28341164/expectation-violation-and-attention-to-pain-jointly-modulate-neural-gain-in-somatosensory-cortex
#1
Francesca Fardo, Ryszard Auksztulewicz, Micah Allen, Martin J Dietz, Andreas Roepstorff, Karl J Friston
The neural processing and experience of pain are influenced by both expectations and attention. For example, the amplitude of event-related pain responses is enhanced by both novel and unexpected pain, and by moving the focus of attention towards a painful stimulus. Under predictive coding, this congruence can be explained by appeal to a precision-weighting mechanism, which mediates bottom-up and top-down attentional processes by modulating the influence of feedforward and feedback signals throughout the cortical hierarchy...
March 21, 2017: NeuroImage
https://www.readbyqxmd.com/read/28334225/pom-thalamocortical-input-drives-layer-specific-microcircuits-in-somatosensory-cortex
#2
Nicholas J Audette, Joanna Urban-Ciecko, Megumi Matsushita, Alison L Barth
Higher-order thalamic nuclei, such as the posterior medial nucleus (POm) in the somatosensory system or the pulvinar in the visual system, densely innervate the cortex and can influence perception and plasticity. To systematically evaluate how higher-order thalamic nuclei can drive cortical circuits, we investigated cell-type selective responses to POm stimulation in mouse primary somatosensory (barrel) cortex, using genetically targeted whole-cell recordings in acute brain slices. We find that ChR2-evoked thalamic input selectively targets specific cell types in the neocortex, revealing layer-specific modules for the summation and processing of POm input...
March 10, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/28331874/the-importance-of-constructive-feedback-implications-of-top-down-regulation-in-the-development-of-neural-circuits
#3
Andrew D Thompson, Chinfei Chen
Neural circuits in sensory pathways develop through a general strategy of overproduction of synapses followed by activity-driven pruning to fine-tune connectivity for optimal function. The early visual pathway, consisting of the retina → visual thalamus → primary visual cortex, has served for decades as a powerful model system for probing the mechanisms and logic of this process. In addition to these feedforward projections, the early visual pathway also includes a substantial feedback component in the form of corticothalamic projections from the deepest layer of primary visual cortex...
2017: Neurogenesis (Austin, Tex.)
https://www.readbyqxmd.com/read/28329692/organization-of-functional-long-range-circuits-controlling-the-activity-of-serotonergic-neurons-in-the-dorsal-raphe-nucleus
#4
Li Zhou, Ming-Zhe Liu, Qing Li, Juan Deng, Di Mu, Yan-Gang Sun
Serotonergic neurons play key roles in various biological processes. However, circuit mechanisms underlying tight control of serotonergic neurons remain largely unknown. Here, we systematically investigated the organization of long-range synaptic inputs to serotonergic neurons and GABAergic neurons in the dorsal raphe nucleus (DRN) of mice with a combination of viral tracing, slice electrophysiological, and optogenetic techniques. We found that DRN serotonergic neurons and GABAergic neurons receive largely comparable synaptic inputs from six major upstream brain areas...
March 21, 2017: Cell Reports
https://www.readbyqxmd.com/read/28325878/perceptual-integration-without-conscious-access
#5
Johannes J Fahrenfort, Jonathan van Leeuwen, Christian N L Olivers, Hinze Hogendoorn
The visual system has the remarkable ability to integrate fragmentary visual input into a perceptually organized collection of surfaces and objects, a process we refer to as perceptual integration. Despite a long tradition of perception research, it is not known whether access to consciousness is required to complete perceptual integration. To investigate this question, we manipulated access to consciousness using the attentional blink. We show that, behaviorally, the attentional blink impairs conscious decisions about the presence of integrated surface structure from fragmented input...
March 21, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28321249/mexican-hat-wavelet-kernel-elm-for-multiclass-classification
#6
Jie Wang, Yi-Fan Song, Tian-Lei Ma
Kernel extreme learning machine (KELM) is a novel feedforward neural network, which is widely used in classification problems. To some extent, it solves the existing problems of the invalid nodes and the large computational complexity in ELM. However, the traditional KELM classifier usually has a low test accuracy when it faces multiclass classification problems. In order to solve the above problem, a new classifier, Mexican Hat wavelet KELM classifier, is proposed in this paper. The proposed classifier successfully improves the training accuracy and reduces the training time in the multiclass classification problems...
2017: Computational Intelligence and Neuroscience
https://www.readbyqxmd.com/read/28299643/retention-of-the-first-trial-effect-in-gait-slip-among-community-living-older-adults
#7
Xuan Liu, Tanvi Bhatt, Shuaijie Wang, Feng Yang, Yi-Chung Clive Pai
"First-trial effect" characterizes the rapid adaptive behavior that changes the performance outcome (from fall to non-fall) after merely a single exposure to postural disturbance. The purpose of this study was to investigate how long the first-trial effect could last. Seventy-five (≥ 65 years) community-dwelling older adults, who were protected by an overhead full body harness system, were retested for a single slip 6-12 months after their initial exposure to a single gait-slip. Subjects' body kinematics that was used to compute their proactive (feedforward) and reactive (feedback) control of stability was recorded by an eight-camera motion analysis system...
February 2017: Geroscience
https://www.readbyqxmd.com/read/28293164/double-barrier-memristive-devices-for-unsupervised-learning-and-pattern-recognition
#8
Mirko Hansen, Finn Zahari, Martin Ziegler, Hermann Kohlstedt
The use of interface-based resistive switching devices for neuromorphic computing is investigated. In a combined experimental and numerical study, the important device parameters and their impact on a neuromorphic pattern recognition system are studied. The memristive cells consist of a layer sequence Al/Al2O3/Nb x O y /Au and are fabricated on a 4-inch wafer. The key functional ingredients of the devices are a 1.3 nm thick Al2O3 tunnel barrier and a 2.5 mm thick Nb x O y memristive layer. Voltage pulse measurements are used to study the electrical conditions for the emulation of synaptic functionality of single cells for later use in a recognition system...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28288158/stimulus-specific-adaptation-in-a-recurrent-network-model-of-primary-auditory-cortex
#9
Tohar S Yarden, Israel Nelken
Stimulus-specific adaptation (SSA) occurs when neurons decrease their responses to frequently-presented (standard) stimuli but not, or not as much, to other, rare (deviant) stimuli. SSA is present in all mammalian species in which it has been tested as well as in birds. SSA confers short-term memory to neuronal responses, and may lie upstream of the generation of mismatch negativity (MMN), an important human event-related potential. Previously published models of SSA mostly rely on synaptic depression of the feedforward, thalamocortical input...
March 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28283576/glucocorticoid-and-cytokine-crosstalk-feedback-feedforward-and-co-regulatory-interactions-determine-repression-or-resistance
#10
Robert Newton, Suharsh V Shah, Mohammed O Altonsy, Anthony N Gerber
Inflammatory signals induce complex feedback and feedforward systems that allow tight temporal control. Whereas glucocorticoids generally repress inflammatory gene expression, GR recruitment increases expression of negative feedback and feedforward regulators, including DUSP1, IRAK3, NFKBIA, TNFAIP3 or ZFP36. Moreover, GR cooperativity with factors, such as NF-κB, can enhance regulator expression to promote repression. Conversely, MAPKs, which are inhibited by glucocorticoids, limit expression of the transcription factor IRF1, and the host defense gene, CXCL10, through a feedforward control mechanism...
March 10, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28273455/a-bach2-cebp-gene-regulatory-network-for-the-commitment-of-multipotent-hematopoietic-progenitors
#11
Ari Itoh-Nakadai, Mitsuyo Matsumoto, Hiroki Kato, Junichi Sasaki, Yukihiro Uehara, Yuki Sato, Risa Ebina-Shibuya, Mizuho Morooka, Ryo Funayama, Keiko Nakayama, Kyoko Ochiai, Akihiko Muto, Kazuhiko Igarashi
Hematopoietic stem cell and multipotent progenitor (MPP) commitment can be tuned in response to an infection so that their differentiation is biased toward myeloid cells. Here, we find that Bach2, which inhibits myeloid differentiation in common lymphoid progenitors, represses a cohort of myeloid genes and activates those linked to lymphoid function. Bach2 repressed both Cebpb and its target Csf1r, encoding C/EBPβ and macrophage colony-stimulating factor receptor (M-CSFr), respectively, whereas C/EBPβ repressed Bach2 and activated Csf1r...
March 7, 2017: Cell Reports
https://www.readbyqxmd.com/read/28269297/quantifying-the-human-finger-reachable-space
#12
Trieu H Pham, Pubudu N Pathirana
Describing the flexibility of the hand using the reachable space concept has drawn the attention of many researchers in recent years. Existing approaches involving numerical techniques to obtain the reachable space are generally computationally expensive. In this study, we propose a resource-friendly approach to determine and quantify the bidimensional reachable space of the finger. The fundamental idea of the approach connects to a set of arc formulae for the boundary of the reachable space. These formulae of the boundary result a unique description to calculate the area of the reachable space using Green's theorem...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268929/cardiovascular-interactions-assessed-via-conditional-joint-transfer-entropy-in-patients-developing-atrial-fibrillation-after-coronary-artery-bypass-graft-surgery
#13
Vlasta Bari, Marco Ranucci, Andrea Marchi, Beatrice De Maria, Valeria Pistuddi, Alberto Porta
Assigned the universe of knowledge Ω as composed by one target and two exogenous signals, the conditional joint transfer entropy (CJTE), assessing the amount of information jointly transferred from the two sources to the target that can be uniquely linked to one of the two sources, was found useful to study cardiovascular control. We propose the assessment of CJTE from systolic arterial pressure (SAP) and respiration (R) to heart period (HP) conditioned on R (CJTESAP, R→HP|R) along the baroreflex, and from HP and R to SAP conditioned on R (CJTEHP, R→SAP|R) along the feedforward mechanical pathway, in 134 patients undergoing coronary artery bypass graft surgery before (PRE) and after (POST) the induction of general anesthesia...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268828/sensor-data-quality-processing-for-vital-signs-with-opportunistic-ambient-sensing
#14
Ibrahim Sadek, Jit Biswas, Zhu Yongwei, Zhang Haihong, Jayachandran Maniyeri, Chen Zhihao, Teo Ju Teng, Ng Soon Huat, Mounir Mokhtari
Opportunistic ambient sensing involves placement of sensors appropriately so that intermittent contact can be made unobtrusively for gathering physiological signals for vital signs. In this paper, we discuss the results of our quality processing system used to extract heart rate from ballisto-cardiogram signals obtained from a micro-bending fiber optic sensor pressure mat. Visual inspection is used to label data into informative and non-informative classes based on their heart rate information. Five classifiers are employed for the classification process, i...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268683/effect-of-vagus-nerve-stimulation-on-neural-adaptation-in-thalamo-cortical-system-in-rats
#15
Tomoyo I Shiramatsu, Rie Hitsuyu, Kenji Ibayashi, Ryohei Kanzaki, Kensuke Kawai, Hirokazu Takahashi
Vagus nerve stimulation (VNS) is a therapy on medically refractory epilepsy, and recently reported to improve cognitive function including learning and memory. The thalamo-cortical system may underlie such VNS-induced cognitive improvements. Thus, the present study targeted the auditory cortex and thalamus in rats, and investigated whether and how VNS modulates stimulus-specific adaptation (SSA) of the neural activity in these nuclei. A depth electrode array recorded auditory evoked potentials from the auditory thalamus and cortex under an oddball paradigm either with or without VNS...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28262824/the-rhythms-of-predictive-coding-pre-stimulus-phase-modulates-the-influence-of-shape-perception-on-luminance-judgments
#16
Biao Han, Rufin VanRullen
Predictive coding is an influential model emphasizing interactions between feedforward and feedback signals. Here, we investigated the temporal dynamics of these interactions. Two gray disks with different versions of the same stimulus, one enabling predictive feedback (a 3D-shape) and one impeding it (random-lines), were simultaneously presented on the left and right of fixation. Human subjects judged the luminance of the two disks while EEG was recorded. The choice of 3D-shape or random-lines as the brighter disk was used to assess the influence of feedback signals on sensory processing in each trial (i...
March 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28260167/the-role-of-the-supplementary-motor-region-in-overt-reading-evidence-for-differential-processing-in-sma-proper-and-pre-sma-as-a-function-of-task-demands
#17
Jacqueline Cummine, Wahab Hanif, Inna Dymouriak-Tymashov, Kavya Anchuri, Stephanie Chiu, Carol A Boliek
A differentiation in function between the pre-SMA (i.e., cognitive load) and the SMA-proper (i.e., motor execution) has been described (Zhang et al., Cereb Cortex 22:99-111, 2012). These differential SMA functions may be influential in overt reading tasks. The present study examined the relationships between various segments of the SMA and overt reading through the modulation of task demands in an effort to explore the complexity of the print-to-speech network. Skilled reading adults (N = 15) took part in five overt reading tasks: pure regular word reading, pure exception word reading, mixed regular word and exception word reading, go/no-go reading with nonword foils and go/no-go reading with pseudohomophone foils...
March 4, 2017: Brain Topography
https://www.readbyqxmd.com/read/28257585/increased-response-to-altered-auditory-feedback-in-dyslexia-a-weaker-sensorimotor-magnet-implied-in-the-phonological-deficit
#18
Mark R van den Bunt, Margriet A Groen, Takayuki Ito, Ana A Francisco, Vincent L Gracco, Ken R Pugh, Ludo Verhoeven
Purpose: The purpose of this study was to examine whether developmental dyslexia (DD) is characterized by deficiencies in speech sensory and motor feedforward and feedback mechanisms, which are involved in the modulation of phonological representations. Method: A total of 42 adult native speakers of Dutch (22 adults with DD; 20 participants who were typically reading controls) were asked to produce /bep/ while the first formant (F1) of the /e/ was not altered (baseline), increased (ramp), held at maximal perturbation (hold), and not altered again (after-effect)...
March 1, 2017: Journal of Speech, Language, and Hearing Research: JSLHR
https://www.readbyqxmd.com/read/28254512/electrocorticographic-delineation-of-human-auditory-cortical-fields-based-on-effects-of-propofol-anesthesia
#19
Kirill V Nourski, Matthew I Banks, Mitchell Steinschneider, Ariane E Rhone, Hiroto Kawasaki, Rashmi N Mueller, Michael M Todd, Matthew A Howard
The functional organization of human auditory cortex remains incompletely characterized. While the posteromedial two thirds of Heschl's gyrus (HG) is generally considered to be part of core auditory cortex, additional subdivisions of HG remain speculative. To further delineate the hierarchical organization of human auditory cortex, we investigated regional heterogeneity in the modulation of auditory cortical responses under varying depths of anesthesia induced by propofol. Non-invasive studies have shown that propofol differentially affects auditory cortical activity, with a greater impact on non-core areas...
February 27, 2017: NeuroImage
https://www.readbyqxmd.com/read/28254455/early-processing-in-primary-visual-cortex-is-necessary-for-conscious-and-unconscious-vision-while-late-processing-is-necessary-only-for-conscious-vision-in-neurologically-healthy-humans
#20
Mikko Hurme, Mika Koivisto, Antti Revonsuo, Henry Railo
The neural mechanisms underlying conscious and unconscious visual processes remain controversial. Blindsight patients may process visual stimuli unconsciously despite their V1 lesion, promoting anatomical models, which suggest that pathways bypassing the V1 support unconscious vision. On the other hand, physiological models argue that the major geniculostriate pathway via V1 is involved in both unconscious and conscious vision, but in different time windows and in different types of neural activity. According to physiological models, feedforward activity via V1 to higher areas mediates unconscious processes whereas feedback loops of recurrent activity from higher areas back to V1 support conscious vision...
February 22, 2017: NeuroImage
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