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Brain Topography

Xiaoyan Wu, Qiuyou Xie, Xiaojin Liu, Huiyuan Huang, Qing Ma, Junjing Wang, Miao Zhong, Yanbin He, Chen Niu, Yan Chen, Feng Deng, Xiaoxiao Ni, Yuan He, Yequn Guo, Ronghao Yu, Ruiwang Huang
Understanding the neural mechanisms of disorders of consciousness (DOC) is essential for estimating the conscious level and diagnosing DOC patients. Although previous studies reported brain functional connectivity (FC) and spontaneous neural activity patterns associated with consciousness, the relationship between them remains unclear. In this study, we identified the abnormal brain regions in DOC patients by performing voxel-wise FC strength (FCS) and fractional amplitude of low-frequency fluctuations (fALFF) analyses on resting-state functional magnetic resonance imaging data of 15 DOC patients and 24 healthy controls...
February 1, 2019: Brain Topography
Monika Bender, Vincenzo Romei, Paul Sauseng
Recent research suggests alteration of visual working memory capacity by modulation of parietal theta frequency via transcranial alternating current stimulation (tACS). However, it remains to be clarified whether this effect is partly driven by co-stimulation of prefrontal cortex and subcortical structures. It was hypothesized that focal tACS over the parietal lobe without additional prefrontal or subcortical stimulation should lead to similar effects as reported in the literature. Healthy, young participants were tested on a visual working memory paradigm while receiving either focal parietal tACS at 4 Hz, at 7 Hz or sham stimulation...
January 29, 2019: Brain Topography
Paul Alexander Schauer, Jonas Rauh, Gregor Leicht, Christina Andreou, Christoph Mulert
Several studies using electroencephalography (EEG) demonstrate that the processing of feedback in patients suffering from borderline personality disorder (BPD) is altered in comparison to healthy controls. Differences occur in the theta (ca. 5 Hz) and high-beta frequency-ranges (ca. 20 Hz) of oscillations in response to negative and positive feedback, respectively. However, alpha (ca. 10 Hz) and low-beta (ca. 15 Hz) oscillations have also been shown to be involved in feedback processing. We hypothesized that additional alterations might occur in these frequency ranges in BPD...
January 28, 2019: Brain Topography
Paul L Nunez, Michael D Nunez, Ramesh Srinivasan
A biophysical framework needed to interpret electrophysiological data recorded at multiple spatial scales of brain tissue is developed. Micro current sources at membrane surfaces produce local field potentials, electrocorticography, and electroencephalography (EEG). We categorize multi-scale sources as genuine, equivalent, or representative. Genuine sources occur at the micro scale of cell surfaces. Equivalent sources provide identical experimental outcomes over a range of scales and applications. In contrast, each representative source distribution is just one of many possible source distributions that yield similar experimental outcomes...
January 25, 2019: Brain Topography
Fabian Herold, Norman Aye, Dennis Hamacher, Lutz Schega
The neuromotor control of walking relies on a network of subcortical and cortical structures. While kinematic differences between treadmill and overground walking are extensively studied, the neuromotor control processes are still relatively unknown. Hence, this study aims to investigate cortical activation during steady-state treadmill and overground walking using functional near-infrared spectroscopy, inertial measurement units and a heart rate monitor. We observed a higher concentration of oxygenated hemoglobin in prefrontal cortices, premotor cortices and supplementary motor areas during treadmill walking...
January 24, 2019: Brain Topography
Carolin Weiss Lucas, Elisa Kallioniemi, Volker Neuschmelting, Charlotte Nettekoven, Julia Pieczewski, Kristina Jonas, Roland Goldbrunner, Jari Karhu, Christian Grefkes, Petro Julkunen
Modulatory effects of transcranial magnetic stimulation (TMS) strongly depend on the stimulation parameters. Here, we compared the immediate, task-locked inhibitory effects on speech-related muscles and the tolerability of different TMS protocols during a language production task. Repetitive TMS (rTMS) and paired-pulse TMS (PP) were applied in 13 healthy subjects over the primary motor cortex (M1) during a finger-tapping/tongue-twisting tasks. The lowest subject-specific TMS intensity leading to movement disruptions was used for TMS over left-sided speech-related areas during picture naming...
January 23, 2019: Brain Topography
Benjamin R Morgan, George M Ibrahim, Vanessa M Vogan, Rachel C Leung, Wayne Lee, Margot J Taylor
Autism spectrum disorder (ASD) is characterized by abnormal functional organization of brain networks, which may underlie the cognitive and social impairments observed in affected individuals. The present study characterizes unique intrinsic connectivity within- and between- neural networks in children through to adults with ASD, relative to controls. Resting state fMRI data were analyzed in 204 subjects, 102 with ASD and 102 age- and sex-matched controls (ages 7-40 years), acquired on a single scanner. ASD was assessed using the autism diagnostic observation schedule (ADOS)...
January 18, 2019: Brain Topography
John G Samuelsson, Sheraz Khan, Padmavathi Sundaram, Noam Peled, Matti S Hämäläinen
Magnetoencephalography (MEG) and electroencephalography (EEG) use non-invasive sensors to detect neural currents. Since the contribution of superficial neural sources to the measured M/EEG signals are orders-of-magnitude stronger than the contribution of subcortical sources, most MEG and EEG studies have focused on cortical activity. Subcortical structures, however, are centrally involved in both healthy brain function as well as in many neurological disorders such as Alzheimer's disease and Parkinson's disease...
January 3, 2019: Brain Topography
Xin Xiong, Yunfa Fu, Jian Chen, Lijun Liu, Xiabing Zhang
To provide optional force and speed control parameters for brain-computer interfaces (BCIs), an effective feature extraction method of imagined force and speed of hand clenching based on electroencephalography (EEG) was explored. Twenty subjects were recruited to participate in the experiment. They were instructed to perform three different actual/imagined hand clenching force tasks (4 kg, 10 kg, and 16 kg) and three different hand clenching speed tasks (0.5 Hz, 1 Hz, and 2 Hz). Topographical maps parameters and brain network parameters of EEG were calculated as new features of imagined force and speed of hand clenching, which were classified by three classifiers: linear discrimination analysis, extreme learning machines and support vector machines...
December 31, 2018: Brain Topography
Robert Markewitz, Sarah Engel, Berthold Langguth, Martin Schecklmann
Paired associative stimulation (PAS), a form of non-invasive cortical stimulation pairing transcranial magnetic stimulation (TMS) with a peripheral sensory stimulus, has been shown to induce neuroplastic effects in the human motor, somatosensory and auditory cortex. The current study investigated the effects of acoustic PAS on late auditory evoked potentials (LAEP) and the influence of tone duration and placebo stimulation. In two experiments, 18 participants underwent a PAS with a 4 kHz paired tone of 400 ms duration using 200 pairs of stimuli (TMS-pulse over the left auditory cortex 45 ms after tone-onset) presented at 0...
December 24, 2018: Brain Topography
Jurgen Hebbink, Dorien van Blooijs, Geertjan Huiskamp, Frans S S Leijten, Stephan A van Gils, Hil G E Meijer
The growing interest in brain networks to study the brain's function in cognition and diseases has produced an increase in methods to extract these networks. Typically, each method yields a different network. Therefore, one may ask what the resulting networks represent. To address this issue we consider electrocorticography (ECoG) data where we compare three methods. We derive networks from on-going ECoG data using two traditional methods: cross-correlation (CC) and Granger causality (GC). Next, connectivity is probed actively using single pulse electrical stimulation (SPES)...
December 6, 2018: Brain Topography
M Rubega, M Carboni, M Seeber, D Pascucci, S Tourbier, G Toscano, P Van Mierlo, P Hagmann, G Plomp, S Vulliemoz, C M Michel
In the last decade, the use of high-density electrode arrays for EEG recordings combined with the improvements of source reconstruction algorithms has allowed the investigation of brain networks dynamics at a sub-second scale. One powerful tool for investigating large-scale functional brain networks with EEG is time-varying effective connectivity applied to source signals obtained from electric source imaging. Due to computational and interpretation limitations, the brain is usually parcelled into a limited number of regions of interests (ROIs) before computing EEG connectivity...
December 3, 2018: Brain Topography
Iulia M Comsa, Tristan A Bekinschtein, Srivas Chennu
As we fall sleep, our brain traverses a series of gradual changes at physiological, behavioural and cognitive levels, which are not yet fully understood. The loss of responsiveness is a critical event in the transition from wakefulness to sleep. Here we seek to understand the electrophysiological signatures that reflect the loss of capacity to respond to external stimuli during drowsiness using two complementary methods: spectral connectivity and EEG microstates. Furthermore, we integrate these two methods for the first time by investigating the connectivity patterns captured during individual microstate lifetimes...
November 29, 2018: Brain Topography
Da-Wei Zhang, Stuart J Johnstone, Hui Li, Robert J Barry, Adam R Clarke, Qihua Zhao, Yan Song, Lu Liu, Qiujin Qian, Yufeng Wang, Li Sun
In this study we extend on behavioural evidence to examine the effect of time on EEG measures related to arousal and emotion/motivation in children with/without AD/HD. Thirty children with AD/HD and 30 age- and sex-matched controls participated. EEG was recorded during an eyes-closed resting condition and divided into three 2.5 min blocks after pre-processing. Time effects for absolute and relative alpha activity were found in healthy controls; these effects did not interact with AD/HD status. Interactions between time and AD/HD status were found for absolute theta, relative theta, and theta/beta ratio (TBR), with these EEG indices increasing over time in children with AD/HD...
November 29, 2018: Brain Topography
Fali Li, Chanlin Yi, Limeng Song, Yuanling Jiang, Wenjing Peng, Yajing Si, Tao Zhang, Rui Zhang, Dezhong Yao, Yangsong Zhang, Peng Xu
Mentally imagining rather physically executing the motor behaviors is defined as motor imagery (MI). During MI, the mu rhythmical oscillation of cortical neurons is the event-related desynchronization (ERD) subserving the physiological basis of MI-based brain-computer interface. In our work, we investigated the specific brain network reconfiguration from rest idle to MI task states, and also probed the underlying relationship between the brain network reconfiguration and MI related ERD. Findings revealed that comparing to rest state, the MI showed the enhanced motor area related linkages and the deactivated activity of default mode network...
November 24, 2018: Brain Topography
Koya Yamashiro, Daisuke Sato, Hideaki Onishi, Kazuhiro Sugawara, Naofumi Otsuru, Hikari Kirimoto, Sho Nakazawa, Yudai Yamazaki, Hiroshi Shirozu, Atsuo Maruyama
Our previous demonstration that the M100 somatosensory evoked magnetic field (SEF) has a similar temporal profile, dipole orientation and source location whether induced by activation (ON-M100) or deactivation (OFF-M100) of electrical stimulation suggests a common cortical system to detect sensory change. While we have not recorded such change-driven components earlier than M100 using electrical stimulation, clear M50 responses were reported using both ON and OFF mechanical stimulation (Onishi et al. in Clin Neurophysiol 121:588-593, 2010)...
November 15, 2018: Brain Topography
S Prinsloo, D I Rosenthal, R Lyle, S M Garcia, S Gabel-Zepeda, R Cannon, E Bruera, L Cohen
Acute pain from mucositis in patients with head and neck cancer (HNC) undergoing radiation therapy (RT) is common, and may not respond well to narcotics. We used low resolution electromagnetic tomography z-score neurofeedback (LFBz) to investigate whether patients could modify brain wave activity associated with acute pain and whether this would reduce the experience of pain. HNC patients scheduled for RT had baseline pre-pain onset measures (EEG and numeric rating scale) collected before RT and then at pain onset before using analgesics, after each LFBz session and at the end of RT...
November 13, 2018: Brain Topography
Arran T Reader, Nicholas P Holmes
Results from neuropsychological studies, and neuroimaging and behavioural experiments with healthy individuals, suggest that the imitation of meaningful and meaningless actions may be reliant on different processing routes. The left posterior middle temporal gyrus (pMTG) is one area that might be important for the recognition and imitation of meaningful actions. We studied the role of the left pMTG in imitation using repetitive transcranial magnetic stimulation (rTMS) and two-person motion-tracking. Participants imitated meaningless and emblematic meaningful hand and finger gestures performed by a confederate actor whilst both individuals were motion-tracked...
November 8, 2018: Brain Topography
Yoon-Hee Cha, Guofa Shou, Diamond Gleghorn, Benjamin C Doudican, Han Yuan, Lei Ding
To determine intrinsic functional connectivity (IFC) related to symptom changes induced by rTMS in mal de debarquement syndrome (MdDS), a motion perceptual disorder induced by entrainment to oscillating motion. Twenty right-handed women (mean age: 52.9 ± 12.6 years; mean duration illness: 35.2 ± 24.2 months) with MdDS received five sessions of rTMS (1 Hz right DLPFC, 10 Hz left DLPFC) over consecutive days. High-density (128-channel) resting-state EEG were recorded prior to and following treatment sessions and analyzed using a group-level independent component (IC) analysis...
November 2018: Brain Topography
Hanna Kaltiainen, Liisa Helle, Mia Liljeström, Hanna Renvall, Nina Forss
Mild traumatic brain injury (mTBI) patients continue to pose a diagnostic challenge due to their diverse symptoms without trauma-specific changes in structural imaging. We addressed here the possible early changes in spontaneous oscillatory brain activity after mTBI, and their feasibility as an indicator of injury in clinical evaluation. We recorded resting-state magnetoencephalography (MEG) data in both eyes-open and eyes-closed conditions from 26 patients (11 females and 15 males, aged 20-59) with mTBI 6 days-6 months after the injury, and compared their spontaneous oscillatory activity to corresponding data from 139 healthy controls...
November 2018: Brain Topography
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