Prior knowledge changes how the brain processes sensory input. Whether knowledge influences initial sensory processing upstream of the brain, in the spinal cord, is unknown. Studying electric potentials recorded invasively and noninvasively from the human spinal cord at millisecond resolution, we find that the cord generates electric potentials at 600 hertz that are modulated by prior knowledge about the time of sensory input, as early as 13 to 16 milliseconds after stimulation.
View Article and Find Full Text PDFThe concepts of executive function (EF) and effortful control (EC) are strikingly similar. EF originates from neurocognitive research and is described as an accumulation of cognitive processes that serve the goal-oriented self-regulation of an individual. EC originates from temperament research and is defined as the efficiency of executive attention, including the ability to inhibit a dominant response, activate a subdominant response, proceed in a planned manner, and recognize conflicts or errors.
View Article and Find Full Text PDFAim: Periodontal disease is driven by oral pathogens, including Porphyromonas gingivalis, and the release of inflammatory cytokines. These cytokines (e.g.
View Article and Find Full Text PDFFunctional electrical stimulation (FES) can support functional restoration of a paretic limb post-stroke. Hebbian plasticity depends on temporally coinciding pre- and post-synaptic activity. A tight temporal relationship between motor cortical (MC) activity associated with attempted movement and FES-generated visuo-proprioceptive feedback is hypothesized to enhance motor recovery.
View Article and Find Full Text PDFPatients benefit from the use of check valves when drugs with a particularly short half-life (e.g., catecholamines) are continually administered through a one-way valve or when an accidental retrograde bolus application must be prevented, as in the event of a rapid sequence induction and intubation.
View Article and Find Full Text PDFThe mechanisms subserving motor skill acquisition and learning in the intact human brain are not fully understood. Previous studies in animals have demonstrated a causal relationship between motor learning and structural rearrangements of synaptic connections, raising the question of whether neurite-specific changes are also observable in humans. Here, we use advanced diffusion magnetic resonance imaging (MRI), sensitive to dendritic and axonal processes, to investigate neuroplasticity in response to long-term motor learning.
View Article and Find Full Text PDFBackground And Aims: Data on number of patients with cirrhosis in Germany are limited. We therefore aimed to estimate prevalence, comorbidities, mortality, utilization of healthcare resources and costs of patients with cirrhosis and incidence of decompensation of cirrhosis in Germany.
Methods: This longitudinal observational study was based on an anonymized representative claims database including 4.
Background: Cerebral microbleeds (MBs) are a hallmark of cerebral small vessel disease (CSVD) and can be found on T2-weighted sequences on MRI. Quantitative susceptibility mapping (QSM) is a postprocessing method that also enables MBs identification and furthermore allows to differentiate them from calcifications.
Aims: We explored the implications of using QSM at submillimeter resolution for MBs detection in CSVD.
Non-invasive studies consider the initial neural stimulus response (SR) and repetition suppression (RS) - the decreased response to repeated sensory stimuli - as engaging the same neurons. That is, RS is a suppression of the SR. We challenge this conjecture using electrocorticographic (ECoG) recordings with high spatial resolution in ten patients listening to task-irrelevant trains of auditory stimuli.
View Article and Find Full Text PDFMultiparameter mapping (MPM) is a quantitative MRI protocol that is promising for studying microstructural brain changes in vivo with high specificity. Reliability values are an important prior knowledge for efficient study design and facilitating replicable findings in development, aging and neuroplasticity research. To explore longitudinal reliability of MPM we acquired the protocol in 31 healthy young subjects twice over a rescan interval of 4 weeks.
View Article and Find Full Text PDFBackground And Purpose: Cerebral small vessel disease contributes to stroke and cognitive impairment and interacts with Alzheimer disease pathology. Because of the small dimensions of the affected vessels, in vivo characterization of blood flow properties is challenging but important to unravel the underlying mechanisms of the disease.
Materials And Methods: A 2D phase-contrast sequence at 7T MR imaging was used to assess blood flow velocity and the pulsatility index of the perforating basal ganglia arteries.
Objective: To assess the incidence of post-operative non-ischaemic cerebral complications as a pivotal outcome parameter with respect to size of cerebral infarction, timing of surgery, and peri-operative management in patients with symptomatic carotid stenosis who underwent carotid endarterectomy (CEA).
Methods: Retrospective analysis of prospectively collected single centre CEA registry data. Consecutive patients with symptomatic carotid stenosis were subjected to standard patch endarterectomy.
Mind-wandering (MW) is a subjective, cognitive phenomenon, in which thoughts move away from the task toward an internal train of thoughts, possibly during phases of neuronal sleep-like activity (local sleep, LS). MW decreases cortical processing of external stimuli and is assumed to decouple attention from the external world. Here, we directly tested how indicators of LS, cortical processing, and attentional selection change in a pop-out visual search task during phases of MW.
View Article and Find Full Text PDFThe brain is universally regarded as a system for processing information. If so, any behavioral or cognitive dysfunction should lend itself to depiction in terms of information processing deficiencies. Information is characterized by recursive, hierarchical complexity.
View Article and Find Full Text PDFExtensive neuroanatomical connectivity between the anterior thalamic nuclei (ATN) and hippocampus and neocortex renders them well-placed for a role in memory processing, and animal, lesion, and neuroimaging studies support such a notion. The deep location and small size of the ATN have precluded their real-time electrophysiological investigation during human memory processing. However, ATN electrophysiological recordings from patients receiving electrodes implanted for deep brain stimulation for pharmacoresistant focal epilepsy have enabled high temporal resolution study of ATN activity.
View Article and Find Full Text PDFObjective: Cerebral microbleeds (MBs) are a common finding in patients with cerebral small vessel disease (CSVD) and Alzheimer disease as well as in healthy elderly people, but their pathophysiology remains unclear. To investigate a possible role of veins in the development of MBs, we performed an exploratory study, assessing in vivo presence of MBs with a direct connection to a vein.
Methods: 7-Tesla (7T) MRI was conducted and MBs were counted on quantitative susceptibility mapping (QSM).
Introduction: Following electrode implantation, a subgroup of patients treated with deep brain stimulation (DBS) for focal epilepsy exhibits a reduction of seizure frequency before stimulation is initiated. Microlesioning of the target structure has been postulated to be the cause of this "insertional" effect (IE). We examined the occurrence and duration of this IE in a group of patients with focal epilepsy following electrode implantation in the anterior nuclei of the thalamus (ANT) and/or nucleus accumbens (NAC) for DBS treatment.
View Article and Find Full Text PDFDiffusion-weighted magnetic resonance imaging (DWI) is undergoing constant evolution with the ambitious goal of developing in-vivo histology of the brain. A recent methodological advancement is Neurite Orientation Dispersion and Density Imaging (NODDI), a histologically validated multi-compartment model to yield microstructural features of brain tissue such as geometric complexity and neurite packing density, which are especially useful in imaging the white matter. Since NODDI is increasingly popular in clinical research and fields such as developmental neuroscience and neuroplasticity, it is of vast importance to characterize its reproducibility (or reliability).
View Article and Find Full Text PDFRegaining communication abilities in patients who are unable to speak or move is one of the main goals in decoding brain waves for brain-computer interface (BCI) control. Many BCI approaches designed for communication rely on attention to visual stimuli, commonly applying an oddball paradigm, and require both eye movements and adequate visual acuity. These abilities may, however, be absent in patients who depend on BCI communication.
View Article and Find Full Text PDFImpulsive decisions arise from preferring smaller but sooner rewards compared with larger but later rewards. How neural activity and attention to choice alternatives contribute to reward decisions during temporal discounting is not clear. Here we probed (1) attention to and (2) neural representation of delay and reward information in humans (both sexes) engaged in choices.
View Article and Find Full Text PDFUnique to humans is the ability to report subjective awareness of a broad repertoire of external and internal events. Even when asked to focus on external information, the human's mind repeatedly wanders to task-unrelated thoughts, which limits reading comprehension or the ability to withhold automated manual responses. This led to the attentional decoupling account of mind wandering (MW).
View Article and Find Full Text PDFObjective: To investigate underlying cerebral small vessel disease (CSVD) in patients with mixed cerebral hemorrhages patterns and phenotype them according to the contribution of the two most common sporadic CSVD subtypes: cerebral amyloid angiopathy (CAA) vs. hypertensive arteriopathy (HA).
Methods: Brain MRIs of patients with intracerebral hemorrhages (ICHs) and/or cerebral microbleeds (CMBs) were assessed for the full spectrum of CSVD markers using validated scales: ICHs, CMBs, cortical superficial siderosis (cSS), white matter hyperintensities, MRI-visible perivascular spaces (PVS).
Objective: One of the main goals of brain-computer interfaces (BCI) is to restore communication abilities in patients. BCIs often use event-related potentials (ERPs) like the P300 which signals the presence of a target in a stream of stimuli. The P300 and related approaches, however, are inherently limited, as they require many stimulus presentations to obtain a usable control signal.
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