Recent evidence in healthy participants suggests that a motor subcomponent of working memory (mWM) may exist. We investigated whether this mWM is impaired in patients with a motor-dominant left hemisphere (LH) stroke and apraxia. Furthermore, we hypothesized that a deficient mWM contributes to deficits in motor cognition, that is, apraxia, in LH stroke.
View Article and Find Full Text PDFMore than two decades ago, the mirror neuron system (MNS) was discovered in non-human primates: Single-cell recordings detected visuo-motor neurons that discharged not only when the monkey performed an action, but also when it observed conspecifics performing the same action. It has been proposed that a fronto-parietal circuitry constitutes the human homolog of the MNS. However, the functional role of a human MNS (i.
View Article and Find Full Text PDFAttention is a complex construct that comprises at least three major subcomponents: alerting, spatial (re-)orienting, and executive functions, all of which have specific neural correlates along frontoparietal networks. Attention deficits are a common consequence of brain damage. Transcranial direct current stimulation (tDCS) has been shown to modulate spatial attention.
View Article and Find Full Text PDFGesture processing deficits constitute a key symptom of apraxia, a disorder of motor cognition frequently observed after left-hemispheric stroke. The clinical relevance of apraxia stands in stark contrast to the paucity of therapeutic options available. Transcranial direct current stimulation (tDCS) is a promising tool for modulating disturbed network function after stroke.
View Article and Find Full Text PDFExperimental allergic encephalomyelitis (EAE) is mediated by neuroantigen-specific pro-inflammatory T cells of the Th1 and Th17 effector class. Th-17 cells can be clearly defined by expression of IL-17, but not IFN-γ, IL-2 or IL-3. Th1 cells do not express IL-17, but it is unclear presently to what extent they co-express the cytokines canonically assigned to Th1 immunity (i.
View Article and Find Full Text PDFSensory stimulation resulting from one's own behavior or the outside world is easily differentiated by healthy persons who are able to predict the sensory consequences of their own actions. This ability has been related to cortical attenuation of activation elicited by self-produced stimulation. To date, however, the neural processes underlying this modulation remain to be elucidated.
View Article and Find Full Text PDFAction understanding and learning are suggested to be mediated, at least in part, by the human mirror neuron system (hMNS). Static images as well as videos of actions with the outcome occluded have been shown to activate the hMNS. However, whether the hMNS preferentially responds to end or means of an action remains to be investigated.
View Article and Find Full Text PDFNeuropsychological studies suggest that patients with left parietal lesions may show impaired localization of parts of either their own or the examiner's body, despite preserved ability to identify isolated body parts. This deficit, called autotopagnosia, may result from damage to the Body Structural Description (BSD), a representation which codes spatial relationships among body parts. We used functional magnetic resonance imaging to identify the neural mechanisms underlying the BSD.
View Article and Find Full Text PDFObjective: Typically, the apraxic deficit of patients with left hemisphere damage is more pronounced for complex, i.e., sequential actions, than for simple ones.
View Article and Find Full Text PDFBody ownership refers to the special perceptual status of one's own body, which makes bodily sensations seem unique to oneself. We studied the neural correlates of body ownership by controlling whether an external object was accepted as part of the body or not. In the rubber hand illusion (RHI), correlated visuotactile stimulation causes a fake hand to be perceived as part of one's own body.
View Article and Find Full Text PDFYawning is contagious: Watching another person yawn may trigger us to do the same. Here we studied brain activation with functional magnetic resonance imaging (fMRI) while subjects watched videotaped yawns. Significant increases in the blood oxygen level dependent (BOLD) signal, specific to yawn viewing as contrasted to viewing non-nameable mouth movements, were observed in the right posterior superior temporal sulcus (STS) and bilaterally in the anterior STS, in agreement with the high affinity of STS to social cues.
View Article and Find Full Text PDFRecall Ag-specific IL-4 was detected in the spleen and in the blood, but not in lymph nodes of mice in which polarized type 1 immunity was induced. This IL-4 was not produced by T cells, but soluble factors secreted by the recall Ag-activated T cells, including IL-3, triggered cells of the innate immune system, primarily mast cells, to secrete IL-4. This notion has profound implications for immunodiagnostics: the detection of apparently recall Ag-specific IL-4 does not necessarily reflect the presence of Th2 or Th0 memory T cells with long-term cytokine commitment as is of interest for assessing adoptive immunity.
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