Search results for " processing"
showing 10 items of 7549 documents
Schizophrenia and automatic processing: an exploratory study.
1991
This study deals with the schizophrenic deficit as one of automatic processing. To test the idea, a special experimental task was designed on which 21 schizophrenics, 21 depressives, and 21 normal subjects had to complete a series of simple geometric figures. When the subjects had thoroughly learned this activity, another information source, a brief story, was introduced, and the subjects had to pay attention to the story while they did the task. Two dependent variables were considered, execution time and performance. There were no differences among the three groups in the first experimental condition; but in the second condition, when the distractor was introduced, schizophrenics needed m…
Voxel-based morphometry depicts central compensation after vestibular neuritis.
2010
Objective Patients who have had vestibular neuritis (VN) show a remarkable clinical improvement especially in gait and posture >6 months after disease onset. Methods Voxel-based morphometry was used to detect the VN-induced changes in gray and white matter by means of structural magnetic resonance imaging. Twenty-two patients were compared an average 2.5 years after onset of VN to a healthy sex-and age-matched control group. Results Our analysis revealed that all patients had signal intensity increases for gray matter in the medial vestibular nuclei and the right gracile nucleus and for white matter in the area of the pontine commissural vestibular fibers. A relative atrophy was observed in…
Two Distinct Auditory-Motor Circuits for Monitoring Speech Production as Revealed by Content-Specific Suppression of Auditory Cortex
2015
Speech production, both overt and covert, down-regulates the activation of auditory cortex. This is thought to be due to forward prediction of the sensory consequences of speech, contributing to a feedback control mechanism for speech production. Critically, however, these regulatory effects should be specific to speech content to enable accurate speech monitoring. To determine the extent to which such forward prediction is content-specific, we recorded the brain's neuromagnetic responses to heard multisyllabic pseudowords during covert rehearsal in working memory, contrasted with a control task. The cortical auditory processing of target syllables was significantly suppressed during rehear…
FAIR and dynamic susceptibility contrast-enhanced perfusion imaging in healthy subjects and stroke patients.
2002
Purpose To compare dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI) and the flow-sensitive alternating inversion recovery (FAIR) technique for measuring brain perfusion. Materials and Methods We investigated 12 patients with acute stroke, and 10 healthy volunteers with FAIR and DSC maps of regional cerebral blood volume (rCBV), mean transit time (MTT), and regional cerebral blood flow (rCBF). Results In volunteers good gray/white-matter contrast was observed in FAIR, rCBF, and rCBV maps. Regions with high signal intensities in FAIR matched well with high values of rCBV and rCBF. In ischemic stroke patients a high correlation (r = 0.78) of the ipsi- to contralate…
Computer assisted evaluation of retinal vessels tortuosity in Fabry disease.
2012
. Purpose: Fabry Disease (FD) is a rare X-linked metabolic disorder characterized by diffuse deposition of sphingolipids in many tissues. Retinal vessel tortuosity is a common ocular manifestation in FD and may represent a useful marker for the disease. Unfortunately its clinical evaluation is poorly reproducibile and alternative means of evaluation may be of interest. We tested a new semi-automatic software measuring retinal vessel tortuosity from eye fundus digital images in a group of FD patients. Methods: Observational case-control study evaluating four mathematical parameters describing tortuosity (relative length, sum of angle metric [SOAM], product of angle distance [PAD], triangul…
Animacy-based predictions in language comprehension are robust: contextual cues modulate but do not nullify them
2015
Couldn't a humble coconut hurt a gardener? At least in the first instance, the brain seems to assume that it should not: we perceive inanimate entities such as coconuts as poor event instigators ("Actors"). Ideally, entities causing a change in another entity should be animate and this assumption not only influences event perception but also carries over to language comprehension. We present three auditory event-related brain potential (ERP) studies on the processing of inanimate and animate subjects and objects in simple transitive sentences in Tamil. ERP responses were measured at the second argument (event participant) in all three studies. Experiment 1 employed all possible animacy comb…
Perceptual processing strategy and exposure influence the perception of odor mixtures
2008
; In flavor perception, both experience with the components of odor/taste mixtures and the cognitive strategy used to examine the interactions between the components influence the overall mixture perception. However, the effect of these factors on odor mixtures perception has never been studied. The present study aimed at evaluating whether 1) previous exposure to the odorants included in a mixture or 2) the synthetic or analytic strategy engaged during odorants mixture evaluation determines odor representation. Blending mixtures, in which subjects perceived a unique quality distinct from those of components, were chosen in order to induce a priori synthetic perception. In the first part, …
Computed tomography-based tracheobronchial image reconstruction allows selection of the individually appropriate double-lumen tube size
1999
Objectives: To determine whether individualized selection of double-lumen tubes or alternatives based on three-dimensional reconstruction of the tracheobronchial image from routine preoperative computed tomography (CT) scans leads to clinically appropriate choices. Design: Prospective observational study; comparison to historic controls. Setting: Anesthesia and radiology facilities of a university medical center. Participants: Forty-nine patients undergoing thoracic surgery requiring one-lung ventilation. Interventions: Three-dimensional image reconstruction of individual tracheobronchial anatomy was performed from routine preoperative spiral CT scans as well as from scans of five left-side…
Assessment of left ventricular function by breath-hold cine MR imaging: Comparison of different steady-state free precession sequences
2005
Purpose To compare steady-state free precession (SSFP) sequence protocols with different acquisition times (TA) and temporal resolutions (tRes) due to the implementation of a view sharing technique called shared phases for the assessment of left ventricular (LV) function by breath-hold cine magnetic resonance (MR) imaging. Materials and Methods End-diastolic and end-systolic volumes (EDV, ESV) were measured in contiguous short-axis slices with a thickness of 8 mm acquired in 10 healthy male volunteers. The following true fast imaging with steady-state precession (TrueFISP) sequence protocols were compared: protocol A) internal standard of reference, segmented: tRes 34.5 msec, TA 18 beats pe…
Dissociable contributions of left and right dorsolateral prefrontal cortex in planning.
2010
It is well established that the mid-dorsolateral prefrontal cortex (dlPFC) plays a critical role in planning. Neuroimaging studies have yielded predominantly bilateral dlPFC activations, but the existence and nature of functionally specific contributions of left and right dlPFC have remained elusive. In recent experiments, 2 independent parameters have been identified which substantially determine planning: 1) the degree of interdependence between consecutive steps (search depth) and 2) the degree to which the configuration of the goal state renders the order of single steps either clearly evident or ambiguous (goal hierarchy). Thus, search depth affects the actual mental generation and eva…