Search results for "Poster"
showing 10 items of 679 documents
The default mode network and the working memory network are not anti-correlated during all phases of a working memory task
2015
INTRODUCTION:\ud \ud The default mode network and the working memory network are known to be anti-correlated during sustained cognitive processing, in a load-dependent manner. We hypothesized that functional connectivity among nodes of the two networks could be dynamically modulated by task phases across time.\ud METHODS:\ud \ud To address the dynamic links between default mode network and the working memory network, we used a delayed visuo-spatial working memory paradigm, which allowed us to separate three different phases of working memory (encoding, maintenance, and retrieval), and analyzed the functional connectivity during each phase within and between the default mode network and the …
Transient topographical amnesia and cingulate cortex damage: A case report
1996
Transient topographical amnesia (TTA) is the temporary inability to find one's way in familiar or unfamiliar surroundings due to the inability to use well known environmental landmarks for route finding. The syndrome has not been described as having any obvious aetiology and has been thought to be caused by a vascular deficit in right hemispheric structures which are crucial for topographic recognition, i.e. parietal association and parahippocampal cortex. The patient described in the present study complained of several critical episodes of TTA and tonic rigidity of the left limbs. Neuropsychological assessment was normal except for a deficit in spatial memory tasks. Magnetic resonance (MR)…
A fronto-parietal network is mediating improvement of motor function related to repetitive peripheral magnetic stimulation: A PET-H2O15 study.
2006
Repetitive peripheral magnetic stimulation (RPMS) is a focused and painless stimulation method, in which muscle contractions are elicited by depolarization of the terminal motor branches. Clinical-experimental investigations on different disorders of sensorimotor integration in the last decade have shown that RPMS can be used for the rehabilitation of motor functions after stroke. It is supposed that this therapeutic effect is based on the RPMS-induced proprioceptive inflow to the CNS. To analyze the conditioning effects of RPMS on reorganization of the motor system on cortical level positron emission tomography (PET) is used. Regional cerebral blood flow (rCBF) has been measured using H(2)…
Thalamic relay or cortico-thalamic processing? Old question, new answers.
2013
Ascending and descending information is relayed through the thalamus via strong, “driver” pathways. According to our current knowledge, different driver pathways are organized in parallel streams and do not interact at the thalamic level. Using an electron microscopic approach combined with optogenetics and in vivo physiology, we examined whether driver inputs arising from different sources can interact at single thalamocortical cells in the rodent somatosensory thalamus (nucleus posterior, POm). Both the anatomical and the physiological data demonstrated that ascending driver inputs from the brainstem and descending driver inputs from cortical layer 5 pyramidal neurons converge and interac…
A supervised learning framework of statistical shape and probability priors for automatic prostate segmentation in ultrasound images
2013
Prostate segmentation aids in prostate volume estimation, multi-modal image registration, and to create patient specific anatomical models for surgical planning and image guided biopsies. However, manual segmentation is time consuming and suffers from inter-and intra-observer variabilities. Low contrast images of trans rectal ultrasound and presence of imaging artifacts like speckle, micro-calcifications, and shadow regions hinder computer aided automatic or semi-automatic prostate segmentation. In this paper, we propose a prostate segmentation approach based on building multiple mean parametric models derived from principal component analysis of shape and posterior probabilities in a multi…
Nonendodontic periapical lesions: a retrospective descriptive study in a Brazilian population
2021
Background Several nonendodontic diseases can occur in the periapical region, resembling endodontic inflammatory conditions. Therefore, the aim of the present study was to determine the frequency of nonendodontic periapical lesions diagnosed in a Brazilian population. Material and Methods The files of two Oral Pathology laboratories were reviewed and all cases including at least one clinical diagnosis of endodontic periapical lesions were selected for the study. After initial selection, demographic and clinical data, clinical diagnosis and final diagnosis were reviewed and tabulated. Final diagnosis included endodontic periapical lesions, and benign and malignant nonendodontic periapical le…
Efferent connections of the "olfactostriatum": a specialized vomeronasal structure within the basal ganglia of snakes.
2005
Abstract The olfactostriatum is a portion of the basal ganglia of snakes that receives substantial vomeronasal afferents through projections from the nucleus sphericus. In a preceding article, the olfactostriatum of garter snakes (Thamnophis sirtalis) was characterized on the basis of chemoarchitecture (distribution of serotonin, neuropeptide Y and tyrosine hydroxylase) and pattern of afferent connections [Martinez-Marcos, A., Ubeda-Banon, I., Lanuza, E., Halpern, M., 2005. Chemoarchitecture and afferent connections of the “olfactostriatum”: a specialized vomeronasal structure within the basal ganglia of snakes. J. Chem. Neuroanat. 29, 49–69]. In the present study, its efferent connections …
Determination of corneal volume from anterior topography and topographic pachymetry: application to healthy and keratoconic eyes
2009
Purpose: To describe a method to measure corneal volume from topography and pachymetry, and test its clinical use on a sample of healthy human subjects and a case of circumscribed posterior keratoconus. Methods: Corneal curvature (PCT 200® corneal topography system; Optopol Technology SA, Zawiercie, Poland) and ultrasonic topographic pachometry on 25 points (Ophthasonic ® A-Scan/Pachometer III; Teknar Inc., St Louis, MO, USA) were measured on each of 12 young healthy corneas and one cornea suffering from circumscribed posterior keratoconus. Topography and pachymetry data were used to calculate the coordinates for the corresponding points on the posterior surface of the cornea. TableCurve 3D…
Spectral clustering of shape and probability prior models for automatic prostate segmentation.
2013
Imaging artifacts in Transrectal Ultrasound (TRUS) images and inter-patient variations in prostate shape and size challenge computer-aided automatic or semi-automatic segmentation of the prostate. In this paper, we propose to use multiple mean parametric models derived from principal component analysis (PCA) of shape and posterior probability information to segment the prostate. In contrast to traditional statistical models of shape and intensity priors, we use posterior probability of the prostate region determined from random forest classification to build, initialize and propagate our model. Multiple mean models derived from spectral clustering of combined shape and appearance parameters…
Cognitive control in auditory working memory is enhanced in musicians
2010
Musical competence may confer cognitive advantages that extend beyond processing of familiar musical sounds. Behavioural evidence indicates a general enhancement of both working memory and attention in musicians. It is possible that musicians, due to their training, are better able to maintain focus on task-relevant stimuli, a skill which is crucial to working memory. We measured the blood oxygenation-level dependent (BOLD) activation signal in musicians and non-musicians during working memory of musical sounds to determine the relation among performance, musical competence and generally enhanced cognition. All participants easily distinguished the stimuli. We tested the hypothesis that mus…