Search results for "Lobe"
showing 10 items of 520 documents
Neural correlates of working memory dysfunction in first-episode schizophrenia patients: an fMRI multi-center study.
2005
Working memory dysfunction is a prominent impairment in patients with schizophrenia. Our aim was to determine cerebral dysfunctions by means of functional magnetic resonance imaging (fMRI) in a large sample of first-episode schizophrenia patients during a working memory task. 75 first-episode schizophrenia patients and 81 control subjects, recruited within a multi-center study, performed 2- and 0-back tasks while brain activation was measured with fMRI. In order to guarantee comparability between data quality from different scanners, we developed and adopted a standardized, fully automated quality assurance of scanner hard- and software as well as a measure for in vivo data quality. After t…
Exploring the relationship between semantics and space
2009
The asymmetric distribution of human spatial attention has been repeatedly documented in both patients and healthy controls. Biases in the distribution of attention and/or in the mental representation of space may also affect some aspects of language processing. We investigated whether biases in attention and/or mental representation of space affect semantic representations. In particular, we investigated whether semantic judgments could be modulated by the location in space where the semantic information was presented and the role of the left and right parietal cortices in this task. Healthy subjects were presented with three pictures arranged horizontally (one middle and two outer picture…
Localization of emotional and volitional facial paresis.
1992
Emotional facial paresis is characterized by impaired activation of face muscles with emotion but normal voluntary activation. We report seven patients with this sign. Their lesions involved the frontal lobe white matter, the striatocapsular territory, the anterolateral thalamus and insula, the posterior thalamus and operculum, and the mesial temporal lobe and insula each in one patient, and the posterior thalamus in two patients. Volitional facial paresis affects facial movements with voluntary effort, sparing activation on emotion. We report four such patients, with lesions involving the motor cortex in one and the pyramidal tract in the cerebral hemisphere in three.
Effects on Heat Stress of a Flame-Retardant Ensemble for Aluminum Smelters
2000
A common belief is that a flame-retardant clothing ensemble will increase the level of heat stress over ordinary cotton work clothes. This is supported by bench tests on fabrics that indicate higher insulation and vapor resistance values for flame-retardant clothing. This research compared a flame-retardant clothing ensemble for an aluminum smelter (Zirpo wool shirt and FR8 denim pants) with typical cotton work clothing. Four young men walked on a treadmill at two work levels inside a climatic chamber under controlled conditions of heat stress. During each test, heart rate, core temperature, and skin temperatures were continuously monitored and recorded every 5 min. After a physiological st…
The importance of pyramidal lobe in thyroid surgery
2008
Pyramidal lobe (PL) is an embryological remnant of the thyro-glossal duct; its incidence varies from 15% to 75% but data concerning its size are lacking and limited to autoptic and radiologic evidences. Aim of our study is to elucidate the intraoperative frequency, location and surgical management of the PL.604 total thyroidectomy were performed between 1999 and 2007 in Unit of General and Thoracic Surgery of the University Policlinico of Palermo. The intraoperative incidence of PL was 12% (57% male, 43% female, mean age 42.5 years), but only about 50% were identified preoperatively with ultrasonography (US) (4% false positive) or with Tc-99m pertechnetate scintigraphy (8% false positive).I…
The Doors and People Test: The Effect of Frontal Lobe Lesions on Recall and Recognition Memory Performance
2016
Objective: Memory deficits in patients with frontal lobe lesions are most apparent on free recall tasks that require the selection, initiation, and implementation of retrieval strategies. The effect of frontal lesions on recognition memory performance is less clear with some studies reporting recognition memory impairments but others not. The majority of these studies do not directly compare recall and recognition within the same group of frontal patients, assessing only recall or recognition memory performance. Other studies that do compare recall and recognition in the same frontal group do not consider recall or recognition tests that are comparable for difficulty. Recognition memory imp…
Parieto-frontal interactions in visual-object and visual-spatial working memory: Evidence from transcranial magnetic stimulation
2001
This study aimed to investigate whether transcranial magnetic stimulation (TMS) can induce selective working memory (WM) deficits of visual-object versus visual-spatial information in normal humans. Thirty-five healthy subjects performed two computerized visual n-back tasks, in which they were required to memorize spatial locations or abstract patterns. In a first series of experiments, unilateral or bilateral TMS was delivered on posterior parietal and middle temporal regions of both hemispheres after various delays during the WM task. Bilateral temporal TMS increased reaction times (RTs) in the visual-object, whereas bilateral parietal TMS selectively increased RTs in the visual-spatial W…
Direction‐dependent visual cortex activation during horizontal optokinetic stimulation (fMRI study)
2005
Looking at a moving pattern induces optokinetic nystagmus (OKN) and activates an assembly of cortical areas in the visual cortex, including lateral occipitotemporal (motion‐sensitive area MT/V5) and adjacent occipitoparietal areas as well as ocular motor areas such as the prefrontal cortex, frontal, supplementary, and parietal eye fields. The aim of this functional MRI (fMRI) study was to investigate (1) whether stimulus direction‐dependent effects can be found, especially in the cortical eye fields, and (2) whether there is a hemispheric dominance of ocular motor areas. In a group of 15 healthy subjects, OKN in rightward and leftward directions was visually elicited and statistically compa…
Anatomical correlate of positive spontaneous visual phenomena: a voxelwise lesion study.
2010
Objectives: Visual phenomena such as phosphenes, photopsias, or complex visual hallucinations occur in patients with lesions affecting the occipital, parietal, or temporal lobe. Whether these phenomena are provoked by lesions in specific anatomical regions is still uncertain. To determine which brain regions might be involved in such visual phenomena, we used new brain imaging and lesion analysis tools that allow a direct comparison with control patients. Methods: Visual phenomena were investigated in a total of 23 patients with acute infarctions along the visual pathways (6 patients with left-sided and 17 patients with right-sided lesions). Results: Ten of these 23 patients (43%) reported …
Specific forms of neural activity associated with tactile space awareness
2002
Left tactile extinction, in which a left tactile stimulus fails to access consciousness only when a right stimulus is presented simultaneously, offers a model for studying tactile awareness from its transitory absence. Pairs of transcranial magnetic stimuli (TMS) on the parietal cortex inhibit contralateral tactile perception when separated by an interval of 1 ms. We have applied this technique on the left parietal cortex of right brain damaged (RBD) patients and normal subjects and have shown a selective lack of paired TMS inhibitory effects on right tactile perception of patients during bimanual stimulation. TMS effects were normal during unimanual right stimulation. These results suggest…