Search results for "Frontal Lobe"
showing 10 items of 158 documents
Grasp with hand and mouth: a kinematic study on healthy subjects
2001
Neurons involved in grasp preparation with hand and mouth were previously recorded in the premotor cortex of monkey. The aim of the present kinematic study was to determine whether a unique planning underlies the act of grasping with hand and mouth in humans as well. In a set of four experiments, healthy subjects reached and grasped with the hand an object of different size while opening the mouth ( experiments 1 and 3), or extending the other forearm ( experiment 4), or the fingers of the other hand ( experiment 5). In a subsequent set of three experiments, subjects grasped an object of different size with the mouth, while opening the fingers of the right hand ( experiments 6–8). The init…
Auditory hallucinations in first-episode psychosis: A voxel-based morphometry study
2019
Abstract Background Auditory hallucinations (AH) are a core symptom of psychosis. The brain abnormalities responsible for AH remain controversial due to inconsistent and conflicting findings across studies, with substantial confounding factors, such as chronicity. Few studies have examined the pathological changes that occur in the gray matter (GM) of patients with first-episode psychosis (FEP) and AH. The present study aims to validate the presence and characteristics of these structural abnormalities in relation to the intensity of psychotic symptoms and AH in a larger homogeneous sample than those of previous studies. Methods A magnetic resonance voxel-based morphometric analysis was app…
Frontal subregions mediating Elevator Counting task performance.
2010
Deficits in sustained attention may lead to action slips in everyday life as irrelevant action sequences are inappropriately triggered internally or by the environment. While deficits in sustained attention have been associated with damage to the frontal lobes of the brain, little is known about the role of the frontal lobes in the Elevator Counting subtest of the Test of Everyday Attention. In the current study, 55 frontal patients subdivided into medial, orbital and lateral subgroups, 18 patients with posterior lesions and 82 healthy controls performed the Elevator Counting task. The results revealed that patients with medial and left lateral prefrontal lesions were significantly impaired…
Location of Gliomas in Relation to Mobile Telephone Use: A Case-Case and Case-Specular Analysis
2011
The energy absorbed from the radio-frequency fields of mobile telephones depends strongly on distance from the source. The authors' objective in this study was to evaluate whether gliomas occur preferentially in the areas of the brain having the highest radio-frequency exposure. The authors used 2 approaches: In a case-case analysis, tumor locations were compared with varying exposure levels; in a case-specular analysis, a hypothetical reference location was assigned for each glioma, and the distances from the actual and specular locations to the handset were compared. The study included 888 gliomas from 7 European countries (2000-2004), with tumor midpoints defined on a 3-dimensional grid …
Lateralized effect of rapid-rate transcranial magnetic stimulation of the prefrontal cortex on mood.
1996
We studied the effects of rapid-rate transcranial magnetic stimulation (rTMS) of different scalp positions on mood Ten normal volunteers rated themselves before and after rTMS on five analog scales labeled ``Tristeza99 (Sadness), ``Ansiedad99 (Anxiety), ``Alegria99 (Happiness), ``Cansancio99 (Tiredness), and ``Dolor/Malestar99 (Pain/Discomfort). rTMS was applied to the right lateral prefrontal, left prefrontal, or midline frontal cortex in trains of 5 seconds9 duration at 10 Hz and 110% of the subject9s motor threshold intensity. Each stimulation position received 10 trains separated by a 25-second pause. No clinically apparent mood changes were evoked by rTMS to any of the scalp positions …
Cognitive functioning and anhedonia in subjects at risk for schizophrenia
1993
This study investigated the performance of individuals with familiar loading of schizophrenia (healthy siblings of schizophrenic inpatients) on three neuropsychological tasks assumed to require frontal lobe functions: Trail Making Test (TMT), verbal fluency and Wisconsin Card Sorting Test (WCST). Healthy siblings of schizophrenics differed in performance from healthy controls not only on the WCST, but also on the Trail Making Test and the verbal fluency task. Furthermore, scores of physical anhedonia, assessed in a self-report rating scale (Chapman et al., 1976) were also significantly higher in the high risk group than in the control sample. However, healthy siblings of schizophrenics did …
Etoposide Treatment in Recurrent Medulloblastoma
1994
Five consecutive patients with recurrent medulloblastoma received etoposide 120 mg/m2 for 5 to 7 days at 2 to 4-week intervals. Three patients with neuroaxis dissemination received additional intrathecal chemotherapy with methotrexate, cytosine arabinoside and prednisone. Toxicity consisted of alopecia and mild neutropenia. Complete response was registered in two patients, partial response in one. Median survival was 19 months with the 3 responders living 6, 30 and 60+ months. Etoposide seems to be an active agent in medulloblastoma.
Dipole Source Analysis of Laser-Evoked Subdural Potentials Recorded From Parasylvian Cortex in Humans
2003
The location of the human nociceptive area(s) near the Sylvian fissure is still controversial in spite of evidence from imaging and evoked potential studies that noxious heat stimuli activate somatosensory areas in that region. Some studies have suggested the secondary somatosensory cortex (SII) on the upper bank of the Sylvian fissure posterior to the central sulcus, others the anterior insula or parietal area 7b. In this study, we applied dipole source analysis techniques to laser-evoked potentials (LEPs) that were recorded from subdural grid electrodes in three patients. As a functional marker, auditory-evoked potentials (AEPs) with a generator on the opposite bank of the Sylvian fissur…
Timing of right parietal and frontal cortex activity in visuo-spatial perception: A TMS study in normal individuals
2001
In a recent study we showed that repetitive transcranial magnetic stimulation (rTMS) with train duration of 400 ms over right frontal and right posterior parietal cortices gives rise to transitory contralateral visuo-spatial neglect in normal subjects. In the present experiment we investigated whether using single-pulse TMS it is possible to obtain information about the timing of cortical activity related to spatial cognition. Nine healthy subjects performed in baseline condition and during TMS a tachistoscopic task, requiring a forced-choice estimation of the length of the two segments of prebisected horizontal lines. Single-pulse TMS was triggered at various time intervals (150 ms, 225 ms…
Assessment of frontal lobe functioning in schizophrenia and unipolar major depression.
1993
This study has used neuropsychological tasks – Wisconsin Card Sort (WCST), Trail Making (TMT) A and B, Verbal Fluency, Digit Span – to compare acute and currently off-medication schizophrenics, patients with unipolar nonpsychotic major depression and healthy controls. Both patient groups differed significantly from healthy controls in their neuropsychological performance. Furthermore there was only little (quantitative) difference between schizophrenics and depressed patients in the frontal lobe associated tasks: WCST, TMT and Verbal Fluency. Depressed patients tended to perform worse than schizophrenics on Digit Span, a task hypothesized to involve other than frontal areas of the brain. Al…