Search results for "Cortex"

Visual cortex hyperexcitability in migraine in response to sound-induced flash illusions

2015

Objective: Sound-induced flash illusions depend on visual cortical excitability. In this study, we explored whether sound-induced flash illusions are perceived differently in migraine, a condition associated with pathologic cortical hyperexcitability. Methods: Sound-induced flash illusions were examined in 59 migraine patients (mean age = 32 ± 16 years; 36 females), 32 without aura and 27 with aura, and in 24 healthy controls (mean age = 42 ± 17 years; 16 females). Patients were studied during attacks and interictally. Visual stimuli (flashes) accompanied by sounds (beeps) were presented in different combinations: a single flash with multiple beeps was given to induce the perception of mult…

Visuospatial learning is fostered in migraine: evidence by a neuropsychological study

2018

Cognitive profile in migraine patients still remains undefined. Contradictory evidence has been provided, with impairments in different cognitive domains, normal cognition, or even better performance compared to healthy controls (HC). The latter is of particular interest considering the evidence of glutamatergic upregulation in migraine, particularly in the visual cortex, and the role of the glutamatergic system in synaptic plasticity and learning. The aim of our study is to compare cognitive performance for visuospatial memory and learning (supraspan modality) between migraineurs without aura (MwoA) and HC. Twenty-one subjects suffering from MwoA and 21 HC were enrolled. Migraineurs during…

Modulation of cortical motor outputs by the symbolic meaning of visual stimuli.

2010

Abstract The observation of an action modulates motor cortical outputs in specific ways, in part through mediation of the mirror neuron system. Sometimes we infer a meaning to an observed action based on integration of the actual percept with memories. Here, we conducted a series of experiments in healthy adults to investigate whether such inferred meanings can also modulate motor cortical outputs in specific ways. We show that brief observation of a neutral stimulus mimicking a hand does not significantly modulate motor cortical excitability (Study 1) although, after prolonged exposure, it can lead to a relatively nonspecific modulation (Study 2). However, when such a neutral stimulus is p…

Impaired control of an action after supplementary motor area lesion: A case study

2000

The kinematics of the action formed by reaching-grasping an object and placing it on a second target was studied in a patient who suffered from an acute vascular left brain lesion, which affected the Supplementary Motor Area proper (SMA-proper) (Matelli M, Luppino G. Thalamic input to mesial and superior area 6 in the macaque monkey. Journal of Comparative Neurology 1996;372:59-87, Matelli M, Luppino G, Fogassi L, Rizzolatti G. Thalamic input to inferior area 6 and area 4 in the macaque monkey. Journal of Comparative Neurology 1989;280:468-488), and in five healthy control subjects. The reach kinematics of the controls was affected by the positions of both the reaching-grasping and the plac…

Gemcitabine plus metronomic 5-fluorouracil or capecitabine as a second-/third-line chemotherapy in advanced adrenocortical carcinoma: a multicenter p…

2010

Adrenocortical carcinoma (ACC) is a rare neoplasm characterized by poor prognosis. First-line systemic treatments in advanced disease include mitotane, either alone or in combination with chemotherapy. Studies evaluating second-line therapy options have obtained disappointing results. This trial assessed the activity and toxicity of gemcitabine plus metronomic fluoropyrimidines in heavily pretreated advanced ACC patients. From 1998 to 2008, 28 patients with advanced ACC progressing after mitotane plus one or two systemic chemotherapy lines were enrolled. They received a combination of i.v. gemcitabine (800 mg/m2, on days 1 and 8, every 21 days) and i.v. 5-fluorouracil protracted infusion (2…

Conduction times of cortical projections to paravertebral muscles in controls and in patients with multiple sclerosis

1994

Memory detection using fMRI - does the encoding context matter?

2015

Recent research revealed that the presentation of crime related details during the Concealed Information Test (CIT) reliably activates a network of bilateral inferior frontal, right medial frontal and right temporal-parietal brain regions. However, the ecological validity of these findings as well as the influence of the encoding context are still unclear. To tackle these questions, three different groups of subjects participated in the current study. Two groups of guilty subjects encoded critical details either only by planning (guilty intention group) or by really enacting (guilty action group) a complex, realistic mock crime. In addition, a group of informed innocent subjects encoded hal…

Plasticity of brain wave network interactions and evolution across physiologic states

2015

Neural plasticity transcends a range of spatio-temporal scales and serves as the basis of various brain activities and physiologic functions. At the microscopic level, it enables the emergence of brain waves with complex temporal dynamics. At the macroscopic level, presence and dominance of specific brain waves is associated with important brain functions. The role of neural plasticity at different levels in generating distinct brain rhythms and how brain rhythms communicate with each other across brain areas to generate physiologic states and functions remains not understood. Here we perform an empirical exploration of neural plasticity at the level of brain wave network interactions repre…

Nicotine effects on anterior cingulate cortex in schizophrenia and healthy smokers as revealed by EEG-informed fMRI

2012

Abstract Nicotine can have beneficial effects on attention performance and corresponding brain function in both schizophrenia patients and healthy controls, but it remains controversial whether nicotine affects brain function differentially in patients vs. controls. The effects of nicotine on brain activity elicited by attention-requiring oddball-type tasks have not been studied in schizophrenia patients. In this study we sought to investigate the impact of nicotine on the p300 evoked potential component and corresponding fMRI (functional magnetic resonance imaging) activation measures in schizophrenia patients and controls. Applying a double-blind, placebo-controlled cross-over design, the…

Association of attentional network function with exon 5 variations of the CHRNA4 gene

2007

Mutational analyses in xenopus oocyte and mice models indicate that the positive effect of nicotine on attention may be modulated by genetic variations within exon 5 of the alpha4 subunit of the nicotinergic acetylcholine receptor gene CHRNA4. The potential relevance of exon 5 is further emphasized by two recent family-based association studies of nicotine dependence because subgroups of nicotine-dependent subjects are thought to 'self-medicate' attentional deficits with nicotine. We investigated a synonymous single nucleotide polymorphisms (SNP): rs1044396, which has recently been associated with nicotine-dependence, plus two adjacent synonymous SNPs rs1044394 and rs1044393 in exon 5 of n …