Miguel Castelo-Branco

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Retinal ganglion cells exhibit oscillatory responses which are precisely synchronized over large distances. Here we examined, with multi-electrode recordings, the time course of synchronization during spontaneous and stimulus-driven oscillatory activity. Spontaneous discharges showed synchronized oscillations at approximately 30 Hz, which were occasionally(More)
We report here retinotopically based magnocellular deficits in a patient with a unilateral parieto-occipital lesion. We applied convergent methodologies to study his dorsal stream processing, using psychophysics as well as structural and functional imaging. Using standard perimetry we found deficits involving the periphery of the left inferior quadrant(More)
BACKGROUND Classification defined in the Trial of Org10172 in Acute Ischaemic Stroke (TOAST) is widely used in trials and practice. Previous studies on pathophysiology suggest a role for endothelial inflammation in atherothrombotic strokes and intracardiac thrombosis in cardioembolic strokes. Data on lacunar and undetermined strokes are limited. The aim of(More)
The effective use of brain-computer interfaces (BCIs) in real-world environments depends on a satisfactory throughput. In a P300-based BCI, this can be attained by reducing the number of trials needed to detect the P300 signal. However, this task is hampered by the very low signal-to-noise-ratio (SNR) of P300 event related potentials. This paper proposes an(More)
PURPOSE To use a new methodological approach, based on luminance noise, to assess without bias the relative damage of blue-yellow and red-green pathways in ocular hypertension and glaucoma and to correlate obtained measurements with clinical markers of disease progression. METHODS A psychophysical procedure modified from Cambridge color test was used to(More)
Sensory deficits have been documented in Parkinson's disease, in particular within the visual domain. However, ageing factors related to the brain and to neural and non-neural ocular structures could explain some of the previously reported results, in particular the claimed impairment within the koniocellular pathway. This study addressed visual impairment(More)
PURPOSE We investigated functional reorganization mechanisms of the human medial temporal lobe (MTL) for episodic memory, in patients suffering from medial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (HS). METHODS We used functional magnetic resonance imaging (fMRI) to measure brain activity changes during matched episodic encoding tasks of(More)
OBJECTIVE Non-invasive brain-computer interface (BCI) based on electroencephalography (EEG) offers a new communication channel for people suffering from severe motor disorders. This paper presents a novel P300-based speller called lateral single-character (LSC). The LSC performance is compared to that of the standard row-column (RC) speller. METHODS We(More)
Motion processing involves multiple hierarchical steps, from the magnocellular pathway, sensitive to high temporal frequency modulations, to subsequent motion integration within the visual cortical dorsal stream. We have tested whether motion integration deficits in mild Parkinson disease (PD) can be explained by visual deficits in earlier processing nodes.(More)
BACKGROUND Lower level of albumin was related to worse prognosis of stroke and clinical trials showed that albumin therapy reduced mortality. However, stroke is heterogeneous and differences in the baseline concentration of albumin among subtypes of stroke were not assessed. The aim was to assess albumin level in patients with ischemic stroke classified by(More)