Amodal completion refers to the phenomenological finding of perceiving partly occluded objects as continuing uninterrupted behind an occluder. The outlying problem is how the visual system processes such non-local stimuli because the known processes of early vision are spatially restricted operations which segregate local differences in the visual image, and little is known about their interact...

Sensory functions and their electrophysiological correlates have not been adequately documented during pregnancy. The present study reports visual evoked potential responses to pattern reversal (VEP-P) in ten third trimester pregnant women and changes in latency of NPN complex when compared with these responses in the non pregnant state. Visual evoked potentials were recorded from O1-A1 and O2-...

Visual evoked potentials (VEPs) to luminance and pattern reversal stimulation were derived for a large number of small areas throughout the central visual field. In one study, the field was tested with a stimulus array consisting of 64 equal-area patches. Local response components were extracted by independent m-sequence modulation of the patches. Field topographies were compared between and wi...

Multifocal visual evoked potentials (mfVEP) were recorded with three channels from 31 control subjects. A principal component analysis was applied to all local responses. The first principal component reversed polarity above and below the horizontal meridian in the case of the midline channel and across the vertical meridian in the case of the lateral channel. In addition, the first principal c...

We introduce a sensitive method for measuring face detection thresholds rapidly, objectively, and independently of low-level visual cues. The method is based on the swept parameter steady-state visual evoked potential (ssVEP), in which a stimulus is presented at a specific temporal frequency while parametrically varying ("sweeping") the detectability of the stimulus. Here, the visibility of a f...

Twenty seven patients with migraine without aura were investigated. The age was between 12 and 54 years; 5 were men and 22 women. The diagnosis of migraine was made according to the classification proposed by the International Headache Society. The method of visual evoked potential was performed with pattern reversal (VEP-PR), with monocular stimulation. The stimulation was performed with patte...

Physiological studies of color processing have typically measured responses to spatially varying chromatic stimuli such as gratings, while psychophysical studies of color include color naming, color and light, as well as spatial and temporal chromatic sensitivities. This raises the question of whether we have one or several cortical color processing systems. Here we show from non-linear analysi...

Steady state visual evoked potentials (SSVEP) are assumed to be regulated by multiple brain areas, yet the underlying mechanisms are not well understood. In this study, we utilized multi-channel intracranial recordings together with network analysis to investigate the underlying relationships between SSVEP and brain networks in anesthetized rat. We examined the relationship between SSVEP amplit...