Baumgartner and colleagues (this issue) report a replication of an ERP study by Kelly, Gomez-Ramirez, and Foxe (2008). Unlike the original authors, they failed to observe a significant modulation of the C1 by visuo-spatial attention. They conclude that initial afferent processing in V1 is impermeable to visuo-spatial attention. Although their study, like any replication effort, is valuable and ...

The watercolor effect is a visual illusion that manifests itself as a combination of long-range color spreading and figure-ground organization. The current study uses behavioral and physiological measures to study the watercolor effect. We utilize a novel technique of measuring the cortical response of the illusion using the visual evoked potential (VEP). To this end, three experiments were don...

The pattern evoked potential (EP) in man to checkerboard stimulation has been shown to consist of various components originating in different regions of the visual cortex. Surface recordings, however, cannot unambiguously localize the sources of these components; for precision, depth recordings seem to be indicated. Considering the close correspondence in cortical architecture to man, rhesus mo...

CASE REPORT A 17 year-old male patient, who since 2000 has referred to a progressive bilateral decrease in visual acuity. A "bicycle wheel" macula pattern was observed in his retina. The electroretinogram showed a decrease in the b-wave amplitude. The visual evoked potentials were normal. Optical coherence tomography showed bilateral macular edema. All this supported the diagnosis of X-linked r...

Parkinson's disease patients have been shown to have abnormal visually evoked cortical potentials (VEPs) to pattern stimulation. Whereas dopamine is not an important neurotransmitter in the central visual pathways, the retina is rich in dopamine and, together with previous animal and human studies, this suggests that the abnormal VEPs in Parkinson's disease patients may be due to a biochemical ...

Attention was directed to the left or to the right of the fixation point by the lateral presentation of a target on which the subject had to perform an attention demanding task. A (task-irrelevant) grating displayed in the left visual field was the visual evoked potential (VEP) stimulus. Gratings modulated either in luminance or colour contrast at various temporal frequencies were used in order...

Original Article Pattern reversal Macro adenoma P100 latency Visual evoked Potentials (VEPs) to checkerboard pattern reversal were recorded from a patient with complaints of severe and sudden headache and unexplained unilateral diminution of vision over 2 years. Since the VEP recordings showed markedly delayed response and severely reduced amplitude of P100 wave form from the left eye, a compre...

The evidence relating prenatal supplementation with DHA to offspring neurological development is limited. We investigated the effect of prenatal DHA supplementation on infant brainstem auditory-evoked responses and visualevoked potentials in a double-blind, randomized controlled trial in Cuernavaca, Mexico. Pregnant women were supplemented daily with 400 mg DHA or placebo from gestationwk 18–22...