Results 131 to 140 of about 6,807 (176)

Temporal Frequency and the Magnocellular and Parvocellular Systems

Neuro-Ophthalmology, 2008
Can the magnocellular system be stimulated exclusively, or predominantly, by using a particular temporal frequency? There are two problems. (1) Many researchers have confused contrast reversal rates with luminance modulation frequencies, even though it is the latter (which is half the reversal rate) that may be compared to neuronal responses.
Bernt Christian Skottun, John R. Skoyles
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Functional organization of the parvocellular red nucleus in the cat

Behavioural Brain Research, 1988
The experiments were performed on cats under pentobarbital anesthesia. The following results were obtained. (1) Most of the neurons in the rostral part of the red nucleus (RN) were activated by stimulation of the parietal association cortex (P) and the lateral cerebellar nucleus (CN).
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Development of the Human Parvocellular Red Nucleus

Developmental Neuroscience, 2008
Morphology of the human parvocellular red nucleus (RNp) was investigated in 14 fetuses aged from 12 to 39 weeks of gestation (WG). The brains were processed into celloidin-embedded serial sections. At 12 WG, the anlage of RNp was observed as an ovoid mass of immature neurons clustering into some groups.
Katsuyuki Yamaguchi, Noboru Goto
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Metacontrast, target recovery, and the magno- and parvocellular systems: A perspective

Visual Neuroscience, 2007
In metacontrast a masking stimulus reduces the visibility of an adjacent target stimulus. This effect has been interpreted in terms of magno-/parvocellular interactions. It has also been found that a second masking stimulus, which precedes the primary mask by about 90 ms reduces the masking effect. This reduction, which is termed “target recovery,” has
Bernt C, Skottun, John R, Skoyles
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Glucosensing in parvocellular neurons of the rat hypothalamic paraventricular nucleus

European Journal of Neuroscience, 2011
AbstractSpecialized hypothalamic neurons responding to rising extracellular glucose via increases or decreases in their electrical activity [glucose‐excited (GE) and glucose‐inhibited (GI) cells, respectively] have been reported in the hypothalamic arcuate, ventromedial and lateral nuclei.
Igor V, Melnick, Christopher J, Price, William F, Colmers   +2 more
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Evaluation of the Functions of the Parvocellular and Magnocellular Pathways in Strabismic Amblyopia

Journal of Pediatric Ophthalmology & Strabismus, 2002
ABSTRACT Purpose: To evaluate the functions of the magnocellular and parvocellular pathways in strabismic amblyopia. Methods: Visual evoked potentials produced by achromatic and chromatic stimuli in 14 children with strabismic amblyopia were compared with those in 14 age-matched control subjects.
Hakan, Demirci, Acun, Gezer, Fazil, Sezen, Tunc, Ovali, Tamer, Demiralp, Ummuhan, Isoglu-Alkoc   +5 more
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The role of the magnocellular and parvocellular systems in the redundant target effect

Experimental Brain Research, 2004
The redundant target effect (RTE) consists in the speeding of reaction time with single versus multiple targets and can be explained either by a neural coactivation or by a race model. To try to understand the role of the magnocellular and parvocellular systems in the determination of the RTE we carried out three experiments using onset or feature ...
Turatto, Massimo, Mazza, Veronica, S. Savazzi, C. A. Marzi   +3 more
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Abnormal Function of the Parvocellular Visual System in Anisometropic Amblyopia

Journal of Pediatric Ophthalmology & Strabismus, 2000
ABSTRACT Purpose: To study the function of the parvocellular (P) and the magnocellular (M) visual systems with steady-state visual evoked potentials (VEPs) in anisometropic amblyopes. Methods: A matrix of isolated checks was superimposed on a steady background with different check sizes and temporal frequencies to form specific ...
Y, Shan, M L, Moster, R A, Roemer, J B, Siegfried   +3 more
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Magno- and parvocellular pathways are segregated in the human optic tract

NeuroReport, 1994
There is abundant psychophysical evidence in humans suggesting the existence of parallel pathways subserving different aspects of vision. However, there is little direct proof of the neural structures underlying the two pathways. We present direct anatomical evidence that in the normal human optic tract fibres are segregated according to size.
Tassinari G., Campara D., Balercia G., Chilosi M., Martignoni G., Marzi C. A.   +5 more
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Colour and brightness signals of parvocellular lateral geniculate neurons

Experimental Brain Research, 1986
We recorded from single neurons in the parvocellular layers of the lateral geniculate body of anesthetized monkeys. Spectral response curves of parvocellular neurons depended on the luminance ratio between the chromatic stimuli and achromatic background.
Creutzfeldt, O., Lee, B., Valberg, A.
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