scholarly journals A comparison of physical and visual light fields structures

2015 ◽  
Vol 15 (12) ◽  
pp. 634
Author(s):  
Tatiana Kartashova ◽  
Dragan Sekulovski ◽  
Huib de Ridder ◽  
Susan te Pas ◽  
Sylvia Pont
Keyword(s):  
Light Fields ◽  
Visual Light

E. T. A. Hoffmann’s Visual Light-Near Dissociation – Prostitute’s Pupil

2020 ◽  
Vol 52 (2) ◽  
pp. 239-252
Author(s):  
Jolyon Timothy Hughes
Keyword(s):  
Main Character ◽  
Visual Disorders ◽  
Visual Light

In E.T.A. Hoffmann’s Nachtstücke (1816/1817) the opening tale, Der Sandmann, has a young physics student Nathanael as its main character, one who suffers from certain psychological, neurotic, and visual disorders stemming from trauma experienced in his childhood. In this somewhat epistolary tale, he is tortured by the idea of the Sandman who comes after children if they won’t go to bed, throws sand in their eyes, and inflicts bleeding from the eyes. The Sandmen have crooked beaks, similar to owls’, with which they can pluck out the eyes of naughty children. In Hoffmann’s tale, the story of the Sandman and what it did to children haunted Nathanael for the rest of his life. A figure called Coppelius, the night visitor, who wanted eyes and was also Nathanael’s father’s master, personified the Sandman for him.

Temporal and spatial characteristics of tonically active neurons of the primate's striatum

1995 ◽  
Vol 73 (3) ◽  
pp. 1234-1252 ◽  
Author(s):  
T. Aosaki ◽  
M. Kimura ◽  
A. M. Graybiel
Keyword(s):  
Light Emitting Diode ◽  
Temporal Analysis ◽  
Tonic Firing ◽  
Light Emitting ◽  
Macaque Monkeys ◽  
Tonically Active Neurons ◽  
The Mean ◽  
Temporal And Spatial Characteristics ◽  
Conditioning Stimuli ◽  
Visual Light

1. Tonically active neurons (TANs) in the primate striatum develop transient responses to sensory conditioning stimuli during behavioral training in classical conditioning tasks. In this study we examined the temporal characteristics of such TAN responses and mapped the sites of TANs responding to auditory and visual conditioned stimuli in the striatum in macaque monkeys. We further mapped the locations of TANs recorded acutely in the squirrel monkey striatum in relation to the neurochemically distinguished striosome and matrix compartments of the striatum, and made quantitative comparisons between the densities and compartmental distributions of TANs and those of four major types of striatal interneuron identified by histochemical and immunohistochemical staining. 2. We made recordings from 858 TANs at different sites in the striatum in two behaving macaque monkeys at different times during training with auditory (click) and visual (light-emitting diode flash) conditioning stimuli. TANs distributed across large parts of the striatum developed responses to the conditioning stimuli. The responses comprised a decrement of tonic firing (pause) followed by a rebound excitation. Measurements were made of the onsets, offsets, and durations of the pauses of individual TANs and of the interspike intervals (ISIs) of the same cells. 3. The mean duration of the pause responses (268.3 ms) was greater than the mean ISI of the same neurons (181 ms), suggesting that the pause represents an active suppression of TAN firing. The coefficient of variation (CV) for the pause responses was 0.28, compared with a CV of 0.63 for the same cells' ISIs. The population CV for the pauses was 0.16, compared with a population CV of 0.20 for the ISIs. These data, together with temporal analysis of the responses and population histograms, suggest that the pauses became temporally aligned across large parts of the striatum after learning. Analyses of variance (ANOVAs) were carried out to determine whether there were differences in the onset and offset latencies of the pause response or in the durations of the pause responses for TANs at different sites. These analyses suggested that, with rare exceptions, there was no difference in the timing of the TAN responses across large (> 10 mm3) parts of the striatum. 4. Comparisons of TAN responses in different regions of the striatum showed that, for responses to a given modality of conditioned stimulus, there were no significant differences in pause offset times for TANs recorded in the caudate nucleus or putamen, or for TANs recorded in more anterior or more posterior parts of these nuclei.(ABSTRACT TRUNCATED AT 400 WORDS)

Nonuniform Spatial Deformation of Light Fields by Locally Linear Transformations

2017 ◽  
Vol 36 (4) ◽  
pp. 1
Author(s):  
Clemens Birklbauer ◽  
David C. Schedl ◽  
Oliver Bimber
Keyword(s):  
Light Fields ◽  
Linear Transformations ◽  
Spatial Deformation ◽  
Locally Linear

scholarly journals A cosmic microscope for the preheating era

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
JiJi Fan ◽  
Zhong-Zhi Xianyu
Keyword(s):  
Scalar Field ◽  
Nonlinear Effect ◽  
Large Scale ◽  
Nonlinear Effects ◽  
Light Fields ◽  
Unique Probe ◽  
Light Scalar ◽  
Spatially Varying ◽  
Near Future ◽  
Scalar Perturbations

Abstract Light fields with spatially varying backgrounds can modulate cosmic preheating, and imprint the nonlinear effects of preheating dynamics at tiny scales on large scale fluctuations. This provides us a unique probe into the preheating era which we dub the “cosmic microscope”. We identify a distinctive effect of preheating on scalar perturbations that turns the Gaussian primordial fluctuations of a light scalar field into square waves, like a diode. The effect manifests itself as local non-Gaussianity. We present a model, “modulated partial preheating”, where this nonlinear effect is consistent with current observations and can be reached by near future cosmic probes.

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