Revealing the Concealed:Alternatives to Random Dots for Stereograms

Investigations of stereoscopic depth perception were transformed via the use of computer-generated random-dot stereograms in the 1960s. They realized Wheatstone’s wish of demonstrating binocular depth without monocular object recognition, and they have been the dominant stimulus for studying stereopsis since then. Alternative carrier patterns to random dots, based on graphics, photographs, and their combinations, are presented as anaglyphs and for free fusion. A wider range of concealed patterns can be revealed with these alternatives, and presenting them as anaglyphs can yield patterns that have visual appeal independent of the depth they conceal.<br/

Seeing with Two Eyes and Hearing with Two Ears

SEEING WITH TWO EYES AND HEARING WITH TWO EARS&nbsp; &nbsp; NICHOLAS J. WADE - Psychology, University of Dundee, U

Ocular Equivocation:The Rivalry Between Wheatstone and Brewster

Ocular equivocation was the term given by Brewster in 1844 to binocular contour rivalry seen with Wheatstone&rsquo;s stereoscope. The rivalries between Wheatstone and Brewster were personal as well as perceptual. In the 1830s, both Wheatstone and Brewster came to stereoscopic vision armed with their individual histories of research on vision. Brewster was an authority on physical optics and had devised the kaleidoscope; Wheatstone extended his research on audition to render acoustic patterns visible with his kaleidophone or phonic kaleidoscope. Both had written on subjective visual phenomena, a topic upon which they first clashed at the inaugural meeting of the British Association for the Advancement of Science in 1832 (the year Wheatstone made the first stereoscopes). Wheatstone published his account of the mirror stereoscope in 1838; Brewster&rsquo;s initial reception of it was glowing but he later questioned Wheatstone&rsquo;s priority. They both described investigations of binocular contour rivalry but their interpretations diverged. As was the case for stereoscopic vision, Wheatstone argued for central processing whereas Brewster&rsquo;s analysis was peripheral and based on visible direction. Brewster&rsquo;s lenticular stereoscope and binocular camera were described in 1849. They later clashed over Brewster&rsquo;s claim that the Chimenti drawings were made for a 16th-century stereoscope. The rivalry between Wheatstone and Brewster is illustrated with anaglyphs that can be viewed with red/cyan glasses and in Universal Freeview format; they include rivalling &lsquo;perceptual portraits&rsquo; as well as examples of the stimuli used to study ocular equivocation

Receptor Visionaries

Sensory receptors were described and illustrated after they had been observed with the aid of microscopes. Most descriptions were made in the 19th century after the introduction of achromatic lenses in microscopes. In some senses (like vision), receptors were named according to their morphology whereas in others (like touch), they are known by the names of those who initially described them. Illustrations of the receptors from original sources are here combined with portraits of their originators. </jats:p

Faces and Photography in 19th-Century Visual Science

Reading faces for identity, character, and expression is as old as humanity but representing these states is relatively recent. From the 16th century, physiognomists classified character in terms of both facial form and represented the types graphically. Darwin distinguished between physiognomy (which concerned static features reflecting character) and expression (which was dynamic and reflected emotions). Artists represented personality, pleasure, and pain in their paintings and drawings, but the scientific study of faces was revolutionized by photography in the 19th century. Rather than relying on artistic abstractions of fleeting facial expressions, scientists photographed what the eye could not discriminate. Photography was applied first to stereoscopic portraiture (by Wheatstone) then to the study of facial expressions (by Duchenne) and to identity (by Galton and Bertillon). Photography opened new methods for investigating face perception, most markedly with Galton’s composites derived from combining aligned photographs of many sitters. In the same decade (1870s), Kühne took the process of photography as a model for the chemical action of light in the retina. These developments and their developers are described and fixed in time, but the ideas they initiated have proved impossible to stop.</jats:p

Observation of High-Energy Gamma-Rays with the Calorimetric Electron Telescope (CALET) On-board the International Space Station

The CALorimetric Electron Telescope (CALET) is a multi-instrument high-energy astrophysics observatory deployed to the International Space Station (ISS) in August 2015. The primary instrument is the calorimeter (CAL), which is intended for measurement of the cosmic ray electron flux in the energy range 10 GeV - 20 TeV. The CAL is also sensitive to gamma-rays in the energy range 1 GeV - 10 TeV and protons and nuclei up to PeV energies. Also present on the CALET payload are an Advanced Stellar Compass (ASC) for the fine determination of the pointing direction and the CALET Gamma-ray Burst Monitor (CGBM) for the observation of hard x-ray/soft gamma-ray emission from gamma-ray bursts (GRBs). This work focuses on the capabilities and current results of the CAL for observation of gamma-ray sources in the GeV-energy regime. The methodology for the isolation of a gamma-ray dataset is presented and the resulting efficiencies and instrument response functions (IRFs) are derived from Monte Carlo simulated events. These results are validated by comparison with the first two years of flight data from CALET and the consistency with established measurements from other instruments is shown. Finally, independent CALET observations are presented, with an emphasis on the potential for detection of high-energy electromagnetic emission from transient events, including short and long GRBs, gravitational wave events seen by the LIGO/Virgo observatories, and high-energy astrophysical neutrino observations