The present study utilizes perceptual hysteresis effects to compare the ambiguity of Mona Lisa's emotional face expression (high-level ambiguity) and of geometric cube stimuli (low-level ambiguity).
...In two experiments we presented series of nine Mona Lisa variants and nine cube variants. Stimulus ambiguity was manipulated by changing Mona Lisa's mouth curvature (Exp. 1) and the cubes' back-layer luminance (Exp. 2). Each experiment consisted of three conditions, two with opposite stimulus presentation sequences with increasing and decreasing degrees of ambiguity, respectively, and a third condition with a random presentation sequence. Participants indicated happy or sad face percepts (Exp. 1) and alternative 3D cube percepts (Exp. 2) by key presses. We studied the influences of a priori perceptual biases (long-term memory) and presentation order (short-term memory) on perception.
Perception followed sigmoidal functions of the stimulus ambiguity morphing parameters. The morphing parameter for the functions' inflection points depended strongly on stimulus presentation order with similar effect sizes but different signs for the two stimulus types (positive hysteresis / priming for the cubes; negative hysteresis / adaptation for Mona Lisa). In the random conditions, the inflection points were located in the middle between those from the two directional conditions for the Mona Lisa stimuli. For the cube stimuli, they were superimposed on one sigmoidal function for the ordered condition.
The hysteresis effects reflect the influence of short-term memory during the perceptual disambiguation of ambiguous sensory information. The effects for the two stimulus types are of similar size, explaining up to 34% of the perceptual variance introduced by the paradigm. We explain the qualitative difference between positive and negative hysteresis with adaptation for Mona Lisa and with priming for the cubes. In addition, the hysteresis paradigm allows a quantitative determination of the impact of adaptation and priming during the resolution of perceptual ambiguities. The asymmetric shifts of inflection points in the case of the cube stimuli is likely due to an a priori perceptual bias, reflecting an influence of long-term memory. Whether corresponding influences also exist for the Mona Lisa variants is so far unclear.
In pursuit of polymathy Robinson, Andrew
The Lancet (British edition),
05/2019, Letnik:
393, Številka:
10184
Journal Article
Recenzirano
Imhotep was the real “Father of Medicine”, wrote William Osler in the 19th century, as quoted by Waqās Ahmed in The Polymath: Unlocking the Power of Human Versatility. In the 20th century, physician ...Albert Schweitzer was a theologian, philosopher, and musician who was awarded a Nobel Peace Prize. Additionally, social acceptance of the division of labour and narrow specialisation has become entrenched as an economic and educational virtue in high-income societies since the Industrial Revolution.
1478 was the year in which Leonardo da Vinci, aged 26, obtained his first official commission and witnessed the Pazzi Conspiracy against the Medici family. In that year, he probably opened his ...independent workshop, leaving that of his master Andrea del Verrocchio, and, in its final months, he began to paint two paintings representing the Virgin Mary. One of these paintings is very likely the Benois Madonna at the State Hermitage, St. Petersburg; a work that marks a strong change in Leonardo's style and power of expression and his representation of light and human emotions.This book provides an in-depth analysis of Leonardo's growth as an artist in this year, detailing his training, his culture, his collaboration with Verrocchio, and his engagement in the artistic and cultural life of 1460s and 1470s Florence.
Sight and salvation Kemp, Martin
Nature (London),
11/2011, Letnik:
479, Številka:
7372
Journal Article
Recenzirano
Painter at the Court of Milan National Gallery, London. ... 5 February 2012. More importantly, examination by infrared reflectography, which involves bouncing infrared light off the white priming of ...the panel, has revealed characteristic signs of Leonardo's idiosyncratic technique.
This volume is dedicated to Leonardo da Vinci's commission for the Virgin of the Rocks. Leonardo completed fewer than 20 paintings in his lifetime, yet he returned twice to this same mysterious ...subject over the course of a 25 year period. Identical in terms of iconography, stylistically these paintings are worlds apart. The first, of c.1482-4, was Leonardo's magnum opus, catapulting the young artist from obscurity to fame. When, in 1508, he finished the second he was nearing the end of his painting career and was an international celebrity. Why did he revisit the Virgin of the Rocks? What was the meaning behind the cavernous subterranean landscape?
Bestselling and world-renowned author Fritjof Capra presents the first in-depth and full description of Leonardo da Vinci's amazing scientific work and discoveries in geology, anatomy, flight, ...mechanics, botany, and fluid dynamics. And Capra reveals what readers can learn for their own lives and work from ten characteristics of Leonardo's genius.
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