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Trending science: Newly discovered da Vinci akin to Mona Lisa’s ‘uncatchable smile’

Research on La Bella Principessa, a recently discovered painting by Leonardo da Vinci, shows that the smile presents an illusion similar to that of the Mona Lisa.
Trending science: Newly discovered da Vinci akin to Mona Lisa’s ‘uncatchable smile’
The study, published last week in Vision Research, says that La Bella Principessa’s mouth appears to change slant depending on both the viewing distance and the level of blur applied to a digital version of the portrait. Through a series of psychophysics experiments, study authors Alessandro Soranzo and Michelle Newberry from Sheffield Hallam University in the UK, found that a perceived change in the slant of La Bella Principessa’s mouth influences her expression of contentment. This generates an illusion that they have coined the ‘uncatchable smile’ which is similar to the elusive quality famously evoked by the Mona Lisa’s smile.

The Mona Lisa effect

Mona Lisa’s smile, with its famously intriguing effect on the viewer, just might be the most renowned of all time. As Scientific American notes, ‘By looking directly at Mona Lisa’s lips, we notice that her smile is understated, almost nonexistent. But after looking into her eyes or the part in her hair (while paying attention to her mouth), her smile becomes much wider.’ Researchers have been keen to explore exactly how da Vinci managed to achieve the enigmatic effect. A previously published study by Professor Margaret Livingstone at Harvard Medical School explained it through a simulation. Scientific American explains how Livingstone obscured and clarified the painting to replicate the transformation in resolution from the centre of our visual field to the far periphery: ‘Mona Lisa’s smile deepens […] as it becomes more blurred. [The effect] is also explained through the notion that different retinal neurons are adjusted to varying the content of spatial size information in the image, which scientists refer to as its spatial frequency distribution. By some estimations, Leonardo da Vinci painted the Mona Lisa as a fusion; a happy Mona Lisa overlaid on a sad one, with each possessing a different spatial-frequency.’

La Bella Principessa

Extensive research was carried out on La Bella Principessa before it was confirmed as a Leonardo da Vinci painting which was actually painted prior to the Mona Lisa. The results of this new study, which reveal a similar illusion to that of the famous smile, are sure to increase the interest of art lovers in this rare new discovery. Although theories abound, the question remains, did Leonardo da Vinci intend the illusion? According to the study authors, the ambiguity only adds to the portrait’s allure.

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Source: Based on a study published in Vision Research and a media report from Scientific American.

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