The neurophysiological study of Vermeer’s Girl With a Pearl Earring that identified a triangle of a “sustained attention loop” (Real art in museums stimulates brain much more than reprints, study finds, 3 October) seems to be an affirmation of the power of the “Rembrandt triangle” in portraiture.
The area identified as the sustained attention focus for gallery viewers corresponds to a painted triangle of light formed by the eye, the shadow of the slope of the nose and the shadow of the cheekbone (in fact an inversion of the triangle shown in the article). Rembrandt identified this painterly device in the mid‑17th century and it has been faithfully copied not only by Vermeer, but by portrait painters and photographers to this day.
Dr Keith Snell
Cockermouth, Cumbria
