In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.

Passage: More recent research from art historians such as Lorne Campbell relies on X-ray and infrared photography to develop an understanding of the techniques and materials used by the painters. The conservation of the Ghent Altarpiece in the mid-1950s pioneered methodologies and scholarship in technical studies. Examination of paint layers and underlayers was later applied to other Netherlandish works, allowing for more accurate attributions. Van Eyck's work, for example, typically shows underdrawings unlike Christus' work. These discoveries, too, hint at the relationships between the masters of the first rank and those in the following generations, with Memling's underdrawings clearly showing van der Weyden's influence.Scholarship since the 1970s has tended to move away from a pure study of iconography, instead emphasizing the paintings' and artists' relation to the social history of their time. According to Craig Harbison, "Social history was becoming increasingly important. Panofsky had never really talked about what kind of people these were." Harbison sees the works as objects of devotion with a "prayer book mentality" available to middle-class burghers who had the means and the inclination to commission devotional objects. Most recent scholarship is moving away from the focus on religious iconography; instead, it investigates how a viewer is meant to experience a piece, as with donor paintings that were meant to elicit the feeling of a religious vision. James Marrow thinks the painters wanted to evoke specific responses, which are often hinted at by the figures' emotions in the paintings.
What, instead, investigates how a viewer is meant to experience a piece, as with donor paintings that were meant to elicit the feeling of a religious vision?