Non-metric distance judgements are influenced by image projection geometry and field of view.

Despite its mathematical simplicity and ubiquity in imaging technology, there has long been doubt about the ability of linear perspective to best represent human visual space, especially at wide-angle fields of view under natural viewing conditions. We investigated whether changes to image geometry had an impact on participants' performance, specifically in terms of non-metric distance estimates. Our multidisciplinary research team developed a new open-source image database to study distance perception in images by systematically manipulating target distance, field of view, and image projection using non-linear natural perspective projections. The database consists of 12 outdoor scenes of a virtual three-dimensional urban environment in which a target ball is presented at increasing distance, visualised using both linear perspective and natural perspective images, rendered, respectively, with three different fields of view: 100°, 120°, and 140° horizontally. In the first experiment (N = 52), we tested the effects of linear versus natural perspective on non-metric distance judgements. In the second experiment (N = 195), we investigated the influence of contextual and previous familiarity with linear perspective, and individual differences in spatial skills on distance estimations. The results of both experiments showed that distance estimation accuracy improved in natural compared with linear perspective images, particularly at wide-angle fields of view. Moreover, undertaking a training session with only natural perspective images led to more accurate distance judgements overall. We argue that the efficacy of natural perspective may stem from its resemblance to the way objects appear under natural viewing conditions, and that this can provide insights into the phenomenological structure of visual space.

Titles and Semantic Violations Affect Eye Movements When Viewing Contemporary Paintings.

The role of titles in perception of visual art is a topic of interesting discussions that brings together artists, curators, and researchers. Titles provide contextual cues and guide perception. They can be particularly useful when paintings include semantic violations that make them challenging for viewers, especially viewers lacking expert knowledge. The aim of this study is to investigate the effects of titles and semantic violations on eye movements. A total of 127 participants without expertise in visual art viewed 40 paintings with and without semantic violations (20 each) in one of three conditions: untitled, consistent titles and inconsistent titles. After each painting was viewed participants also rated liking and understanding. Our results suggest that titles affect the way paintings are viewed: both titled conditions were associated with shorter first fixation duration, longer saccade durations, and amplitudes and higher dynamic entropy than the untitled conditions. Titles were fixated on more frequently (but only in the time window between 1,200 and 2,800 ms) when presented alongside paintings with semantic violations than paintings without violations, and the percentage of fixations to titles was particularly high in the case of paintings with double inconsistencies (inconsistent titles and semantic violations). Also, we found that semantic violations attracted attention early on (300-900 ms), whereas titles received attention later (average first fixation on title was at 936.28 ms) and inconsistencies in titles were processed even later (after 4,000 ms). Finally, semantic violations were associated with higher dynamic entropy than paintings without violations. Our results demonstrate the importance of titles for processing of artworks, especially artworks that present a challenge for the viewers.

Perceived cognitive challenge predicts eye movements while viewing contemporary paintings.

Contemporary art is often challenging for the viewer, especially when it violates classic rules of representation. Also, viewers usually have little knowledge about this type of art, making its reception even more difficult. Our main research question was how the cognitive challenge associated with contemporary art affects eye movement. In particular, we aimed to assess the impact on eye movements of (a) object-related cognitive challenge in terms of image properties (syntactic and semantic violations) and (b) subject-related cognitive challenge (composite subjective estimate of image inconsistency, ambiguity, and complexity). The eye movements of expert and naive participants were recorded while they freely viewed digital copies of contemporary paintings (four groups of five paintings each, differing in presence of semantic and syntactic violations). We found that neither violations nor art expertise alone predicted eye movements, although perceived, subjectively experienced cognitive challenge did. In particular, subject-related cognitive challenge was associated with an increase in visual exploration (longer and more numerous fixations, bigger area of exploration, longer viewing time). The roles of object-related and subject-related indicators of cognitive challenge in perception of contemporary art are discussed.