Assessing perceptual change with an ambiguous figures task: Normative data for 40 standard picture sets

Abstract

In many research domains, researchers have employed gradually morphing pictures to study perception under ambiguity. Despite their inherent utility, only a limited number of stimulus sets are available, and those sets vary substantially in quality and perceptual complexity. Here we present normative data for 40 morphing picture series. In all sets, line drawings of pictures of common objects are morphed over 15 iterations into a completely different object. Objects are either morphed from an animate to an inanimate object (or vice versa) or morphed within the animate and inanimate object categories. These pictures, together with the normative naming data presented here, will be of value for research on a diverse range of questions, from perceptual processing to decision making.

Updating impairments and the failure to explore new hypotheses following right brain damage

“…One major assumption of our study is that the benefit for the gradual over the random presentation sequence is indicative of active exploration. While this benefit has also been reported elsewhere in the literature (see Egré et al 2018 for review), to our knowledge our study was the only one that showed this benefit in the context of morphing objects (Stöttinger et al 2016 ). In the original study, we used a between subjects design.…”

“…Prior to the patient study, we conducted an online study to determine the benefit of gradual presentations in a within subject design (Stöttinger et al 2016 ). The same picture sets used in the online study were then used in the patient study.…”

“… To evaluate whether updating impairments seen in RBD patients can be explained by a failure to explore, we calculated the difference in performance between the random–gradual conditions. We know that healthy individuals tend to switch categories earlier in the morph series when presented in a gradual context (e.g., when the object is still 60% shark and only 40% plane) than when single images from the same sequence are presented in isolation, outside the morphing context (Egré et al 2013 ; Raffman 2011 ; Stöttinger et al 2016 ; see Egré et al 2018 for review). This suggests that healthy individuals are exploring alternative interpretations conditional on the evolving history they have viewed (e.g., “I know it was a shark but what else could it be?…”

“…In the context of the rock–paper–scissors game, we found that RBD patients explored a limited selection of alternative strategies (Danckert et al 2012b ) and employed less efficient exploration strategies (Sepahvand et al 2014 ). If updating impairments in RBD patients are due to a generic failure to explore alternatives evident across different tasks and domains, we expect them to show no benefit from the contextual information provided by the gradual morphing sequence (Egré et al 2013 ; Raffman 2011 ; Stöttinger et al 2016 ; Table 1 , second row). To evaluate whether RBD patients would always struggle to proactively shift to a new interpretation, (irrespective of whether they are naïve as to the second object), we compared performance in the repeat condition across participant groups.…”

Children struggle beyond preschool-age in a continuous version of the ambiguous figures task

“…Adult participants consistently report the target object at a point when the picture still represents more the first object than the second. Interestingly, this is only the case when the picture is presented in a gradual context compared to when the same picture is presented outside of the morphing context (Egré, Ripley, & Verheyen, 2018;Stöttinger et al 2018;Stöttinger, Sepahvand, Danckert, & Anderson, 2016). This effect is reversed after damage to the right hemisphere: right-brain-damaged patients need significantly more pictures to identify the emerging object when it is presented in the gradual compared to the individual condition (Stöttinger et al, 2018).…”